DeepMind AI Beats Physics Models to Add Day to Hurricane Warnings

Can AI help us better predict the weather? — Google DeepMind

Google DeepMind

Machine learning outperforms traditional supercomputer physics by synthesizing global observational data directly into forecasts, avoiding runaway numerical simulation errors and giving emergency responders an extra day of preparation for extreme storms.

AI-assisted summary of Can AI help us better predict the weather? — original source. Check the original for full context.

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Key ideas

  • DeepMind's AI models provided early Category 5 warnings for Hurricane Melissa roughly a week in advance, matching 48-hour accuracy at a 72-hour lead time and bolstering the National Hurricane Center's operational confidence. (0:54)
  • WeatherNext 3 collapses the traditional multi-stage weather pipeline into an end-to-end architecture, directly mapping raw satellite imagery to ground weather stations and updating forecasts every hour. (26:15)
  • Unlike traditional numerical weather prediction models that risk explosive numerical divergence when errors accumulate, AI architectures naturally regress to the climatological mean under uncertainty. (35:00)
  • To capture probabilistic atmospheric uncertainty efficiently, DeepMind developed Functional Generative Networks (FGNs), which adapt neural network parameters to outperform conventional diffusion models in both speed and fidelity. (21:49)

Detailed notes

## Background Published on September 9, 2026, by Google DeepMind via RSS and web feeds, this episode features host Professor Hannah Fry in conversation with Peter Battaglia, Senior Director of Research at Google DeepMind. The discussion explores how artificial intelligence and machine learning models like GraphCast and WeatherNext 3 build upon decades of numerical fluid dynamics to tackle atmospheric chaos, predict renewable energy loads, and provide crucial early warnings for severe weather events like Hurricane Melissa.

## TL;DR In this episode, Peter Battaglia outlines how Google DeepMind transitioned from localized precipitation nowcasting to end-to-end global weather forecasting systems that match or outperform traditional numerical supercomputing models. Through real-world case studies like 2025's Hurricane Melissa, Battaglia explains how AI provides up to an extra day of predictive lead time by identifying subtle atmospheric patterns across planetary scales. The dialogue examines key algorithmic developments, including deterministic modeling with GraphCast, probabilistic forecasting via diffusion and Functional Generative Networks in GenCast, and WeatherNext 3's streamlined sensor-to-forecast architecture. Looking ahead, the speakers discuss the broader horizon of atmospheric AI, moving from predicting raw physical variables like wind speed to forecasting direct socioeconomic and infrastructure impacts on power grids, agriculture, and human safety.

## Atmosphere & style The conversation carries an intellectually vibrant, collegial, and accessible tone, blending Hannah Fry's lively curiosity with Peter Battaglia's measured, technically rigorous explanations. While grounded in the sobering reality of intensifying climate extremes and catastrophic Category 5 storms, the mood remains optimistic about computational progress and scientific discovery. Listening to the episode feels like sitting in on a lucid, high-level masterclass that balances complex concepts like thermodynamics, fluid dynamics, and generative architectures with tangible human stakes.

## Bulletin - `00:54` DeepMind's AI models provided early Category 5 warnings for Hurricane Melissa roughly a week in advance, matching 48-hour accuracy at a 72-hour lead time and bolstering the National Hurricane Center's operational confidence. - `26:15` WeatherNext 3 collapses the traditional multi-stage weather pipeline into an end-to-end architecture, directly mapping raw satellite imagery to ground weather stations and updating forecasts every hour. - `35:00` Unlike traditional numerical weather prediction models that risk explosive numerical divergence when errors accumulate, AI architectures naturally regress to the climatological mean under uncertainty. - `21:49` To capture probabilistic atmospheric uncertainty efficiently, DeepMind developed Functional Generative Networks (FGNs), which adapt neural network parameters to outperform conventional diffusion models in both speed and fidelity.

## Key takeaways - `00:00` Terrestrial weather prediction remains one of science's most chaotic physics problems due to fluid dynamics and extreme sensitivity to initial micro-scale perturbations. - `06:50` DeepMind's dedicated tropical cyclone models consistently deliver an extra day of predictive lead time, matching standard 48-hour error margins at 72 hours out. - `10:00` Global warming acts as an influx of thermal energy into an open atmospheric system, driving more severe extremes and increasing the urgency for accurate AI forecasting. - `11:47` AI models capture subtle early statistical signatures ('breadcrumbs') left by micro-perturbations that traditional numerical solvers often miss. - `18:24` The evolution of AI in atmospheric science spans three waves: sub-grid parametrization, localized image/video perception, and global end-to-end atmospheric simulation. - `20:00` GraphCast simultaneously models local uniform physical laws and planetary-scale representations, projecting between micro and macro structures to track large systems like cyclones. - `21:49` Probabilistic systems like GenCast generate scenario ensembles ('spaghetti plots'), enabling calibrated confidence scoring and epistemic humility during chaotic events. - `26:15` WeatherNext 3 short-circuits the traditional 'weather tree' by consuming raw satellite inputs directly and outputting ground station readings with intra-window hourly granularity. - `30:00` Modern AI models directly incorporate specialized variables like solar irradiance, wind speed, and surface temperature to forecast power grid demand and renewable supply. - `35:00` AI systems can forecast unprecedented, record-breaking storms because atmospheric physics acts as a spatial mosaic where localized extremes observed elsewhere can be synthesized into novel configurations. - `40:00` The frontier of AI meteorology is shifting from predicting raw physical metrics to forecasting actionable socioeconomic impacts, such as electrical power grid failures. - `42:04` Atmospheric AI data throughput requires tens to hundreds of gigabytes per cycle, driving cross-pollination with video generative models and multimodal LLM interfaces.

## Detailed walkthrough ### `00:00` The Physics Challenge of Weather and the Rise of AI Forecasting

Hannah Fry introduces the critical stakes involved in severe weather forecasting, emphasizing that when a hurricane approaches land, time is the ultimate resource: an extra day of advance notice allows communities to clear evacuation routes, empty hospitals, open storm shelters, and move people to safety. While celestial mechanics allow scientists to compute the precise second the sun will rise a millennium from now, predicting terrestrial weather remains one of science's most chaotic physics puzzles due to extreme sensitivity to tiny initial variations—the classic butterfly effect, where a minuscule air-pressure fluctuation can cascade into a massive storm a week down the line.

For decades, the standard approach has relied on supercomputers numerically solving fluid dynamics equations. Google DeepMind began exploring machine learning alternatives back in 2020, starting with satellite-image models for short-term precipitation nowcasting, before progressing to global systems like WeatherNext that generate hourly forecasts across the planet. Peter Battaglia, Senior Director of Research at Google DeepMind, joins Fry to discuss how machine learning fundamentally reframes atmospheric prediction.

```mermaid flowchart TD accTitle: Evolution of Weather Forecasting Approaches accDescr: Comparison showing the traditional physics-based supercomputing path versus Google DeepMind's data-driven machine learning path.

subgraph Traditional["Traditional Numerical Weather Prediction"] T1["Atmospheric Observations"] --> T2["Supercomputers Solving Fluid Dynamics Equations"] T2 --> T3["Numerical Physics Forecasts"] end

subgraph DeepMind["DeepMind AI Weather Prediction"] D1["Historical Reanalysis & Observational Data"] --> D2["Graph Neural Networks / Deep Models"] D2 --> D3["2020: Precipitation Nowcasting (Satellite Images)"] D3 --> D4["WeatherNext / GraphCast: Global Multi-Day Forecasting"] end ```

`00:54` Hurricane Melissa: Early Warnings and the National Hurricane Center

Battaglia illustrates the real-world utility of AI forecasting through the case of Hurricane Melissa, an exceptionally powerful storm that struck Jamaica and several other Caribbean islands in October 2025. Earlier that year, DeepMind launched an experimental public portal called Weather Lab to provide live hurricane track and intensity predictions. They also established formal collaborations with operational forecasters, notably the National Hurricane Center (NHC) under NOAA in the United States.

About a week before Melissa made landfall, while it was still an unremarkable tropical depression or generic atmospheric disturbance, DeepMind's models began signaling that it would undergo extreme intensification into a Category 5 hurricane—the highest classification on the Saffir-Simpson scale. As Battaglia recounts, the independent meteorological community on X (formerly Twitter) began flagging that Google's system was aggressively projecting an unprecedented Category 5 landfall.

```mermaid flowchart LR accTitle: Hurricane Melissa Forecast and Response Timeline accDescr: Sequence showing the progression from an early disturbance to NHC Category 5 warning and final landfall.

A["~7 Days Out<br/>Weak Disturbance / Depression"] --> B["DeepMind Model<br/>Signals Rapid Intensification to Cat 5 (~80% Confidence)"] B --> C["Online Meteorology Community (X)<br/>Notices Google Model Projections"] C --> D["Saturday (~3 Days Out)<br/>NHC Issues Official Cat 5 Warning"] D --> E["Monday - Tuesday<br/>Rapid Intensification & Jamaica Landfall (190 mph winds)"] ```

- Hurricane Melissa formed from a weak tropical disturbance over warm Atlantic waters, initially lingering at very low intensity before undergoing rapid intensification. - While traditional models showed some strengthening, DeepMind's model projected both the specific trajectory and Category 5 intensity with high confidence nearly a week in advance. - The NHC integrates diverse inputs—traditional numerical physics ensembles, statistical packages, and emerging machine learning forecasts—to synthesize its official advisories.

`04:47` Rapid Intensification, Landfall, and Operational Collaboration

On the Saturday preceding landfall—while the system had not even achieved Category 1 status—the National Hurricane Center officially forecasted that Melissa would undergo severe rapid intensification over a 48-to-60-hour window, reaching Category 5 strength by Monday before striking Jamaica around Tuesday. This provided roughly three full days of lead time, triggering large-scale evacuations, emergency preparations, and shelter openings across vulnerable regions.

Battaglia notes that NHC officials later shared that this was the lowest-intensity storm they had ever projected to escalate to Category 5, and that the unwavering confidence displayed by DeepMind's model (which updated every six hours and reached roughly 80% probability) was instrumental in bolstering their own confidence to issue the rare alert. Melissa ultimately slammed into Jamaica with record-shattering sustained winds of 190 miles per hour, causing catastrophic damage and the loss of 95 lives, though the extensive lead time mitigated what could have been an even worse human toll.

> “And we learned later that they said they were heavily informed by watching our model, that our model confidence in the forecast was really increasing their own confidence.” — Peter Battaglia

The close relationship with NHC forecasters provides reciprocal value: researchers observe the criteria operational meteorologists require to make high-stakes life-safety decisions, feeding those practical requirements back into DeepMind's model architecture and output metrics.

`06:50` The Mechanics of Data-Driven Cyclone Modeling and an Extra Day of Lead Time

Asked whether AI possesses an inherent advantage over numerical simulations or simply approaches the problem from a fresh angle, Battaglia explains that the fundamental physics governing the atmosphere do not change over time. If a machine learning model possesses sufficient capacity, meticulous data pipelines, and training over vast historical records, it can identify the subtle physical dynamics that dictate future atmospheric states without needing to explicitly integrate differential equations at runtime.

> “The way I think about it, it's pretty simple. What's happened in the past is the same physical process that happens in the future. So when you get enough evidence of the past, and you have models that are capable of really making sense of the fine, sort of subtle structure among these models... you just get more accurate predictions.” — Peter Battaglia

To tackle these high-impact extremes, DeepMind formed a dedicated sub-team approximately two years prior, focusing specifically on tropical cyclone track and intensity modeling. Across comprehensive historical benchmarks worldwide, the specialized system delivers roughly an extra day of predictive accuracy: a forecast issued three days in advance exhibits the accuracy previously associated with a two-day lead time. This advance notice affords emergency agencies and citizens critical time to prepare before the weather window closes.

- DeepMind's broader global weather modeling initiative began roughly four years prior, targeting surface and atmospheric variables across 10- to 15-day horizons. - The dedicated tropical cyclone project underwent months of rigorous evaluation with academic partners and trusted operational testing centers prior to its public deployment. - Hurricane Melissa set historical records with measured 190 mph wind speeds upon Caribbean landfall. - The model's primary operational advantage is converting lead time: matching the error margins of standard 48-hour forecasts at 72 hours out.

`10:00` Accessing Weather Models and Why Weather Is Getting More Extreme

Peter Battaglia outlines the multiple avenues through which users can interact with Google DeepMind's forecasting models. For direct programmatic access, there is a live feed under the WeatherNext umbrella. Specialized interfaces exist as well: Weather Lab offers tropical cyclone tracking and has expanded to provide data on temperature, wind, and atmospheric pressure. Everyday consumers encounter these outputs integrated into consumer products such as Google Search and Pixel devices. Whether serving enterprise clients who require raw data feeds or ordinary users glancing at a forecast icon on their phones, the model outputs filter through multiple layers.

Hannah Fry turns the conversation to the rising frequency of severe weather, questioning if forecasting has grown increasingly urgent. Battaglia affirms this shift, framing weather through the lens of thermodynamics:

> “The real reason is because weather is energy.”

The atmosphere behaves as an open energy system driven by physical processes: incoming electromagnetic radiation from the sun, mechanical energy manifest as wind, and kinetic energy experienced as temperature. A warmer Earth holds higher total energy, resulting in more intense, energetic meteorological conditions that disrupt historical baseline patterns and become harder to predict. Battaglia notes that recent years have consistently broken records, with virtually all of the hottest years on record occurring within the past few decades. This surplus thermal energy directly fuels intensified wildfires and severe flooding, creating an imperative for advanced AI to address escalating climate challenges.

`11:47` The Butterfly Effect and the Fluid Dynamics of the Atmosphere

Fry raises a classic layperson critique: despite astounding scientific breakthroughs, meteorologists can still struggle to reliably state whether it will rain on a specific day a week away. Battaglia connects this unpredictability directly to the butterfly effect and the inherent constraints of observation:

> “We can't observe every butterfly. So there's a fundamental limit to what we can observe. And that translates to a fundamental limit in what we can predict.”

Because the atmosphere is a fluid, minute, unobserved localized perturbations can cascade into massive macro-scale systems. While scientists cannot track every individual air current or microscopic disturbance, these micro-events leave subtle clues and statistical signatures. Battaglia illustrates this with the metaphor of dropping a small pebble into a pond: the initial impact generates fine droplets and small rings, but recognizing those early indicators allows one to anticipate the concentric waves that will eventually strike the opposite shore. Machine learning leverages this by analyzing historical data to identify subtle "breadcrumbs" that traditional models overlooked, translating minute precursors into larger, reliable predictive signals.

```mermaid flowchart LR accTitle: The Butterfly Effect to Pattern Recognition accDescr: Micro-scale perturbations cascade through fluid dynamics, leaving subtle signatures that machine learning detects to predict macro weather. subgraph MicroScale["Micro-Scale Causes"] A["Unobserved Perturbations<br/>(Butterfly flapping wings / Rock in pond)"] end subgraph Dynamics["Atmospheric Dynamics"] B["Non-Linear Fluid Coupling<br/>(Cascading across scales)"] C["Subtle Statistical Traces<br/>('Breadcrumbs' / Small ripples)"] end subgraph MacroScale["Macro-Scale Impacts"] D["Large-Scale Events<br/>(Cyclones / Concentric waves)"] E["ML Statistical Pattern Recognition<br/>(GraphCast / WeatherNext)"] end

A --> B B --> C B --> D C --> E E -.->|"anticipates"| D ```

`13:58` Why Google DeepMind Tackled Weather

Fry questions why a frontier artificial intelligence laboratory like Google DeepMind chose to invest heavily in weather forecasting. Battaglia cites two principal motivators. First, weather prediction represents one of humanity's oldest, most universal scientific endeavors:

> “Part of our mission at Google DeepMind is to try to solve major scientific challenges that humanity faces.”

Unlike purely theoretical or abstract scientific questions, weather touches the day-to-day existence of everyone on Earth. Second, the technical prerequisites were already converging inside the lab. Battaglia and his colleagues had spent years exploring machine learning for physical simulations, specifically fluid dynamics. When internal groups focused on simulation and weather came together, they recognized that atmospheric science was fundamentally a fluid simulation challenge.

Crucially, the raw materials were already organized. The European Centre for Medium-Range Weather Forecasts (ECMWF) had spent decades compiling vast, highly structured historical datasets of global atmospheric observations. This historical archive provided the ideal foundation for training deep statistical models, providing the deep data infrastructure that enabled both Google DeepMind and ECMWF to construct performant AI weather engines.

`15:43` Numerical Weather Prediction vs. Data-Driven Machine Learning

Battaglia explains the operational architecture of traditional numerical weather prediction (NWP), describing it as a monument of twentieth-century science and engineering. NWP operates on massive supercomputers executing algorithms that approximate the partial differential equations of fluid dynamics (such as the Navier-Stokes equations). The system takes the current estimated state of the global atmosphere, solves these physical equations forward in time by a fixed step (e.g., one to six hours), and iteratively feeds its own output back into the system to march forward into the future.

Because exact analytical solutions are computationally impossible across all spatial scales, NWP approximates reality across a coarse, discretized grid. Battaglia emphasizes that NWP remains an extraordinary human accomplishment, moving society from an era where predicting 24 hours out was difficult to routinely anticipating weather two weeks ahead.

Google DeepMind’s machine learning paradigm inverts the mechanics:

> “So in the same way that you might fit a line to a trend of numbers that are increasing, here we fit a very complicated line to a very complicated set of weather from the past and then extrapolate it out into the future.”

Instead of integrating explicit governing physics equations from first principles at every time step, deep learning networks ingest decades of observed global weather evolutions, map high-dimensional statistical patterns, and learn how atmospheric states transform over time.

`18:24` The Three Generations of AI in Weather Forecasting

When tracing the lineage of machine learning in atmospheric science, Battaglia divides the field’s evolution into three distinct historical waves:

- **First Wave (Sub-grid Parametrization):** Machine learning operated strictly as an auxiliary component to traditional NWP, deployed to "fill in the blanks" for sub-grid scale processes that supercomputers were too coarse to simulate explicitly. - **Second Wave (Localized Image/Video Modeling):** Emerging over the last 8 to 10 years alongside computer vision advancements, these models discarded global numerical simulation in favor of localized perception tasks—such as radar-based precipitation nowcasting over a single country for a 90-minute window or short-term regional wind velocity estimation. - **Third Wave (Global End-to-End Simulation):** The modern era—represented by GraphCast and WeatherNext—which tackles the entire planet simultaneously. These systems model the atmosphere from the Earth's surface across vertical atmospheric levels worldwide, directly matching the scope of comprehensive numerical models while capturing global weather dynamics purely through learned representation.

`20:00` GraphCast and the Power of Multi-Scale Global Representations

Hannah Fry and Peter Battaglia explore how GraphCast operates, identifying it as a foundational Phase 3 weather model capable of taking the entire Earth's atmospheric state and simulating an accurate forecast out to 10 days. Battaglia explains that unlike traditional numerical weather prediction (NWP)—which computes interactions purely on a localized grid—GraphCast uses learned functions that run locally everywhere (reflecting the principle that physical laws are identical across the globe) while simultaneously aggregating information into large representations covering the entire planet. It then projects these planetary representations back down to pinpoint localized events, continually moving up and down between macro and micro scales.

```mermaid flowchart TD accTitle: GraphCast Multi-Scale Processing Flow accDescr: Diagram showing how GraphCast transforms local surface weather data into global representations and projects back down to local forecasts. subgraph Input ["Input Layer"] A["Global Weather State<br/>(Local Observations)"] end subgraph Processing ["Multi-Scale Graph Processing"] B["Learned Local Platform<br/>(Uniform Physics)"] C["Global Representations<br/>(Planetary Patterns)"] end subgraph Output ["Forecast Layer"] D["Refined Local Forecast<br/>(e.g., London Weather)"] end A --> B B -->|"Aggregate scale"| C C -->|"Project back down"| D ```

As Battaglia points out, this multi-scale capability provides a major advantage over traditional NWP when predicting massive phenomena like hurricanes, which can measure 100 kilometers or more across:

> “Because they can see the whole globe at once. They can see large scale patterns as well and learn that structure and exploit that as well as the local structure.”

- **Global-to-local symmetry**: GraphCast processes local physics identically across the globe, compresses the state to capture worldwide atmospheric patterns, and decodes back down to local areas like London. - **Atmospheric coherence**: Large systems contain immense internal structure; understanding conditions on the west side of a 100-kilometer hurricane provides crucial information about the behavior of its east side. - **Contrast with traditional NWP**: Numerical weather prediction models focus primarily on localized updates, missing out on the macro-level visual and spatial patterns that statistical machine learning models naturally exploit.

---

`21:49` Transition to Probabilistic Forecasting: GenCast, Diffusion, and Functional Generative Networks

Addressing the limitations of deterministic models—which produce only a single outcome for a given set of inputs—Fry and Battaglia turn to probabilistic modeling. Battaglia clarifies that probabilistic models roll out multiple potential futures to reveal the range of possibilities, from the most probable track down to severe 5% or 10% outlier events. Around 2023, Google DeepMind followed up GraphCast with GenCast, moving away from predicting merely the mean expected weather and instead generating ensembles of likely scenarios, which produce the characteristic "spaghetti plots" or cones of uncertainty used by meteorologists.

To generate these varied scenarios inside neural networks without breaking the underlying physics, Battaglia describes two distinct machine learning methods:

1. **Diffusion Models**: Similar to modern video and image generation pipelines, the model begins with a noisy baseline image and refines it into coherent weather dynamics. Starting from distinct randomized noise fields guides the model toward slightly different, realistic atmospheric outcomes. 2. **Functional Generative Networks (FGNs)**: A novel technique invented by DeepMind where varying input scenarios induce slight modifications directly into the neural network's parameters and internal weights, yielding diverse but physically grounded forecast tracks.

> “And that is how you get this diversity in these different scenarios.”

---

`25:00` Spaghetti Plots, Uncertainty, and Operational Confidence

Battaglia and Fry discuss how running hundreds or thousands of probabilistic scenario runs allows forecasters to determine true forecast confidence. Referencing real-world storm tracking such as Hurricane Melissa, Battaglia notes that when hundreds of generated tracks converge tightly on the same storm intensity and trajectory, meteorologists can state with high certainty what is about to happen. Conversely, widely diverging spaghetti plots indicate high chaotic instability in the atmosphere, signaling to forecasters that the system is inherently unpredictable.

> “And that's a very important thing because it's a fact of how we forecast, whether we cannot know certain things. So it's important for our models to recognize that and to essentially be sort of humble in the sense of not trying to be overly confident about that.”

- **Confidence calibration**: Consensus across hundreds of generated forecast runs directly supplies the model's confidence scores. - **Epistemic humility**: AI weather tools must explicitly capture atmospheric chaos rather than forcing false certainty during unpredictable conditions.

---

`26:15` Reshaping the "Weather Tree": WeatherNext 3 and End-to-End Prediction

Fry asks how WeatherNext 3 advances beyond previous systems like GraphCast and GenCast. Battaglia introduces the concept of the traditional "weather tree" that has historically governed meteorological services: roots that gather diverse environmental data, a trunk where numerical bureaus compute intermediate baseline atmospheric states, branches housing specialized regional or energy models, and leaves representing the consumer apps delivering local forecasts to a smartphone. WeatherNext 3 collapses this multi-stage pipeline into a single end-to-end architecture.

```mermaid flowchart LR accTitle: WeatherNext 3 End-to-End Pipeline accDescr: Diagram illustrating how WeatherNext 3 shortcuts traditional multi-stage meteorological workflows. subgraph TraditionalPipeline ["Traditional Multi-Stage Process"] R1["Raw Inputs<br/>(Roots)"] --> T1["Bureau Analysis<br/>(Trunk)"] T1 --> B1["Regional Models<br/>(Branches)"] B1 --> L1["Local Surface Forecast<br/>(Leaves)"] end subgraph WeatherNext3 ["WeatherNext 3 Architecture"] R2["Raw Satellite Data<br/>(Roots)"] -->|"Direct End-to-End Model"| L2["Direct Weather Station Forecasts<br/>(Leaves)"] end ```

Rather than ingesting pre-processed state analyses produced by weather bureaus, WeatherNext 3 consumes raw satellite imagery directly and predicts ground-truth readings measured at high-quality physical weather stations (such as airport sensors). Battaglia highlights the leap:

> “We want to change the whole value chain of weather and we want to reshape this weather tree. So a single model takes the information from the roots and makes predictions about the leaves, all at once.”

Fry playfully asks if this represents an AI version of looking out the window at the sky and anticipating rain. Battaglia agrees that it collapses several human and institutional processing steps into a single algorithm, delivering major improvements in spatial and temporal granularity:

- **End-to-end processing**: Eliminates intermediate approximations by directly linking raw sensor observations to surface-level outcomes. - **Hourly forecast refresh**: Instead of updating forecasts every six hours like traditional NWP workflows, WeatherNext 3 generates an updated forecast every single hour by consuming fresh hourly satellite data. - **High temporal granularity**: Natively outputs intra-window predictions for every hour (one o'clock, two o'clock, three o'clock) across a six-hour block, providing critical granular foresight for applications like renewable energy management.

`30:00` WeatherNext 3, Grid Load Forecasting, and Agricultural Impacts

Peter Battaglia explains that many of the design choices in WeatherNext 3 were directly guided by feedback from stakeholders needing next-generation atmospheric modeling, particularly for renewable energy and load forecasting. Hannah Fry asks for clarification on "load forecasting," which Battaglia explains is the technical industry term for electricity demand. Power demand is acutely sensitive to temperature and humidity because consumers turn on heating during freezing spells and air conditioning during heatwaves, creating dramatic peaks in electrical demand at the height of summer and dead of winter. Conversely, renewable electricity supply depends directly on weather conditions: wind generation is governed by wind speed, while solar power relies on cloud cover and solar irradiance. To address both sides of the energy balance, WeatherNext 3 incorporates dedicated wind and solar variables alongside higher-resolution surface temperatures to enhance generation forecasts and demand modeling.

```mermaid flowchart TD accTitle: WeatherNext 3 Dual-Side Energy Forecasting Flow accDescr: Diagram illustrating how WeatherNext 3 predicts both energy demand and renewable supply from atmospheric variables. subgraph AtmosphericInputs["Atmospheric Variables"] T["Surface Temperature & Humidity"] W["Wind Speed & Solar Irradiance"] end subgraph GridImpacts["Power Grid Modeling"] Demand["Load Forecasting (Consumer Heating & AC Demand)"] Supply["Renewable Generation (Wind & Solar Supply)"] end AtmosphericInputs --> GridImpacts T --> Demand W --> Supply ```

Fry observes that agriculture represents another sector with enormous sensitivity to atmospheric conditions. Battaglia agrees, remarking that farmers are likely humanity's oldest weather forecasters since planting and harvest cycles hinge entirely on rainfall and temperature. Having access to accurate weekly rainfall projections or monthly average temperatures allows growers to make operational decisions, such as choosing drought-resistant or flood-tolerant seed varieties. Battaglia notes that as AI weather models expand into these downstream impact areas, researchers are beginning to study longer-range horizons and model specific agronomic thresholds—such as identifying precisely how much rainfall is dangerous enough to require active preparation versus normal precipitation that can be disregarded.

When Fry inquires whether adding these features required completely rewriting the underlying architecture, Battaglia clarifies that the changes were mixed. Introducing variables like wind and solar radiation was relatively straightforward, though non-trivial because their physical distributions behave differently from standard fields. By contrast, moving to finer temporal resolutions, ingesting raw satellite imagery, and predicting ground observation station readings required profound and dramatic architectural transformations to the model design and data-training pipelines.

- Load forecasting measures power grid electricity demand, which spikes during temperature extremes due to heating and air conditioning usage. - WeatherNext 3 introduced dedicated solar and wind variables to model electricity supply alongside higher-resolution surface temperatures for demand forecasting. - Agricultural decision-making benefits from medium-to-long-range forecasts that inform crop selection (e.g., drought-resistant vs. flood-tolerant seeds) and risk mitigation. - Architectural upgrades ranged from simpler variable additions to sweeping structural revisions required for satellite data ingestion, finer temporal stepping, and ground-station predictions.

`32:51` Evaluating Model Performance and Tropical Cyclone Milestones

Discussing how AI weather models stack up against traditional numerical weather prediction (NWP), Battaglia emphasizes the speed of recent advancements. GraphCast served as the pioneer by outperforming traditional deterministic baselines, while GenCast subsequently surpassed the top operational probabilistic forecasts produced by numerical methods. While Google DeepMind's newest models build upon these foundations and often lead the field, Battaglia warns against making blanket claims that any single model is uniformly superior across the board. Real-world performance depends heavily on the specific variable (such as wind or temperature), the forecast lead time (short-range vs. far horizon), and the geographic region.

Tropical cyclones illustrate the nuance of model evaluation. Historically, meteorologists had to employ two separate systems: coarse-resolution, large-scale models to predict storm tracks, and fine-grained, localized models to predict intensity. Google DeepMind managed to achieve state-of-the-art results for both track and intensity simultaneously within a single unified model. However, Battaglia stresses that operational forecasters must still evaluate whether a system is superior in the Atlantic versus the Pacific basin or across different storm intensity classes before relying on it in life-or-death scenarios.

> “It’s hard to say that we’re better than anyone uniformly, the models, but when we evaluate, we tend to outperform the competitors at the ones we’re comparing.” — Peter Battaglia

`35:00` The Compounding Error Paradox and Extreme Event Modeling

Fry raises a classic machine learning concern: if an AI autoregressively feeds its own output back in to predict the next time step, will small errors compound over time and cause the simulation to drift into chaos? Battaglia reveals that catastrophic error divergence is actually a weakness of traditional numerical methods. Because numerical equations only calculate physical laws, once an error nudges the system into an unrealistic state, the underlying equations have no inherent mechanism to pull the forecast back toward plausible weather. In contrast, when an AI model encounters uncertainty or errors, its failure mode is to regress to the mean. Predicting climatological averages is a statistically safe baseline that prevents the model from blowing up or producing unphysical explosions.

This tendency to regress to the mean prompts Fry to question an apparent paradox: if AI models naturally default toward average weather, how can they accurately predict unprecedented, record-breaking weather events fueled by climate change? Battaglia explains that global weather is essentially a mosaic of localized weather phenomena. While an AI model might never have encountered a record-shattering hurricane at one specific latitude following an exact track, it has observed elements of intense localized physics and storms across various points on Earth throughout its training data. By learning the statistical dynamics of local components, the model can synthesize these patterns into novel, physically consistent extreme events.

> “It’s a strange phenomena that these statistical learning methods can also predict the strongest hurricanes that have ever been recorded.” — Peter Battaglia

- Traditional numerical physics solvers risk runaway divergence when errors accumulate because physics equations lack an innate bias toward climatological plausibility. - AI forecasting architectures exhibit graceful degradation; when uncertain, their failure mode is regression to the mean rather than explosive numerical instability. - Unprecedented extreme events can be forecasted because the atmosphere operates as a spatial mosaic; models combine localized statistical physics observed across disparate historical storms to project novel severe events. - Learning efficiency remains an active research challenge: models must learn to generalize rare, once-a-year weather extremes from limited historical records spanning only a few decades.

`37:46` Untapped Data and the Future Frontiers of Weather Forecasting

Looking toward the future of WeatherNext and AI atmospheric science, Battaglia emphasizes that weather directly influences roughly one-third of the global economy. While better forecasting cannot solve every macroeconomic problem, it intersects critically with sectors like energy, agriculture, insurance, transportation, and disaster relief. Each of these fields requires granular, tailored predictions. Furthermore, industry sectors often maintain their own private meteorological sensors—especially within the energy space—which have never been ingested into operational global models.

Battaglia points out that existing meteorological agencies actually leave the vast majority of raw global weather observations unused. Consequently, the next phase of AI research involves bridging global macro-forecasts down to localized scales below one kilometer, while ingesting entirely new modalities of observational data. Having proven that machine learning can beat supercomputer-driven numerical forecasts on global benchmarks, the team sees this milestone not as a conclusion, but as the starting line for addressing a vast landscape of downstream atmospheric puzzles.

> “We’ve just sort of demonstrated that we can make a very accurate forecast and now it’s time to really get to work, I think.” — Peter Battaglia

`40:00` Moving Beyond Numerical Equations to Impact Forecasting

Peter Battaglia reflects on the fundamental paradigm shift underway in atmospheric science. While meteorological forecasting is shifting away from numerically approximating the solutions to differential equations, it is emphatically not leaving physics behind. Battaglia explains that the empirical training data itself was produced by the laws of physics; the machine learning approach merely approximates those underlying mechanics through a different, data-driven pathway. Looking forward, he envisions this shift catalyzing new commercial ecosystems and cottage industries by enabling forecasts that move beyond raw physical quantities to direct socioeconomic consequences. Instead of solely calculating wind speeds, future models could directly estimate downscaled consequences, such as structural damage to electrical power grids. As Battaglia puts it: “So instead of forecasting the wind, maybe you forecast the damage that the wind will cause to the power lines.” He concludes: “If we can get to a regime where we're starting to forecast the impact, I think the sky's the limit.”

```mermaid flowchart LR accTitle: Evolution of Weather Forecasting Paradigms accDescr: Diagram tracing the shift from traditional physics equations to impact-based forecasting via machine learning.

subgraph Classical ["Classical Approach"] A["Physical Laws & Equations"] --> B["Numerical Approximations"] B --> C["Atmospheric Metrics<br/>(Wind speed, Pressure, Temp)"] end

subgraph DataDriven ["ML & Impact Paradigm"] D["Physical World Data"] --> E["Machine Learning Models"] E --> F["Actionable Impact Forecasts<br/>(Grid failure, Structural damage)"] end

C -.->|"Evolves towards"| F ```

- **Rethinking physics in AI**: Machine learning does not replace physics; because real-world observation data is inherently governed by physical laws, training on it represents an alternative method of approximating physical reality. - **Impact-based forecasting**: Developing tools that directly predict end-user harm and infrastructure disruption (such as downed power lines) rather than expecting non-specialists to infer impacts from raw meteorological metrics.

---

`41:07` Interpretability vs. Rigorous Evaluation in AI

Hannah Fry brings up the lingering question of interpretability, asking whether researchers are exploring why these deep models manage to forecast the atmosphere so well. Battaglia acknowledges that while dissecting the model's inner workings is intellectually valuable—especially for meteorologists who need to communicate with the system in the language of domain physics—it is ultimately disciplined benchmarking that governs true progress. He emphasizes that verification against empirical reality must remain the central benchmark for machine learning development. As Battaglia summarizes: “To some extent, the lesson that I've learned about AI and machine learning is that ultimately it's the evaluation that determines the truth and the quality of the model.”

- **Role of domain expertise**: Making models explainable in meteorological terminology helps domain scientists understand failure modes and trust algorithmic outputs. - **Evaluation over intuition**: Expanding empirical validation across hundreds of diverse observational variables and sensor platforms matters more for improving accuracy than speculative interpretability.

---

`42:04` Cross-Pollination: Video Modeling, LLMs, and Atmospheric Data

Addressing Fry's observation that popular attention is overwhelmingly captured by large language models (LLMs), Battaglia highlights the technical sophistication required for weather forecasting, where data throughput outstrips standard multimodal benchmarks. The volume of data passing through weather models is massive, scaling to tens or hundreds of gigabytes per cycle, far exceeding standard generative video workloads. DeepMind's work has spurred algorithmic innovations like the Functional Generative Network (FGN) for probabilistic forecasting, which proved significantly more efficient to train and more effective than conventional diffusion models. Battaglia sees a two-way street between generative media and atmospheric modeling: insights from weather architectures can improve video modeling, while LLM multimodal capabilities could allow atmospheric models to ingest unstructured text or enable conversational interrogation of forecasts. As Battaglia imagines: “Maybe you can interrogate the model with an LLM the same way that you can interrogate a video model with an LLM and ask it questions about what's happening in the video.”

```mermaid flowchart TD accTitle: Cross-Pollination Between Weather AI and LLMs accDescr: Map showing how weather prediction technologies and language models mutually enhance one another.

subgraph WeatherTech ["Weather AI Innovations"] W1["Massive Data Throughput<br/>(Gigabytes per cycle)"] W2["Functional Generative Networks<br/>(More efficient than diffusion)"] end

subgraph SharedImpact ["Bidirectional Transfer"] T1["Advanced Video Modeling & Generative Systems"] T2["Multimodal Natural Language Weather Queries"] end

subgraph LLMTech ["Language Model Capabilities"] L1["Ingesting Unstructured Text Reports"] L2["Targeted Local Question-Answering"] end

W1 --> T1 W2 --> T1 L1 --> T2 L2 --> T2 ```

- **Functional Generative Networks (FGNs)**: Developed as an alternative to diffusion models for probabilistic forecasting, offering higher computational efficiency and fidelity when modeling atmospheric uncertainty. - **Massive scale**: The input-output data pipes required for global weather forecasting require continuous ingestion of multi-gigabyte datasets, outpacing generative video frameworks. - **Conversational weather interfaces**: Exploring how LLMs could let users query spatial forecasts directly—asking targeted questions such as whether it will rain on a specific mountaintop versus a valley floor.

---

`43:40` Conclusion: Buying Time with Real-World AI

In her closing monologue, Hannah Fry traces the long historical arc of human meteorology. For millennia, humanity relied on folk heuristics, from the color of the evening sky to aching joints predicting rain. A century ago, numerical weather prediction emerged, using systems of differential equations to calculate future atmospheric states. Today, AI represents the next major evolutionary step, delivering practical impact outside the lab by buying societies precious lead time ahead of severe weather events. Wrapping up the episode, Fry underscores the tangible human value of these tools: “Now, this is one place where AI is out there in the real world, making a gigantic difference already, buying ourselves a bit more warning, an extra hour, an extra day. But on the right day, that makes all the difference.”

- **Historical progression**: Meteorology has evolved from folklore and empirical observation to numerical physics equations, and now to machine learning models that process planetary-scale datasets. - **Real-world stakes**: The ultimate metric of success for atmospheric AI is extending advance warning windows by hours or days to protect vulnerable populations during catastrophic storms.

## Notable quotes > `11:47` We can't observe every butterfly. So there's a fundamental limit to what we can observe. And that translates to a fundamental limit in what we can predict. — Peter Battaglia

> `40:00` So instead of forecasting the wind, maybe you forecast the damage that the wind will cause to the power lines. — Peter Battaglia

> `41:07` To some extent, the lesson that I've learned about AI and machine learning is that ultimately it's the evaluation that determines the truth and the quality of the model. — Peter Battaglia

> `35:00` It’s a strange phenomena that these statistical learning methods can also predict the strongest hurricanes that have ever been recorded. — Peter Battaglia

## Mentioned Hannah Fry, Peter Battaglia, Google DeepMind, Hurricane Melissa, National Hurricane Center (NHC), National Oceanic and Atmospheric Administration (NOAA), European Centre for Medium-Range Weather Forecasts (ECMWF), GraphCast, GenCast, WeatherNext, WeatherNext 3, Weather Lab, Google Search, Pixel, X (formerly Twitter)

## Video description Can artificial intelligence solve one of science’s most chaotic physics puzzles? In this episode, Professor Hannah Fry sits down with Peter Battaglia, Senior Director of Research at Google DeepMind, to explore how machine learning is transforming global weather forecasting. From providing critical early warnings for Category 5 storms like Hurricane Melissa to predicting renewable energy supply and agricultural impacts, see how models like GraphCast and WeatherNext 3 are building upon decades of numerical physics to reshape our understanding of the atmosphere.

[Source](https://afp-920373-injected.calisto.simplecastaudio.com/36cf10bf-f6dd-4a98-96a9-8eda9f59db4f/episodes/e969cd6f-d389-41e3-b342-bacfa33ca198/audio/128/default.mp3?aid=rss_feed&awCollectionId=36cf10bf-f6dd-4a98-96a9-8eda9f59db4f&awEpisodeId=e969cd6f-d389-41e3-b342-bacfa33ca198&feed=JT6pbPkg)

中文简报

DeepMind人工智能击败物理模型,飓风预警提前量增加一天 机器学习通过直接将全球观测数据综合生成预测,性能优于传统超级计算机物理模型,避免了数值模拟误差的失控,并为应急响应人员争取到了额外一天的极端风暴准备时间。 在本期节目中,Peter Battaglia概述了Google DeepMind如何从局部降水临近预报,过渡到媲美或超越传统数值超算模型的端到端全球天气预报系统。通过2025年飓风“梅丽莎”等真实案例,Battaglia解释了AI如何通过识别行星尺度的微弱大气模式,提供长达额外一天的预测提前量。对话探讨了核心算法进展,包括GraphCast的确定性建模、GenCast中通过扩散和函数生成网络实现的概率预测,以及WeatherNext 3简化的“传感器到预报”架构。展望未来,演讲者讨论了大气AI的更广阔前景,即从预测风速等原始物理变量,转向预测对电网、农业和人身安全的直接社会经济及基础设施影响。 DeepMind的AI模型提前约一周为飓风“梅丽莎”提供了5级飓风预警,在提前72小时的预报中达到了以往提前48小时的精度,增强了美国国家飓风中心的业务决策信心。 (0:54) WeatherNext 3将传统的多阶段气象流程精简为端到端架构,直接将原始卫星图像映射到地面气象站,并每小时更新一次预报。 (26:15) 与误差累积时可能面临爆炸性数值发散风险的传统数值天气预报模型不同,AI架构在不确定性下会自然回归至气候学均值。 (35:00) 为了高效捕捉大气概率不确定性,DeepMind开发了函数生成网络(FGN),通过调整神经网络参数,在速度和保真度上均超越了传统扩散模型。 (21:49)

Reading summary

Google DeepMind's machine learning models are fundamentally reframing atmospheric science by shifting from numerical approximations of fluid equations to data-driven global prediction. Peter Battaglia and Hannah Fry argue that this approach delivers critical extra lead time for life-threatening storms and establishes a direct pipeline from planetary observations to actionable socioeconomic impact. Operational Lead Time and Cyclone Prediction (0:54) The practical value of atmospheric AI centers on extending the warning window before severe weather strikes. Across global historical benchmarks, DeepMind's dedicated tropical cyclone system delivers roughly an extra day of predictive accuracy, matching the error margins of standard 48-hour forecasts at 72 hours out. This extended horizon proved critical during Hurricane Melissa in October 2025. While Melissa was still a weak disturbance, DeepMind's models projected an escalation to Category 5 status with roughly 80% confidence nearly a week in advance. The Evolution from First-Principles Physics to Deep Learning (15:43) Traditional numerical weather prediction relies on supercomputers approximating partial differential equations across discretized grids. While effective, these solvers risk runaway numerical instability when errors compound over time. In contrast, deep neural networks ingest decades of observational records, such as ECMWF reanalysis archives, to learn underlying dynamics without explicitly solving fluid equations at runtime. Battaglia notes that when machine learning systems encounter extreme uncertainty, their failure mode is regression to the climatological mean rather than explosive numerical divergence. Deep learning can still predict record-shattering extremes because the atmosphere acts as a spatial mosaic. By synthesizing learned statistical interactions from disparate localized storms across its training history, a model can assemble novel, physically plausible Category 5 events. The architecture has evolved across three waves: sub-grid parametrization, localized image-based perception like radar nowcasting, and modern global end-to-end simulators such as GraphCast, which simultaneously processes macro-planetary patterns and micro-local physics. Quantifying Atmospheric Chaos with Probabilistic Ensembles (21:49) Because fluid dynamics are acutely sensitive to microscopic, unobserved perturbations—the classic butterfly effect—deterministic forecasts that output a single trajectory are inherently limited. To quantify uncertainty, DeepMind introduced GenCast to generate scenario ensembles that map out probability cones and spaghetti plots. Instead of relying solely on standard diffusion methods, the system utilizes Functional Generative Networks (FGNs), which induce slight modifications directly into model weights to produce diverse, physically grounded outcomes with greater computational efficiency. Tightly converging ensemble paths indicate high forecast certainty, whereas widely divergent tracks signal intrinsic atmospheric chaos. Battaglia stresses that operational forecasting requires this epistemic humility, ensuring models reflect the limits of what can be known rather than projecting false confidence during volatile conditions. Collapsing the Meteorological Pipeline with WeatherNext 3 (26:15) WeatherNext 3 restructures the traditional meteorological workflow, which historically relied on sequential steps: raw data collection, baseline state calculation by national bureaus, regional downscaling, and consumer app distribution. The new architecture collapses these stages into a unified end-to-end network that ingests raw satellite imagery directly to predict readings at physical ground weather stations. This design supports hourly forecast refreshes and generates intra-window predictions for every hour within a six-hour block. This granularity supports sectors directly sensitive to weather, such as agriculture and power grid management. WeatherNext 3 models both sides of the energy balance: power demand, which spikes during temperature and humidity extremes due to heating and cooling, and renewable power supply, which is governed by cloud cover, solar irradiance, and wind velocity. Impact Forecasting and Data Integration Frontiers (40:00) Battaglia emphasizes that AI weather modeling does not abandon physics, because empirical observational data is fundamentally governed by physical laws. The next frontier involves shifting beyond raw meteorological metrics toward direct impact forecasting—such as projecting infrastructure disruption and downed power lines rather than simply wind speeds. Achieving this requires ingesting currently unexploited private datasets and downscaling macro-forecasts to resolutions below one kilometer, alongside evaluating cross-pollination opportunities with large language models to enable conversational, text-based forecast interrogation. While machine learning models now match or exceed traditional numerical baselines across various benchmarks, Battaglia cautions against claims of uniform superiority, noting that performance varies by variable, lead time, and geographic basin. The central operational challenge remains balancing empirical verification against interpretability while training models to reliably generalize rare, once-a-century extremes from only a few decades of historical observational data.

精炼阅读摘要

Google DeepMind 资深研究总监 Peter Battaglia 与主持人 Hannah Fry 指出,气象预测正由传统的超算数值求解微分方程向数据驱动的机器学习范式演变;通过学习历史大气物理规律并重构端到端预测流程,AI 模型已在飓风预警实战中将高精度前置时间提前约一天,并将预报由物理指标测算延伸至社会经济影响预测。 从偏微分方程到数据驱动的大气物理模拟 (15:43) 数十年来,传统数值天气预报(NWP)依靠超级计算机对流体力学偏微分方程(如纳维-斯托克斯方程)进行网格离散化近似求解。尽管 NWP 是现代工程的里程碑,但受制于网格分辨率与庞大的计算开销。DeepMind 研究团队指出,大气的基本物理规律历来保持恒定,机器学习并非抛弃物理规律,而是通过拟合欧洲中期天气预报中心(ECMWF)累积数十年的全球观测与再分析数据,间接掌握高维状态下的物理演变特征,无需在运行时进行逐步显式积分。 Battaglia 将 AI 气象发展梳理为三代历程:第一代作为 NWP 的辅助手段填补次网格尺度物理参数;第二代随计算机视觉兴起,专注局部雷达降水即时预报或区域风速估算;第三代以 GraphCast 和 WeatherNext 为代表,实现全球尺度的端到端模拟,在三维大气垂直层次上直接对标经典数值预报的覆盖范围。 飓风梅利莎实战检验与额外一天预警窗口 (0:54) AI 预测在现实防灾中的关键价值在 2025 年 10 月的五级飓风“梅利莎”(Hurricane Melissa)中得到验证。在梅利莎尚处于微弱热带低压阶段时,DeepMind 实验性平台 Weather Lab 提前约一周即输出其将急速增强为五级飓风的高置信度信号(更新概率达约 80%),而传统模型当时仅显示温和增强。最终梅利莎以创纪录的每小时 190 英里持续风速登陆牙买加及加勒比岛屿,造成 95 人遇难与灾难性破坏。 美国国家海洋和大气管理局(NOAA)旗下的国家飓风中心(NHC)随后将 DeepMind 模型的稳定预报纳入综合研判,在风暴尚未达到一级强度前 3 天破例发布罕见的五级预警。Battaglia 表示,该专研热带气旋的模型在多项历史基准测试中展现出约一天的前置预警优势,即提前 72 小时的误差水平相当于传统 48 小时的预报精度,为疏散安置与医院转移赢得了关键行动窗口。 架构重构与不确定性量化演进 (20:00) 针对大尺度天气系统的内在空间关联,GraphCast 采用多尺度架构,在保持局部物理规律一致性的同时,将观测聚合为覆盖行星尺度的全局表征,再向下投影以捕捉局部事件,克服了传统 NWP 仅依赖局部网格更新的局限。针对确定性预测难以反映大气混沌特征的痛点,DeepMind 进一步推出 GenCast,通过扩散模型(Diffusion)与自主研发的功能生成网络(FGN),生成数百次模拟轨迹(“意大利面图”),以量化预测置信度并展现低概率的极端偏差风险。 最新的 WeatherNext 3 则重构了由“根(原始观测)、干(气象局分析场)、枝(区域模型)、叶(终端应用)”构成的传统气象流水线。该模型直接摄取原始卫星图像并输出高精度地面观测站读数,不仅将更新频率由传统 NWP 的 6 小时压缩至逐小时,还能原生输出逐小时的精细化预测,大幅提升了对时间敏感型场景的响应速度。 误差收敛特性与面向实际影响的预测前沿 (35:00) 面对自回归预测中误差累积的质疑,Battaglia 指出,数值求解器一旦出现偏差便容易失去物理约束而发散,而 AI 模型在遭遇不确定性时的失效模式是向气候均值回归,从而避免数值爆炸。针对“向均值回归如何预测破纪录极端天气”的悖论,他解释大气表现为局地物理现象的“空间拼贴”:即便某种极值路径在特定区域从未发生,模型已在训练数据中见过全球不同区域类似强度的局部物理特征,从而能合成前所未见但符合物理一致性的极端事件。 在应用层面,随着天气深度影响全球约三分之一的经济活动,气象预测正从提供温度、风速等抽象指标,转向直接评估电力负荷与新能源发电供给平衡、农业适播期判断,乃至预测强风对输电线网的物理损耗。Battaglia 认为,利用当前大量未被传统机构消纳的气象传感器数据,实现低于一公里的超局部下尺度预测与直接影响预报,是下一阶段的核心方向。 气象预报正从经验法则与微分方程逐步进入基于大数据的统计物理学时代,严谨的跨变量实证评测已成为替代黑盒推测的检验准绳。尽管 AI 气象模型在面对罕见极端事件的泛化学习上仍面临数据跨度挑战,但它与大语言模型的多模态交互、端到端影响预报已展现广阔前景;在突发灾害面前所争取到的额外预警时间,正是此类技术目前产生最实质性社会价值的基石。

Detailed notes — zh

## Background 本期播客由 Google DeepMind 于 2026 年 9 月 9 日在 RSS 及网络平台发布。节目中,Hannah Fry 教授与 Google DeepMind 研究高级总监 Peter Battaglia 展开对谈,探讨机器学习如何颠覆传统数值天气预报,以及 GraphCast 和 WeatherNext 3 等尖端气象模型如何在 5 级飓风预警、可再生能源调控和农业决策中发挥关键作用。 ## TL;DR 节目围绕人工智能对全球天气预报范式的重塑展开,重点回顾了 AI 模型在 2025 年“梅丽莎”飓风中提前数天精准锁定爆发性增强并为防灾争取黄金时间窗的实战案例。Peter Battaglia 深入解析了从传统超算求解偏微分方程(NWP),到 GraphCast 的全球多尺度表征、GenCast 的概率集合预测,再到 WeatherNext 3 端到端直连卫星观测的技术演进。探讨还延伸至 AI 捕捉混沌扰动、服务电网负荷与农业生产的机制,并指出了直接预测天气物理破坏(Impact Forecasting)及跨模态结合的未来前沿。 ## Atmosphere & style 对话洋溢着严谨深邃的科学探讨氛围与面对宏大自然谜题时的敬畏感,Hannah Fry 的机敏提问与 Peter Battaglia 扎实的物理学直觉碰撞出极高密度的思想火花。交流既有拆解扩散模型与流体力学底层的理性沉着,也有面对 5 级超级飓风防灾决策时的惊心动魄与生死关切。整场节目生动展现了在不可知混沌中保持“科学谦逊”的精神,传递出前沿科技切实行走于现实世界、为人类避险争取生死时速的厚重责任感。 ## Bulletin - `01:25` Google DeepMind 的 AI 气象模型在 2025 年 10 月飓风“梅丽莎”仍处于微弱扰动阶段时,提前一周高置信度预测其将跃升为五级超强飓风,为牙买加等地的减灾疏散赢得了整整三天的黄金决策期。 - `06:23` AI 模型在大规模热带气旋回测中实现了代际飞跃,达到了“传统数值天气预报在 2 天前才能实现的预测精度,AI 模型提前至 3 天前即可完成”,整整抢出了一天的预警时间。 - `25:00` WeatherNext 3 打破了传统气象“从观测到数据同化再到多级后处理”的级联树状流程,实现了从原始卫星影像到地面气象站真实读数的端到端直接预测,并支持滚动每小时更新。 - `21:40` 为了解决极端天气概率推演难题,DeepMind 自研了“函数生成网络(FGNs)”,在概率集合预测上的训练效率和拟合表现均显著优于传统扩散模型。 ## Key takeaways - `00:00` 天气预测依赖的大气物理学本质上属于混沌非线性流体系统,微小的扰动会导致巨大的未来偏差,传统超级计算机主要依靠对微分方程组进行网格离散近似来求解。 - `04:08` 在飓风“梅丽莎”应对中,美国国家飓风中心(NHC)受 DeepMind 预测高置信度的启发,打破历史纪录在系统初始强度极低时直接预报其将发生爆发性增强并升级为五级飓风。 - `10:00` 全球变暖向地球大气系统注入了更多热能与机械能,导致极端天气事件的频率与烈度激增,同时也使天气的宏观模式更难以通过常规手段预测。 - `14:00` 欧洲中期天气预报中心(ECMWF)数十年积累的高质量 ERA5 再分析数据集,构成了当前基于深度学习进行全球气象模拟的核心数据基石。 - `18:00` 机器学习在气象领域的演进经历了三个阶段:从早期的局部降尺度辅助,到计算机视觉驱动的短临雷达外推,最终演进为全要素全球端到端物理动力模拟。 - `20:00` GraphCast 采用多尺度图神经网络,通过在局部学习通用物理规律并聚合为全球大尺度表征,实现了单次表征即囊括跨数百公里的飓风宏观关联并反哺局部预测。 - `21:40` 面对极端灾害预警,GenCast 摒弃了单一平均状态拟合的确定性输出,利用扩散模型与函数生成网络输出概率集合,以便评估发生概率仅 5%-10% 的严重边缘风险。 - `25:00` 当概率集合轨迹高度发散成“意大利面条图”时,模型输出的置信度评分体现出科学的“谦逊”,向决策者客观警示当前物理边界条件具有极高的不确定性。 - `30:00` WeatherNext 3 引入专用的风能、太阳能指标及更高分辨率地表温湿度预测,旨在同时解决电网侧由于风光波动引起的供应预测与由于空调暖气引起的电力负荷预测难题。 - `35:00` 面对自回归迭代时的误差累积,传统物理微分方程容易陷入数值发散崩溃,而 AI 模型则倾向于保守地“回归均值”,展现出完全不同的数值失效特征。 - `35:00` 虽然全球历史样本中百年一遇的极端风暴极少,但全球天气是由局部物理马赛克拼成的,AI 模型通过学习局部极端物理条件组合,依然具备推演出前所未有超级极端风暴的能力。 - `40:00` 未来气象预报范式正从单纯预报物理要素(如风速)转向直接预报社会经济影响(如电网破坏与线路倒伏),且模型迭代的最高准则始终是全方位的严格评测而非仅靠可解释性。 - `41:15` 气象预报模型处理着规模远超日常视频的高维数据流,其在概率建模上催生的函数生成网络等架构创新,正在反哺通用视频生成及与大语言模型的多模态交互探索。 ## Detailed walkthrough ### `00:00` 混沌物理与天气预报:从传统超算流体力学到 AI 气象模型 当飓风直奔陆地而来时,时间就成了最宝贵的生命线。哪怕只是多出一天的预警时间,人们就能从容疏散道路、清空医院病患、开放避难所,确保公众撤离至安全地带;在危机与灾难之间,几个小时的差距往往就是生与死的分水岭。然而,人类虽然能够精准计算出一千年后太阳升起的具体秒数,预测未来的天气却始终是物理学中最棘手的难题之一。大气系统对微小的扰动极度敏感——正如著名的“蝴蝶效应”所描述的那样,今天气压的一丝微小起伏,可能在一周后演变为一场席卷一切的特大风暴。 传统的天气预报方式依赖超级计算机求解复杂的流体力学方程组,而 Google DeepMind 正在探索一条完全不同的技术路径。团队从 2020 年利用卫星图像预测短期降水开始切入,如今最新的 WeatherNext 系统已经能够为全球范围提供细致到逐小时的天气预测。Google DeepMind 研究高级总监 Peter Battaglia 指出,过去几十年来气象学家所积累的数值物理学基础,正与深度学习技术深度结合,重塑人类对大气动态的认知与掌控。 ```mermaid flowchart TD accTitle: 气象预报范式对比 accDescr: 对比传统数值天气预报与现代人工智能气象大模型在数据输入、核心计算引擎与预测输出上的差异 subgraph TRAD["传统数值天气预报 (NWP)"] A1["气象观测数据"] --> B1["超算集群求解物理流体力学方程组"] B1 --> C1["中远期确定性与集合预报"] end subgraph AIDM["AI 气象大模型 (如 WeatherNext)"] A2["数十年历史再分析数据与多源卫星数据"] --> B2["深度图神经网络与时空动力学学习"] B2 --> C2["逐小时全球预测与极端气旋高置信度预警"] end ``` ### `01:25` 飓风“梅丽莎”危机:从微弱扰动到五级超级飓风的惊人预测 2025 年 10 月横扫牙买加和多个加勒比海岛屿的“梅丽莎”(Hurricane Melissa)飓风,成为检验人工智能气象实战能力的标杆案例。当时 Google DeepMind 刚刚发布了其性能最优的天气模型,并通过名为 Weather Lab 的平台向公众与专业机构提供实时的飓风预测数据。与此同时,团队与包括美国国家海洋和大气管理局(NOAA)旗下的国家飓风中心(National Hurricane Center, NHC)在内的多个气象机构建立了深度的合作机制。 在大西洋上空,“梅丽莎”最初的表现极为反常:它最初只是一个极其微弱的热带扰动,甚至在很长一段时间内仅仅是热带低压,连正式的热带风暴级别都尚未达到。然而,在大规模海水表面温度偏暖的背景下,Google DeepMind 的模型在大风暴登陆前约一周,便敏锐捕捉到了其能量积聚的潜在路径,并给出了高度确信的预测结果。Peter Battaglia 回忆道:“So about a week before, a little less than a week before, we started to see the model becoming quite confident, that it was going to turn into a category five hurricane, which is the strongest category of hurricane.”(大约在风暴登陆前一周或稍短一点的时间,我们开始看到模型变得非常有信心,预测它将演变成五级飓风,也就是威力最强的一级飓风。) 社交平台 X(原 Twitter)上活跃的气象学者社区最先察觉到了这一异常预测,并引发了广泛关注和热议。虽然其他数值物理模拟也在运行,并且预测其强度会上升,但几乎没有哪个传统模型能够对风暴会增强到如此极端的级别、精确的移动轨迹以及具体强度等级展现出如此高的置信度。 ### `04:08` 赢得生死攸关的三天:国家飓风中心与 Google DeepMind 的决策联动 官方机构的预测决策流程极其审慎。国家飓风中心需要汇集并研判来自传统数值模型、前沿新型模型以及各项观测指标的繁复信息,将其拼接整合为官方预报结论。在那个决定性的周六,国家飓风中心发布了正式裁决:预报该系统将在短短两到两天半的时间内发生“爆发性增强”(rapid intensification),从一个尚未达到一级飓风标准的低级别气旋暴增为最高级别的五级飓风,并直击牙买加。 - **超前预警时间窗**:模型在周六即锁定风险,预测系统将于周一达到五级强度,并于周二登陆,为当地防灾减灾部门赢得了整整三天的黄金筹备期。 - **历史最低起报强度**:该预警打破了国家飓风中心的历史纪录——这是该机构有史以来在系统初始强度如此之低的情况下,首次直接预报其将跃升为五级飓风。 - **高确定性概率输出**:Google DeepMind 团队以每六小时一次的频次生成最新预测,模型对风暴升级为五级飓风的置信概率最终攀升至约 80%。 - **不可磨灭的减灾效益**:风暴登陆牙买加时阵风风速高达每小时 190 英里,造成了巨大的基础设施破坏,并导致 95 人丧生。虽然灾情惨重,但若没有提前三天启动医院疏散、人群转移和避难所设立,后果不堪设想。 事后国家飓风中心向 DeepMind 反馈,气象专家在做决断时深受其 AI 模型预测结果的启发。Peter Battaglia 总结道:“And we learned later that they said they were heavily informed by watching our model, that our model confidence in the forecast was really increasing their own confidence.”(我们后来得知,他们表示在很大程度上受到了我们模型的启发,我们模型在预报中表现出的高度信心极大地增强了他们自身的信心。)这次实践也让研究团队获得了极其珍贵的反哺经验,理解一线防灾决策者真正需要何种粒度的数据支持。 ### `06:23` 历史物理规律的重塑:AI 气旋预测专项与“提前一天”的精度飞跃 针对 Hannah Fry 提出的疑问——AI 究竟是具备某种跨越远期时间尺度的固有优势,还是仅仅采用了与传统数值计算不同的处理方式,Peter Battaglia 从机器学习的本质给出了直接的物理学解释。他认为,过去发生的大气物理规律与未来发生的完全一致。当机器学习模型接触到足够海量的历史观测数据,并且网络架构能够充分解析数据输入与输出、过去状态与未来演化之间错综复杂的精细结构时,模型自然能够做出更加准确的判断。 正是基于这一物理一致性认知,DeepMind 在四年前全面启动了覆盖地表与高空大气、面向 10 至 15 天中期跨度的全球气象大模型研发。随着基础模型的成熟,团队希望进一步聚焦下游重大实际灾害的精准防御,于是在大约两年前抽调骨干组建了专门的热带气旋攻坚团队。 热带气旋属于地球上能量最极端、破坏力最强且相对罕见的大气物理过程。在与学术界、一线气象业务机构紧密合作并经过长达数月的可信测试者(trusted testers)验证后,团队面向全球发布了专用的气旋预测能力。在大规模的回测评估中,该模型展现出显著的代际优势:传统气象预报在两日前预测所能达到的精确度水准,AI 模型在三日前预测中便能同等实现。这种在关键防灾周期上整整“提前一天”的精度飞跃,正在为全球气象防灾决策者提供前所未有的战略响应纵深。 ### `10:00` 获取预测结果的方式与极端天气的日益严峻 公众和企业可以通过多种渠道获取 Google 的天气预测成果。Peter Battaglia 介绍,他们提供实时预测数据流,直接在 Google 搜索“WeatherNext”即可找到不同形式的服务;如果专门关注热带气旋预测,可以访问 Weather Lab,该平台近期已将能力拓展至温度、风速和气压预测;而普通用户在日常设备(如 Pixel 手机或 Google 搜索)中查看天气时,底层同样整合了 WeatherNext 的预测模型。 面对 Hannah Fry 关于极端天气预测紧迫性的提问,Peter 直言天气正变得越来越极端。他从物理本质进行了解释:天气本质上就是能量——太阳带来电磁辐射,风是机械能,温度则是动能。“当地球变暖时,能量就会增加,因此天气会更加剧烈,而这种剧烈程度至少按照历史标准来看,也会使其更难以预测,因为天气的形态模式正在改变。”过去十到十五年间,全球几乎集中经历了有记录以来最炎热的年份,导致野火和洪水等灾害频发,这也让利用 AI 应对这一重大科学与民生挑战变得愈发紧迫。 - **获取途径**:Live feed 数据流(WeatherNext)、面向极端风暴与综合气象的 Weather Lab,以及面向普通终端用户的 Google Search 和 Pixel 天气应用。 - **物理机理**:全球气温上升导致大气系统内的总能量增加(热能、动能、机械能激增),直接推高了极端天气的强度并降低了其常规可预测性。 --- ### `12:00` 混沌系统中的“蝴蝶效应”与 AI 的模式识别优势 很多公众常常困惑:现代科学已经取得如此多惊人突破,为什么有时连“下周三会不会下雨”都很难准确预报?Peter 用经典的“蝴蝶效应”解释了这一物理局限:大气的本质是一种流体,流体动力学具有跨尺度的强耦合特性,极微小的扰动可能引发巨大的连锁反应。人类无法观测到每一只蝴蝶的扇翅动作,这种观测极限直接转化成了预测极限。 然而,微小事件会在系统中留下微弱的线索和痕迹。Peter 打了个生动的比方:正如往池塘里扔一颗小石头,水面会溅起小水滴并形成细微波纹,如果系统能捕捉到这些微小涟漪,就能推断出后续会有一圈圈更大的同心圆波纹扩散并拍打到对岸。“这就是我认为人工智能和机器学习真正发挥作用的地方。它们能够意识到:等等,我以前见过水滴溅到这里,接着就会有一圈大波浪拍打到池塘对岸。”AI 擅长在海量历史数据中进行复杂的统计模式学习,捕捉传统方法难以察觉的隐秘信号。 ```mermaid flowchart TD accTitle: 流体微小扰动与机器学习模式识别的关系 accDescr: 展示从微观扰动、观测极限到机器学习捕捉线索并预测宏观结果的过程 subgraph PhysicalWorld["物理现实:流体耦合系统"] A["微小扰动<br/>(如蝴蝶振翅/小石子入水)"] --> B["微弱物理痕迹<br/>(小涟漪/微气压差)"] B --> C["宏观天气演变<br/>(强风暴/同心圆波浪)"] end subgraph ObservationLimit["观测与数据瓶颈"] D["无法观测所有微观细节<br/>(根本性观测极限)"] A -.-> D end subgraph AIRecognition["AI 与机器学习"] E["海量历史数据统计学习"] B --> E E --> F["识别隐秘线索与模式匹配"] F --> G["预测宏观天气趋势"] end ``` --- ### `14:00` Google DeepMind 涉足天气预报的初衷与核心数据契机 谈及 DeepMind 为何选择涉足天气这一传统领域,Peter 指出背后有两大驱动力。首先,天气预测可能是科学史上最古老的预测难题之一,而 DeepMind 的使命正是运用 AI 攻克人类面临的重大科学挑战。“天气本身是一个挑战,但它并不是一个抽象的问题,它与每个人息息相关,切实影响着每一个人每一天的日常生活。”其次,Peter 团队自身有着多年利用机器学习进行物理仿真(尤其是流体模拟)的技术积累,当团队意识到流体模拟技术可以直接迁移到大气建模时,各个研究方向迅速合流。 更为关键的催化剂是高质量历史气象数据的可得性。欧洲中期天气预报中心(ECMWF)数十年来积累了跨越数十年的地球天气再分析数据集(如 ERA5),为数据驱动的机器学习提供了完美的“原材料”。这让深度学习模型拥有了前所未有的训练基础,促成了 AI 气象学的爆发式突破。 - **研究契机**:DeepMind 攻克宏大科学难题的使命,与团队长期深耕“基于机器学习的流体仿真”技术产生交集。 - **数据基石**:ECMWF 积累的长达数十年的权威气象历史数据,为 AI 模型提供了坚实的训练土壤。 --- ### `16:00` 传统数值天气预报(NWP)的物理近似与演进 为了阐明 AI 的革新之处,Peter 详细剖析了占据气象领域数十年统治地位的“数值天气预报”(Numerical Weather Prediction,简称 NWP)。NWP 的运作逻辑是:超级计算机获取地球当前的实际气象观测估算值,利用流体动力学物理方程组推求未来一小时或六小时的状态;随后将该预测输出作为新的输入重新喂入模型,层层自回归迭代,推算出未来数天的天气。 由于大气运动方程(如纳维-斯托克斯方程)极其复杂且存在混沌效应,计算机无法在无限精细的尺度上求出精确解析解。因此,传统气象工程选择在较为粗糙、模糊的网格尺度上对方程进行数值离散与近似求解。Peter 给予了传统方法高度评价:“在实践中,这几十年来一直是科学与工程领域的一大胜利。事实上,你能提前一周半到两周知道天空会发生什么、会不会下雨,这真的太不可思议了。”这凝聚了人类在物理学、工程计算和数据采集领域数十年的智慧结晶。 --- ### `18:00` 从局部降水外推到全球全要素仿真:AI 天气模型的演进脉络 与 NWP 求解微分方程截然不同,Google DeepMind 构建的 AI 天气模型完全建立在对海量历史天气演变序列的统计学习之上。Peter 形象地比喻道:“就像你给一组不断增长的数字拟合一条趋势线一样,在这里,我们是为过去极其复杂的一整套天气数据拟合一条高度复杂的曲线,然后将其外推到未来。” Peter 梳理了机器学习在气象预报领域的演进历程,划分为三个清晰的代际发展阶段: | 发展阶段 | 核心技术与应用形式 | 预测范围与代表场景 | 对物理仿真的依赖程度 | |:--- |:--- |:--- |:--- | | **第一阶段(辅助阶段)** | 填补空白、降尺度(Downscaling) | 补充传统数值模型未能显式模拟的精细尺度结构 | 强依赖传统 NWP,仅作为后处理或辅助模块 | | **第二阶段(短临外推阶段)** | 计算机视觉驱动的图像/视频生成模型(如雷达外推) | 预测局部区域/单国未来 90 分钟的降雨量或风速 | 脱离 NWP,但不进行全球气象动力模拟,仅做局部图像序列建模 | | **第三阶段(全球端到端仿真阶段)** | 全球全要素 AI 大模型(如 GraphCast、WeatherNext) | 预测全球范围内地表及不同大气层高度的全部核心气象要素 | 完全独立模拟全球天气系统,直接对标并超越传统数值预报 | Peter 总结道,当前正处于第三阶段的高峰期,AI 模型已经能够像传统数值预报一样,在原理上全面捕捉并模拟整个地球从地表到高空大气的所有气象动态。 ### `20:00` GraphCast 的多尺度表征机制与传统数值模式的差异 Hannah Fry 引导讨论回到具体的模型实现上,询问这种机制是否正是 GraphCast 的核心逻辑。Peter Battaglia 确认了这一点,并指出 GraphCast 是该领域第三阶段的开创性模型之一——它能够接收全球完整的气象状态,并直接模拟出长达 10 天的天气预报。其内部运作机制与现代 AI 及机器学习的核心思想高度契合:模型在整个地球网格上应用相同的局部学习函数(learned function),这在物理直觉上契合了“物理规律在世界各地都是统一的”这一客观现实。随后,系统将这些局部状态逐步向上聚合,构建出覆盖整个地球的大尺度多层级特征表征(large set of representations),紧接着再向下投影解码,重新生成具体的局部预测。正如 Hannah 生动总结的那样:“先看伦敦会发生什么,再看这套逻辑在全球范围是否说得通,然后重新映射回伦敦未来的变化”,这种在大尺度与局部尺度之间持续往复的架构,正是该模型强大的关键。 Peter 强调,传统数值天气预报(NWP)在机理上并不具备这种全局抽象能力,它们主要在极小的局部空间网格上依赖差分方程逐步推进。然而,基于统计学习的 AI 算法天生善于捕捉宏观结构。以直径可达数百公里的超大型飓风为例,气旋系统内部存在着极其强烈的内在物理关联,西侧的气流动态其实能够直接揭示东侧未来的演化走势。通过单次表征囊括整个飓风全貌,AI 可以更深刻地反哺局部预测。Peter 明确断言,这正是 AI 气象模型之所以表现出色的深层原因:“And this is one big difference between AI weather models and traditional numerical weather prediction models. That is probably why the AI models are so effective. Because they can see the whole globe at once.” 这种将宏观形态与微观物理无缝咬合的能力,构成了 AI 颠覆传统流体动力学模拟的基础。 ```mermaid flowchart TD accTitle: GraphCast 多尺度表征与预测流程 accDescr: 展示 GraphCast 如何从全球初始输入经过多尺度图表征再向下预测局部天气 subgraph Input ["输入层"] A["全球气象初始状态数据<br/>(Full Global Weather State)"] end subgraph Representation ["多尺度图神经网络处理"] B["局部学习函数<br/>(通用物理规律建模)"] C["全局多尺度特征聚合<br/>(捕捉宏观系统如跨数百公里飓风)"] D["向下多层级解码投影<br/>(自全局反哺局部微观动态)"] end subgraph Output ["预测输出"] E["高精度局部演化预报<br/>(如伦敦具体天气 / 10天轨迹)"] end A --> B B --> C C --> D D --> E ``` ### `21:40` 从确定性到概率性:GenCast 与极端事件预警 随着讨论深入,Hannah 询问模型究竟是在哪一阶段跨入“概率预测”(probabilistic)门槛的。Peter 剖析了确定性模型与概率性模型的根本哲学差异:确定性模型输入一组数据,永远只能输出唯一的单一解;而概率模型则会吐出多个推演分支,展示“这个可能发生,那个也可能发生”的完整可能域。这不仅能描绘出概率最高的主流情景,还能照亮那些概率较低、但一旦发生将带来灾难性后果的边缘事件。气象学界很早就意识到概率预测的必要性,传统超级计算机通常通过运行具有微小扰动的初始集合(Ensemble)来生成不同的未来情景。Google DeepMind 团队在完成 GraphCast 之后紧接着于 2023 年立项研发概率模型,其成果便是下一代核心模型 GenCast。 GenCast 最大的技术飞跃在于摒弃了对“天气平均状态”的单一拟合,转而生成多元可能情景的预测集合。Peter 严肃地指出,这对于极端天气应对和防灾决策具有不可替代的价值,因为在面对灾难性事件时,哪怕只有 5% 到 10% 的发生概率,社会与应急部门也必须提前准备。Hannah 联想到风暴预报中常见的飓风移动轨迹锥体(cones of probability),以及由无数条发散轨迹组成的“意大利面条图”(spaghetti plots)。针对 AI 如何实现概率推演的技术细节,Peter 披露了团队的双轨路径: - **扩散模型(Diffusion Models):** 借鉴 AI 视频生成的技术范式,模型学习如何将纯高斯噪声图像逐步“去噪”还原为物理上合乎逻辑的气象状态。只要每次从不同的随机初始噪声出发,去噪过程就会自然演化至略有差异但同样符合物理规律的天气分支,从而产生多样性输出。 - **功能生成网络(Functional Generative Networks, FGNs):** 这是 DeepMind 自主发明的专有架构,它直接在推理时对神经网络内部的权重和参数进行微小的定向扰动,使其每次计算都能自发映射出略微不同的未来走向。 Hannah 将这种机制比作统计层面的“蝴蝶效应”探索:就像在代码中放置了一只无形的蝴蝶,通过一次次微小的扰动再向前推演,观察整个系统的发散程度。 ### `25:00` 科学的谦逊:置信度评估与 WeatherNext 3 的全栈重构 面对数百乃至数千次模拟运行,Peter 阐述了如何解读预测的密集程度与离散度。当所有集合成员在预测飓风强度时高度收敛,决策者就能建立起强烈的确定性;而一旦预测轨迹像乱线团一样四处散开,模型其实是在直白地向人类发出警示——当前的物理边界条件存在极高不确定性。Peter 对此发出了极具科学哲思的阐述:“if they're spaghetti plots and they're all over the place, then the model is saying it's very difficult for us to understand the what could happen. And that's a very important thing because it's a fact of how we forecast, whether we cannot know certain things. So it's important for our models to recognize that and to essentially be sort of humble in the sense of not trying to be overly confident about that.” 这种在不可预测面前保持“谦逊”的特质,正是模型输出客观置信度评分(confidence scores)的技术根基。 随后,对话转向了更为激进的革新——WeatherNext 3。Peter 勾勒了传统气象预测链路的经典“天气树”(weather tree)隐喻: - **树根(Roots):** 分散在全球各地的初始观测数据源(卫星、气球、浮标、雷达)。 - **根茎结合部(Trunk Base):** 气象局花费巨大算力将杂乱数据融合同步,估算出当前地球基准气象状态(数据同化)。 - **树干(Trunk):** 运行在全球超算中心的宏观物理动力学模式,推演全求大尺度天气演变。 - **树枝(Branches):** 各细分领域根据大模型输出开发的下游分支,例如区域小尺度模型、极端气候模型或新能源电力预测模型。 - **树叶(Leaves):** 最终端的用户应用,比如普通人在手机上查看自己所处位置的实时气温。 ```mermaid flowchart LR accTitle: 气象预测体系演进对比(天气树 vs WeatherNext 3 端到端) accDescr: 展现传统多阶段气象树结构与WeatherNext 3一体化架构的形态差异 subgraph Traditional ["传统气象体系 (多阶段级联)"] direction TB T1["树根:异构观测数据"] --> T2["基座:数据同化"] T2 --> T3["树干:全球物理大模式"] T3 --> T4["树枝:区域/能源专用模型"] T4 --> T5["树叶:端侧具体气象预报"] end subgraph Modern ["WeatherNext 3 (端到端深度学习)"] direction TB M1["输入:原始卫星遥感影像"] --> M2["统一神经网络算法内核<br/>(更高空间/时间分辨率)"] M2 --> M3["输出:机场等高品质地面站观测"] end ``` WeatherNext 3 彻底打破了这一被数十年行业规范层层分割的冗长链条。它跳过了中间复杂的同化与多级后处理环节,直接将“树根”接入“树叶”——输入端直接灌入原始卫星观测图像(raw satellite imagery),输出端直接精准预测机场等高质量地面气象站(weather stations)的真实读数。尽管学界此前对“端到端”(end-to-end)理念有所探讨,但 WeatherNext 3 是首个在预测精度上显著超越传统动力模式及过往 AI 模型的全端到端系统。Hannah 幽默地反问这是否相当于“AI 版的探头望向窗外看天”,Peter 欣然认可了这一生动的比喻,并进一步披露了 WeatherNext 3 的两项跨越式升级: - **超高时间更新频率:** 依托于卫星观测每小时更新的特性,模型打破了传统预报每 6 小时输出一次的死板周期,实现了每 1 小时即可重新滚动生成最新预报。 - **精细化时空解析能力:** 模型在单一预测周期内具备极高的时间颗粒度,不再仅给出 6 点或 12 点的离散切片,而是能够连续预测未来 6 小时窗口内 1 点、2 点、3 点的逐小时精细天气演变,这对风能与太阳能等可再生能源的瞬时功率预测至关重要。 ### `30:00` 天气模型服务于可再生能源与农业生产 Hannah Fry 与 Peter Battaglia 深入探讨了下一代气象模型 WeatherNext 3 的研发动机。Battaglia 指出,WeatherNext 3 的很多产品设计决策直接源于下游用户的诉求,其中最关键的领域就是可再生能源预测与电力负荷预测(Load Forecasting)。Battaglia 向 Fry 解释了“负荷预测”这一专业术语背后的直观物理逻辑:风电主要取决于风速,太阳能发电主要取决于日照强度,而电网的供电负荷则深受温度影响——极寒冬天下人们开启电暖气,酷暑夏天人们开启空调,从而在冬夏两季形成巨大的用电高峰。精准预测气温和湿度能够摸准电力需求端,而提供精准的风力和日照预测则能锁定供应端。为此,WeatherNext 3 引入了过往模型未曾提供的新变量(包括专用的风能和太阳能变量,以及更高分辨率的地表温度),力求在供需两侧同时赋能电网调度。 不仅是能源行业,农业更是气象预测的核心受益者。Battaglia 风趣地推测:“我认为农民可能是最古老的一类气象预报员,因为何时播种、何时收割完全取决于气温和降雨。”如果 AI 模型能够提前给出哪怕是一周的降雨趋势或一个月的平均气温预测,就能彻底改变农业决策。农民能够基于模型挑选抗旱种子或耐涝种子;AI 预测走向长远规划后,还能直接量化降雨阈值——明确究竟多少降水量属于需要提前防御的灾害,多少属于可以忽略的常规降水。关于 WeatherNext 3 底层架构的革新程度,Battaglia 坦言,加入太阳能和风能变量相对简单,虽然变量特性各异需要调校,但并未动摇模型根基;然而,若要实现更高的时间分辨率、直接输入卫星图像或预测地面气象观测站数据,则需要对模型架构及基于真实数据的训练流程展开极其深刻且剧烈的重构。 ```mermaid flowchart TD accTitle: WeatherNext 3 能源与农业预测支持架构 accDescr: 展示 WeatherNext 3 预测变量如何分别支持能源供给端、需求端以及农业生产决策。 subgraph Inputs["核心气象预测变量"] W["风能变量 (风速等)"] S["太阳能变量 (光照强度)"] T["地表高分辨率温度与湿度"] R["周/月尺度降雨量与长周期趋势"] end subgraph Energy["能源网络支持 (电网调控)"] Supply["电力供应预测<br/>(风力发电 / 光伏输出)"] Demand["电力负荷预测<br/>(夏季空调用电 / 冬季取暖用电)"] end subgraph Agri["农业决策支持"] AgriDec["播种与收割时机规划<br/>(抗旱/耐涝作物品种选择)"] end W --> Supply S --> Supply T --> Demand R --> AgriDec ``` - 引入可再生能源变量:WeatherNext 3 增加了针对风能、太阳能的新预测指标,并提升地表温度分辨率,以同时解决电网供给和负荷预测的难题。 - 架构调整分级:直接增加预测变量难度中等,但引入极细时间分辨率、卫星遥感图像与地面测站数据则牵涉重大的模型架构与训练管线重构。 --- ### `32:32` AI 气象模型超越传统数值计算的优越性与局限 当 Hannah Fry 询问 AI 模型与传统数值天气预报(NWP)的性能对比时,Battaglia 指出 AI 气象预测近年取得了历史性突破:GraphCast 率先证明了 AI 模型在确定性预报(Deterministic Forecast)上能全面击败传统的确定性模型;而随后的 GenCast 则在集合概率预报(Probabilistic Forecast)上显著超越了最先进的传统数值模型。尽管 Google DeepMind 以及业界同行开发的模型精度普遍领先,但 Battaglia 提醒大家不要盲目宣称某一个模型“在所有维度上绝对占优”。气象预报极其复杂,涵盖气温、风力、近程与远程预报周期以及不同地理大区,单一指标的胜出无法代表全貌。 以热带气旋(台风/飓风)为例,传统预报体系往往需要两套截然不同的模型协同运作:一套粗粒度的大尺度模型用于预测路径,另一套高度解析局部精细特征的模型用于预测风暴强度。Battaglia 自豪地表示:“我们的模型在路径和强度预测上都是最优秀的,而且它是一个单一模型。”(“Our model was the best at track and intensity, and it's a single model.”)但即便如此,仍需审视模型在太平洋与大西洋、或者在不同强度等级风暴中的差异化表现。Battaglia 强调科学界不应对外轻易夸下海口,因为这些数据直接关乎避灾防灾的实际生死决策:“我们确实处于一段旅程中;很难说我们的模型在任何方面都一致性地优于所有人,但每当我们进行评估时,面对横向对比的竞品,我们往往能脱颖而出。” --- ### `35:00` 极端灾害预测:统计回归均值与局部马赛克的悖论 Hannah Fry 提出了一个尖锐的算法问题:AI 模型是利用当前时间步的输出作为下一步预测的输入,这种自回归预测(Autoregressive Prediction)会不会导致微小的误差随时间指数级放大?Battaglia 解释称,这恰恰是传统物理动力学方程最容易遇到的崩溃情况,因为物理方程缺少将离群数值拉回真实合理范围的约束机制;一旦传统数值模拟滑向罕见的物理发散态,方程本身并不会制止它。相反,AI 模型最常见的失效模式反而是“回归均值”(Regress to the Mean)——当模型遇到不确定性或产生误差时,它倾向于保守地预测出季节性的平均天气。这种特性保证了 AI 模型不会像传统数值微分方程那样轻易出现计算发散或数值“爆炸”。 Fry 紧接着质疑:如果模型总是趋向预测平均天气,那它如何能预报前所未有的极端气候和统计离群事件?Battaglia 承认这种“能预测出历史最强飓风的统计学习模型”表面上极具矛盾感。他深入剖析了背后的科学机理:全球天气在本质上是无数“局部天气构成的马赛克”。即使模型从未在某个特定经纬度见过某种行进轨迹的超级风暴,但它在训练集里的其他区域或较小尺度上观察过风暴形成的极端局部物理条件。模型通过学习这些局部统计规律,在遇到新的极端组合时便能够拼装出全新的极端预报。Battaglia 同时也强调:“但我认为这同样是一个需要深入探索的领域。”由于百年一遇的极端天气数据样本极其稀少,AI 研究必须着力提高学习效率(Data Efficiency),确保算法在面对极少历史样本时依然能做出无偏且高度精准的极端预报。 --- ### `38:00` 挖掘未触及的广阔数据源与 AI 的未来落地 谈及未来的发展方向,Battaglia 援引数据表示,天气本身直接或间接地影响着全球大约三分之一的经济体量。尽管更精准的天气预报并不等于能解决这三分之一的经济难题,但它深刻牵动着能源、农业、保险、交通运输和防灾救援等重大支柱产业。在许多细分领域(如能源工业),企业自身早已部署了极其密集的气象监测传感器并收集了大量实测数据,而目前的 AI 基础气象模型尚未接入这些数据源。 Battaglia 总结认为,团队目前仅仅完成了“准确预测全球天气”这第一步,未来将面临海量未被解决的分支难题。例如,现实中许多关键的天气模式发生在小于 1 公里的超高分辨率尺度上。更重要的是,现阶段各国气象局所使用的传统系统,实际上未曾有效利用绝大部分现存的地表与民间观测数据。海量未被消化的数据结合针对具体应用场景定制的端到端学习,意味着 AI 气象预报的征途才刚刚拉开序幕。正当 Hannah Fry 追问“AI 是否会在未来彻底淘汰现有的超级计算机与基于物理规律的传统数值方法”时,对话迎来了最关键的理论分野讨论。 - 全球经济关联度:气象因素牵动着全球近 1/3 的经济运作,对保险精算、电网调度、交通物流等有着广泛影响。 - 数据与分辨率前沿:未来的突破口在于挖掘传统气象部门未利用的私有与边缘气象数据,并将空间预测精度推向 1 公里以下的微观尺度。 ### `40:00` 从物理方程求解转向影响预测与模型可解释性 Peter Battaglia 探讨了气象预报范式的深层转变:我们正在逐步告别传统数值天气预报中单纯对微分方程进行近似求解的做法,但这绝不意味着抛弃了物理学,因为训练模型所使用的气象观测数据本身就是物理定律造就的。AI 只是在用一种截然不同的方式来拟合和逼近背后的物理规律。未来,天气预报的应用场景将被极大拓宽,甚至为下游细分产业(cottage industries)带来前所未有的机遇和价值。预报的终极目标将不仅仅停留在测算基础气象要素,而是直接预测天气带来的实际破坏与社会经济影响。 针对 Hannah Fry 提出的疑问——既然团队尚无法完全厘清模型为何表现如此出色,是否在同步推进“可解释性(interpretability)”研究?Peter 直言,自己在人工智能与机器学习领域学到的深刻教训是,评估(evaluation)才是裁定模型质量与客观真实性的最终依据。尽管理解模型的工作机制对于辅助气象学家极具价值,但要想追求更高的预报精度,核心依然在于保持对严谨评测的绝对专注,并将评测范围拓展到温度、风速之外的更多物理变量与海量观测中。 > “So instead of forecasting the wind, maybe you forecast the damage that the wind will cause to the power lines.” —— Peter Battaglia > “To some extent, the lesson that I've learned about AI and machine learning is that ultimately it's the evaluation that determines the truth and the quality of the model.” —— Peter Battaglia - **范式重塑**:从“数值求解流体力学方程”迈向“直接利用物理衍生数据进行逼近”。 - **直接影响预测(Impact Forecasting)**:未来预报可直接测算倒伏的电线杆、电力中断风险或电网承载力,而不再仅仅预报风速等级。 - **可解释性与评测的关系**:解释机制有助于用气象学家的语言进行沟通,但驱动模型迭代的最关键支柱仍是多变量、全方位的基准评测。 ```mermaid flowchart LR accTitle: 气象预报范式转变路径 accDescr: 展示从传统数值天气预报到AI物理近似,再到天气影响直接预测的演进过程 subgraph Traditional["传统数值模式"] A["偏微分方程求解"] --> B["基础气象要素预报<br/>(风速/气温/气压)"] end subgraph AIApproach["AI 驱动范式"] C["物理真实数据"] --> D["模型近似物理"] D --> E["端到端影响预测<br/>(电网破坏/农业灾害)"] end B -.->|"范式演进"| E ``` --- ### `41:15` 跨领域技术互哺:生成网络、视频建模与大语言模型 当公众的注意力几乎全被大语言模型(LLM)所吸引时,Peter Battaglia 强调,气象预报在工程与计算规模上丝毫不逊色,甚至比视频生成还要庞大得多。气象模型吞吐的是极大规模的高维数据流,每时每刻都有数以千兆字节(gigabytes)的数据进出系统。为了攻克概率预报难题,团队专门发明了“函数生成网络(Functional Generative Networks, FGNs)”,该技术在训练效率和实际表现上均显著优于传统的扩散模型(Diffusion Models),目前团队正致力于将这些在气象领域打磨出的前沿架构反哺回通用视频生成和概率建模任务中。 双向的技术流动同样体现在气象学对 LLM 的借鉴上。Peter 展望道,人们日常充斥着关于天气的讨论,未来的气象模型完全有可能直接摄入文本数据进行联合推理。此外,用户可以像用 LLM 质询视频一样,直接用自然语言向气象大模型提问:“那座山顶或者山谷里待会儿会下雨吗?”AI 预报正站在与视频模型、语言模型跨界融合的交叉路口,眼下的探索才刚刚揭开冰山一角。 > “Even the technique we've used, we've invented for the probabilistic forecasting, the functional generative network is a new technique of... It's much more efficient to train and turned out to be much more effective for us than diffusion models.” —— Peter Battaglia > “Maybe you can interrogate the model with an LLM the same way that you can interrogate a video model with an LLM and ask it questions about what's happening in the video.” —— Peter Battaglia - **海量数据吞吐**:模型处理的数据维度远超日常视频文件,包含持续进出的海量高时空分辨率观测与格点数据。 - **概率生成技术演进**:放弃或补充传统扩散模型,采用训练开销更低、拟合更高效的函数生成网络。 - **多模态问答设想**:将 LLM 作为气象模型的自然语言交互前端,实现精细化到特定局部地形(如山峰、峡谷)的即时问答。 --- ### `43:10` 百年预测演进与 AI 争取到的“生机时间” Hannah Fry 教授在节目尾声对天气预报的演化历史进行了全景式总结。天气预测是人类文明最古老的智力谜题之一;在数千年的漫长岁月里,人类只能依赖近乎民谚的自然表象来揣摩阴晴,比如黄昏时天边的一抹红霞,或是关节炎患者在雨前隐隐作痛的膝盖骨。直到大约 100 年前,随着现代气象学与流体力学的发展,科学家才开始尝试用精密的物理方程去推演大气的未来状态。 如今,人工智能正在走出纯粹的理论实验室,在全球气候与减灾现实中掀起一场风暴。AI 模型不仅运算极快,更在面对恶劣极端天气时,为人类社会多争取出了极其宝贵的避险时间——可能仅仅是一个小时,或者提前整整一天。但正如 Hannah 所强调的,当致命飓风或灾难性风暴真正来临的那一天,多争取出来的这微小时间窗口,就足以成为划分生与死的全部界线。 > “Now, this is one place where AI is out there in the real world, making a gigantic difference already, buying ourselves a bit more warning, an extra hour, an extra day.” —— Hannah Fry > “But on the right day, that makes all the difference.” —— Hannah Fry - **历史沿革跨度**: - 古代经验期:观察晚霞暮色、生物与生理反应等粗糙迹象。 - 近现代数值期(约100年前始):依赖流体动力学偏微分方程组进行计算。 - AI 现代期:融合历史数据、机器学习与物理机制,在真实世界落地。 - **实战核心价值**:提前数小时乃至一整天预警飓风登陆或极端对流天气,直接转化为人员疏散、应急电网加固和挽救生命的黄金窗口。 ## Notable quotes > `40:00` So instead of forecasting the wind, maybe you forecast the damage that the wind will cause to the power lines. — Peter Battaglia > `20:00` And this is one big difference between AI weather models and traditional numerical weather prediction models. That is probably why the AI models are so effective. Because they can see the whole globe at once. — Peter Battaglia > `40:00` To some extent, the lesson that I've learned about AI and machine learning is that ultimately it's the evaluation that determines the truth and the quality of the model. — Peter Battaglia > `43:10` Now, this is one place where AI is out there in the real world, making a gigantic difference already, buying ourselves a bit more warning, an extra hour, an extra day. — Hannah Fry > `41:15` Maybe you can interrogate the model with an LLM the same way that you can interrogate a video model with an LLM and ask it questions about what's happening in the video. — Peter Battaglia ## Mentioned Hannah Fry, Peter Battaglia, Google DeepMind, GraphCast, WeatherNext, WeatherNext 3, GenCast, Weather Lab, Hurricane Melissa, NOAA, National Hurricane Center, ECMWF, ERA5, Pixel, Google Search, X ## Video description Can artificial intelligence solve one of science’s most chaotic physics puzzles? In this episode, Professor Hannah Fry sits down with Peter Battaglia, Senior Director of Research at Google DeepMind, to explore how machine learning is transforming global weather forecasting. From providing critical early warnings for Category 5 storms like Hurricane Melissa to predicting renewable energy supply and agricultural impacts, see how models like GraphCast and WeatherNext 3 are building upon decades of numerical physics to reshape our understanding of the atmosphere. [Source](https://afp-920373-injected.calisto.simplecastaudio.com/36cf10bf-f6dd-4a98-96a9-8eda9f59db4f/episodes/e969cd6f-d389-41e3-b342-bacfa33ca198/audio/128/default.mp3?aid=rss_feed&awCollectionId=36cf10bf-f6dd-4a98-96a9-8eda9f59db4f&awEpisodeId=e969cd6f-d389-41e3-b342-bacfa33ca198&feed=JT6pbPkg)

Source quotes

[40:00] Peter Battaglia: So instead of forecasting the wind, maybe you forecast the damage that the wind will cause to the power lines. [20:00] Peter Battaglia: And this is one big difference between AI weather models and traditional numerical weather prediction models. That is probably why the AI models are so effective. Because they can see the whole globe at once. [40:00] Peter Battaglia: To some extent, the lesson that I've learned about AI and machine learning is that ultimately it's the evaluation that determines the truth and the quality of the model. [43:10] Hannah Fry: Now, this is one place where AI is out there in the real world, making a gigantic difference already, buying ourselves a bit more warning, an extra hour, an extra day. [41:15] Peter Battaglia: Maybe you can interrogate the model with an LLM the same way that you can interrogate a video model with an LLM and ask it questions about what's happening in the video.

Source quotes

[11:47] Peter Battaglia: We can't observe every butterfly. So there's a fundamental limit to what we can observe. And that translates to a fundamental limit in what we can predict. [40:00] Peter Battaglia: So instead of forecasting the wind, maybe you forecast the damage that the wind will cause to the power lines. [41:07] Peter Battaglia: To some extent, the lesson that I've learned about AI and machine learning is that ultimately it's the evaluation that determines the truth and the quality of the model. [35:00] Peter Battaglia: It’s a strange phenomena that these statistical learning methods can also predict the strongest hurricanes that have ever been recorded.

Original transcript

[0:00] Welcome to Google Deep Mind the podcast, I'm Hannah Frey. When a hurricane is heading towards land, time becomes absolutely critical. An extra day of warning can clear the roads, empty the hospitals, open up shelters and get people to safety. Even a few hours can be the difference between a crisis and a catastrophe. But while we can calculate the exact second the sun will rise a thousand years from now, predicting the weather in the future with certainty remains one of the trickiest physics How do you handle something that is so sensitive to tiny fluctuations, where a small change in today's air pressure can turn into a major storm a week later? the famous butterfly effect. Well, the traditional way is solving fluid dynamics equations with supercomputers. But now, there is another way that is doing something completely different. The team at Google DeepMind have been thinking about the challenge of AI weather prediction for years. They started back in 2020 with models that use satellite images to predict short-term rainfall. Today, the latest system, WeatherNext, provides detailed hour-by-hour predictions for the entire planet. Joining me to discuss how AI models the weather is Peter Battaglia, Senior Director of Research at Google DeepMind. Welcome to the podcast, Peter. Thank you. I want to start with a really concrete example of how AI has made a difference. Tell me the story about Hurricane Melissa. Yeah, so Hurricane Melissa was a very powerful hurricane. that struck Jamaica and several Caribbean islands in October 2025. And we had been working on... specific models for hurricane forecasting for several years. And earlier in 2025, about a year ago, we... released our best weather model, and we created a website called Weather Lab that had live hurricane forecasts. We had also established these partnerships with a number of agencies, including the National Hurricane Center, which is in the U.S. under NOAA. So throughout the season, we had been seeing that the model was fairly accurate at predicting hurricanes. And when what became Hurricane Melissa started to form in the Atlantic about a week before it eventually made landfall, our forecast started showing that it was going to become a very intense hurricane. Because unusually, it started really small, didn't it? And stayed small for a while. Yeah, and this is how they work. They start as a disturbance. It's just some pattern that could eventually, given the warm sea temperature, draw up enough energy to then become a very intense and ferocious storm. So about a week before, a little less than a week before, we started to see the model becoming quite confident, that it was going to turn into a category five hurricane, which is the strongest category of hurricane. And what was it at this point? I don't think it was even a tropical storm yet. It might have been a tropical depression at that point. So actually, we watch the folks on Twitter or X. There's actually a pretty active meteorological community, and they follow a lot of the models. So they started to notice and say, this is, you know, the Google model is forecasting a very intense storm. and they're saying it's going to be Category 5, and people started to notice, and we were really watching intently. Were the other models, I mean, because there's numerous other simulations that are running, looking at exactly that area at the same time, were they also predicting at this point that it was going to be catching fire? Some were predicting that it was going to rise in intensity, but none, to my knowledge, had the confidence around that it was going to become that intense and the specific trajectory and the specific level of intensity. taking guesses and determinations and trying to refine their own official projection about what's going to happen. They're drawing on all sorts of different information, like traditional models that are well understood, newer models. And they're designed as a center. They're sort of set up to take lots of different pieces of information and then sort of stitch that all together to form their forecast. And so on Saturday, they made an official determination that it would become a Category 5 storm and hit Jamaica, and It still wasn't even, I don't think it was even a category one storm yet. So it was, they had predicted that it was going to undergo rapid intensification in like a two day, two and a half day period. So this is Saturday and it was predicted to hit land on what day? I think it was going to reach category five, I think on Monday and maybe make landfall on Tuesday if I remember correctly. Right. So this is still actually a fair amount of warning then? Yes. I think it had about three day, you know, lead time and when they issue that category five that also prompts, it triggers a set of preparatory responses. And then the local officials know, okay, this is, [5:00] There's a lot of confidence, information suggesting this is going to be very dangerous, we're going to start evacuating, we're going to do all the different things that wouldn't have taken place had it been a less intense storm. And this was, we were told later, this was the lowest intensity storm that the National Hurricane Center had ever forecast to become Category 5. They had never made a Category 5 forecast from such a low intensity. And we learned later that they said they were heavily informed by watching our model, that our model confidence in the forecast was really increasing their own confidence. Because you were saying it with 80% confidence, right? Yeah, I think it varied by which forecast because we made forecasts every six hours. But about, yeah, about 80, you know, as the week unfolded, it went from, you know, lower probability to a pretty high probability. So they issued a Category 5 warning. It did strike Jamaica, I think 95 people lost their lives, a huge amount of damage. I think on record it was the highest wind ever recorded. Yeah, 190 mile an hour winds. I mean, the thing is, as devastating as it was, it could have been worse had there been less warning. Yeah, we can never really know what would happen, but we do know that… These types of operational centers are crucially important for protecting people and protecting property and, again, also getting the services back online once the storm passes. So, yeah, and just in general through that whole experience, that was very – We've had this wonderful partnership with the National Hurricane Center and our researchers talk to them all the time. And we learn a lot about how they make their determination. So then we can feed that back into how we operate. So even though it's sort of a case study in a single instance, we actually that partnership and seeing that whole thing through lets us then. learn about how to improve our models and the types of information that the decision makers need to see in order to inform their decisions. We're going to get into the model a little bit later, but I just wonder on this topic of Melissa, do you think that the AI model has a sort of kind of advantage when it comes to predicting hurricanes that far out in the future? Or is it just that? Is it just that you're doing something different to the other models and that's maybe why you get a different result? The way I think about it, it's pretty simple. What's happened in the past is the same physical process that happens in the future. So when you get enough evidence of the past, And you have models that are capable of really making sense of the fine, sort of subtle structure among these models. you know, input and output and past and future relationships, you just get more accurate predictions. So the better you do your sort of modeling and your machine learning and your evaluation and your data, you know, all the data handling, the better your models are going to be. Because it's still according to the same rules. It's still the same rules. You just have to extract as much information about that data from the past. as you can, and then use it to forecast the future. So tell me a bit about this, this cyclone forecasting that you're releasing to the world. Tell me a bit about that. What was the motivation behind that? We wanted to make a special case of the model that was designed to predict tropical cyclones. These are some of the most intense, strongest, rarest, really, weather phenomena. And we felt if we could do this well, it will have impact. It'll also be a pretty significant scientific challenge that'll force us to improve our methods. This is sort of phase of our project began in earnest about four years ago. And we were working on global models, sort of forecasting all the weather on the surface and the atmosphere and for 10, 15-day forecasts. As we made progress on that, we wanted to have like downstream impact, forecasting the actual weather events. So we looked at things like tropical cyclones have been in all of our papers. We've done... little analyses. Okay, so this predicted the temperature, you know, in seven days, but can it predict the track of a tropical cyclone? So that had been going on for a while, but then we began a sort of focused line of work, a work stream with a dedicated sub team about two years ago or so. And we put a lot of investment in this and we also build partnerships right from the get-go. academics, operational meteorological centers. We had trusted testers for many months before we released it, but then we released it last year and we made improvements to it over time. When we run the experimental evaluations over the last several years and across the globe, we see about an extra day of accuracy in the sense that a forecast which would have had an accuracy of some level at a two-day forecast, we achieve that same accuracy at a three-day forecast in many cases. And this allows you to make, again, preparations for the storm and plan and issue warnings earlier. And in general, this is going to potentially be a pretty impactful tool for people to use. Do people have access to these forecasts? Like if I wanted to know whether it was going to rain next week, could I look at your forecast? Yeah. there's [10:00] different ways to access the forecast. One way is we actually have a live feed of our forecast that you can access. So you can Google for weather next and you'll find it in various forms. If you want the tropical cyclone forecast, you can go on Weather Lab. We actually just released beyond the tropocyclones like temperature and wind and pressure as well. And if you want to know what the weather is going to be, like if you want to just use your weather app, you can use Pixel or Search. And the Weather Next forecasts are also contributing to those forecasts as well. So there's a lot of ways, you know, whether you're an enterprise customer and you want to get the data or you just want to kind of see the icon, you can see the forecast. And we were talking about all of these extreme weather events, right, of hurricanes and cyclones and so on. Is weather prediction becoming more urgent as time goes on? Weather is becoming more extreme as time goes on. That's pretty clear. The real reason is because weather is energy. I mean, you have like, you know, the sun is electromagnetic radiation. The wind is mechanical energy. Temperature is kinetic energy. when you have a warmer Earth, you have more energy, and so the weather will be more intense, and that intensity also may at best less predictable, at least by historical standards, because it's sort of changing weather patterns. And we're seeing that there's warmer temperatures globally. I think last year or the year before was the hottest year on record. And if you look back over the last 10, 15 years, all of the hottest years on record have basically been occurring in the last few decades. And so I think we see much more wildfires, other types of flooding and things like this. So as we see AI advance, its calling is there to try to apply it to some of the challenges that are also becoming more difficult and important. I can imagine there's some people listening to this who are like, look, Why is it so hot? We've done amazing, phenomenal things with science. Why can't you tell me whether it's going to rain next Wednesday? little things can have big effects. So this is like the butterfly effect. If a butterfly has its wings or doesn't, And this can have actually an impact on what large scale, if it's a storm or it's clear or what. Well, we can't observe every butterfly. So there's a fundamental limit to what we can observe. And that's... and translates to a fundamental limit in what we can predict. But that doesn't mean that, again, on the basis of all the evidence we've ever seen, we can't detect subtle little patterns that maybe have gone unnoticed historically with previous methods. And as technology advances and gets better, we're always going to see an increase in our ability to predict things more accurately. Yeah. That's the reason it's hard. It's hard because we don't observe important features of that drive it. But they do leave little hints and breadcrumbs that we can capture with statistical learning. Because when people talk about the butterfly effect, I mean, it's sort of not meant metaphorically, right? It's like, it's sort of quite literally true, right? That in theory, a butterfly could cause a hurricane. I'm not sure like how many butterflies have actually caused hurricanes. Like I couldn't say. But I, but the, the, The point is that the atmosphere is a fluid, and a fluid has a particular type of physical characteristics that mean that little things can make big things. impact. So again, even if you drop a small rock into a pond, you might see a little ring or a little wave or a little splash of droplet of water. And if you can capture that and understand that that indicates that there's probably something happened that will cause a concentric circle to grow, you can take advantage of that. So this is where I think AI and machine learning are really how they work. They're able to realize, wait a second, I've seen droplets before that got over here. And then what happens is you get a big ring of, you know, little waves that hit the other shore of the pond. When you put it like that, it sort of does make sense that this might be an AI problem because it's pattern recognition in a lot of ways. But why was an AI lab like DeepMind? Why did you guys get involved in weather forecasting in the first place? What was the motivation? I think there was two main reasons. So one is because weather is very important. It's like probably the oldest prediction problem, one of the oldest problems in science. And... Part of our mission at Will DeepMind is to try to solve major scientific challenges the humanity faces. One of the goals of AI is to... be able to, you know, increase our ability to solve major scientific challenges that we face. Weather itself is a challenge, but it's not a... you know, kind of abstract problem. It's actually touch with it. Literally everybody knows a lot about weather and it impacts everyone's lives every single day. For me, more than [15:00] Personally, I had been working on machine learning for simulation for many, many years, even before this. And we had even been working on using machine learning to simulate fluids. So several teams at DeepMind came together. Folks were interested in weather, folks were interested in simulation, and we realized that the methods that we had probably could apply to some of the methods, some of the problems in weather. And then one other thing that actually helped us helped push us over to work on weather was that there was amazing data sets on weather that were already available. So the ECMWF, the European Center for Media Range Weather Forecasting, have been building these records of weather on Earth that span decades. So we see this and we're like, this is perfect for machine learning. We're so fortunate to be able to build on this. And it's no surprise that they also have very powerful, good AI weather models as well. So when the time is right, you have the right sort of raw materials, and then you have the teams that can put this together and it's aligned with your mission. It's a good choice to work on it. We should probably describe actually what the more traditional numerical methods, what was happening before? How would we solve for weather before? Yeah, so, you know, one of the dominant methods of forecasting the weather is called numerical weather prediction. So the way this works is You have a supercomputer, And it runs an algorithm that takes in the current estimate of the weather on the Earth. AND THEN IT makes a prediction about the weather in the next hour or six hours. and then it takes its own prediction, and it feeds it back in, and it makes another prediction for a few hours later, And it's all based on essentially physics equations. So, yeah, the algorithm itself, it's an approximation to... the solution to the equations of fluid motion. So again, the atmosphere is a fluid, but if you say, "I only know the variables of the present," and I want to solve for the variables of the future, I need to solve that somehow. Now, because, again, because The butterfly effect, and because there's coupling across scales, it's very difficult to solve these equations exactly, because you'd have to know very, very detailed information to be able to solve for the whole thing, and it's a very big problem. So instead, they approximate this, and they approximate it by... simulating the weather at a sort of coarse, blurry scale, and they find approximate solutions to those equations. And I mean, really, in practice, this has been a sort of triumph of science and engineering for decades, right? The fact that you can know what's going to happen in a week and a half or two weeks, like what the sky is, you know, whether there's rain that's going to fall or something, is amazing, really. Like, this was never, historically, this was never possible, maybe a day or two in advance. It just sort of shows that through decades of physics and engineering and computing and data collection... This has already been a huge triumph for you know, humanity and an amazing demonstration of like, you know, human ingenuity and intelligence. But then how does Google DeepMind's approach differ from everything that went before it? So these AI weather forecasts that we're building are based on looking at a history of weather and how it unfolds in time. and then learning the statistical patterns And on the basis of the past patterns, making predictions about the future in the same way. So in the same way that you might fit a line to a trend of numbers that are increasing, here we fit a very complicated line to a very complicated set of weather from the past and then extrapolate it out into the future. Talk me through the lineage then of AI and weather forecasting. How has it progressed over time? So the earliest use of machine learning and AI and weather forecasting was usually to help traditional numerical models fill in the blanks, especially in the finer scale structure that they weren't explicitly simulating. we saw as the image modeling work in machine learning evolved in the last maybe years, eight, ten years. a new type of weather, AI weather model that was predicting, say, the rain over a country for 90 minutes. or directly trying to predict the wind velocities in a small region. They weren't using numerical weather prediction, but they also weren't simulating all the weather over the earth. They were just trying to basically do image or video modeling, but with weather images and video. And this third phase we're in now is simulating all the weather over the Earth in the same way that the numerical weather prediction methods are also simulating them. trying to predict what's happening on the surface and in the atmosphere at all parts of the globe. And in principle, these are able to capture everything about the weather. [20:00] At least at the resolution they're modeling the same way that numerical weather prediction does. That thing you're describing, that's GraphCast, essentially, is it? Yeah, GraphCast was one of the first models in phase three, where they were taking all the weather on the Earth and then simulating a forecast out to 10 days. So GraphCast, the way it works is It takes the full state of the weather over the globe. And similar to other AI and machine learning method, It runs the same local platform or learned function... everywhere, and this roughly reflects that physics is the same everywhere, and then it processes this into a larger set of representations that cover the whole globe. And then it takes that and then predicts back down to what will happen locally again. What will happen in London? Does this make sense across the entire globe all at once and back down to what's going to happen in London? And you carry on going up and down and up and down. That's right. And the reason that's helpful, so numerical weather prediction doesn't do that. It just makes predictions at a very local scale. But statistical learning methods are able to learn large-scale structure of weather. So, for example, a very large hurricane... can span 100 or more kilometers. And there's a lot of structure there. So Even the west side of a hurricane can tell you a lot about the east side of the hurricane. So by having the model able to represent the whole hurricane in one representation, it can better inform the local properties of what's going to happen next. And this is one big difference between AI weather models and traditional numerical weather prediction models. That is probably why the AI models are so effective. Because they can see the whole globe at once. They can see large scale patterns as well and learn that structure and exploit that as well as the local structure. That makes sense. At what point did these models become probabilistic? Probabilistic means probability or probably. So a deterministic model always makes exactly one guess based on its inputs. A probabilistic model makes many guesses because this could happen or that could happen. And this allows a model to express the range of scenarios, most likely, and even some of the more unlikely but still possible events. So in the field of weather forecasting, they've been moving toward probabilistic forecast for a while. So even traditional numerical weather forecasting has been... using probabilistic models. And they just roll out different scenarios that represent different possible futures. We started working on probabilistic weather models just after GraphCast. So this was around 2023. And the first model we had in that was called GenCast. So it was in many ways a follow-on to GraphCast. It changed a bunch of things But the biggest difference was instead of trying to predict the average weather that was expected to happen, It predicted many different scenarios that were likely to happen. And this is much more useful for extreme events and for any kind of decision-making scenario where... If you have extreme things or rare things that matter a lot, you really want to kind of know – even if it's only a 5% or 10% chance of happening, you probably want to prepare for it. I mean, these are, I guess, in a way, the sort of cones of probability that you see when you're looking at the trajectory of a hurricane. Exactly. It will probably land somewhere within this round. Exactly. If you've seen all the little lines, they call them spaghetti plots, the different scenarios. Yeah, absolutely. So how do you do it then within the AI models? How do you get them to be probabilistic? Because by nature, they're making a prediction at a time, aren't they? Yeah. So now we have two different ways of doing this. One way of doing it is Again, like many other AI techniques for video generation, we use diffusion models. And the idea there is the model, it learns to take a very noisy image and turn it into something that looks... like weather in this case. By starting with lots of different noisy images, when you refine it to look like weather, you wind up at a slightly different scenario. And that is how you get this diversity in these different scenarios. So it's almost like we were talking earlier about the butterfly and these little perturbations. So it's almost like you're injecting a bit of statistical perturbation and then running it forward so that you can see if anything changes. Yeah. So I think there's, again, we have two techniques. So diffusion models are traditionally used. We have another technique we use, which we invented, called functional generative networks. different input scenarios and it changes the actual weights in the neural network, the parameters of the neural network slightly, and this gives a diversity of outputs. So it's almost like you're saying, what would the world look like if there was a butterfly here or a butterfly? [25:00] Yeah, exactly. run them over and over and over and over again. And then when you've done it, hundreds, maybe thousands of times, you sort of get a sense of of what the future is most likely to look like. Yeah, the best way to just, you know, it's just these models just... give a range of scenarios, each of which could have happened. And that allows people to look at the thing. They can, you know, again, I'm going back to the Hurricane Melissa example. when you see them all sort of making the same prediction about the intensity, you can start to have a lot of confidence that's what's going to happen. if they're spaghetti plots and they're all over the place, then the model is saying it's very difficult for us to understand the what could happen. And that's a very important thing because it's a fact of how we forecast, whether we cannot know certain things. So it's important for our models to recognize that and to essentially be sort of humble in the sense of not trying to be overly confident about that. And I guess the flip side of that is that is how you are coming up with your confidence scores for the predictions that you do make. That's right. That's right. So when they all are making the same prediction, you know that the model is that there's a very high chance that will happen. How's Weather Next 3 different to all of this then? So WeatherNext 3 differs because instead of strictly taking in the estimate of the state of the weather that's produced by a weather bureau, it also takes in raw satellite imagery. And instead of simply predicting the estimate of the global weather, it also predicts what's measured at high quality weather stations like airports. So this is one big, big feature where Weather Next 3 is moving beyond traditional numerical weather prediction. take raw data as input and predict raw data as output. So traditionally in the field of weather forecasting, there's actually a pretty... mature and robust sequence of steps. So I like to use this analogy of a tree. I call it like the weather tree. The roots represent the data. So you get data from all sorts of places. And then where the roots meet the trunk, that's where we make the guess about the state of the weather at the The trunk represents the operational models that predict all the weather on the earth And then as you go up into the branches, you start using the weather forecast for many, many different things. So you can maybe have like a regional model or a model that's focused on energy forecasting or extremes. you have all sorts of different types of weather models that start to be developed by different groups for specific use cases. And at the leaves of the tree, that's like, your applications. I want to know what the weather is. I pull out my phone. I want to know What's the temperature right where I am right now? We want to change the whole value chain of weather and we want to reshape this weather tree. So a single model takes the information from the roots. and makes predictions about the leaves, all at once. And so WeatherNext is the first attempt for us to do that, where we're taking in raw satellite observations, and we're also predicting raw station observations on the other side, all in a single model. Traditionally, this has been done in at least three or four different stages. Many groups are thinking about this. It's a pretty obvious idea to take more raw data and try to do the thing end to end. But Weather Next 3 is probably the first that... is doing this at a level that's significantly more accurate than any previous AI or traditional model. Is this sort of the AI version of looking out the window? In some ways, yes. It's a very sophisticated way. It uses more computers. But yeah, I mean, that's exactly right. When you look out the window, you're looking at the sky. You kind of go, oh, well, it's like cloudy. It's probably not going to be as warm. You know, there's rain, so I'm going to get wet. And so we are... collapsing the many, many stages of processing into a more singular architecture and algorithm. Some other features are that it's operating at a higher resolution. So this means instead of seeing a sort of blurry or pixelated image, it's a much more refined image. And in fact, it has different resolutions that you can see make predictions at. Another feature is instead of making a prediction about the weather every six hours, it makes a new prediction forecast every one hour. And the reason we can do that is because it's taking in satellite imagery that changes weather. on an hourly basis. So by having data that's changing more frequently, we can then make forecasts that are different more frequently. And those forecasts themselves also have a higher temporal resolution. The model natively predicts a range of different weather states across a six-hour window. So it says in one o'clock, two o'clock, three o'clock, we're going to get this weather instead of just saying at 6 o'clock at 12 o'clock we're going to have this weather which I can imagine ends up being quite useful for I don't know renewable [30:00] energy prediction as to what you're actually going to get. Yeah, so I think a lot of the decisions that went into Weather Next 3 were made on the basis of what people have been telling us they would like to see from the next generation of weather models. So for renewable energy forecasting or load forecasting. What do you mean load forecasting? Energy? Yeah, that's a technical term for electricity demand. So, you know, renewable wind power is mostly dependent on the wind speed. The solar power is dependent on how sunny it is. It turns out that the amount of electricity that the power grid needs to provide is tends to be highly... influenced by the temperature because people turn on the heat when it's cold. They turn on their air conditioners when it's hot. So you get peaks in the hottest parts of the summer and the coldest parts of the winter in electrical demand. So if we can predict the wet, the temperature, and also the humidity, more accurately, we can make better predictions of the grids, the demand for electricity. And then we also, if we can make better wind and solar predictions, we can make better predictions about the supply of electricity. So Weather Next 3 also offers new wind and solar variables that we hadn't been providing before. And that should help with the generation and also with the higher resolution surface temperature, we should be able to help with the electrical demand forecasting. I'm thinking about the impact on agriculture here as well. I mean, they care a lot about weather. I think, I'm not sure this is true, but I think farmers are probably the oldest category of weather forecasters because timing when to plant and when to harvest is completely determined based on the temperature and the rain. So if you could start to forecast even weekly rainfall or average temperature over a month, things like this. that can inform agricultural decision-making. You can also... plant different types of crops, drought-resistant seeds, rain-resistant seeds. As AI weather models start to bridge out into these impact areas, we can think about making much longer-term forecasts, which people are starting to study, and also trying to model more directly these... agricultural decisions, how much rainfall is too much rainfall that we'd want to then prepare for, how much is sort of normal and it's okay to just sort of ignore. Has this required a complete overhaul of the architecture that went before, or are you able to just sort of plug in the data into what was there already? Some parts of the innovations in Weathernext 3 were relatively straightforward. So adding in solar variables and wind variables was relatively straightforward. It wasn't trivial because these variables have different characteristics that have to be accounted for. But making predictions about finer temporal resolutions or taking in satellite imagery or predicting stations were much more profound, dramatic changes to the architecture of the model and the training process that we use to actually train it with data. So let me ask about their performance then. How do they compare to the sort of more traditional numerical processes? Yeah, I mean, these days, the AI weather models are considerably more accurate. the first AI weather model to be more accurate than the traditional deterministic forecast. Gencast was the first that was significantly more accurate than the best probabilistic forecast from numerical weather prediction. Our new models are building on the performances of our old models. There's other, again, there's many other groups who are doing great work. I think the models we're building tend to be more accurate than those. But it's also hard to say because... there's different variables, there's temperature, there's wind, there's different forecast horizons in the far future, the near term, there's lots of regions. So you can't always say one model is uniformly better, even in tropical cyclones. Historically, They usually relied on two different types of models to predict the track and the intensity. It turned out that predicting the track was better for models that were sort of coarse grain and large scale, The intensity was better predicted by models that had very fine-grained, highly resolved local features. Our model was the best at track and intensity, and it's a single model. Even then, though, you say, well, you have to look at, is it better at Most intense storms is better in the Pacific. Is it better in the Atlantic? It's very important to... not make a single claim about this because it actually matters for decision makers. If you say, this is the best model, and then, well, in this region, it's not. You don't want people to rely on it as much. So there's a lot. The way I would say it is we're really on a journey. It's hard to say that we're better than anyone uniformly, the models. But when we evaluate, we tend to outperform the competitors at the ones we're comparing. [35:00] What about extreme weather events? Are our models as good as the traditional ones? Our models appear to be best on tropical cyclones. That's some of the most extreme weather on Earth. There's been less work on things like extreme heat, extreme cold, even fine-grained tornadoes and things like this. There's less work that I'm aware of, but I think all of this stuff is going to when you apply these same methods and... using high-quality data sets, the next few years you're going to see most of these phenomena be best predicted by AI models. Here's one question about the fact that you are using the current time step to predict the next time step. If you end up getting a prediction slightly wrong, if there's like a little error in there, can those errors not compound over time? So that's that tends to be more a problem of traditional methods. There's nothing to kind of bring them back to what's most plausible. Because you're just using the equations, the physics equations. Once it just starts to go off into something that's rare, there's nothing about the equation that says it must... be like normal weather. With AI models, their failure mode tends to be when they start to make errors, they tend to more just predict average weather. Like predicting the average weather is actually a pretty good way to predict weather. And it's actually the oldest way to predict weather. So if you're like a farmer and you're trying to figure out like, you know, when do I plant my seeds? You use like the season, like in the spring before it gets warm, when we're going to have a they just tend to predict, you know, they regress to the mean, it's called. They regress to the average weather. So they don't really blow up or explode very much like we see in kind of traditional numerical methods. But then I also wonder about unusual weather events, you know, that we're getting more and more of with climate change, these sort of statistical outliers, as it were. So those two things feel almost contradictory, that it tends towards the average weather, but can also do even weather events you haven't seen before. Exactly. It's a strange phenomena that these statistical learning methods can also predict the strongest hurricanes that have ever been recorded. Right. is possible is because the weather is, it's really a mosaic of lots of local weather. So while the model might not have seen this specific impact, instance of this storm at this location this trajectory, it has seen intense weather in other parts of the globe, in other smaller scale things like storms and things like this. So the models learn the statistics of the local statistics, and then they can form a sort of novel, new, extreme forecast because they've seen the parts. And that's the best that we, to our understanding of why this works. But I think also this is an area that probably needs to be explored better as well. So as we try to get into regimes where we want to predict happen once a year. We just don't really actually have many examples of this. And we want to make sure that we're also innovating on the efficiency of the learning, that it can take not that many examples and still make use of them in a way that's sort of unbiased and accurate. Because even if you've got a few decades worth of data, it's still... It's not that many. Yeah. ...for the points. Right, right. What's next for weather next then? What improvements would you like to see in the future? So there's so many applications of weather forecasting. They estimate whether it's itself affects like a third of the economy. Now, it's not that a better weather forecast can help a third of the economy necessarily, but it makes contact with all sorts of things, energy, agriculture, insurance, transportation, again, disasters. All of those things need... very specific information about what's going to happen. And also, there's a lot of applications, weather, like an energy especially, where they're also collecting a lot of weather observations themselves. And we could potentially incorporate these into our weather models. And we haven't done any of this yet. So the way I think about it is we've kind of made a significant advance on just forecasting the global weather. But now as we go into the many, many different branches of weather, there's just zillions of problems that can be tackled. And you can bring in data from the problem itself. much higher resolution. I mean, you often want to, you see weather patterns that are like happening on a less than a kilometer scale. Uh, And there's all sorts of data sources that can be brought in as well. I mean, most weather observations are actually not even used by weather agencies. So I actually think there's a ton of data, there's a ton of problems that haven't even been touched yet. We've just sort of demonstrated that. We can make a very accurate forecast and now it's time to really get to work, I think. Some people sort of, I think, imagine that there'll be a point where the AI stuff just replaces the existing numerical methods, the existing supercomputers and so on that they've got running. Do you think that that will be the case? Do you think we'll move away from physics-based equations? [40:00] and those kind of simulations. Yes. So I think we will move away from approximating the solutions to equations, but we're not moving away from physics. The data was also created by physics. We're just going to... approximate the physics in a different way. And I actually think that we're probably going to open a lot more applications of weather forecasting. My hope is that this will actually... create a lot more opportunities and value in cottage industries and things like this as it's possible to make forecasts that are more accurate and also make forecasts that are more directly tied to the impact of weather. So instead of forecasting the wind, Maybe you forecast the damage that the wind will cause to the power lines. Mm-hmm. if we can get to a regime where we're starting to forecast the impact, I think the sky's the limit. It's just so interesting though, this idea that you're still not quite sure why it's able to do it so well. Like, are you working on interpretability too? To some extent, the lesson that I've learned about AI and machine learning is that ultimately it's the evaluation that determines the truth and the quality of the model. So while it's very helpful, I think, to understand how the model is making its predictions, why it makes errors and things like this, and it can also help folks who want to understand why the weather is – maybe they are meteorologists and they actually have a lot of knowledge about how the weather works, so if the model can – help can speak to them in that language, then they can make more use of it. But at the end of the day, I think if we want more accurate models, we need to be very diligent about it. keeping our focus on the evaluation and we just expand our evaluation beyond you know, the temperature or the wind to, again, these many more variables and many more observations. That's what's most important. My final question, I think the public is really focused on large language models at the moment, right? And sort of, to some extent, forgotten that there are all of these other phenomenal research projects that are going on all over the place. Do you think there's things that... the work on weather prediction has learned that can be applied to other applications. Yeah, I mean, our weather forecasts are much bigger than the videos that we generate. The scale that we're operating at is enormous. The data is enormous. These are gigabytes of data, many gigabytes of data that are going in and out of the models. Even the technique we've used, we've invented for the probabilistic forecasting, the functional generative network is a new technique of... It's much more efficient to train and turned out to be much more effective for us than diffusion models. So we're also looking at that, how to incorporate some of the technical advances here. back into video modeling, probabilistic modeling that can span into other areas. By the same token, I want for us to also think about how to take LLMs and draw in insights from them and And you can start to think about maybe the weather model takes in text data. Why not? People are talking about the weather. Why doesn't it operate on that? Maybe you can interrogate the model with an LLM the same way that you can interrogate a video model with an LLM and ask it questions about what's happening in the video. Maybe you can say, Is it going to rain on that mountaintop or in that valley? Yeah. So we haven't even really scratched the surface of this, but I think there's a nice two-way interaction between the innovations we're making and feeding those back into video modeling and large-scale technology. models and also taking the insights from language and these models take very diverse information. So much exciting stuff going on. Peter, thank you so much. Thank you for having me. Thank you. Weather prediction is one of the oldest puzzles we have. For most of human history, all we had to go on were signs like whether the sky was red at dusk or if you got a bad knee before the rain. And about 100 years ago, we started calculating the future using the best equations we had at Now, this is one place where AI is out there in the real world, making a gigantic difference already, buying ourselves a bit more warning, an extra hour, an extra day. But on the right day, that makes all the difference. You have been listening to Google Deep Mind, the podcast with me, Professor Hannah Fry. We've got lots more coming up in this series, so make sure you subscribe and we'll see you next time.