Michael Wehner

Special issue on Artificial intelligence and machine learning in climate & weather science in Advances in Statistical Climatology Meteorology & Oceanography. ML/AI in atmosphere, ocean & hydrological sciences welcomed. www.advances-statistical-climatology-meteorology-oceanography.net/articles/sch...

Over 50,000 estimated to have died in urban areas during Europe’s sweltering summer in 2026, with climate change responsible for two thirds, finds two new studies by @lshtm.bsky.social @imperialcollegeldn.bsky.social in @nathealth.nature.com @clairbarnes.bsky.social explains the findings 🎬 👇 [1/4]

This paper was enabled by the published temperature/mortality response functions of Masselot et al. for 854 European cities demonstrating how important these functions are. Unfortunately, the underlying daily mortality data in the US & elsewhere is nearly impossible to obtain. At least for me 🥵

Using Granger causal inference, we attribute human and natural contributions to high fire weather risk during the 2025 LA fire. GHGs exacerbated a particularly bad ocean configuration. iopscience.iop.org/article/10.1...

California's 5th Climate assessment is out. Generally a good report but my involvement in its projections leads to serious questions about their robustness at regional scales given model data limitations. climateassessment.ca.gov

Day 4 of our class on the Detection and Attribution of Human Induced Changes to Extreme Weather. Extreme Event Impact Attribution (EEIA) (This video is 44 minutes long) youtu.be/_aGu_PSkLhE

Day 2 of our class on the Detection and Attribution of Human Induced Changes to Extreme Weather. Attribution using Granger causal inference. (This video is 35 minutes long) youtu.be/5HUH1ji3U-M

New Commentary out in Nature Climate Action: we now live in a fundamentally different climate system due to the burning of fossil fuels. Because of this, any extreme weather event now occurs in a changed climate and is influenced by fossil fuel-driven climate change to some degree.

Major Nor’easter! Also, Cat 5 Hurricane #Polo in context. And “Cool” #Florida weekend! It’s all packed into this short video. #noreaster

I talk about my extraordinary experience in Moscow in 2004 in the latest edition of the Totally Cooked podcast as well as other aspects of my career in climate science. Includes extra details to what I wrote about in Hot Air including the Russian prostitutes. 21centuryweather.org.au/totally-cook...

Very sad news. www.downtoearth.org.in/climate-chan...

I am pleased to be visiting IPSL-Institut Pierre-Simon Laplace in Paris @ipsl.bsky.social to work on extreme event attribution with Davide Faranda @davifaranda.bsky.social and colleagues. We also will be teaching a 4 session mini-course on extreme event attribution, starting in early October.

“Snow-eater heat waves are caused by the buildup of atypical high pressure," says @berkeleylab.lbl.gov's Alan Rhoades. "Like a boulder diverting water in a stream, the unusual high pressure diverts storms away from mountains."

After the hottest month on record

I've been talking a lot about the disastrous recent loss of American institutional capacity regarding climate science. But today, I'd like to announce something we've been working on, quietly, in the meantime to offer a lifeline to some of those affected. [Thread]

Scientists define a new category of heat wave: ‘Snow eaters’

Port of SF just released their “study” (army corp term for “plan”) to protect against sea level rise. Cost: $17B to avoid damages of $23B. Big problem: Trump raised bar for design standards, so project cannot receive fed $ at this time. www.kqed.org/news/1209452...

Is anybody else having trouble submitting abstracts to AGU26? I am not sure if "server error" is them or me. Thanks!

Come learn about some cool science my research group has been working on 🌧️❄️💧🌀! Virtual link on flyer.

eos.org/research-spo...

Abstract: The case is made that machine-learning statistical estimation neither can nor should be expected to supplant physics-based simulation for weather forecasting. journals.ametsoc.org/view/journal...

Poetry heard at the AMS Tropical Meteorological meeting : "Big whorls have little whorls, Which feed on their velocity, And little whorls have lesser whorls, And so on to viscosity." — Lewis Fry Richardson

‘Snow-Eater’ Heat Wave Behind Big Sierra Melt Is a Look at Our Climate Future “Without a long-term warming trend, these events were previously either unlikely or statistically impossible. We kind of unlock that possibility” @kqednews.kqed.org @kqedscience.bsky.social www.kqed.org/science/2000...

How well do ML weather models capture severe storms? A new analysis of Storm Amy compares ECMWF’s forecasting systems. Read the blog ➡️ www.ecmwf.int/en/about/med...

The American Meteorological Society seeks nominations for the 2026 Syukuro Manabe Climate Research Award. Nominations due 5/1/26. This award is granted to researchers who have made outstanding contributions to the fundamental understanding of Earth’s climate system. www.ametsoc.org/stac/committ...

New(ish) paper: journals.plos.org/climate/arti...

Latest paper on impact attribution. A must read for those interested in the topic doi.org/10.3389/fcli...

Not being an actual meteorologist, I have a question about the NCEP Stage IV radar precipitation dataset. The attached picture is a snapshot of the current SoCal radar. The concentric circles at Hanford and Santa Maria are clearly artifacts. Does NCEP correct for this?

It's happening! Canada launched two programs to recruit international researchers. Canada Impact+ Research Chairs (1 million/yr for 8 yrs +) Canada Impact+ Emerging Leaders. I will do my best to facilitate the process for those interested. Hit me up. www.canada.ca/en/impact-pl...

New paper: Assessing the performance of solar radiation management geoengineering simulations at link.springer.com/article/10.1...

The attack on @frediotto.bsky.social was seeded years ago by Roger Pielke Jr, who started arguing that this table from a recent @ipcc.bsky.social report proved that climate science cannot attribute extreme weather to climate change. But Roger is of course lying. And we know this for 2 reasons. 🧵

📣 PRESS RELEASE Registration for experts interested in serving as Expert Reviewers and providing scientific comments on the First Order Draft of the Special Report on Climate Change and Cities is now open! Registration closes 30 Nov 2025. Read more 🔗 www.ipcc.ch/2025/09/17/p...

Thank you for posting. I have hundreds of hours into these (2,3,4,& 5) . At taxpayer expense, I might add.

Delighted to announce that Ben Santer is now an Honorary Professor @ueaenv.bsky.social & the Climatic Research Unit (CRU). Ben is returning to his "academic home": he did his PhD in CRU before his stellar career developing "fingerprint" methods to identify human & natural effects on climate.

What caused deadly landslides in Colombia? Finding out, should be easier. Tropical climates are complex, but if data are held by companies & organisations hiding them behind walls of bureaucracy it becomes impossible. @wwattribution.bsky.social study: www.worldweatherattribution.org/growing-expo...

It can get pretty hot.

Heatwaves affect different places in different ways. Leafy suburbs are cooler than more built up, concrete heavy areas, which means that disadvantaged communities are more likely to be more severely affected. Watch our super short video on heatwaves to find out more... #heatwave

I explained what extreme event attribution is in this article. doi.org/10.1063/PT.3...

The study by Xueke Li and colleagues was published here in the Proceedings of the National Academy of Sciences of the USA: www.pnas.org/doi/10.1073/... (see their ref. 37 for our original Petoukhov et al. 2013 paper)

A resonance phenomenon is causing big waves in the atmosphere. And that has increased due to #globalwarming, causing wild summer extremes, a new data analysis finds. The mechanism was first identified in 2013 by the late Vladimir Petoukhov at the Potsdam Institute. apnews.com/article/extr...

Important postscript on our recent study: We can confirm now that the recent heat domes over North America & Europe were part of a resonant "wave 7" hemispheric pattern that emerged in mid June, persisting through most recent data [analysis by @xuekeli.bsky.social]

The flooding of the Guadalupe River in Texas was undoubtedly made worse because of climate change. I would estimate that there was 7-20% more rainfall than w/o the human interference in the climate. But w/o detailed attribution studies on the storm and associated runoff, we can't know for certain.

It's an older clip (11/01/23) but I think worth posting. Senate Environment And Public Works Committe Hearing on Impact of Climate Change on Severe Weather

"Increased frequency of planetary wave resonance events over the past half-century" | Our new article in @pnas.org by @xuekeli.bsky.social, @michaelfwehner.bsky.social, Shannon Christiansen & yours truly: www.pnas.org/doi/10.1073/...