Of course there are occasions when this has good reason, but if you've accepted a review request and know you'll be late, just email the editor. If you know you can no longer do the review due to other commitments, just email the editor. They will be grateful!

Can AI weather models predict out-of-distribution gray swan extremes? We report @pnas.org that the answer is NO for global gray swans, YES for regional ones: AI models can't extrapolate from weaker events but can learn from similar events in other regions during training! doi.org/10.1073/pnas...

I think narrow question here is: Are end to end AI models structurally capable, at all, of capturing historically unseen extremes? We know physically based ones can, even if they don't always, because we've seen them so it. Not clear with AI ones, at least so far, so this would be a critical test.

"Taken together, these results indicate that conclusions about AI performance in weather forecasting remain highly sensitive to how extremes are defined, which hazards are considered & where the extreme events occur. This underscores the need for consensus-driven, standardized evaluation protocols."

BIG, EXCITING NEWS! Dr. Kate Marvel @drkatemarvel.bsky.social -- world-leading climate scientist and author -- is coming to Project Drawdown after leaving NASA. She will be a Senior Scientist, leading an exciting new initiative on "Emergency Brake" climate solutions. drawdown.org/news/world-r...

My resignation letter

The work they took to make sure the app can still get data from the MTA's systems when the cell phone networks underground get clogged up is very impressive

www.curbed.com/article/mta-... A common issue that pervades a lot of app design - people in SV don’t seem to conceive of worlds where you don’t have service bc you’re underground, you run out of data completely, etc. Really great to see @mta.info move this in-house!

I just resigned from NASA. It breaks my heart to leave, but I’ve become convinced the best path forward is to do the best science I can, and that can’t be here anymore. I’m still in love with the promise of those four magic letters. Ad astra per aspera, and remember: Earth is the only good planet.

Heute ist internationaler Welttag der Meteorologie. Das Motto dieses Jahr: Observing today, protecting tomorrow. Miene Gedanken dazu heute im ZiB-Wetter:

acronym goals

here’s a crazy fact: more Americans have been killed in disputes over parking spots than on the NYC subway this year

I know everyone is very excited, but

Whew. All signs are increasingly pointing to a significant, if not strong to very strong, El Niño event. I'll have more to say in coming weeks & months, but for now I'll just say that this is increasingly likely to become a major regional-to-global climate driver in 2026-2027.

🚨We're excited to announce our initial launch of the Bias-Corrected and Downscaled Massive Ensemble (BCD-ME), the largest collection of analysis-ready future temperature data out there, ideal for getting a better sense of what's driving the _climate_ spread in climate impact projections! 🧵 below:

"2021–2023: Extreme Years of Global Drought in the Context of Long- and Short-Term Hydroclimate Trends" New work, led by LDEO PhD student Aandishah Samara (w/ JE Smerdon, R Seager): journals.ametsoc.org/view/journal...

December 2025 through February 2026 was the 2nd warmest winter on record for the Contiguous U.S. according to Prism climate data. The widespread record to near record warmth in the west easily outweighed the cool temps in the east. 🔥🔥🔥

I continue to be fascinated by the phenomenon whereby an expert engages with any of the LLMs on their field of expertise and is instantly horrified by the wrong answers, and then goes on to use it for things they are not experts in as though it won’t be just as bad for those.

There are way more tourists in Bangkok, Istanbul, and NYC than in Barcelona, Venice, and Dubrovnik, but they’ve got enough going on around the tourists that the tourism doesn’t drown out the real life.

Forecast: 18 - 22 inches of snow.   Wind: Strong. Gusts up to 50 mph.   Coastal flooding: Possible. Up to 2.5 feet in high tide.   Code Blue: Live. Outreach teams working 24/7.   Alternate side parking: Suspended Monday.   Libraries: Closed Monday.   DSNY: Ready to take on the snow.

Schnee-Ereignisse wie heute sind in Wien durch den Klimawandel deutlich seltener geworden, das zeigen die Daten der GeoSphere Austria sehr deutlich. Auch die Häufigkeit nimmt ab: 15cm Jahresmaximum gab es zwischen 1961 und 1990 noch fast jedes Jahr. nun nur noch alle 2 bis 3 Jahre.

With Walter (Redmond) Burnett talking about the demand for West Loop greenspace today, I am once again urging us to turn Randolph St. (left) into our version of Barcelona's La Rambla pedestrian boulevard (right).

Seoul is one of the largest strong mayor cities in the world, and the city is having a major mayoral election this year. I've written a lot about Seoul mayors and how they played a role in the development of Seoul's massive transit network. I wanted to organize them in a single thread 🧵

Honored to be featured among some brilliant women! With my Miso (he was not impressed)

Huh, a Swiss regional line (run with tramway-like rolling stock) is running w GoA2 automation (driver only presses go, train accelerates, brakes, etc. by itself) now, using CBTC. Notable I think also because of the char. of line - many complex rural grade crossings www.bahnonline.ch/84315/walden...

While there *is* evidence of both "wetter wets" & "drier dries" in warming climate, temperatures are going almost universally in one direction: Up. We're just not seeing "colder colds." Some interesting potential Arctic-related caveats still remain TBD, but that doesn't change big picture.

Tbh this is what I always pictured when people talked about last mile connectivity. Then always disappointed in places that don’t take that part seriously (LA, I’m looking at you. Delhi, you’re the worst I’ve ever seen on this).

Stop Guessing, Start Planning. Ever look at a single snow forecast and think, "But what are the actual odds?" The Probabilistic Precipitation Portal is a resource to help you get ahead of the storm by moving beyond a single number to give you the full picture. www.wpc.ncep.noaa.gov/Prob_Precip/ 👇

Kelvin-Helmholtz-Instabilität über der Nordsee am Freitag/Samstag, erzeugt durch eine Verwirblung im Lee des Riesengebirges (CZ):

The extreme cold across eastern N America is due to the Alaskan Ridge regime, which on average brings the coldest winter weather to this region. Is this happening more often? No. During the modern warming era, there has been no observed trend in the occurrence of this regime at this time of year.

We're excited to be a(n almost-) launch partner for @earthmover.io 's awesome new Data Marketplace. Stay tuned for a launch announcement for the largest set of bias-corrected and downscaled climate projections out there, helping you better diagnose the range of climate risks :)

Wait, Canada just gave retroactive citizenship to anyone born to a Canadian parent with no generational limit?

The EU's Anti-Coercion instrument has Wikipedia pages in English, French (created this afternoon), Danish (also created this afternoon and titled "EU's handelsbazooka"), and Indonesian (created last August)

In Amerika würde man sagen, „Not a good look“

Call for papers: HISTORY OF CLIMATE ECONOMICS Details at: journals.openedition.org/oeconomia/19... Editors of the Special Issue Christophe Cassen (CNRS, CIRED Paris) Béatrice Cointe (CNRS, CSI Paris) Antoine Missemer (CNRS, CIRED Paris) Deadline for abstracts : January 15th, 2026

BTW, a Moscow (trinocular) or London/Stockholm/Wien/Istanbul (split platforms + connecting vestibules) approach of having circulation between the two platforms rather than above is really the better design for deep station. Cavern station is just too much volume for nothing.

Märchenstimmung heute einfach auf der #Mühlkreisbahn. #Winter #Schnee

An excerpt from my latest, on the one year anniversary of the fires, now up at torched.la

#ClimateModels can't match #LongTerm observed changes in the #TropicalPacific zonal #SSTGradient, implying model responses to growing radiative forcing from #GHG is diverging. #ClimateChange #CMIP6 @hannah-byrne.bsky.social @lamont.columbia.edu @climate.columbia.edu www.nature.com/articles/s41...

I'd make the case that Brooklyn and Queens are the two biggest news deserts in the whole country.

Catch me at #AGU25 next week talking about climate uncertainty in projections of climate impacts in two ways! - Wed: uncertainty from the choice of historical obs. used to train impact models, post-process projections - Thur: how systemic GCM biases affect impacts projections in the coming decades

THIS IS AMAZING! This Firefox extension https://addons.mozilla.org/en-GB/firefox/addon/on-voie-tous/ by @bovine3dom (who got the idea from @HaTetsu) SHOWS YOU SNCF DEPARTURE PLATFORMS MORE THAN 20 MINS AHEAD SNCF *does have this data* But does not show it to […] [Original post on gruene.social]

Anyone else going to #AGU25 going to be stuck delayed at JFK T5 for the next many hours? 🙄

Of course, climate system uncertainties mean that a central estimate of 2.7C warming (e.g. under SSP2-4.5) could actually reflect a wide range of 2100 warming outcomes!

Catch me at #AGU25 next week talking about climate uncertainty in projections of climate impacts in two ways! - Wed: uncertainty from the choice of historical obs. used to train impact models, post-process projections - Thur: how systemic GCM biases affect impacts projections in the coming decades

Everyone getting excited about #AGU25?? To keep up with the madness, I've updated my AGU conference feeds! Collects posts from the official AGU account, + #AGU25 and #AGU2025 hashtags AGU 2025 is chronological: bsky.app/profile/did:... What's Hot AGU25 for algorithm sort: bsky.app/profile/did:...

Excited to be giving two invited presentations on the influence of monsoon systems on extreme (humid) heat at this year's #AGU25! Stop by NH44B-02 Thursday afternoon and A51H-01 Friday morning to learn more and chat!

I won’t dare to hope but I’ll dare to dream I guess

This composition had eluded me for nearly a decade, but yesterday I was finally able to capture it. A train rolled through just as the Duquesne Incline was crossing over the tracks in #Pittsburgh, creating a picture perfect winter scene. It was worth the hours and hours I've waited over the years.

Climate nerds! Make sure you have the newly updated NMME viewer from U. Miami RSMAS bookmarked! nmme.earth.miami.edu/figures/inde...