Flavio Lehner
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climateflavors.bsky.social
Flavio Lehner
@climateflavors.bsky.social

Climate Scientist
Assistant Professor @ Cornell University
Chief Climate Scientist @ Polar Bears International
https://flaviolehner.eas.cornell.edu/

Environmental science 55%
Geography 18%

Glad to hear. I’ve been missing your awesome loops.

Lego day (this past Wednesday)
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/
👇
NWS Probabilistic Precipitation Portal
www.wpc.ncep.noaa.gov
Join UCAR President Antonio Busalacchi at a town hall meeting this afternoon at #AMS2026 to discuss the threats facing NSF NCAR.

https://bit.ly/3NNXHS5

Reposted by Flavio Lehner

2-meter temperatures, jet stream (light blue), and stretched stratospheric polar vortex (dark blue), for 12 UTC, 26 Jan 2026.

Cascadilla Creek

Reposted by Flavio Lehner

We knew the NSF letter about NCAR would come. I think this is an occasion that will require great coordination and strategical thinking. UCAR should respond as a block, coordinating a response across universities (especially in the South, and large public universities that use NCAR data a lot)
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.
Really excited to see this paper out!! Led by @vtcoop.bsky.social we show that if you use cold and warm paleoclimates together, you can reduce uncertainty in Earth's climate sensitivity by quantifying the pattern effect and more precisely constrain future climate change www.pnas.org/doi/10.1073/...
Paleoclimate pattern effects help constrain climate sensitivity and 21st-century warming | PNAS
Paleoclimates provide examples of past climate change that inform estimates of modern warming from greenhouse-gas emissions, known as Earth’s clima...
www.pnas.org
Check out the new version of my climate science textbook. Free, accessible and online. Let me know what you think. open.oregonstate.education/climatescien...
Introduction to Climate Science
Introduction to climate science is for college students of both science and non-science majors and for everybody interested in the topic.
open.oregonstate.education

Reposted by Flavio Lehner

I honestly thought December was way colder in the Northeast than what the numbers indicate. Seven mild Decembers in a row really messes up your perception...

Indeed, the world will turn gray at 2°C. 🤪

Late-night plotting in R for me is like speaking French after a few too many glasses. I can do it but it's not going to be great. 😅

Thanks! Here it is relative to "preindustrial" (1850-1900).

(since ERA5 does not go back that far, I used the difference between 1850-1900 and 1940-1969 from DCENT as an offset, i.e., ~0.25°C)

I created this one but it's inspired by @erwanrivault.com's version from previous years.
2025 goes down as the ~3rd-warmest year on record (based on ERA5).

Like in 2024, every single day this past year was warmer than the average of even the most recent reference period (1991-2020).

Reposted by Flavio Lehner

This past month showed us once again how extraordinary our weather and climate community is (scroll for 🧵).

Whether you’re joining us as student, scientist, hobbyist, or concerned citizen, let’s #SaveNCAR and put an end to the war on science together 💯
Looking for: postdoc on quantitative history of China; postdoc on measuring wildfire fuels with LiDAR; PhDs on modeling fire in the boreal forest and the Pacific Northwest; MSc’s on earth system science; interns in many topics. Check it out!
I've updated the opportunities part of my website with fresh openings for researchers interested in climate and vegetation science, archaeology, history, and geography at all levels from undergraduate intern to postdoc. Take a look! jedokaplan.github.io/opportunities/
Work with me!
jedokaplan.github.io

Reposted by Flavio Lehner

🧵How might snowfall change in a warming world? I set up a very simple “toy” statistical model to explore this question.

Isn't it obvious that snowfall decreases as temperatures get warmer? Yes, but …
Our guide to approaching (and starting!) conversations about NCAR and the importance of weather and climate science. #SaveNCAR
There aren't a lot of resources for what people can do to prevent the destruction of NCAR, so I made this:

#NCAR #climate #climatescience #weather #meteorology #activism #myresources
From wildfire warnings to flood forecasts, NCAR's research impacts everyone in America.

President Trump's attempt to dismantle it for political vengeance is beyond reckless.

We will fight against this dangerous scheme every step of the way.
From @AGU.org: Senators are working on legislation to save NCAR, but we need extra support for these 8 states. Your Senators in Alabama, Alaska, Florida, Louisiana, Mississippi, North Carolina, Texas, and Wyoming need to hear from you.
On #AGVTV at #AGU25, Dr. Melissa Kenney and I talked about the opportunity for the entire scientific community to contribute towards climate assessment research. Submit your papers at USclimatecollection.org. youtu.be/7Kb-hfwIUxQ?...
Introducing the U.S. Climate Collection: Connecting Climate Science for a Brighter Future
YouTube video by WebsEdgeScience
youtu.be

I spoke too soon - OT!

It was entertaining for sure, maybe more so than the game
I came to the US over 10 years ago for a postdoc at NCAR. It changed my life and supercharged my ability to do science. NCAR's unique community nature makes it a global node in atmospheric and climate research. It's really not possible to overstate its value for science and society.
Exclusive: The Trump administration is moving to dismantle the National Center for Atmospheric Research in Colorado, according to a senior White House official, taking aim at one of the world's leading climate research labs.
Trump moves to dismantle major US climate research center in Colorado
The Trump administration is breaking up the National Center for Atmospheric Research, taking aim at one of the world's leading climate research labs.
bit.ly

Reposted by Flavio Lehner

For 40+ years, the U.S. gov has conducted highly respected & productive polar bear research. At a time when many in power question the value of gov-supported scientific research, some involved express concern about what is at stake. Learn why gov-led polar bear research is vital. pbears.org/4a1eRVE
The Impact of Government Polar Bear Programs: United States | Polar Bears International
At a time when too many in power refuse to acknowledge the reality of climate change and question the value of government-supported scientific research, some of those who have been intimately involved...
polarbearsinternational.org

Reposted by Flavio Lehner

Join us! In a few days, @climatecentral.org will be launching a new webinar series on the state of our climate! I’ll provide monthly overviews of current global and U.S. conditions, along with special guests, featured topics, and written reports.

➡️ Sign up at www.climatecentral.org/climate-brie...