Tom Di Liberto

A time series of the January–February frequency (in days) of the AKR regime from 1979 to 2025 using ERA5 data, based on the year-round classification of Lee et al. 2023 (J. Climate) updated through 2025.

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.

YouTube video by climatecentral No winter games in Salt Lake City in 2034? Not out of the realm of possibility.

No Winter Olympics in Salt Lake City in 2034? It's possible says Rocky Anderson, former Salt Lake City Mayor during the 2002 Winter Games.
youtube.com/shorts/w2uhr...

Line graph for February temperatures in Cortina D'Ampezzo. White trend line is up.

⛷️ ⛸️ The 2026 Winter Olympics in Milan and Cortina d'Ampezzo, Italy starts soon on February 6! 🔥 And it's a heck of a lot warmer—+6.4°F—than the first time Cortina held the Winter Games back in 1956.

📊 Let's ski jump right in ⬇️

Today we release our Gallagher Re 2025 Natural Catastrophe and Climate Report.

Full Report: www.ajg.com/gallagherre/...

Economic Loss: $296bn (-25% vs 10 Yr Avg; $394 bn)
Insured Loss: $129bn (-5% vs 10 Yr Avg; $136 bn)

(1/n)

A year ago, Southern California was parched. Now, it’s soaked, thanks to atmospheric rivers. This animation shows GOES satellite images from dawn to dusk on December 31, 2025, as an atmospheric river (right of bottom center of the frame) feeds a storm. Read the feature story at Climate.us.

The first half of meteorological winter was record warm for an extraordinary swath of the West, from Las Vegas to Denver, Salt Lake City to Seattle and Phoenix to Portland. The anomalously temperatures are fueling a snow drought, concerning scientists.
www.sfchronicle.com/weather/arti...

Oh that takes me back.

🌊🔥

Mark it down on your calendars! Our next monthly climate brief will be on January 20th

One more for the to-read pile

Best TikTok thing going is the two dudes trying food from every country without leaving NYC. If you haven’t seen them yet, it’s incredible. My favorite so far is last week’s. Legit got me emotional.

I read all the studies on the economic impact of bike lanes. Here's what I learned. Research proves that bike lanes are good for business. So why do so many stores and restaurants still oppose them?

“Survey after survey has shown that business owners overestimate how many customers drive to their stores vs walking or biking. In a 2012 Los Angeles study, more than half of the store owners on the bike-laned part of the boulevard thought most of their customers drove. The actual number was 15%.”

The amount of times I think of this comic strip when I'm feeling down, hopeless or in a rut.

Next Monthly Climate Brief from @climatecentral.org is on January 20! Register below.

November 2025 ranked as the 4th warmest November on record for the contiguous U.S.🌡️

December brought cooler conditions to the Northeast, but record warmth across the West. We’ll dig into what’s driving December in our next webinar.

🗓️Tuesday, January 20 | 12pm ET
🔗Please Register: buff.ly/tvpvvHG

Records roasting over an open fire.

Holiday heat check (Dec 22-28):
- 2,135 record highs set
- 2,610 record warm lows
vs just 25 record lows and 30 record cool highs

Not your classic December weather...

/1

Bonkers heat🔥

Climate change isn't the sole culprit of this holiday heat, but it did make it much more likely than past generations would have experienced.

Climate Shift Index shows human-caused climate change made this widespread warmth far more likely -- and in some areas, nearly impossible without it.

Half of the Alaska upper air sites with no observations Sunday morning. 😡 This data loss impacts every global weather model in the world. #akwx #weather @wxmanms1.bsky.social @climatologist49.bsky.social

Wow

🎒Public Schools in Urban Heat Islands

“Extreme heat is dangerous, and seeing how many students attend schools in supercharged heat was shocking. The interactive maps really help tell this story, neighborhood by neighborhood.” - @tdiliberto.bsky.social

🔗 www.climatecentral.org/climate-matt...

Check out some of our favorite stories/resources from @climatecentral.org this year.

What's one thing we can all do in the fight against climate change? Talk about it, as daunting as that may seem!

Because people care about climate change (and want to talk about it) more than you probably think.

Some tips in this week's Climate Matters:
www.climatecentral.org/climate-matt...

The Weather & Climate Livestream Join us starting May 28th, as meteorologists and climate scientists from across the US share their research and answer your questions.

For those at #agu25 #saveNCAR

12:15pm - Group Photo/Video at the "science strong" wall across from the Plenary Hall at the entrance to the convention center

1:30-5:30pm - drop in interviews at PJs Coffee in front of Hall C - look for the person with the "We ❤️ NCAR" sign.

More info:

All roads lead to Boulder (and NCAR) I share my NCAR stories spanning my career in atmospheric science.

I had to write or I’d explode. open.substack.com/pub/tornatri...

These people are nuts. NCAR developed the GPS dropsonde, which revolutionized the understanding of TC structure, improved forecasts, and validated remote sensing platforms, as documented in over 400 peer-reviewed publications in the last 25 years. And that’s just one of NCAR’s countless advances.

Before the 1990s, plane crashes caused by microbursts used to kill planeloads of people fairly regularly.

Dr. Ted Fujita and NCAR scientists figured out how to detect microbursts and warn pilots about them.

Since then? Zero airliner crashes from microbursts.

Stupid.

From record warming to rusting rivers, 2025 Arctic Report Card shows a region transforming faster than expected The 20th anniversary of the annual report tracks how sea ice, snow cover and many other vital signs of the Arctic have changed, and the impact that’s having on people and wildlife.

We’ve got a piece in The Conversation about the 2025 Arctic Report Card and the implications of 20 years of tracking rapid Arctic change. #Arctic #akwx #Climate

theconversation.com/from-record-...