Dear Diary. Starting in January the United States has seen much colder weather than during last year’s all-time warmest winter on record for the lower 48 states. This should be expected because warming trends due to climate change are not pure straight upward trajectories on graphs. There are a lot of gigs and zags. Indeed, going into the last half of January the planet will cough up a big correction compared to last year:
Looking at the following GFS surface chart, we may see a borderline historic CAT4 system that we will dub Cold Wave Chione for the ancient Greek goddess of snow using criteria described here:

Anytime there is a plus 1055 millibar pressure entering the U.S. in association with a cold wave, all-time records will be in jeopardy.
Unlike with the last system named after the Weather Channel’s Blair because it coincided with a winter storm, this cold snap will occur with the absence of a major storm, thus the need for some other name. Here is my last for this season:
- Aisoyimstan: Blackfeet Nation Winter God
- Chione: Greek Goddess of Snow
- Heikki Lunta: Finnish American Snow God
- Nane Sarma – Iranian Grandma Of Winter
- Morana: Slavic Winter Goddess
- Poli’ahu – Hawaiian Snow Goddess
- Skaði – Norse Winter Goddess
- Ullr – Norse Winter God
- Kuraokami: Japanese Dragon Of Rain And Snow
- Jack Frost (Old Man Winter): American Personification Of Winter
- Nane Sarma (Bibi Barfi): Iranian Grandma Of Winter
- Morana (Marzaana): Slavic Goddess Of Winter And Death
- Poli’ahu: Hawaiian Snow Goddess
- Skaði: Norse Goddess/Giant Of Skiing & Snowshoes
- Tengliu (Teng Liu): The Chinese God(dess) Of Winter
- Ullr: Norse “God” Of Winter Hunting
Blair was more or less a dangerous but typical cold snap that occurred the first week of 2025. Interestingly there were very few daily records set in association with this cold wave. I fear that Chione will be much worse, and looked at guidance the thing could rival many Arctic outbreaks prior to the turn of the century.
Chione will be in association with a deep trough or lobe of the polar vortex as depicted from today’s deterministic GFS:

Will the system produce a historic southern ice and snow event? Today’s deterministic 12Z model run suggests so:

On the flip side of Chione will be the far western quarter of the United States, which will continue to see above average temperatures with Santa Ana outbreaks hampering fire containment efforts in Southern California.
Of course, I’ll be posting many notes on Chione as it invades the lower 48 states starting this weekend.
Here are more “ETs” recorded from around the planet the last couple of days, their consequences, and some extreme temperature outlooks, as well as any extreme precipitation reports:
Here is some brand new 2024 climatology. More reports are archived on prior January 2025 posts:
Many of the latest notes concerning the Southern California fires:
Here is More Climate News from Tuesday:
(As usual, this will be a fluid post in which more information gets added during the day as it crosses my radar, crediting all who have put it on-line. Items will be archived on this site for posterity. In most instances click on the pictures of each tweet to see each article. The most noteworthy items will be listed first.)