{ "number": 839, "headline": "January 12, 2026 Monday Winter Weather", "standfirst": "Ensembles went much colder into Week 2 as Canadian cold pool reloads", "desk": "winter", "dateline": { "place": "Weather Trader", "state": null, "lat": null, "lon": null, "site_key": null, "site_name": null, "site_url": null, "accent": null }, "edition": "2026-01-13", "published": "2026-01-13T01:38:10.503000Z", "updated": null, "access": "free", "body_html": "
\"\"

This is post number 839: Good Evening, thank you to more renewing subscribers for Year 2 and 3 (!) \u2014 your generous support keeps this blog going without advertising \u2014 churning out on average 28 posts per month \u2014> Day 12 of 2026.

Author: Dr. Ryan Maue (X @RyanMaue X @weathertrader)

Returning again this evening to the extended range Day 14 global temperatures from the European flagship full-physics ensemble \u2014 the control (HRES) and the ensemble mean. Both show remarkable Northern Hemisphere land cooling to about 1\u00b0C below normal, and the global number to near the 30-year normal (1991-2020). This is widespread, extreme cold for billions of global population into the end of January primarily due to a weakened / perturbed stratospheric polar vortex. This is 2 weeks in the future, so the details and intensity will change, but we are poised to see a potentially historic Arctic \u201cpolar vortex\u201d blast across North America and Eurasia into the end of January.

Control Day 14

\"\"

Ensemble Mean Day 14

\"\"

Other major story was the Week 2 ensemble mean sharply moved colder by upwards of 5\u00b0F to 6\u00b0F centered on the Midwest and Great Lakes. We\u2019ll see if the basket of ensembles grows \u2014 and this cold pool intensifies in the ensemble mean \u2014 or we see windshield wiper effect and again a decrease in the 00z suite.

\"\"

Headlines Monday Evening

Weather Trader is an reader-supported publication with no advertising. To receive new posts (28+ per month) and support our work, consider becoming a free or paid subscriber.

ECMWF AIFS-Single 18z | Height Anomaly (500 hPa) Next 10-days

\"\"

A strong blocking ridge forms over the Pacific Northwest and retrogrades to Alaska finally dislodging the extreme cold pool that has been tormenting the 49th State for weeks. The jet stream will need to go up and over this ridge meaning a dip or weakness in the Great Lakes and Northeast. This allows the \u201cpolar vortex\u201d anchored over Hudson Bay to drop multiple lobes or extrusions of \u201ccold pool\u201d air even into the Southeast U.S.

Multiple Hudson Bay origin \u201cpolar vortex\u201d events dip across the eastern U.S.

And, looking at Day 10, the western extent of the Canadian cold pool increases by eroding the Alaska block from the East. Quick look at Day 12 upper-level 500 mb temperature and the corresponding 2-meter temperature anomaly.

ECMWF AIFS-Single 18z | Temperature (500 hPa) Next 10-days

\"\"

The temperature at 500 mb is the easiest way to highlight the \u201cpolar vortex\u201d across North America with the coldest pool at -40\u00b0C (pink) with the -25\u00b0C contour usually associated with below freezing temperatures at 2-meters (surface).

The Western U.S. and Pacific Northwest ridge is very apparent and firmly entrenched vs. the Hudson Bay / Arctic Canada undulations are dipping southward into the eastern U.S. = cold.

HRRR Next 48-hours Radar | Through Wednesday Afternoon 1 PM ET

\"\"

The Great Lakes Clipper remains the only show in town

ECMWF 18z | Precipitable Water Next 6-days | My Favorite Parameter

\"\"

Colder Arctic air dips into the Eastern U.S. by way of the Midwest and Great Lakes in two major waves: Wed-Thurs and then again Sat-Sun

ECMWF 12z | Integrated Vapor Transport Next 10-days

\"\"

Western blocked upper level pattern shuts off the West Coast from atmospheric rivers \u2014 and keeps the Gulf of Mexico closed for business.

Not seeing any Nor\u2019easters with East Coast impacts in the next 10-days

ECMWF 18z Precipitation Type and Intensity | Next 6-days

\"\"

Northwesterly flow out of Alberta \u2014> clipper systems into the Great Lakes and Northeast but do not phase too well with the upper-level polar vortex for \u201cbombogenesis\u201d.

We need to watch the Southeast for any moisture from the Gulf of Mexico combing with the very cold Arctic air \u2014> light wintry precipitation in Atlanta (10% chance)

Eastern U.S. | Two areas of low pressure wobble through the Northeast with light accumulating snowfall events but not a major storm

\"\"

Extreme cold across Southeast and Florida \u2014> Friday Morning Lows

\"\"

222 million below freezing

\"\"

22\u00b0F in Atlanta, 18\u00b0F in Macon, 20\u00b0F in Tallahassee

\"\"

Freezing to Interstate 4

Europe Storm Systems next 6-days

\"\"

ECMWF 12z EPS | Temperature Anomaly | Next 15-days

\"\"

Major Arctic blast of cold air again next week \u2014 Wed-Thursday \u2014 with the Canadian cold pool reloading into Days 10-14

NWS Precipitation Next 72-hours

\"\"

NWS Snowfall Next 72-hours

\"\"
\"\"
\"\"

RTMA | Temperature Analysis | 7:00 PM ET

\"\"

Average Lower 48 temperature was 44.2\u00b0F with 19 million below freezing.

Temperature Anomaly | 7:00 PM ET

\"\"

Lower 48 Temperature Anomaly above normal by 7.8\u00b0F

Tuesday Morning Low Temperatures

\"\"

162 million below freezing \u2014 nationwide average of 32.7\u00b0F

Tuesday High Temperatures

\"\"

46 million at least 70\u00b0F \u2014> nationwide average of 53.2\u00b0F

Wednesday Morning Low Temperatures

\"\"

Only 55 million below freezing \u2014 nationwide average of 33.2\u00b0F

Wednesday High Temperatures

\"\"

Blend of Models | 7 Days Precipitation Total

\"\"

Blend of Models v5.0 | Total Snowfall Next 7-Days

\"\"

Western U.S. nary a snowflake \u2014> winter is busted

Lake Effect Snow Machine \u2014> cranks up again!

ECMWF 18z | Snowfall Next 6-days

\"\"

European Winter | Snowfall Next 6-days

\"\"

ECMWF EPS 12z | Ensemble Median Snowfall Next 14-days

\"\"

Probability of 1-inch or more Snowfall in the next 14-days

\"\"
\"\"
\"\"

10% chance of 1-inch or more in Atlanta within next 2-weeks

Probability of 6-inch or more Snowfall in the next 10-days

\"\"
\"\"
\"\"

Ensemble Median Snowfall for Europe Next 14-days

\"\"

Eurasia Temperature Anomaly | Week 1 and Week 2

\"\"
\"\"

Lower 48 Temperature Anomaly | Next 15-days | ECMWF EPS 12z

5-Day Chunk #1 | Temperature Anomaly | Jan 12 - Jan 16

\"\"

5-Day Chunk #2 | Temperature Anomaly | Jan 17 - Jan 21

\"\"

5-Day Chunk #3 | Temperature Anomaly | Jan 22 - Jan 26

\"\"

Compared to Previous 00z Temperature Anomaly for 5-day Chunk | Jan 22-26

\"\"

And the Week 2 difference from the previous model cycle \u2014> much colder!

\"\"

Maps sourced from weathermodels.com designed and innovated by yours truly! Please subscribe there for real-time access to the newest maps, charts from all of the weather models including ECMWF and AIFS, NOAA AI-GFS/AI-GEFS

", "body_key": null, "teaser_html": "

Returning again this evening to the extended range Day 14 global temperatures from the European flagship full-physics ensemble \u2014 the control (HRES) and the ensemble mean. Both show remarkable Northern Hemisphere land cooling to about 1\u00b0C below normal, and the global number to near the 30-year normal (1991-2020). This is widespread, extreme cold for billions of global population into the end of January primarily due to a weakened / perturbed stratospheric polar vortex. This is 2 weeks in the future, so the details and intensity will change, but we are poised to see a potentially historic Arctic \u201cpolar vortex\u201d blast across North America and Eurasia into the end of January.

Control Day 14

", "claims": [], "assets": [], "provenance": { "built_at": "2026-09-10T14:46:14Z", "model": null, "cycle": null, "stores": [ "https://weather.substack.com/p/january-12-2026-monday-winter-weather" ], "mint_sha256": null, "pairing_rule": null, "detector": null, "detector_version": null, "inputs": { "substack_post_id": "184387502.january-12-2026-monday-winter-weather", "audience": "everyone", "type": "newsletter", "imported_from": "substack export" } }, "strength": 0.0, "tags": [ "archive", "everyone" ], "supersedes": null, "superseded_by": null, "source": "substack", "canonical": "https://weather.substack.com/p/january-12-2026-monday-winter-weather", "slug": "january-12-2026-monday-winter-weather", "path": "/mp/839/", "url": "https://forecastpost.com/mp/839/", "desk_label": "Winter", "digest": "d46112e9e1b5e472a6e0ebc53e33f41060b9536656e4d9e40573263c10e3e37f" }