{ "number": 823, "headline": "December 22, 2025 Monday Evening Winter Weather", "standfirst": "Flooding for Christmas in California from Atmospheric River storm systems", "desk": "winter", "dateline": { "place": "Weather Trader", "state": null, "lat": null, "lon": null, "site_key": null, "site_name": null, "site_url": null, "accent": null }, "edition": "2025-12-23", "published": "2025-12-23T01:57:35.286000Z", "updated": null, "access": "free", "body_html": "
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This is post number 823: Good Evening \u2014 less than 3-days until Christmas! Welcome to new subscribers, long-time supporters, and visitors! Author: Dr. Ryan Maue (X @RyanMaue X @weathertrader)

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White Christmas Around the World

We should still have snow on the ground in the Midwest, Great Lakes, and Northeast including some freshly fallen \u2026 as it won\u2019t be warm enough (30s and 40s) to do much damage to the snowpack. Where it\u2019s going to be much warmer in the 60s or even 70s+ we don\u2019t expect a White Christmas in a typical year. Canada is almost entire snow covered as well as vast majority of Russia \u2014> Siberia. However, Europe will only have snow at higher elevations, and in the northern reaches of Scandinavia.

Headlines Monday Evening

A lot going on \u2014 and this post got way too big, and I need to hit publish

ECMWF 18z | Next 6-days Temperature Anomaly

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The western Canada cool pool is looking to escape in any direction and sends a blast of cold air out in the Pacific with a \u201cPolar Vortex\u201d lobe and upper-level trough \u2014 all linked with a complex of powerful surface storm systems (low pressure) off the California coast.

New England sees a puff of much colder air toward Friday and it lingers into the weekend.

ECMWF 18z Precipitable Water Next 6-days | My favorite parameter

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

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Northeast Winter Storm Chances = Saturday highest probability of significant winter precipitation (Snow/Mix/Slop)

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Powerful West Coast Storm Systems \u2014 Wednesday and Thursday

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High Pressure builds across the Pacific off the West Coast into the weekend \u2014 so the atmospheric rivers will be directed into Alaska and British Columbia

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This evening\u2019s winter weather \u2014> into Tuesday Noon \u2014> continues into tomorrow evening (See the 48-hour GIF)

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HRRR 18z | Next 48-Hours Sim Radar through Wednesday 1 PM ET

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RRFS-A Total Snowfall Through 84-hours \u2014> Friday 1 AM

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RRFS-A Total Precipitation Through 84-hours \u2014> Friday 1 AM

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Enormous precipitation across Southern California | Wed-Thurs

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Southern California Zoom | RRFS-A

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NWS Precipitation Next 72-hours Doesn\u2019t Capture Entire California Event

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NWS Snowfall Next 72-hours

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RTMA | Current Temperature Analysis | 7:00 PM ET

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Average Lower 48 temperature was 49.0\u00b0F with 30 million below freezing.

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Brutally cold in Alaska and Yukon, Canada into the minus 50s (actual temperatures)

Temperature Anomaly | 7:00 PM ET

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Lower 48 Temperature Anomaly was scorching (!) 12.4\u00b0F ABOVE normal

Tuesday Morning Low Temperatures

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66 million below freezing with the edge of brutal subzero air along the Canadian border in Montana and North Dakota

Tuesday High Temperatures

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More than 81 million at/above 70\u00b0F

Christmas Eve Low Temperatures

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Only 77 million below freezing \u2026 but not too bad. Seasonable.

Christmas Eve High Temperatures

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Almost 124 million at least 70\u00b0F \u2014 comfortable in the Midwest, Great Lake and Northeast in the 30s and 40s

Christmas Day Temperatures | Morning Lows

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78 million below freezing for low temperatures Christmas morning

Christmas Day Temperatures | Daily Highs

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109 million at/above 70\u00b0F on Christmas Day \u2026 very warm across the southern half of the eastern U.S.

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

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Ridge breaks down by Monday/Tuesday of next week allowing an Arctic Blast to dump out east of the Rockies \u2014 then the ridge returns (!)

Alaska / Western Canada go into the DEEP freeze while Greenland warms up + Lower 48 is much above normal.

Blend of Models | 7 Days Precipitation Total

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Enormous rainfall totals across California | Deluge

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Blend of Models | Total Snowfall Next 7-Days

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

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

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Polar Vortex (tropospheric) monitor \u2014> the pink = coldest at 500 mb and we see the arrival of some cold air from Siberia over the pole into the New Year to reinforce the PV over Alaska and Canadian Arctic.

ECMWF 12z | Integrated Vapor Transport Next 10-days

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Look at the IVT source from the Tropical Pacific heading westward out of the Caribbean and then pulled northward into Southern California and the U.S. Southwest.

Parameter used for monitoring \u201catmospheric rivers\u201d usually along the U.S. west coast, but the idea works well for many other areas \u2014 highlighting midlatitude storm systems with warm conveyor belts (moisture plumes)

ECMWF 18z | Snowfall | Next 6-days

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Snowfall for New England \u2014> could be significant in a narrow band as winter is not taking a break. 5\u201d in NYC \u2014 mainly on Saturday and up to 8\u201d-10\u201d to the WNW

ECMWF EPS 12z | Ensemble Median Snowfall Next 15-days

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Probability of 6-inches or more Snowfall in the next 15-days

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

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The Northeast will be below normal for the 15-day period in the -6\u00b0F range with some blue (-2\u00b0F) south into Florida. Of course, this is a 15-day average of ensemble mean temperature anomaly \u2014 so a LOT of smoothing going on here.

5-Day Chunk #1 | Temperature Anomaly | Dec 22 - Dec 26

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5-Day Chunk #2 | Temperature Anomaly | Dec 27 - Dec 31

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5-Day Chunk #3 | Temperature Anomaly | Jan 1 - Jan 5

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

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We should still have snow on the ground in the Midwest, Great Lakes, and Northeast including some freshly fallen \u2026 as it won\u2019t be warm enough (30s and 40s) to do much damage to the snowpack. Where it\u2019s going to be much warmer in the 60s or even 70s+ we don\u2019t expect a White Christmas in a typical year. Canada is almost entire snow covered as well as vast majority of Russia \u2014> Siberia. However, Europe will only have snow at higher elevations, and in the northern reaches of Scandinavia.

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