FXUS01 KWBC 122012

PMDSPD



Short Range Forecast Discussion

NWS Weather Prediction Center College Park MD

300 PM EST Fri Dec 12 2025



Valid 00Z Sat Dec 13 2025 - 00Z Mon Dec 15 2025



...Record warmth across portions of the west, while arctic air

surges into the eastern two-thirds of the country through the

weekend...



...Another clipper will bring accumulating snow across the

Northern Plains to the Midwest and Ohio Valley through Saturday,

then from central Appalachians to possibly the northern

Mid-Atlantic on Sunday...



...Lake effect snow re-invigorates this weekend...



...A break from the wet weather this weekend for the Pacific

Northwest before the arrival of the next round of rain on Sunday...



The weather pattern across the country this weekend will allow a

break in the atmospheric river across the Pacific Northwest as

arctic air from Canada will be unleashed into the eastern

two-thirds of the country.  As this weather pattern unfolds,

another clipper low pressure wave will bring a stripe of

accumulating snow through tonight across the northern High Plains

to the northern Plains.  This snow will then spread swiftly from

the northern Plains to the Midwest on Saturday before moving into

the Ohio Valley toward the central Appalachians Saturday night

behind an arctic cold front.  By early on Sunday, the northern

Mid-Atlantic can expect some snow to develop before sunrise behind

this arctic cold front with support from the upper-level dynamics

of a potent jet stream.  Blustery conditions will also accompany

the snow as the arctic rushes in behind the cold front.  This

surge of arctic air will challenge or break some record low

maximum temperatures especially where the snow is expected to

accumulate.  The arctic air will also bring a re-resurgence of

lake-effect snows across the Snowbelt downwind from the Great

Lakes through the weekend.  The snow should be last to taper off

across the Mid-Atlantic during the day on Sunday.  An arctic high

pressure system diving into the Plains will make for a frigid

Sunday for much of the eastern two-thirds of the country.  The

exception will be near the Gulf Coast and much of the Sunshine

States where it will take some more time for the cold air to push

out the showers and embedded thunderstorms.



Meanwhile, the Pacific Northwest will experience a break from the

recent extreme wet weather this weekend.  Nevertheless, the major

to catastrophic flooding effects are likely to continue into the

weekend across portions of western Washington State and

northwestern Oregon.  By Sunday, rain from the next system is

forecast to reach the Pacific Northwest.  Rainfall amounts are

expected to be light to locally moderate by later on Sunday across

western Washington, but mainly light across northwestern Oregon. 

The lull in the Pacific Northwest heavy rains is in response to

the continued amplification of the large scale flow across North

America, characterized by a building mid-to-upper level ridge

across the West and a broad deep upper low over the middle to

eastern portions of the U.S.  This amplified pattern will produce

big temperature contrasts from west to east across the Lower 48

going into this weekend.  Much above average temperatures are

forecast from the West coast, through the Southwest, Great Basin,

Rockies and into the Southern Plains.  The exception continues to

be in the central California Valley where low clouds and fog are

expected to remain stuck, keeping temperatures much cooler than

surrounding cloud free areas. Some record high afternoon

temperatures and record high morning low temperatures are possible

in scattered locations across the western states.





Kong/Oravec/Kebede



Graphics available at

https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php



$$