465
FXUS01 KWBC 101947
PMDSPD

Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
246 PM EST Wed Dec 10 2025

Valid 00Z Thu Dec 11 2025 - 00Z Sat Dec 13 2025

...Ongoing Atmospheric River event over the Pacific Northwest will
begin to diminish Wednesday night into early Thursday...

...Arctic air to surge south into the Northern Plains late
Thursday into Friday...

...Active lake effect snows Wednesday night through Thursday
downwind of much of the Great Lakes...

...Fast moving low to bring moderate to heavy snows from the Mid
Mississippi Valley into the Upper Ohio Valley and Central
Appalachians...

...Much above average temperature expected from the West coast,
across the Rockies, Central to Southern Plains into the Lower
Mississippi Valley..

The atmospheric river event that has been impacting the Pacific
Northwest over the past several days, producing widespread
rainfall totals of 5 to 10 inches+ across western Washington State
into northwest Oregon, will be coming to an end Wednesday night
into early Thursday.  The strong moist onshore flow off the
eastern Pacific into the Pacific Northwest that has supported the
very heavy rainfall amounts will weaken in response to an
amplifying mid to upper level ridge along the West coast.  While
the rain will diminish tonight into early Friday, ongoing major
river flooding and the threat of landslides will continue across
portions of western Washington state and northwest Oregon for
several days.

In addition to bringing an end to the wet Pacific Northwest
pattern, the amplifying mid to upper level ridge along the West
coast will also help push arctic air southward into the Northern
Plains late Thursday into Friday.  Much above average temperatures
over the Northern Plains today and Thursday will be replaced by
much below average temperatures on Friday.  In many places the
high temperatures Friday will be 30 degrees colder than on
Thursday, with high temperatures in the single digits across North
Dakota into central to eastern Montana.  Below average
temperatures also forecast across much of the eastern third of the
nation from the Mid-West, Great Lakes into the Northeast in the
wake of a lead strong front moving into the Northeast Wednesday
night into Thursday.  Cold air moving across the relatively warm
great lakes will support active lake effect snows downwind of Lake
Superior, northern Lake Michigan, Lake Erie and Lake Ontario.  The
heaviest snow totals expected downwind of the eastern end of Lake
Erie and the eastern end of Lake Ontario across northwest
Pennsylvania, far western New York State and northwestern New York
State where snow totals in excess of a foot are possible.  Winter
storm warnings and Lake Effect Snow Warnings are currently in
effect across these areas.  Lighter lake effect snow totals in the
4 inch plus range expected downwind of Lake Superior across the
Upper Peninsula of Michigan, across northwest Lower Michigan,
downwind of the northern Lake Michigan and over northeast Ohio on
the south side of Lake Erie.

Accumulating snows also possible Thursday into early Friday in
association with a fast moving area of low pressure dropping
southeastward from the Central Plains into the Ohio Valley.  This
will support a narrow axis of moderate locally heavy snows to the
north and northeast of this low track from eastern Iowa, across
central Illinois, southern Indiana, far southern Ohio, northeast
Kentucky into much of West Virginia and far Southwest Virginia.

While large sections of the north central to eastern U.S. will
have below average temperatures over the next few days, the
opposite will be true across the West from the West coast into the
Great Basin, Southwest and Rockies.  High temperatures are
expected to be 10 to 20 degrees above average Thursday and Friday
across these areas.  The exception to this will be in the interior
Central Valley of California where fog and low clouds are expected
to persist and keep temperatures much cooler than surrounding
areas that will be cloud free.  In the cloud free areas, there is
the potential for several record high afternoon temperatures and
record high morning low temperatures late this week into this
weekend across large portions of the western U.S.  Much above
average temperatures also on tap for the Central to Southern
Plains Thursday and Friday and eastward into the Lower Mississippi
Valley and Central Gulf Coastal region on Friday.


Oravec


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

$$