Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
300 PM EST Sat Dec 16 2023

Valid 00Z Sun Dec 17 2023 - 00Z Tue Dec 19 2023

...A rapidly intensifying low pressure system will bring an increasingly
stormy end to the week for the entire Eastern Seaboard reaching up into
New England on Monday...

...Colder air behind the storm will trigger lake-enhanced snow from west
to east across the Great Lakes toward the Appalachians on Monday...

...A slow-moving oceanic storm in the Pacific will spread unsettled
weather up the West Coast through the next few days...


A low pressure system currently developing and expanding over the
relatively warm waters of the Gulf of Mexico is forecast to interact with
a surge of cold air mass from central Canada to deliver quite a stormy end
to the week for the Eastern Seaboard.  Showers and thunderstorms ahead of
this intensifying storm system have already been expanding steadily over
much of Florida this Saturday afternoon.  This is only a precursor of what
is to come as the storm center is still located over the eastern Gulf of
Mexico while gathering strength more rapidly.  East to northeasterly winds
will further strengthen over all of Florida as the storm center is
forecast to reach the west coast of the peninsula early Sunday morning. 
The wind shear ahead of the storm center could trigger a few tornadoes
across the Florida peninsula tonight.  By Sunday, the low pressure center
is forecast to skirt the Southeast U.S. coast, with the biggest threat of
heavy rain up through the coastal plains as the day progresses with heavy
thunderstorms possibly containing damaging winds and severe weather.  By
Sunday night, the heavy rain should be tapering off over the Southeast
while spreading up rapidly into the Mid-Atlantic states ahead of the storm
center, with some strong thunderstorms possible.  The storm center will
then track more quickly northward into New England on Monday while the
entire system expands its influence across much of the eastern U.S. 
Wind-swept rain, heavy at times, will then overspread the entire Northeast
during the day on Monday.  Meanwhile, colder air from central Canada will
be pulled southeastward across the Great Lakes on Monday behind the big
storm, triggering lake-enhanced snow from west to east across the Great
Lakes and toward the Appalachians by Monday evening as rain begins to
taper off across the Mid-Atlantic.  Even though the big storm will begin
to depart the Northeast Monday evening, the huge circulation of the storm 
will overspread the entire eastern U.S. with very blustery conditions.

Meanwhile, a large and slow-moving oceanic storm in the Pacific will
gradually make its presence known for the West Coast as unsettled weather
ahead of the system gradually spreads up the West Coast through the next
few days.  The rain is expected to reach central California first but not
until Sunday night.  The unsettled weather is forecast to expand northward
through California by Monday evening while getting ready to reach the
coastal sections of the Pacific Northwest.  The reminder of the western
and central U.S. will remain dry through Monday under a stable and
expansive high pressure system.  The entire country will remain milder
than normal for this time of year.  In fact, some record high temperatures
are possible across New England on Monday as warm and moist air from the
Atlantic surges into the region amid wind-swept heavy rain in the height
of the big eastern storm.

Kong



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