Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
302 PM EST Thu Nov 30 2023

Valid 00Z Fri Dec 01 2023 - 00Z Sun Dec 03 2023

...Storm system to bring a threat of severe thunderstorms and heavy rain
through tonight across southeast Texas and southern Louisiana...

...Areas of light to moderate precipitation expected from the Central
Plains to the interior Northeast, with a wintry mix possible for some
locations...

...Atmospheric river activity arriving across the Pacific Northwest by the
end of the week and into the weekend with heavy rain for the coastal
ranges, and heavy snowfall to the Cascades...

An upper-level trough over the Four Corners region currently will move
east across the Southern Plains through this evening which will help to
focus a strengthening area of low pressure north of the Red River Valley
as a couple of trailing cold fronts drop southeastward across Texas. This
low center will then move into the Middle Mississippi Valley by early
Friday with a cold front gradually reaching and crossing the northwest
Gulf Coast. Going through this evening and the overnight period ahead of
these fronts, very moist southerly return flow from the Gulf of Mexico
will result in a threat for both severe weather and some flash flooding as
numerous showers and thunderstorms develop.

The best threat for this has become a little more concentrated and is
generally focused across southeast Texas and southern Louisiana. The Storm
Prediction Center currently has a Slight Risk of severe weather (level
2/5) for the threat of a few tornadoes along with isolated large hail and
strong wind gusts. Additionally, some of the thunderstorms will also be
capable of producing very heavy rainfall, and the Weather Prediction
Center has depicted a Slight Risk of excessive rainfall (level 2/4) for
much of the same area where locally a few inches of rain will be possible
which may result in some areas of flash flooding. The remainder of the
broader Arklatex region and Lower Mississippi Valley should see a threat
for some locally heavy rainfall overnight and early on Friday, but much of
this should be beneficial in nature. As the aforementioned low center
crosses through the Middle Mississippi Valley and toward the Ohio Valley
on Friday, some very localized concerns for severe weather and flash
flooding could spread farther east along the central Gulf Coast.

Additional light to moderate precipitation is expected to the north of the
surface low track, impacting portions of the Central Plains and Middle
Mississippi Valley into early Friday, and then transitioning downstream
across the Ohio Valley, Lower Great Lakes and the interior of the
Northeast late Friday into Saturday. Sufficient cold air should be in
place for at least a swath of a couple of inches of accumulating snow
along the northern edge of the precipitation shield.

Meanwhile, an active pattern of atmospheric river activity will impact the
Pacific Northwest and spill over into the Northern Rockies heading into
the weekend. The coastal ranges and lower elevations of the Cascades will
see moderate to heavy rain, with locally several inches of rain expected
over the multi-day period heading through the weekend. This may result in
some river flooding concerns. Very heavy snowfall will impact the higher
terrain of the Cascades where locally a few feet of snowfall can be
expected. Travel will be difficult and hazardous due to both heavy and
blowing snow. As this Pacific moisture and energy tracks inland, heavy
accumulating snowfall will also arrive across the higher terrain of the
Northern Rockies where up to a couple of feet of new snow can be expected
by Sunday.

Putnam/Orrison

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