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

Valid 12Z Thu Nov 30 2023 - 12Z Sat Dec 02 2023

...Storm system to bring threat of severe thunderstorms and heavy
rain from the Southern Plains to the Lower Mississippi Valley on
Thursday, spreading further into the Southeast Friday...

...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 will bring heavy rain to the
coastal ranges, and heavy snowfall to the Cascades...

...Locally heavy snowfall possible for higher mountain elevations
in the Four Corners region...

An upper-level shortwave over the Southwest will move over the
Southern Plains Thursday, helping to better organize/strengthen a
surface frontal system and bring increasing storm chances from
eastern portions of the Southern Plains to the Lower Mississippi
Valley. Very moist southerly return flow from the Gulf will result
in a threat for both severe weather and some flash flooding. The
best chance for severe weather Thursday will be in southeastern
Texas where strengthening wind fields will overspread the more
buoyant air close to the Gulf Coast. The Storm Prediction Center
has issued an Enhanced Risk of severe weather (level 3/5) for the
threat of a few tornadoes. Additionally, some very heavy downpours
will be possible, with a Slight Risk of Excessive Rainfall now in
place for the greater Houston area east through southwestern
Louisiana where the greatest chance for a few instances of flash
flooding is expected. A more isolated threat for severe weather
and flash flooding will exist further north into the Arklatex and
Lower Mississippi Valley. Storm chances will shift slowly eastward
into the Southeast and along the central Gulf coast Thursday, with
a continued risk of a couple isolated instances of severe weather
and flash flooding.

Additional light to moderate precipitation is expected to the
north of the surface low track, stretching from the Central
Plains/Middle Mississippi Valley Thursday into the Great Lakes,
Ohio Valley, and interior Northeast Friday. Some snow will likely
mix in to the north of a quasi-stationary boundary draped through
the region, most likely for portions of the Central Plains
Thursday and from the Great Lakes into the interior Northeast
Friday. Some light accumulations of 1-2" will be possible. 

An active pattern of Atmospheric River activity looks to set up
along the West Coast through at least this weekend with a series
of shortwaves and influx of moisture overspreading the Pacific
Northwest/northern California. Coastal/lower elevations will see
moderate to locally heavy rain, with the heavier rainfall more
likely Friday and then into the weekend. The flood threat
currently looks low with this initial rainfall, though will likely
slowly increase as antecedent conditions become wetter. Heavy
snowfall is forecast for higher elevations in the Cascades, with
totals exceeding a foot through the end of the period. Moisture
will also spread inland through the Great Basin and Northern
Rockies, with a rain/snow mix for lower elevations and moderate to
heavy snow in the regional mountain ranges. Any accumulations
should be limited for the lower elevations, but some of the
mountains could see 6-12", with locally higher amounts. A
rain/snow mix at lower elevations and moderate to heavy snow for
higher mountain locations will also continue in the Four Corners
region through Friday as the upper-level wave currently over the
Southwest departs but the pattern remains active with shortwaves
dropping southward from the Northwest.

Elsewhere, milder temperatures are forecast to return to the East
Coast after several chilly days. Conditions will be dry Thursday
but rain chances will increase by late Friday as the storm system
to the west approaches. Temperatures will be near average with dry
conditions from the Northern Plains to the Upper Midwest.
 
Putnam

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