Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
300 AM EST Wed Nov 29 2023

Valid 12Z Wed Nov 29 2023 - 12Z Fri Dec 01 2023

...Below average temperatures continue Wednesday for the East Coast and
South with freeze-related advisories for the Florida Panhandle and south
Georgia...

...New storm system to bring threat of severe thunderstorms and heavy rain
from Texas into the Mississippi Valley by Thursday...

...Unsettled weather to arrive for the Pacific Northwest and California
late Wednesday through Thursday...

High temperatures will once again be chilly and below average by about
15-20 degrees Wednesday along the East Coast and into the South as broad
upper-level troughing remains in place over the region. Forecast highs
range from the 20s and 30s in New England, 30s and 40s for the
Mid-Atlantic into the Carolinas, and 50s and 60s through much of the South
outside of South Florida. Frost and freeze-related advisories remain in
place from the Florida Panhandle into south Georgia as temperatures
Thursday morning may once again dip to near or below the freezing mark,
potentially damaging/killing sensitive crops and vegetation. Conditions
will moderate Thursday as the upper-level trough begins to shift eastward,
with highs 10-15 degrees warmer and much closer to average to close
November. Some lingering lake-effect snow showers downwind of Lakes Erie
and Ontario should taper off through Wednesday morning, with otherwise
mostly dry conditions along the East Coast.

An upper-level wave passing quickly over the Four Corners and out over the
Plains will help to encourage lee cyclogenesis late Wednesday/early
Thursday, helping to organize a surface frontal system over the Southern
Plains. Some light to moderate rain/snow showers will be possible in the
colder air over the Four Corners region Wednesday into Thursday, with a
few inches of accumulations possible in the higher mountain elevations.
Showers and thunderstorms are expected overnight Wednesday ahead of the
system over eastern portions of the Southern Plains and into the Lower
Mississippi Valley. Continued very moist southerly flow from the Gulf and
increasing shear as the upper-level wave approaches will lead to the
threat of severe thunderstorms into the day Thursday over southeastern
Texas. The Storm Prediction Center has issued an Enhanced Risk of severe
weather (level 3/5) for the threat of a few tornadoes. Storm coverage
should continue to expand north and eastward through the Southern Plains
into the Lower/Middle Mississippi Valley by later Thursday into the early
morning hours Friday. Some locally heavy downpours are expected, with a
few isolated instances of flash flooding possible, though dry antecedent
conditions in the area should keep this threat limited. Forecast highs
will be running in the 50s and 60s from the Southern Plains into the
Lower/Middle Mississippi Valley, with 40s and 50s for the Central Plains.
Some cooler temperatures will flow into portions of the Central/Southern
High Plains following a cold front passage Thursday, dropping into the
40s. 

Some light coastal showers will be possible from central to southern
coastal California Wednesday as a weak Pacific system approaches the
coast. Then, a stronger series of systems will approach the Pacific
Northwest/northern California by late Wednesday bringing increasing
precipiation chances with lower elevation/coastal rain and mountain snow.
The precipitation will spread inland into the Great Basin Thursday, with a
wintry mix for the interior valleys and snow for the mountains. Some
heavier snow accumulations are possible for the Cascades and Sierra
Nevada, with some light to moderate snow for other regional higher
elevations/mountain ranges. Any accumulations in the valleys should be
limited. Forecast high temperatures more broadly across the West will be
in the 30s and 40s for the Great Basin/Rockies/Pacific Northwest, the 50s
and 60s for California, and the 60s and 70s for the Desert Southwest.
Elsewhere, conditions will be dry across the Northern Plains into the
Upper Midwest. Highs will be well above average Wednesday particularly for
the Northern Plains, with some temperatures into the 50s possible.
Otherwise, highs will generally be in the 30s and 40s.  

Putnam

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