Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
300 PM EST Sat Dec 23 2023

Valid 00Z Sun Dec 24 2023 - 00Z Tue Dec 26 2023

...Heavy rainfall and flash flash flooding potential to shift east from
the Southern Plains today, to the Central Plains and central Gulf Coast on
Christmas Eve, then into the Southeast on Christmas Day...

...Confidence is growing in an impactful winter storm across parts of the
Central Plains and Upper Midwest for both Christmas Eve and Christmas Day,
resulting in a White Christmas and treacherous travel for some...

...Unusually mild temperatures along and east of the Mississippi River
with some record breaking warmth possible in the Midwest and Great Lakes
both Christmas Eve and Christmas Day...

An increasingly active weather pattern is taking shape just in time for
Christmas Eve and Christmas Day. One upper level disturbance tracking
through the Four Corners region this afternoon is responsible for periods
of snow in the higher terrain of the southern Rockies, in addition to a
plume of Gulf of Mexico moisture fostering the threat for Excessive
Rainfall and severe weather. The Weather Prediction Center (WPC) issued
Slight Risks for the Upper Texas coast and parts of southern Oklahoma and
north-central Texas. The Storm Prediction Center (SPC) has a Slight Risk
in place for West Texas, as well as a Marginal Risk that stretches north
into the Texas Panhandle due to the potential for large hail, damaging
wind gusts, and possibly tornadoes. The second upper level disturbance and
its associated cold front are racing south and east through the Northern
Rockies, ushering in a colder air-mass and causing periods of snow to
ensue across the Intermountain West.

By the morning of Christmas Eve, the cold front formerly over the Northern
Rockies will dash across the Great Plains, forcing precipitation to fall
in the form of snow from the Central Rockies to the Dakotas. Up to a few
inches of snow is possible in these areas, as well as minor ice
accumulations thanks to a wintry mix along the Columbia River in eastern
Nebraska on north into the Red River Valley of the North and northern
Minnesota. To the south, the conveyor belt of rich Gulf moisture will
stretch from the central Gulf Coast to the central Plains. WPC posted
Slight Risks for Excessive Rainfall in portions of these regions. By
Christmas Eve night, both the East and West Coasts will generally be dry,
while the Mid-South on north through the central Plains and Upper
Mississippi Valley can expect unsettled weather. Motorists and reindeer
should be sure that their headlights and noses are lit up brightly in
areas where snow and rain are expected Christmas Eve.

As the sun rises on Christmas Day, the storm system in the Central Plains
will strengthen further and become a bonafide winter storm from northern
Kansas and eastern Nebraska into eastern South Dakota and northern/western
Minnesota. For Nebraska and eastern South Dakota, this will make for a
White Christmas, but snow will fall heavily at times and blustery winds
may cause near blizzard conditions. WPC's Probabilistic Winter Storm
Severity Index (WSSI-P) shows moderate chances (40-60%) for hazardous
driving conditions in southeast South Dakota and northeast Nebraska. For
portions of northern and western Minnesota, there is a growing concern for
treacherous ice accumulations greater than 0.1" in some areas. The WSSI-P
does depict moderate chances (40-60%) for Minor Impacts due to ice
accumulations in southwest Minnesota, across Interstate 94 in central
Minnesota, and as far north and east as the Minnesota Arrowhead. To the
south, the Excessive Rainfall threat continues to march east into the
Southeast U.S. as WPC has a Slight Risk in place for the Florida Panhandle
and a Marginal Risk that reaches as far north as the southern
Appalachians.

Temperature-wise, it will not begin to feel a lot like Christmas for much
of the Midwest on east to the East Coast this extended holiday weekend.
After an exceptionally mild day throughout the Heartland on Saturday, by
Christmas Eve, record warm minimum temps will be common in the Midwest
where many low temps will be considerably higher than the average high
temps for late December. Even parts of the Southern Plains and Middle
Mississippi Valley may witness record breaking warm highs and lows on
Christmas Eve. By Christmas Day, the most unusually mild temperatures are
expected in the Upper Midwest and Great Lakes where highs could range
between 15-25 degrees above normal. The East Coast will not witness quite
the anomalous warmth that the Midwest and Great Lakes will, but daily
average temps will still be rather mild and could still range between
10-15 degrees above normal in parts of the Northeast by Christmas Day. In
contrast, the central/southern Plains and central/southern Rockies will be
the coolest versus normal thanks to a recent cold frontal passage
injecting the region with an air-mass that feels a lot more like Christmas
compared to their neighbors on the East and West Coasts.


Mullinax


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