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

Valid 12Z Sat Dec 23 2023 - 12Z Mon Dec 25 2023

...Heavy rainfall and flash flash flooding threats shift east into the
southern Plains today, spreading into the central Gulf Coast and west of
mid-Mississippi Valley by Christmas Eve...

...Mountain snow and valley rain traverse from the Pacific Northwest
through the northern Rockies today...

...Snow is forecast to spread from the central Rockies Saturday night
before expanding across the central to northern Plains into Christmas
Eve...

...Unusually mild temperatures with some reaching record levels in the
upper Midwest on Sunday...

A low pressure system currently bringing areas of heavy rain across the
Desert Southwest will work in tandem with an upper-level trough
progressing steadily through the Pacific Northwest to develop and
consolidate an elongated low pressure system over the mid-section of the
country for the holiday weekend.  The upper trough and associated
cold front over the Northwest will bring a quick round of mountain snow
and valley rain through the northern Great Basin today, into the northern
and central Rockies by tonight.  Meanwhile, the heavy rain threat across
the Desert Southwest this morning is expected to ease as today progresses,
as the low pressure system responsible for the heavy rain moves
northeastward toward the central Rockies.  When the two systems meet over
the central Rockies tonight, a low pressure system is forecast to develop
over the central High Plains with a swath of snow beginning to extend
northeastward into the central High Plains toward the northern Plains on
Sunday, Christmas Eve.  In the mean time, warm and moist air from the Gulf
of Mexico will be pulled northward across the western Gulf Coast region
toward the southern Plains, where scattered showers and embedded
thunderstorms are expected to become more widespread Saturday night and
into the morning of Christmas Eve.  Excessive Rainfall rates are possible
particularly in north-central Texas and southern Oklahoma where a Slight
Risk is in place.  Farther northeast, a weaker system in the Great Lakes
will make its way into the Northeast by this evening with a mix of rain
and snow showers.  Little snowfall accumulations are expected.

As the elongated low pressure system further develops and expands 
across the central Plains on Christmas Eve, the threat of heavy rain
will then shift farther east into the central Gulf Coast region while
extending back to the west of the mid-Mississippi Valley ahead of an
eastward-moving cold front with a warm front lifting north from the Gulf
of Mexico.  Farther north in the cold air, a few inches of snow is
possible across the northern Plains behind a cold front.  Minor ice
accumulations are also expected farther east.  By Christmas Eve night to
Christmas morning, the low pressure system is forecast to intensify as the
storm center shifts east toward the Midwest.  Rain/ice/snow could begin to
expand and pick up intensity over the central to northern Plains when the
system intensifies with winds increasing in strength by Christmas morning.

Temperature-wise, it will not feel too much like Christmas from the
mid-section of the country east to the East Coast this holiday weekend. On
Saturday, many places in the Great Plains can expect daytime highs that
range between 10-25 degrees above normal. Morning lows will even be milder
with a wide footprint of 20-30 degrees above normal temps from central
Texas to the Upper Great Lakes. 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. The
East Coast will not witness quite the anomalous warmth that the Midwest
will, but daily average temps could still top 10-15 degrees above normal
in parts of the Northeast on Christmas Eve. By Christmas Day, the most
unusually mild temperatures are expected in the Great Lakes and Northeast
where highs could range between 10-20 degrees above normal. 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.

Kong/Mullinax


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