Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
303 PM EST Tue Dec 06 2022

Valid 00Z Wed Dec 07 2022 - 00Z Fri Dec 09 2022

...Isolated flash flooding possible over the Central Plains later on
Wednesday into Thursday...

...Accumulating snows across the Northern Plains and through portions of
the Northern and Central Rockies...

...Widespread much above average temperatures across the southern and
eastern U.S. in stark contrast with Arctic air across the Northern
Plains...

A slow-moving front draped across the south-central portion of the CONUS
continues to focus much of the active weather over the CONUS, and will
continue to do for the next several days. Since this morning, scattered
showers and thunderstorms have expanded from the Tennessee Valley into
portions of the Northeast and New England as an influx of moisture races
toward the Eastern Seaboard. Moderate to locally heavy rainfall is
possible with this activity, although no excessive rainfall is anticipated
today.

In the meantime, a jet stream arriving from the Eastern Pacific will begin
to interact with a moisture laden portion of the front across the Southern
Plains. This interaction will yield a more robust round of heavy rain from
the Southern Plains eastward across the Lower Mississippi Valley, and into
the Tennessee Valley Wednesday through Thursday morning. In all, the
latest WPC forecast calls for rainfall totals upwards of 2 inches over
portions of the Ozarks through Thursday. This rainfall may lead to
isolated instances of flash flooding over portions of Eastern Oklahoma,
Missouri, and Arkansas through Thursday morning, where a Slight Risk
(level 2/4) of Excessive Rainfall is in effect. In addition, temperatures
will be cold enough to support wintry precipitation across portions of the
Central Plains.

The overall pattern supporting the wet weather from the southern Plains
into the Northeast will also support much above average temperatures over
the next few days over the Central to Southern Plains, and  eastward into
the East Coast.  After a few record high minimum and maximum temperatures
were set yesterday over the Southern Plains, a much more expansive area of
potentially record high minimum (and a few daily maximum) temperatures are
forecast Wednesday and Thursday across portions of the southern Plains,
Lower Mississippi Valley, Tennessee Valley, Mid-Atlantic and Northeast.

Below average temperatures over the next few days are expected west of the
Rockies and across the Northern Plains. The greatest below average
temperatures are expected across the Northern Plains where Arctic air will
keep temperatures 15-20 degrees below average from eastern Montana, across
the Dakotas and into Minnesota Wednesday into Thursday.  However, record
cold temperatures are not expected across this region.  This area will
also see the threat of periods of accumulating snows over the next two
days.  Amounts are not expected to be very heavy, generally in the 1 to 4
inch range. The heaviest snows over the next few days expected through the
Rockies of Colorado, northwest Montana and northern Idaho where totals in
excess of a foot are possible. By Thursday however, another Pacific system
arriving along the West Coast will spread low elevation rainfall and high
elevation snows to the Pacific Northwest into Central California. The
current WPC Winter Storm Severity index currently indicates minor (level
1/5) to locally moderate (level 2/5) impacts are possible from this wintry
weather over the Olympics and Cascades Thursday.  

Asherman/Kong


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