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

Valid 12Z Tue Dec 06 2022 - 12Z Thu Dec 08 2022

...Heavy rain and isolated flash flooding potentials shift westward from
the Tennessee Valley today to 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 frontal boundary will continue to be the focus of active
weather across the south-central portion of the country during the next
couple of days.  The first episode of heavy rain has already been
impacting areas from the interior Deep South eastward into northern
Georgia and portions of Tennessee early this morning.  The moisture will
be carried rapidly northeast across the interior eastern U.S. today and
into New England by tonight.  The associated rainfall is expected to be
more scattered in nature.  However, parts of the Appalachians, as well as
northern Mid-Atlantic into New England will have the best chance of seeing
periods of moderate rainfall later today into Wednesday as a low pressure 
wave forms along the front.  In the mean time, a jet stream arriving from 
the eastern Pacific will begin to interact with the front across the southern
Plains.  This interaction will bring a second round of heavy rain from the
southern Plains eastward across the lower Mississippi Valley and into the
Tennessee Valley starting on Wednesday.  Portions of these regions have
had above average precipitation over the past few weeks, resulting in
increasingly saturated soils, with heavy rain potential on these saturated
soils increasing the flash flood threat.  By Wednesday night into Thursday
morning, a low pressure wave is forecast to develop over the southern High
Plains along the front.  This system is forecast to shift the heavy rain
threat slightly northward across Oklahoma toward the Missouri-Arkansas
border Wednesday night/early Thursday.  In addition, temperatures will be
cold enough to support wintry precipitation across 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  eastward into the
East Coast.  A few record high minimum temperatures are forecast this
morning across the lower Mississippi Valley, with a much more expansive
area of potentially record high minimum temperature possible Wednesday
morning 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 across
areas 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.  However, record cold
temperatures are not expected across this region over the next two days. 
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.

Kong/Oravec


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