Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
300 AM EST Wed Dec 07 2022

Valid 12Z Wed Dec 07 2022 - 12Z Fri Dec 09 2022

...Heavy rain and flash flooding threat across the central Plains later on
Wednesday into Thursday...

...Accumulating snows across the northern Plains today, then over parts of
the central Rockies tonight/early Thursday...

...Next round of heavy precipitation expected to reach the Pacific
Northwest by Thursday before spreading inland and down into California
Thursday night into early Friday...

A meandering front will continue to be the focus of active weather across
the south-central portion of the mainland U.S. over the next couple of
days.  Fast upper-level southwesterly flow has already transported
moisture all the way up the East Coast into New England early this morning
with areas of moderate to locally heavy rainfall.  In the meantime, a jet
stream arriving from the eastern Pacific will begin to interact with the
trailing 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 mid-Mississippi Valley toward the Tennessee Valley
through Thursday morning.  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.  In addition, a low pressure system is forecast to form over the
central High Plains today and begin to track eastward into the central
Plains on Thursday.  Temperatures will be cold enough to support snow
across portions of the north-central Plains where a few inches of
accumulation is forecast by Friday morning.  In the shorter term, a swath
of snow is forecast across the far northern Plains today behind an arctic
front.

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.  An expansive area of record high minimum (and a few daily
maximum) temperatures are forecast today and Thursday across portions of
the southern Plains, lower Mississippi Valley, Tennessee Valley,
Mid-Atlantic and Northeast.

By Thursday, the next Pacific system arriving along the West Coast will
bring the next round of unsettled weather into the Pacific Northwest and
then down into northern and central California by early on Friday.  Heavy
mountain snow can be expected to overspread first along the Cascades
followed by the Sierra Nevada beginning later on Thursday.  Periods of
moderate to heavy rain can also be expected along the coastal sections. 
The snow will begin to penetrate farther inland across the Intermountain
region early Friday.

Kong/Asherman


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