Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
301 PM EST Tue Feb 19 2019
Valid 00Z Wed Feb 20 2019 - 00Z Fri Feb 22 2019
...Significant winter storm for the Mid-Atlantic region on Wednesday...
...Heavy rain will continue a threat for flooding from the Lower
Mississippi Valley into the Ohio Valley...
...Heavy snow for portions of the Upper Midwest tonight/Wednesday...
...Continued cold and snowy west of the Continental Divide...
A large winter storm will affect locations from the Upper Midwest to the
East Coast beginning tonight. A dome of high pressure currently in place
across the Great Lakes region has set the stage for wintry precipitation
with temperatures near or below freezing from the Mid-Mississippi Valley
to the northern Mid-Atlantic region. As an upper level system lifts
through the Great Plains tonight, significant amounts of moisture will
spread north and east from the Gulf of Mexico. This moisture will meet
with cold air across the Upper Midwest where an area of low pressure is
forecast to develop and track across the Upper Mississippi Valley on
Wednesday. Widespread snowfall totals of 4-8 inches (locally higher) are
expected from eastern Nebraska into eastern Minnesota and northwestern
Wisconsin through the day on Wednesday.
Meanwhile, snow will move from southwest to northeast into the
Mid-Atlantic region late tonight, changing to a wintry mix of sleet and
freezing rain and eventually all rain for many. The time of changeover
will depend on location but will be delayed for locations near the central
Appalachians where significant ice accumulations near 0.25 inches along
with 4-8 inches of snow (locally higher) will be possible. Farther to the
south, heavy rain is expected to continue from the Lower Mississippi
Valley into portions of the Ohio Valley where an additional 1-3 inches of
rain, on top of already saturated ground, can be expected through
Wednesday afternoon. Flood and flash flood watches are already in effect
for many of these locations.
Out West, temperatures will continue to run 10-20 degrees below average
along and west of the Continental Divide through Thursday. Another storm
system is forecast to drop south from the Pacific Northwest tonight,
reaching the Southwest by Thursday morning. Additional snowfall totals of
over a foot are forecast for some of the major mountain ranges extending
from Washington and Oregon into Arizona and southwestern Colorado.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php