Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
258 PM EST Fri Jan 24 2020
Valid 00Z Sat Jan 25 2020 - 00Z Mon Jan 27 2020
...Wintry weather expected across portions of the Great Lakes,
Appalachians and Northeast...
...Heavy rain and some areas of flooding will be possible in the central
and southern Appalachians, and the Mid-Atlantic...
...Waves of unsettled weather in the Pacific Northwest where multiple
bouts of heavy rain and heavy mountain snow are expected...
There will be no shortage of active weather over the eastern U.S. this
weekend thanks to a potent upper-level low pressure system slowly
advancing towards the East Coast. Winter Weather Advisories are in effect
for portions of the Midwest, Great Lakes and Northeast where locally
several inches of snow will accumulate through tonight. Also, there will
be the threat for some areas of freezing rain, especially across the
northern Appalachians and interior portions New York and New England later
tonight and through Saturday as the storm pushes east, and interacts with
shallow subfreezing temperatures. Hazardous travel conditions can be
expected locally, but fortunately the major cities of the Mid-Atlantic and
Northeast should be warm enough for just plain rain.
Aside from the winter weather impacts, heavy rain with the storm system
will be a concern as rainfall totals of as much as 1 to 2 inches are
expected tonight through Saturday for the Mid-Atlantic and southern New
England. However, even heavier amounts reaching up to 3 inches or more are
expected for the higher terrain of the Appalachians, including the Blue
Ridge from southern Pennsylvania southward to western North Carolina.
These rainfall totals may be enough to result in some flooding problems
given the relatively wet antecedent conditions. As the storm system lifts
northeast through New England by Sunday and begins to pull away, drier and
somewhat colder air will arrive from the Midwest, although there should be
plenty of snow shower activity across the Great Lakes and central
Appalachians on Sunday with locally a few inches of snow possible.
Meanwhile, multiple bouts of heavy precipitation will continue for the
Northwest into the weekend as a series of cold fronts move in off the
Pacific Ocean. This will include heavy rain for the coastal ranges where
as much as a few inches of rain will be possible, and also heavy snow for
the higher peaks of the Washington and Oregon Cascades where as much as 2
feet of new snowfall can be expected through the weekend. Some of this
heavy snowfall will also spill over into the Intermountain West with
locally heavy accumulations for the northern Rockies.
Weekend temperatures across the contiguous U.S. will generally be near to
above normal. The warmest anomalies will be found over the High Plains,
Upper Midwest, and Great Lakes region which is mainly a reflection of the
level of milder upstream Pacific air advancing east across the country,
and a lack of any cold high pressure dropping south from Canada.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php