Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
328 PM EDT Fri Mar 17 2023

Valid 00Z Sat Mar 18 2023 - 00Z Mon Mar 20 2023

...Heavy showers and thunderstorms will impact portions of the eastern
Gulf Coast and Southeast tonight into Saturday...

...Heavy lake-effect snow and snow squalls to impact areas of the Great
Lakes, Ohio Valley and Northeast this weekend...

...Below to much below normal temperatures expected across much of the
central and eastern U.S. this weekend...

A strong area of low pressure associated with the latest winter storm
impacting the Great Lakes region will advance into southeast Canada
tonight and through the weekend. However, strong winds and much colder air
surging south around the departing low center will keep a threat of heavy
lake-effect snow going across the U.P. of Michigan where snowfall totals
of as much as 1 to 2 feet can be expected by early Saturday. Heavy
lake-effect snow will also develop and impact areas of northwest and
southwest Lower Michigan tonight and Saturday downwind of Lake Michigan,
and as much as 6 to 12 inches may accumulate here.

The exiting low center will also drive a strong cold front through the
eastern U.S., and this coupled with a secondary surge of Arctic air
dropping south from Canada will transport a large area of below to much
below normal temperatures across the Plains, Midwest and gradually into
much of the East heading into the weekend. The cold air and strong winds
crossing the remainder of the Great Lakes region will also set the stage
for heavy lake-effect snow to develop downwind of Lake Erie and Lake
Ontario, and portions of northwest Pennsylvania and especially western New
York will see heavy accumulations. Areas near the Tug Hill Plateau will
likely see as much as 12 to 18 inches of snow by Sunday. As this secondary
surge of cold air and the associated front arrives across the Ohio Valley
and into the Northeast on Saturday, there will concerns for multiple bands
of intense snow squalls which will likely produce areas of low visibility,
blowing snow, and thus hazardous travel conditions.

Prior to the arrival of cold air across the South, there will still be
some mild air lingering across the Gulf Coast states and the Southeast
going through this evening and into early Saturday. Locally heavy showers
and thunderstorms are expected along and ahead of the cold front as it
crosses the region. A few severe thunderstorms will be possible this
evening across areas of the northeast Gulf Coast region with damaging
winds and possibly a tornado possible with the stronger storms. Areas of
heavy rain may lead to an isolated concern for some runoff problems, and
these rains will spread into the Florida Peninsula this weekend as the
front settles southward.

Drier air and tranquil weather will remain in place across much of the
West through Saturday with temperatures near to slightly below normal,
except for the Pacific Northwest where temperatures will be slightly above
normal. However, a new storm system will be approaching the West Coast on
Sunday, and this will bring a new round of locally heavy rains into
central and northern California, and southwest Oregon. This storm will be
bringing more heavy snow to the higher elevations of the Sierra Nevada.

Kong/Orrison


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