Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 AM EDT Sat Mar 18 2023

Valid 12Z Sat Mar 18 2023 - 12Z Mon Mar 20 2023

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

...Next round of rain and heavy mountain snow expected to overspread the
West Coast Sunday into early Monday...

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

A deep and expansive low pressure system associated with the latest winter
storm across the Great Lakes region continues to track further into
southeastern Canada.  However, strong winds and much colder air surging
south behind the departing low center will keep a threat of heavy
lake-effect snow going across the U.P. of Michigan today before
diminishing tonight.  As the low pressure system advances eastward, a
reinforcing surge of cold air is forecast to overspread the Ohio Valley
and into the Northeast today.  There will be concerns for heavy
lake-effect snow to develop and impact areas farther east across the lower
Great Lakes downwind of Lake Erie and Lake Ontario, and portions of
northwest Pennsylvania and especially northern New York tonight and into
Sunday.  Areas upwind from the Tug Hill Plateau will likely see as much as
12 to 18 inches of snow on Sunday.  Multiple bands of intense snow squalls
will likely produce areas of low visibility, blowing snow, and thus
hazardous travel conditions at the height of the squalls.

Across the Southeast and into northern Florida, the threat of heavy
showers and thunderstorms are expected to gradually diminish today as the
associated cold front slides steadily southeastward.  However, areas of
heavy rain may lead to an isolated concern for some runoff problems, and
these rains will spread into the Florida Peninsula later today as the
front settles southward.  By Sunday night, the threat of heavy rain 
should be confined to South Florida.

Drier air and relatively tranquil weather will prevail across much of the
West today along with temperatures near to slightly below normal, except
for the Pacific Northwest where temperatures will be slightly above
normal.  However, unsettled weather is on the horizon as the next storm
system from the Pacific is forecast to bring a new round of locally heavy
rains into central and northern California, and southwest Oregon early on
Sunday.  The Sierra Nevada can once again expect another foot of heavy
snow through the rest of Sunday and into Monday.  Widespread
high-elevation snow and low-elevation rain will then spread quickly inland
across the Great Basin, Intermountain West, and reaching the Four Corners
Sunday night into early Monday.

Kong/Orrison


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