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

Valid 12Z Fri Mar 17 2023 - 12Z Sun Mar 19 2023

...Heavy rain and possibly severe thunderstorms shift eastward into the
Southeast and the central to eastern Gulf Coast today and into tonight...

...Snow departing the upper Midwest/Great Lakes today followed by
intrusion of below to much below normal temperatures across the Plains and
into the eastern U.S. going into the weekend...

A consolidating and intensifying low pressure system centered over the
upper Great Lakes this morning is forecast to track northeast into eastern
Canada today and going into the weekend. This system has brought the
latest round of accumulating snow across the upper Midwest and the U.P. of
Michigan, and is forecast to spread some wintry precipitation from west to
east across the interior Northeast through tonight.  On Saturday, the low
center will advance northeast further into southeast Canada, but 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.
The exiting low center will drive a strong cold front across 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. Some portions of the Plains and Midwest
will see high temperatures as much as 15 to 25 degrees below normal, with
some areas of the Northern Plains seeing low temperatures by Saturday
morning that will be below zero.

Meanwhile, a large area of mild air will surge north ahead of the low
pressure system.  This relatively warm air coupled with an influx of
moisture from the Gulf of Mexico has continued to trigger heavy showers
and thunderstorms ahead of a potent cold front that is forecast to sweep
across the Great Lakes, Ohio Valley and the Deep South today, followed by
the entire eastern U.S. tonight.  The threat of heavy rain and severe
thunderstorms should peak early this morning across the lower Mississippi
Valley before shifting steadily east into the interior Southeast later
today, with the central and eastern Gulf Coast having the highest chance
of seeing severe thunderstorms.  Showers and thunderstorms are also
expected to move across the Mid-Atlantic this evening ahead of the cold
front. By Saturday, the front will move off the East Coast while the
trailing portion of the front will advance into Florida, where some heavy
rainfall and a marginal chance of severe thunderstorms is expected.  By
Sunday morning, the precipitation should reach into South Florida.

Drier air and much more tranquil weather will be the story across much of
the West for the end of the week and into the first part of the weekend
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 by the latter part of the
weekend, with the next round of precipitation likely reaching northern and
central California by early on Sunday.

Kong/Orrison


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