Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
305 AM EDT Mon Mar 13 2017

Valid 12Z Mon Mar 13 2017 - 12Z Wed Mar 15 2017

...Late-season winter storm for the East Coast on Tuesday...

It continues feeling like winter across much of the country, despite it is
now mid-March.  A large surface high pressure ridge over south-central
Canada is sprawling southward into the central and eastern U.S., allowing
for a continuous supply of January-like temperatures through the middle of
the work week.  Afternoon highs are expected to be on the order of 15 to
30 degrees below normal from the northern Plains to the Mid-Atlantic
region, with the possibility of some record lows.

Things get interesting for the East Coast beginning Monday night.  A low
pressure system crossing the Midwest states and Ohio Valley is expected to
phase with another low off the southeast U.S. coast.  This will allow for
a strong nor'easter to develop near the coast and cause a late-season
snowstorm from the central Appalachians to New England, including many of
the big cities in the Northeast U.S.  Widespread winter storm warnings are
now in effect for heavy snowfall accumulations, with some areas likely
getting in excess of a foot from eastern Pennsylvania to southern New
England.  The tricky part of the forecast deals with the rain/snow line
over the Mid-Atlantic region with a tight gradient in accumulations
expected near the greater Washington DC metro area.  Closer to the coast
from southern New Jersey to the Carolinas, rain is expected with amounts
in excess of an inch likely.

Elsewhere across the continental U.S., expect warm conditions to continue
across the southwestern U.S. with no rain or snow in the forecast.  The
lower elevations of the Desert Southwest could even reach the lower 90s
for highs over the next few days with an upper level ridge in place. 
Onshore flow across the Pacific Northwest will keep scattered showers
around, with snow in the Cascades and northern Rockies.

D. Hamrick


Graphics available at <a href="http://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php"><u>www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php</u></a>