Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
440 AM EDT Mon May 20 2013

Valid 12Z Mon May 20 2013 – 12Z Wed May 22 2013

…Moderate risk of severe weather for eastern Oklahoma and the
southern Ozarks through Tuesday morning…

…Slight risk of severe weather for the Midwest and upper half of
the Mississippi Valley today and tonight…

…Heavy rainfall possible for the Upper Missouri and Mississippi
Valleys…

…Slow-moving Pacific system to bring rainfall…windy conditions
and cooler weather to the Pacific Northwest and northern Rockies…

Deep…slow-moving trough of low pressure in the north central
Plains and broad fetch of moist…southerly flow off the Gulf of
Mexico is expected to produce widespread showers…thunderstorms
and locally heavy rainfall over a large portion of the
Plains…Midwest and central Great Lakes today and Tuesday. Along
with the threat of heavy rainfall…there is a moderate risk of
severe storms for the southern Plains and Ozarks and a slight risk
of severe weather for the upper half of the Mississippi Valley.
Please refer to the Storm Prediction Center for the latest
information and updates concerning the potential severe weather
threat through Tuesday morning.

Out West…low pressure in the Gulf of Alaska will slowly move
across the Pacific Northwest and northern Rockies. Inland…low
pressure is expected to intensify over southwest Canada with an
increase in southerly flow and threat for mountain showers and
thunderstorms. By Tuesday morning…a strong cold front and windy
conditions surges across the Cascades and spreads cooler and
wetter weather into the northern Rockies and produces scattered
showers and a few thunderstorms into western sections of
Washington and Oregon.

In the East…scattered showers will continue across Maine and
portions of northern New England through this evening…as a
slow-moving Canadian cold front sweeps into the north Atlantic.
For Monday night and Tuesday…a broad warm front and more humid
conditions will work their way up the East Coast…with the threat
of showers and a few thunderstorms for the mid-Atlantic
states…Appalachians and Northeast…including the upper Ohio
valley and Eastern Great Lakes.

Vojtesak