Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
442 AM EDT Wed May 22 2013

Valid 12Z Wed May 22 2013 - 12Z Fri May 24 2013

...A slow-moving cold front will be the focus for heavy rain and a threat
of severe weather today and Thursday...

...Much cooler conditions for the Pacific Northwest...with scattered
convection and high-elevation snowfall possible through Thursday...

A slow-moving upper trough and its associated surface cold front edges
slowly eastward across the eastern half of the US during the next few
days...reaching the Atlantic coast on Friday morning.  Warm humid air
ahead of the front...courtesy of a southerly flow off the Gulf of Mexico
will allow showers and thunderstorm development to produce locally heavy
rainfall and the threat of severe weather for the Ohio Valley today and
tonight. These conditions will translate to the East Coast on Thursday and
Thursday evening. Please refer to the Storm Prediction Center for the
latest information and updates on the severe weather potential through
Thursday night.

Out west...a deep Pacific cold front will slowly migrate eastward across
the Intermountain West...with localized snowfall possible across the
Washington Cascades and Olympic Mountains. Across the northern Rockies and
lee of the Cascades...gusty winds...scattered showers and isolated
thunderstorms will accompany the front which surges to the Continental
Divide tonight and early Thursday. This front then stalls along the Divide
until late Thursday night into Friday morning. With an easterly flow from
the Plains over running the slowing front from central Montana into
southern Wyoming... additional precipitation is expected to develop east
of the Divide.

Vojtesak

Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php