Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
348 PM EDT Sat May 18 2013

Valid 00Z Sun May 19 2013 - 00Z Tue May 21 2013

...There is a slight risk of severe thunderstorms from parts of the
Northern Plains to North-Central Texas, with an embedded area of moderate
risk of severe thunderstorms from West-Central Oklahoma to Southwestern
Nebraska...

...Heavy rain is possible over parts of the Upper Midwest and Central
Carolinas...

A deep upper-level trough over the Rockies will develop into a closes
upper-level low over the Northern/Central Plains by Monday.  A much weaker
upper-level low over Western Ohio will drift eastward to the Southern
Mid-Atlantic by Monday.  The energy will trigger showers and thunderstorms
over parts of the Southeast, Tennessee Valley, and the Mid-Atlantic.  Rain
will also develop over parts of the Ohio Valley to parts of the
Northeast/Mid-Atlantic through Monday.  Overnight Sunday, upper-level
energy over Southeastern Canada will move over Maine producing an area of
light to moderate rain on Monday morning. 

Another area of upper-level energy over the Pacific Northwest will enter
into the deep upper-level trough over the Rockies, that will aid in
developing the upper-level closed.  As the disturbance moves inland,
showers and thunderstorms will develop over parts of the Northern/Central
Rockies and the Northern/Central High Plains on Saturday evening, becoming
rain overnight Saturday, remaining mostly rain through Monday over the
Northern/Central Rockies.  Additionally, onshore flow will produce rain
over parts of the Pacific Northwest through late Saturday night. 

Under the developing upper-level low, showers and thunderstorms, some with
moderate rain, will develop over parts of the Plains Saturday into Sunday,
moving into parts of the Upper/Middle Mississippi Valley by Sunday
evening.  The showers and thunderstorms, with moderate rain, will be
confined mostly to the Northern Plains by Monday morning.  Some scattered
showers and thunderstorms will develop over parts of the Lower/Middle
Mississippi Valley, also by Monday.  In addition, areas of light to
moderate rain will develop over parts of the Northern High Plains and the
Upper Great Lakes overnight Sunday into Monday morning.       


Ziegenfelder


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