Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
304 PM EST Thu Nov 20 2014
Valid 00Z Fri Nov 21 2014 - 00Z Sun Nov 23 2014
...Heavy rain possible over parts of the Southern Plains...
...Heavy rain possible over parts of the Pacific Northwest...
...Lake effect snow to taper off over the Great Lakes...
Upper-level energy over the Great Lakes will move eastward out over the
Western Atlantic by Friday evening. The lake effect snow associated with
the upper-level energy will wind down over the Great Lakes by Friday
evening as well. Moisture from the Gulf of Mexico will begin to overrun
the cold air over the Lakes that will aid in producing rain/freezing rain
over parts of the Great Lakes by Saturday morning.
Meanwhile, high pressure over Mississippi Valley will move eastward to the
Mid-Atlantic Coast by Saturday. Circulation around the high will draw
moisture from the Western Gulf of Mexico over the Southern Plains into the
Middle Mississippi Valley and the Great Lakes by Saturday. The moisture
will overrun an east-west boundary over the Southern Plains/Lower
Mississippi Valley will produce showers and thunderstorms over Eastern
Texas that will expand into the Southern Plains by Saturday morning. In
addition, rain will develop over parts of the Lower/Middle Mississippi
Valley by Friday morning and expand into parts of the Ohio Valley by
Saturday. Additionally, easterly flow off the Atlantic and a front near
Southern Florida will produce showers and thunderstorms over the Southern
tip of Florida from early Friday morning through Saturday.
An upper-level low off the California Coast will move southeastward to
Northern Mexico by Saturday. The energy will aid in producing rain over
parts of the California Coast that will wind down by Friday morning.
Areas of rain and snow will develop over parts of the higher elevations of
California on Thursday evening. A front over the Eastern Pacific will
move onshore over the West Coast on Friday into Saturday morning. The
system will produce rain over parts of the Pacific Northwest on Friday
morning that will increase in intensity to light to moderate rain by
Friday evening. The intensity will weaken to light rain by Saturday
morning by Saturday morning. Light snow will develop over parts of the
Northern Intermountain Region by Friday evening. The snow will become
moderate over parts of the region on Saturday morning. Likewise, snow
will begin to develop over parts of the Northern Rockies on Saturday
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php