Short Range Forecast Discussion
NWS Weather Prediction Center College Park MD
400 PM EDT Sat Apr 21 2018
Valid 00Z Sun Apr 22 2018 - 00Z Tue Apr 24 2018
...Storm system to bring threats for heavy rain, flash flooding and
possible severe storms from eastern Texas/Oklahoma to the Southeast U.S...
...Accumulating snow expected for portions of southern Montana into
northwestern Wyoming Sunday night through Monday...
An upper level storm system will move through the central and southern
Plains this evening, across the lower Mississippi River valley on Sunday
and reach the Southeast for Monday. The coverage of thunderstorms is
expected to increase this evening over Texas, some of which may be severe
across northern Texas into Louisiana, also while posing a threat for heavy
rainfall and possible flash flooding. As the storm system's cold front
moves east for Sunday, the threats for severe storms and flash flooding
will shift primarily east of the Mississippi River into Gulf Coast States.
As the system slows down into Monday however, higher chances for heavy
rain and flash flooding will exist. The focus will be from portions of
Georgia into the southern Appalachians into most of South Carolina where a
broad 2-4 inches, locally higher, can be expected through Monday evening.
High temperatures in the wake of the storm system will be a good 5 to 15
degrees cooler than average for late April.
The only other significant weather maker across the lower 48 will be in
the vicinity of the northern Rockies ahead of an upper level trough,
forecast to enter the Pacific Northwest on Sunday. Expect rain and higher
elevation snow to develop from Idaho into western Montana by Sunday
evening, followed by cooling temperatures and a changeover to snow for
most of the northern Rockies by Monday morning. Outside of the higher
elevations, a few inches of snow are expected but with rainfall to
possibly mix in at time during the day on Monday, with localized wet snow
into the northern High Plains.
Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php