Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 351 PM EDT Sun May 20 2018 Valid 00Z Mon May 21 2018 - 00Z Wed May 23 2018 ...Shower and thunderstorm activity will continue across portions of the southern Plains, Ohio Valley, and Mid-Atlantic states... ...Another day of heavy rain with embedded thunderstorms expected for much of Florida on Monday... ...Afternoon showers and thunderstorms will continue to develop over California, the central Great Basin, and northern Rockies... A quasi-stationary front extending from the Northeast to the Ohio Valley westward to the Middle Mississippi Valley then southwestward to the Southern Plains will have the southwestern portion of the boundary dissipate by Monday evening. The far eastern part of the front will slowly sink southward to the Mid-Atlantic while a new western half of the boundary develops from the Middle Mississippi Valley westward to the Central High Plains by Monday evening into Tuesday. Rain and thunderstorms developing along the eastern end of the boundary will move off the Northeast and most of the Northern Mid-Atlantic Coast overnight Sunday. Showers and thunderstorms will also develop along and near the front from parts of the Ohio Valley westward to the Middle Mississippi Valley and from the Middle Mississippi Valley southwestward to the Southern Plains through Monday evening. Meanwhile, upper-level energy over parts of Central Northern Florida into the Southeast Coast will slowly drift northwestward into parts of the Tennessee Valley by Monday evening. The system will produce showers and thunderstorms from the Southern Mid-Atlantic Coast to Florida Peninsula that will expand westward into the Southeast and the Tennessee Valley by Sunday evening. The showers and thunderstorms will continue from the Central Gulf Coast/Tennessee Valley eastward to the Southern Mid-Atlantic Coast/Southeast through Monday evening. Furthermore, an upper-level trough over the West Coast will deepen while an upper-level low develops over South-Central California by early Monday morning then settles over parts of Southern California into the Great Basin by Monday evening. The energy will aid in developing rain and embedded thunderstorms over parts of the Pacific Northwest into parts of the Great Basin on Sunday morning that will develop into an area of showers and thunderstorms extending from parts of the interior Pacific Northwest/Northern California into Northern/Central Rockies and Great Basin that will have a diurnal component through Monday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php