Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 453 PM EDT Thu Apr 05 2018 Valid 00Z Fri Apr 06 2018 - 00Z Sun Apr 08 2018 ...Heavy rain possible over the California/Pacific Northwest and the Lower Mississippi/Tennessee Valleys... ...Heavy snow possible over parts of the Central Plains ...Snow over parts of the Cascades, Sierras, the Northern/Central Rockies, Great Lakes/Northern New England, and Ohio Valley/Central Appalachians/Southern Mid-Atlantic... ...Temperatures will be 20 to 35 degrees below average over the Northern/Central Plain into Upper/Middle Mississippi Valley... One front followed by another front will move into the Pacific Northwest and Northern/Central California on Thursday evening with the second boundary moving inland to the Northern Rockies/Great Basin and California by Saturday. Moisture from the Pacific will stream into Northern/Central California through Saturday, too. The systems will produce rain over most of the Pacific Northwest into Northern California with rain and higher elevation snow extending into the Northern Rockies by Thursday evening. The rain will expand southeastward into Central California and the Great Basin by Friday morning and into parts of Southern California by Friday evening. On Saturday when the second boundary moves inland, the snow levels will lower over the Northwest into the Northern Rockies with snow developing over higher elevations of the Pacific Northwest into Northern California and over parts of the Northern Rockies by Saturday afternoon into evening, while the rain continues over the lower elevations. Meanwhile, a strong cold front along the foot hills of the Northern Rockies into the Central High Plains will sink southward to the Southern Rockies and the Texas/Mexican border into the Western Gulf Coast by Saturday. Very cold air will move into the Plains and most of the Mississippi Valley by Saturday. The boundary will aid in producing snow over parts of the Northern High Plains that will expand into the Central Rockies with lower elevation rain as snow develops over parts of the Central Plains by Friday morning. The snow will end over the Northern High Plains by Saturday morning. The snow will also move southward and eastward into parts of the Southern Plains and the Middle Mississippi Valley overnight Friday into Saturday morning. In the meantime, moisture from the Western Gulf of Mexico will flow northward over the Southern Plains/Lower Mississippi Valley on Thursday evening expanding eastward into the Tennessee Valley by Friday evening. Upper-level energy moving from the Southern High Plains will move eastward to the Tennessee Valley by Friday evening. The energy will aid in developing showers and thunderstorms over parts of the Southern Plains into the Lower Mississippi Valley on Thursday evening. The showers and thunderstorms will continue over the region through Friday evening and move off most of the Central/Western Gulf Coast by Saturday as the strong front move through the area. Furthermore, upper-level energy over the Upper Midwest will move eastward across the Great Lakes into Northern New England by Saturday. Snow will develop over parts of the Upper Midwest through Friday evening. A wave of low pressure along the eastern end of the strong front will move across the Great Lakes into Eastern Ontario by Friday evening emerging over Northern New England by Saturday. Moisture will begin to pool along the front overnight Thursday expanding eastward to the Mid-Atlantic and Southern New England by Friday evening continuing through Saturday. Rain and snow will develop along and near the surface low overnight Thursday over the Great Lakes/Ohio Valley expanding eastward into the Mid-Atlantic and parts of the Northeast by Friday evening with rain changing to snow over Northern New England by Saturday morning. Snow will fill in north of the boundary by Friday evening over parts of the Middle Mississippi and Ohio Valleys into parts of the Central Appalachians. The rain and snow will move southeastward into Mid-Atlantic/Southeast by Saturday morning. In addition, showers and thunderstorms will continue over parts of the Central/Eastern Gulf Coast and parts of the Southeast through Saturday, too. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php