Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 425 PM EDT Fri Apr 09 2021 Valid 00Z Sat Apr 10 2021 - 00Z Mon Apr 12 2021 ...Stormy and unsettled weather pattern throughout the East to kickoff the weekend; rounds of severe weather and areas of flash flooding expected across the Deep South... ...Elevated to Critical Risks of fire weather remain in place for the Southwest to Southern High Plains... ...Cooler than normal temperatures and mountain snow in the Northwest, warmer than normal in the Southwest and Northeast... A large occluded low pressure system in the Midwest will continue to generate spotty areas of showers and thunderstorms from the northern Plains to the Mid-Atlantic coast into Saturday morning. As this system dissipates and moves into Canada, a new potent upper level disturbance will strengthen as it tracks into the Central Plains this afternoon. This results in a deepening area of low pressure in the South Central U.S. and an increasingly favorable environment for intense thunderstorm activity in the Southern Plains and Southeast tonight through Sunday. The Storm Prediction Center has issued a Moderate Risk of severe weather today for portions of the Lower Mississippi Valley with an expansive Slight Risk area that stretches from eastern Texas and Oklahoma to southern Georgia. Severe storms will be capable of producing damaging winds, large hail, and tornadoes. In addition to the severe threat, there is also a threat for flash flooding and a Slight Risk for excessive rainfall has been outlined from the Arklatex region to central Alabama. Widespread rainfall totals between 1 to 2 inches are likely with locally higher amounts above 3 inches possible. The severe weather and flash flood threat advances further east on Saturday as an intensifying low pressure system and associated cold front track from the Mississippi Valley to the Great Lakes by evening. Ahead of the front, the Storm Prediction Center has outlined an Enhanced Risk of severe storms from the Mississippi Delta east to the western Florida Panhandle and north into southern Alabama for the potential of significant wind gusts as well as hail and tornadoes. There is also a Slight Risk for excessive rainfall with deep, gulf moisture and the potential for training storms leading to rainfall amounts as high as 4 inches along the central Gulf Coast. Widespread showers and thunderstorms are also possible for the Great Lakes south through the Ohio Valley into the Mid-Atlantic and Carolinas with a few storms potentially becoming severe. The chance for showers and thunderstorms will overspread most of the East Coast through the overnight hours Saturday into Sunday as the cold front approaches from the west. The storm system will move east into the Atlantic later in the day on Sunday but showers will continue to spread northeast into New England. Behind this system, a second system upstream will move into the Northern Plains/upper Midwest bringing additional rain chances. Meanwhile in the Southwest, drier conditions combined with breezy winds, low relative humidity, and favorable fuels continue to support Critical Fire Weather conditions from west Texas to central New Mexico through tonight. Elevated Risk areas are also in place throughout much of the Southern High Plains and southern Rockies. Fire Weather conditions continue on Saturday with an Elevated Risk for parts of southern Arizona, much of New Mexico, and southwestern Texas on Saturday. Depending on the timing of another cold frontal passage, fire weather conditions may remain favorable for at least some portions of the Southwest on Sunday. In the Northwest, below normal temperatures and another round of valley/coastal rain and mountain snow will continue as another strong Pacific cold front moves inland late Friday and into Saturday. Saturday daytime highs throughout the Northwest are forecast to range between 10 to 20 degrees below normal. The injection of subfreezing temperatures aloft provides mountain ranges such as the Cascades, the Bitterroots, and northern Rockies a chance for accumulating snowfall through Saturday evening. The heaviest totals are most likely to transpire in the Cascades where over a foot of snow is expected. While the Northwest turns quite cool, above normal temperatures will continue for eastern portions of the Great Lakes region and interior New England, with highs up to 20 to 25 degrees above normal on Saturday. More seasonable temperatures will return by Sunday as cooler air moves in from the north and behind the storm system approaching from the west. Elsewhere, temperatures will be seasonable ahead of the cold front along the East Coast, cooler than average throughout portions of the Plains and Midwest behind the cold front, and hot in the desert Southwest with highs into the 90s likely. Mullinax/Putnam Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php