Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 336 PM EDT Sat Apr 13 2019 Valid 00Z Sun Apr 14 2019 - 00Z Tue Apr 16 2019 ...Severe thunderstorms and flash flooding expected tonight for portions of the Lower Mississippi Valley and Tennessee Valley, shifting into the Ohio Valley and the East on Sunday... ...Warm temperatures in the East on Sunday, with record high overnight mins possible. Temperatures will warm significantly the next few days across the Great Plains... A potent spring storm system will continue tracking through the Lower Mississippi Valley into the Tennessee Valley tonight. Strong thunderstorms and heavy rainfall is likely from the central Gulf States to the western Tennessee Valley where both SPC and WPC have slight to moderate risks of severe weather and excessive rainfall, respectively, continuing through tonight. Refer to the outlooks from these centers for additional details. By Sunday, this storm system should lose some of its intensity but will continue to pose a threat for severe storms and localized heavy to excessive rainfall from the Tennessee Valley to the Ohio Valley and eventually moving into the Eastern states. SPC has a slight to enhanced risk for severe weather from the Gulf Coast to the Ohio Valley and northern Mid-Atlantic on Sunday, while WPC has a marginal to slight risk for excessive rainfall. On the north side of the system, temperatures should be cold enough to support light to moderate snow accumulations from northern Illinois to Lower Michigan, and also across far northern Maine. Behind the cold front, high temperature departures will be well below average across the eastern Plains and the Mississippi River Valley on Sunday, with daytime highs 10 to 20+ degrees below normal, especially across parts of the Upper Midwest. In the East on Sunday, temperatures will be above average, with some record warm overnight temperatures possible. Following the frontal passage, temperatures to moderate to near or below normal by Monday. Across the western Great Plains, temperatures will warm significantly this weekend and by Monday could be 10 to 20 degrees above normal. Unsettled weather will continue through the weekend out west starting with a cold front crossing the Pacific Northwest states tonight and into the northern Intermountain West/Rockies tomorrow. Rain and higher elevation snows will accompany this system, some moderate accumulations possible in the higher elevations. The best chance for snow will be across parts of northwest Wyoming where as much as 1 to 2 feet of snow is possible through Monday. Yet another storm system will approach the West Coast on Monday, bringing a renewed round of rain and mountain snows for the beginning of the work week to Oregon and northern California. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php