Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 351 PM EDT Sat Apr 29 2017 Valid 00Z Sun Apr 30 2017 - 00Z Tue May 02 2017 ...Severe thunderstorms and flash flooding threats will continue through portions of the southern Plains to the mid-Mississippi and Ohio valleys... ...Snow will be possible for portions of the northern/central Rockies and the adjacent High Plains in addition to the Upper Midwest... ...Above average temperatures expected for much of the eastern U.S... The frontal boundary which has given way to flash flooding and severe weather across the southern Plains and middle Mississippi Valley will slowly lift north and east over the next few days. An upper level low is expected to deepen as it moves across the southern and central Plains. This will continue sustaining deep southerly flow throughout the southern Plains/Southeast and will tap into copious amounts of moisture from the Gulf of Mexico. Meanwhile, a frontal boundary at the surface will be a focal point for convection--setting off slow moving thunderstorms that will produce flash flooding and severe weather. A high risk for flash flooding will still be present through Sunday morning as the front meanders eastward toward the Mississippi Valley in addition to an enhanced risk of severe weather. Once the upper level low moves toward the Upper Midwest by Sunday, the cold front will progress toward the Southeast. Showers and thunderstorms are expected to move along this front and once again will bring the threat of flash flooding and severe weather throughout Sunday. By Monday, precipitation will continue along the front from the Northeast southward to Florida; however, the flash flooding and severe weather threat will not be as potent. See the Storm Prediction Center for specific information on the severe weather threats with this system (www.spc.noaa.gov). Snow will spread from the central and southern Rockies to the central High Plains tonight and into tomorrow as the low pressure lifts north and east. With this northeastward movement, snow will spread into the northern Plains and Upper Midwest by Sunday night and into Monday. A weakening frontal system will bring precipitation to the Pacific Northwest later on today and into Sunday. Rain and higher elevation snow is expected to only last for a day--once the front moves toward the Intermountain West/High Plains on Monday morning, most of the precipitation in the Pacific Northwest region will taper off. Reinhart Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php