Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 356 PM EDT Thu Apr 27 2017 Valid 00Z Fri Apr 28 2017 - 00Z Sun Apr 30 2017 ...Heavy rain likely for portions of the Southern Plains, lower/middle Mississippi Valley, and the Southern Ohio/Tennessee Valleys... ...Heavy snow likely over parts of the Northern/Central Rockies... A low pressure system tracking through the Southern/Central Rockies will generate snow across portions of the Northern/Central Rockies...likely producing heavy amounts over the favored upslope regions of Montana, Wyoming and Colorado. Showers and thunderstorms will develop across the Southern and Central Plains as the front pushes out into the Plains/lower Mississippi Valley, linking up with another boundary lifting through the lower Mississippi Valley and Gulf states. Showers and thunderstorms are also expected along and ahead of the front moving through the Great Lakes, Ohio Valley, the Northeast and Mid-Atlantic Coast through late Friday afternoon. As cold air filters into the northern states, snow will develop over parts of the Upper Mississippi Valley into parts of the Upper Great Lakes ending by Friday morning. The event setting up over the south-central U.S. will be a significant rain producer and will likely lead to rapid run off into local streams and rivers. Widespread flooding may result from the forecast excessive rainfall over this region. Elsewhere, onshore flow will aid in producing rain and higher elevation snow over parts of the Pacific Northwest on Thursday into early Friday morning. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php