Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 342 AM EDT Mon May 15 2017 Valid 12Z Mon May 15 2017 - 12Z Wed May 17 2017 ...Heavy precipitation possible over parts of the Cascades... ...Heavy rain possible over portions of the Southern/Central Plains and the of the Upper Midwest... ...Slight chance for severe thunderstorms from the Southern Plains to the Upper Midwest... Much of the northern-tier will be in an active wet pattern as a couple of lows rotate through the the upper-level trough moving through the West. Rain and higher elevation snow will spread across parts of the Pacific Northwest and northern California eastward into parts of the Northern Rockies as an approaching frontal system tracks across the Pacific Northwest/Intermountain West. Portions of the Cascades could have periods of heavy precipitation during this time. For areas east of the Continental Divide, scattered to numerous showers and thunderstorms will develop from the Southern High Plains to the Upper Midwest/Great Lakes region as surface front moves out into the Plains and lifts northeast through the Upper Midwest into Canada by midweek. Any one of these thunderstorms will have the potential to become strong or severe. The Storm Prediction Center has highlight much of the High Plains and portions of the Upper Midwest as having a slight risk for severe weather. Please refer to the SPC webpage for additional information on the slight risk. A reinforcing shot of cooler air will surge into the Northern High Plains which will keep showers and thunderstorms over much of the north-central U.S. Embedded areas of heavy rainfall will likely set up over portions of Minnesota, Wisconsin and northern Michigan and may lead to rapid runoff and flash flooding. This particular region has forecast amounts of 3 to 4 inches. Elsewhere, an upper-level low over the Great Lakes/Northeast will slowly move off the Northeast Coast and move to the Canadian Maritimes by Tuesday. Rain will develop over the Northeast that will slowly diminish to a small area over Northern Maine by Tuesday morning. Additionally, upper-level energy over the Florida Peninsula will aid in producing showers and thunderstorms over parts of the southern tip of Florida through Tuesday. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php