Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 347 PM EDT Fri Sep 20 2019 Valid 00Z Sat Sep 21 2019 - 00Z Mon Sep 23 2019 ...There is a slight risk of excessive rainfall over parts of the Upper Midwest and parts of the Southern Plains... ...There is a slight risk of severe thunderstorms over parts of the Northern Plains/Central High Plains... ...Isolated early season snow likely across parts of the Northern Rockies... Moisture associated with what was once Tropical Depression Imelda will still bring heavy rain and scattered localized areas of flash flooding to portions of the Southern Plains. A Slight Risk of excessive rainfall is in effect, where 1 to 3 inches of rain is forecast. This comes after over 40 inches of rain fell in parts of southeast Texas during the last four days. Meanwhile, a low pressure system over the Northern Plains will move northeastward into Ontario overnight Saturday into Sunday. An associated cold front will move into the Plains tonight and move to the Upper Great Lakes southwestward to the Southern High Plains by Sunday. The boundary will produce showers and thunderstorms in the Northern/Central Plains Friday night into Saturday. Some of the storms could be severe, with frequent lightening, large hail, damaging winds, and a couple of tornadoes possible are the primary threats. The Storm Prediction Center has issued a Slight Risk for severe thunderstorms across the Northern Plains into parts of the Central High Plains. Areas of scattered localized flash flooding will also be possible with these storms, over parts of the Upper Midwest. Colder air will continue to push through the western states behind the cold front, and this is expected to lead to isolated areas of accumulating snow in the higher elevations of the interior North Rockies. Winter Weather Advisories have been issued across these regions, where up to a foot of snow is possible. High temperatures will be as much as 15-25 degrees below average in these areas. Ahead of the cold front, high temperatures will be above average in the Plains and Central U.S., with the warmth spreading to the East Coast this weekend. Temperatures may produce record breaking high low night time temperatures over parts of the Upper Midwest. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php