Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 353 AM EDT Sat Sep 21 2019 Valid 12Z Sat Sep 21 2019 - 12Z Mon Sep 23 2019 ...Severe thunderstorms and flash flooding possible this weekend from the Central Plains to the Midwest... ...Below average temperatures continue across the Northwest, while above average temperatures are found in the East... A potent low pressure system will continue pushing across the Northern Plains today and will enter Ontario overnight Saturday. Meanwhile, an associated cold front is forecast to move eastward through the northern and central Plains this weekend, before entering the Great Lakes and Southern Plains by late Sunday. This boundary will produce showers and thunderstorms in the Upper Midwest and Central Plains/Mid Missouri Valley today. Some of the storms could be severe, with frequent lightning, large hail, damaging winds, and a couple of tornadoes possible. The Storm Prediction Center has issued a Slight Risk for severe thunderstorms across northern Minnesota, as well as an area stretching from central Kansas to Iowa. Flash flooding will also be possible, particularly across northeast Kansas and northern Missouri. A Moderate Risk of excessive rainfall has been issued for this region, where 2 to 4 inches of rain is possible by Monday morning. Colder air will continue to linger across the western states behind the cold front, with temperatures running 10 to 20 degrees below average for this time of year on Saturday. These cold temperatures will allow for snow to fall above 7000 feet across portions of Wyoming and Montana today. Winter Weather Advisories and Winter Storm Warnings have been issued across these regions, where up to a foot of snow is possible. Temperatures will moderate slightly on Sunday across the Northwest, but will still remain below average. Ahead of the cold front, temperatures will run as much as 15 degrees above average across the Great Lakes and eastern U.S. through the weekend. This equates to widespread high temperatures in the 80s and low 90s, with overnight lows only dropping into the 60s. Snell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php