Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 349 AM EDT Fri Oct 01 2021 Valid 12Z Fri Oct 01 2021 - 12Z Sun Oct 03 2021 ...There is a Slight Risk of excessive rainfall over parts of the Southern Plains through Saturday morning... ...Temperatures will be 10 to 20 degrees above average over parts of the Northern High Plains and the Upper/Middle Mississippi Valley, including the Great Lakes... A quasi-stationary front will be over the Upper Midwest to the Southern Plains through Sunday. Additionally, an upper-level low positioned over the Southwest will slowly move northeastward to the Middle Mississippi Valley while weakening by Sunday. The circulation around the upper-level low will aid in streaming moisture over the Plains and Mississippi Valley and as far north as the Great Lakes. Showers and thunderstorms will develop along and near the boundary, with some storms producing heavy rain over the Southern Plains. Therefore, the WPC has issued a Slight Risk of excessive rainfall with these thunderstorms for much of central/eastern Texas and southern Oklahoma. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams the most vulnerable through Saturday morning. The threat of excessive rainfall will lessen slightly to a Marginal Risk of excessive rainfall over parts of the Middle Mississippi Valley to parts of the Southern Plains/Lower Mississippi Valley on Saturday into Sunday morning. The axis of showers and thunderstorms will move into the Great Lakes, extending southward across parts of the Ohio and Middle/Lower Mississippi Valleys by Sunday. Meanwhile, upper-level ridging ahead of this system will allow the temperatures to be 10 to 20 degrees above average over parts of the Northern High Plains, the Upper/Middle Mississippi Valley and the Great Lakes. In contrast, the temperatures over the Southern Rockies and Southern High Plains will be slightly below average. Elsewhere, Air Quality Alerts are up over parts of the San Joaquin Valley through Sunday. Ziegenfelder Graphics are available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php