Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 339 AM EDT Sun Aug 30 2020 Valid 12Z Sun Aug 30 2020 - 12Z Tue Sep 01 2020 ...Heavy rainfall and flash flooding possible across parts of the Tennessee/mid-Mississippi Valleys, with additional heavy rains across the Mid-Atlantic on Monday... ...Severe weather and heavy rainfall a threat on Sunday for the north-central U.S., while much below normal temperatures overspread the Northwestern U.S.... ...Locally heavy rain could cause flash flooding in portions of the Southwest while fire weather threats continue across the central Great Basin... A stalled frontal boundary draped from the Tennessee Valley back into the middle Mississippi Valley will continue to provide a focus for showers and thunderstorms the next couple of days. Heavy rainfall is possible, which would elevate the flash flood threat, especially considering much of this region is already saturated after former tropical cyclone Laura moved through last week. A surface low riding along this boundary is forecast to lift towards the Mid-Atlantic states by Monday, with another round of moderate to heavy rainfall and flash flood potential across portions of the interior Mid-Atlantic and central Appalachians. By Tuesday, a second cold front approaching from the west will increase chances for heavy rainfall and severe weather again across parts of the south-central Plains. A strong cold front pushing eastward across the northern Plains today (Sunday) will bring with it a chance for heavy rainfall and severe weather, with showers and storms pushing into the Upper Midwest by Monday. Both SPC and WPC highlight marginal to slight risks for severe thunderstorms and flash flooding, respectively. Behind the front, a much cooler airmass will be ushered in across the northern Rockies and northern/central Plains, with daytime highs 10 to 20 degrees below normal. Meanwhile, across the southern High Plains, triple digit heat will continue on Sunday, with some easement of the heat expected by Monday. Meanwhile, monsoonal moisture streaming into the Southwestern states could cause locally heavy rainfall and the possibility of flash flooding the next few days. To the north, dry and windy conditions will contribute to elevated to critical fire weather threats across portions of the Great Basin and into the Central Rockies, especially by Monday following the cold frontal passage. Red flag warnings are widespread throughout this region. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php