Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 403 AM EDT Fri Sep 04 2020 Valid 12Z Fri Sep 04 2020 - 12Z Sun Sep 06 2020 ...Scattered severe thunderstorms and excessive rainfall expected across parts of the Upper Mississippi Valley Saturday... ...Heavy rainfall and localized flash flooding possible for parts of the Southern Plains... ...Record-setting heat and dry weather are expected to envelope much of the West going into the weekend... A slow-moving cold front draped from the Northeast to the South Plains will be a focus for Scattered showers and thunderstorms today and into Saturday. Very heavy rainfall rates that may exceed 2 inches per hour will be possible will keep concerns for flash flooding elevated for parts of southern Texas. The leading edge of the front will continue to press east across the eastern U.S. Showers and thunderstorms are expected along the front as it passes through the Mid-Atlantic and Southeast. Cooler and drier air will settle into the Midwest, Great Lakes and much of the Eastern U.S. this weekend. Temperatures will return to normal, or slightly cooler than average for early September. With high pressure sliding into behind the front, the cooler and drier airmass will reach the southern states by the end of the weekend/early next week. This will trigger some showers across the Gulf states/Gulf Coast. Another low pressure system will develop in the Northern Rockies Saturday morning and will cross out into the Plains Saturday afternoon and beyond. This system will set the stage for strong/severe thunderstorms that produce heavy rainfall across the Upper Mississippi Valley. SPC and WPC have Slight Risks for this region. Further West, hot and dry conditions will persist under the strong ridge. Near record, or record-breaking temperatures are forecast for a vast portion of the Western U.S. Some locations may record values upwards of 20 to 25 degrees higher than normal for this time of the year. Many areas across the Great Basin and especially the Desert Southwest could climb well above 100 degrees. Temperatures overnight are not likely to cool off much, and given the very dry airmass in place, this greatly increases the risk for the spread of wildfires. A large portion of the West/Southwest have Red Flag Warnings and Excessive Heat Warnings in effect. Low temperatures will be very warm across the area in and around the Carolinas, Southwest and Southeast tonight through Saturday night to the point that they might break records. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php