Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 356 PM EDT Sat Sep 05 2020 Valid 00Z Sun Sep 06 2020 - 00Z Tue Sep 08 2020 ...There is an enhanced risk of severe thunderstorms and a slight risk of excessive rainfall over parts of the Upper/Middle Mississippi Valley... ...Potentially record breaking heat in the West... ...Critical conditions for wildfires persist across the West, Northern/Central Rockies/Plains... A developing strong storm over the Northern Plains will produce showers and thunderstorms overnight Saturday and continue into the Great Lakes on Sunday into Monday morning. The SPC has issued an enhanced risk of severe thunderstorms over Upper/Middle Mississippi Valley through Sunday morning with a slight risk surrounding the area. The main hazards associated with the severe thunderstorms are strong thunderstorm wind gust, large hail with a 10 % probability of two inches or greater. The WPC has issued a slight risk of excessive rainfall over the most of the same area through Sunday morning. The heavy rain associated with the severe thunderstorms will produce mainly localized scattered areas of flash flooding. Strong high pressure over Western Canada begin to move over the Northern High Plains on Sunday into Monday. Upslope flow associated with the high pressure will aid in producing rain over the Northern High Plains expanding into the Northern Rockies and the Northern High Plains on Monday that will expand into the Upper Midwest by Monday evening. Cold air will move over the Upper Midwest bringing much below average temperatures for the next several days. Meanwhile, scattered showers and thunderstorms will be possible through the weekend along the Gulf Coast and across parts of Texas and Florida as the front slowly descends from the north and slows. Across the West, hot and dry conditions will persist thanks to the ridge parked over the western states. Daily temperatures for some locations may reach 20 to 30 degrees above average, which would be daily highs in the upper 90s to triple digits. These values may tie or establish new daily records. Lows will be in the upper 70s in Florida this weekend which may break records across the state. Overnight low temperatures will struggle to cool down, relative humidity/dewpoints will likely not be able to recover. These means that fuels (grass, trees, shrubs, dried leaves etc) will be very dry and slightest of sparks could cause a wildfire that quickly spreads out of control. The fire risk remains elevated as dry and windy conditions will continue for the region through the weekend. A vast portion of California, Great Basin, Intermountain West and the Northern/Central High Plains have Excessive Heat Warnings, Heat Advisories and Red Flag Warnings in effect. Several large wildfires across the region are also causing areas to have hazy skies and reduced/poor air quality. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php