Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 404 PM EDT Tue May 26 2020 Valid 00Z Wed May 27 2020 - 00Z Fri May 29 2020 ...There is a slight risk of severe thunderstorms and excessive rainfall over parts of the Upper/Middle Mississippi Valley... ...Temperatures will be 10 to 15 degrees above average for parts of the California, The Great Basin, and the Southwest as well as parts of the Northeast... A quasi-stationary front over the Mississippi Valley will produce showers and thunderstorms over parts of the Upper/Middle Mississippi Valley on Tuesday into Wednesday morning. The SPC has issued a slight risk of severe thunderstorms over the area with hazards of damaging thunderstorm wind, tornadoes, and hail. Heavy rain associated with these thunderstorms are expected and the WPC has issued a slight risk of excessive rainfall over parts of the Upper/Middle Mississippi Valley. The heavy rain will produce mainly localized scattered flash flooding. The severe thunderstorms will shift to the Southern Plains on Wednesday into Thursday morning. Low pressure will lift northeastward across Florida on Tuesday evening into Wednesday. The WPC has issued a small slight risk of excessive rainfall associated with this low through Wednesday morning. The heavy rain associated with the low is expected to produce scattered flash flooding over parts of the southern section of the Florida peninsula Tuesday afternoon and evening. The upper-level ridging in the West and another ridge over the Northeast will allow temperatures to be greater than average. With the heat forecast to persist in California, and widespread temperatures over 100 degrees are forecast in central parts of the state. The potentially record-setting high temperatures should spread eastward into the Great Basin and Southwest on Wednesday. Excessive Heat Warnings and Heat Advisories are in effect. Meanwhile, the Lower Great Lakes into parts Northeast will expect high temperatures 10 to 15 degrees above average through Wednesday, as temperatures approach or even exceed 90 degrees. Rain and cloudiness will keep temperatures more moderate from Southeast Coast into the Southern Mid-Atlantic. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php