Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 433 AM EDT Thu Aug 13 2020 Valid 12Z Thu Aug 13 2020 - 12Z Sat Aug 15 2020 ...There is an enhanced risk of of severe thunderstorms and a slight risk of excessive rainfall over parts of the Upper Mississippi Valley... ...A Slight Risk of excessive rainfall over parts of the Mid-Atlantic and Lower Mississippi Valley... ...Elevated fire weather conditions & Excessive Heat Warnings are in effect over portions of the Western U.S through Thursday... ...Record heat from the Southern Plains into the Southwest possible through Friday... A front will become quasi-stationary over the Northeast/Mid-Atlantic into the Ohio Valley into Friday, before sagging southward late Friday as high pressure builds southward from eastern Canada. High moisture air will pool along the front, which when lit by daytime heating sparks showers and thunderstorms near and south of the boundary with potentially heavy rainfall. A Slight Risk of excessive rainfall exists over the Mid-Atlantic through Friday morning due to recent and expected heavy rainfall, the Slight Risk means there will be mainly localized scattered flash flooding over the region. A slowly moving cold front is expected to produce windy conditions, but little precipitation, which will factor into elevated to critical fire weather conditions Thursday and Friday across portions of the Northwest, Northern Rockies and Great Basin. Red Flag Warnings are in effect for many of these areas. Meanwhile, potentially record heat spreads westward from the Southern Plains through the Southwest into California. Excessive Heat Watches and Warnings have been posted for portions of California and the Southwest. High temperatures above 105 degrees should be commonplace, with Death Valley itself likely to reach the mid 120s; record highs are possible across these areas. The aforementioned front over the Northern Rockies movies into the Northern Plains, moisture in advance of the slow moving front will aid in producing showers and thunderstorms with heavy rainfall across the Northern Plains and the Upper Mississippi. The SPC has issued an enhanced risk of of severe thunderstorms and the WPC Slight Risk of excessive rainfall over parts of the Upper Mississippi Valley. The severe thunderstorm hazards are dangerous lightning, severe thunderstorm wind gust, large hail, and a few tornadoes over the Upper Mississippi Valley through Friday morning. The associated heavy rain will produce mainly localized scattered flash flooding over the area through Friday morning. A third area of Slight Risk of excessive rainfall will be over parts of the Lower Mississippi Valley where showers and thunderstorms will produce heavy rain which in turn will produce mainly localized scattered flash flooding over the Lower Mississippi Valley also through Friday morning. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php