Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 342 AM EDT Tue Jun 22 2021 Valid 12Z Tue Jun 22 2021 - 12Z Thu Jun 24 2021 ...There is a Slight Risk of excessive rainfall over parts of the southern Mid-Atlantic to the Eastern Gulf Coast through Wednesday morning... ...There is a Slight Risk of severe thunderstorms over parts of the Central Plains and the Middle Mississippi Valley through Wednesday morning... ... Fire weather conditions forecast across the Great Basin... A front extends from the Northeast roughly southwestward to the Southern Plains, moves eastward off the Northeast Coast by Tuesday evening and off most of the Southeast Coast by Wednesday morning. High moisture content air will be pooling along the boundary helping produce showers and thunderstorms along and ahead of the front through late Tuesday night. The WPC has issued a Slight Risk of excessive rainfall with these thunderstorms over parts of the southern Mid-Atlantic to the Eastern Gulf Coast through Wednesday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams the most vulnerable through Wednesday morning. On Wednesday, the excessive rainfall threat lessens as showers and thunderstorms continue along the Gulf Coast and parts of the Southeast into Thursday morning. Additionally, a weak warm front over the Northern/Central Plains will move eastward and dissipate overnight Tuesday. The boundary will produce showers and thunderstorms over parts of the region. The SPC has issued a Slight Risk of severe thunderstorms over parts of the Central Plains and the Middle Mississippi Valley through Wednesday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, and hail. The severe thunderstorm threat weakens on Wednesday. Meanwhile, a plume of moisture surges into the Southwest and Southern California through Thursday morning. Impulses of upper-level energy moving around an upper-level high over the U. S. and Mexican border will trigger showers and thunderstorms over parts of Southern California and the Southwest early Wednesday morning. The showers and thunderstorms will expand into parts of the Great Basin and the Central/Southern Rockies through Thursday morning. Arid soils, downslope wind, low relative humidity, and gusty wind, along with dry thunderstorms, will create conditions favorable for Elevated and Critical Risk of fire weather across parts of the Great Basin and Southwest. Furthermore, a front moving southward out of South-Central Canada on Wednesday will move to parts of the Upper Midwest by Thursday. The boundary will trigger showers and thunderstorms over parts of the Upper Midwest Wednesday into Thursday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php