Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 348 AM EDT Sat Jul 24 2021 Valid 12Z Sat Jul 24 2021 - 12Z Mon Jul 26 2021 ...There is a Moderate Risk of excessive rainfall over parts of the Southwest through Sunday morning... ...There is a Slight Risk of severe thunderstorms over parts of the Great Lakes through Sunday morning... ...Excessive Heat Watch over parts of Idaho and eastern Oregon... Monsoonal moisture and upper-level energy will aid in producing showers and thunderstorms, some of which will produce heavy rain over the Southwest and the Central/Southern Rockies through Monday. Therefore, the WPC has issued a Moderate Risk of excessive rainfall with these thunderstorms. The associated heavy rain will create numerous areas of flash flooding. Furthermore, many streams may flood, potentially affecting larger rivers through Sunday morning. The excessive rainfall threat will continue from Sunday into Monday as the showers and thunderstorms remain with the monsoonal moisture. A front extending from the Upper Great Lakes southwestward to the Great Basin will move slowly to the Northeast Coast to the Ohio Valley by Monday. Showers and thunderstorms will develop along and ahead of the boundary over parts of the Great Lakes today. The SPC has issued a Slight Risk of severe thunderstorms over parts of the Great Lakes through Sunday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. While the severe thunderstorm risk weakens, these showers and thunderstorms will move into the Northeast and Mid-Atlantic on Sunday. This activity will continue to advance through the Northeast and into the Ohio/Tennessee Valleys on Monday. Additionally, tropical moisture over the Florida and Central Gulf Coast will spawn showers and thunderstorms over the region through Sunday. Meanwhile, there is an Excessive Heat Watch over parts of Idaho and eastern Oregon, where temperatures rise into the 100s through Sunday. The 100s will move into Northern Plains and Northern High Plains on Monday. Furthermore, Heat Advisories are currently in effect for portions of the Middle/Lower Mississippi Valley, while an Excessive Heat Warning affects the Kansas City metro area. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php