Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 351 AM EDT Sat Jun 24 2023 Valid 12Z Sat Jun 24 2023 - 12Z Mon Jun 26 2023 ....There is a Slight Risk of excessive rainfall over parts of the Northern Plains and Upper Mississippi Valley... ...There is a Slight Risk of severe thunderstorms over parts of the Middle Mississippi Valley on Saturday and over the Ohio/Tennessee Valleys on Sunday... ...Excessive Heat Warnings and Heat Advisories over southern Texas and New Mexico... ...Air Quality alerts over parts of the Upper Midwest and the Ohio Valley... A front extending from parts of the Upper Great Lakes to the Plains will move eastward to the Ohio Valley/Southern Plains by Monday. The boundary will produce showers and thunderstorms with heavy rain over parts of North/South Dakota, Minnesota, and Wisconsin. Therefore, the WPC has issued a Slight Risk of excessive rainfall over parts of the Northern Plains and Upper Mississippi Valley through Sunday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams the most vulnerable. Moreover, the front over parts of Iowa and Missouri will create showers and severe thunderstorms over the area. Therefore, the SPC has issued a Slight Risk of severe thunderstorms over parts of the Middle Mississippi Valley. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. Additionally, there is a threat of severe thunderstorm wind gusts of 65 knots or greater over parts of the region through Sunday morning. Furthermore, the threat of excessive rainfall decreases slightly over the Great Lakes and Ohio Valley on Sunday. Therefore, the WPC has issued a Marginal Risk of excessive rainfall over parts of the Great Lakes, Ohio Valley, Tennessee Valley, and Lower Mississippi Valley from Sunday into Monday morning. The associated heavy rain will create localized areas of flash flooding, affecting areas that experience rapid runoff with heavy rain. Further, the threat of severe thunderstorms moves eastward and continues over parts of Indiana, Ohio, Kentucky, and Tennessee on Sunday. Therefore, the SPC has issued a Slight Risk of severe thunderstorms over parts of the Ohio/Tennessee Valleys from Sunday through Monday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. Additionally, there is a threat of severe thunderstorm wind gusts of 65 knots or greater over parts of the region through Monday morning. Meanwhile, upper-level energy over the Northeast/Mid-Atlantic moves slowly northeastward into Southeastern Canada by Monday. The energy and deep moisture will produce showers and thunderstorms over parts of the Ohio Valley, Mid-Atlantic, Central Appalachians, and Northeast through late Saturday evening. On Sunday, the energy will produce showers and thunderstorms over parts of the Northeast and northern Mid-Atlantic. Upper-level impulses and a developing upper-level trough will also trigger scattered showers and thunderstorms over parts of the Great Basin and Pacific Northwest on Saturday, continuing into Monday. Furthermore, an upper-level high over Northern Mexico, western Texas, and New Mexico, along with high temperatures and temperatures not cooling off much overnight, have contributed to Excessive Heat Warnings and Heat Advisories over southern/western Texas, southern New Mexico, eastern Oklahoma, and southwestern Louisiana. Lastly, smoke from wildfires in Canada will reduce air quality over parts of the Upper Midwest and the Ohio Valley prompting Air Quality Warnings over the area. Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php