Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 405 AM EDT Wed Jun 28 2023 Valid 12Z Wed Jun 28 2023 - 12Z Fri Jun 30 2023 ...There is a Slight Risk of severe thunderstorms over parts of the Upper Mississippi Valley on Wednesday, moving to the Middle Mississippi/Ohio Valleys on Thursday... ...Excessive Heat Watches/Warnings and Advisories over parts of the Southern Rockies, Southern Plains, Middle/Lower Mississippi Valley, Central Gulf Coast... ...Air Quality alerts over parts of the Upper/Middle Mississippi Valley, Great Lakes, Western Ohio Valley, Central Appalachians, and Mid-Atlantic... Persistent upper-level energy over the Northeast will trigger showers with embedded thunderstorms through Friday. Additionally, moisture streaming northward over the Mississippi Valley and upper-level energy will create showers and severe thunderstorms over parts of Wisconsin and southeastern Minnesota. Therefore, the SPC has issued a Slight Risk of severe thunderstorms over the Upper Mississippi Valley through Thursday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. Low pressure and a front over the Middle Mississippi Valley will produce showers and severe thunderstorms on Thursday. Therefore, the SPC has issued a Slight Risk of severe thunderstorms over parts of the Middle Mississippi/Western Ohio Valleys from Thursday into Friday 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 two-inch or greater hail over parts of the area on Thursday. Further, upper-level energy moves eastward over the Upper Midwest, producing showers and severe thunderstorms on Wednesday. Therefore, the SPC has issued a Slight Risk of severe thunderstorms over parts of the Upper Mississippi Valley from Wednesday into Thursday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. Meanwhile, upper-level impulses and an upper-level trough will trigger scattered showers and thunderstorms over parts of the Great Basin, Northern Intermountain Region, and the Northern Rockies on Wednesday, tapering off over the Northern Intermountain Region by Thursday morning. Moreover, upper-level energy moving eastward from California/Great Basin to Central Rockies/Central Plains will produce showers and thunderstorms over parts of the Great Basin, Northern/Central Rockies into parts of the Southern Rockies, and Northern/Central High Plains from Thursday evening into Friday. Furthermore, wildfire smoke from Canada will reduce air quality over parts of the Upper/Middle Mississippi Valley, Great Lakes, Western Ohio Valley, Central Appalachians, and Mid-Atlantic, prompting Air Quality Warnings over the area. Lastly, upper-level ridging over the south-central portion of the country will expand northward into the Middle Mississippi Valley bringing with the ridge hot high temperatures and temperatures not cooling off much overnight, which have contributed to Excessive Heat Warnings and Heat Advisories over most of Texas, southern New Mexico, southeastern Oklahoma, eastern Kansas, Missouri, southern Arkansas, Louisiana, and southern Mississippi. Also, Excessive Heat Watches are over parts of southern Illinois, Western Tennessee, Mississippi, and Alabama. Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php