Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 406 AM EDT Tue Jul 16 2024 Valid 12Z Tue Jul 16 2024 - 12Z Thu Jul 18 2024 ...There is a Slight Risk of severe thunderstorms over parts of the Central/Southern Plains and Northeast/Mid-Atlantic/Central Appalachians on Tuesday and the Mid-Atlantic to New England on Wednesday... ...There is a Slight Risk of excessive rainfall over parts of the Central/Southern High Plains roughly eastward to the Ohio Valley on Tuesday and the Southern Rockies, Lower Mississippi Valley, and Central Appalachians on Wednesday... ...There are Excessive Heat Warnings/Watches and Heat Advisories over parts of the Pacific Northwest and parts of the Southern Plains to the Middle/Lower Mississippi Valley, Ohio/Tennessee Valleys, and Central Gulf Coast... A front extending from the Great Lakes/Ohio Valley across the Middle Mississippi Valley into the Central Plains will move slowly to the Northeast, Mid-Atlantic/Central Appalachians across the Lower Mississippi Valley, and then into the Southern Plains by Thursday. The boundary will produce showers and severe thunderstorms over the Northeast/Mid-Atlantic/Central Appalachians. Therefore, the SPC has issued a Slight Risk (level 2/5) of severe thunderstorms over parts of the Northeast/Mid-Atlantic/Central Appalachians through Wednesday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. A Second area of showers and severe thunderstorms will develop over parts of the Central/Southern Plains. Therefore, the SPC has issued a Slight Risk (level 2/5) of severe thunderstorms over parts of the over parts of the Central High Plains from Tuesday through Wednesday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. In addition, the showers and thunderstorms will create heavy rain over parts of the Central/Southern High Plains roughly eastward to the Ohio Valley. Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive rainfall over parts of the Central/Southern High Plains eastward to the Ohio Valley through Wednesday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, and low-lying areas the most vulnerable. Moreover, moisture over the Southwest and diurnal heating will produce late afternoon into late evening showers and thunderstorms over parts of the Great Basin, Southwest, and Central/Southern Rockies. Furthermore, on Tuesday, upper-level energy and tropical moisture will produce showers and thunderstorms from parts of the Central Gulf Coast eastward to the Southeast. On Wednesday, as the front moves eastward, showers and severe thunderstorms will develop over parts of the Eastern Ohio Valley, Lower Great Lakes, Central Appalachian, Mid-Atlantic, and Northeast. Therefore, the SPC has issued a Slight Risk (level 2/5) of severe thunderstorms over parts of the over parts of the Mid-Atlantic to New England from Wednesday through Thursday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, and a minimal threat of hail and tornadoes. Furthermore, showers and strong to severe thunderstorms will develop over parts of the Central/Southern High Plains. Areas along the front will produce heavy rain over parts of the Lower Mississippi Valley. Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive rainfall over parts of the Lower Mississippi Valley and adjacent parts of the Southern Plains and Tennessee Valley from Wednesday through Thursday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, and low-lying areas the most vulnerable. A second area of heavy rain will develop over parts of the Central Appalachians. Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive rainfall over parts of the Central Appalachians from Wednesday through Thursday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, and low-lying areas the most vulnerable. In addition, moisture from the Gulf of Mexico will extend northwestward into the Southern Rockies, producing heavy rain. Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive rainfall over parts of the Southern Rockies from Wednesday through Thursday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, and low-lying areas the most vulnerable. Also, on Wednesday, upper-level energy and tropical moisture will produce showers and thunderstorms over parts of the Central Gulf Coast to the Southeast. Further, moisture over the Southwest and the Central/Southern Rockies, along with diurnal heating, will produce late afternoon into late evening showers and thunderstorms over parts of the Great Basin, Southwest, and Central/Southern Rockies. Furthermore, on Wednesday, upper-level energy moving over parts of the Pacific Northwest will produce rain with embedded thunderstorms over the area. Meanwhile, upper-level ridging will build over the Northwest, spawning Heat Advisories over the region from Tuesday into Thursday. Moreover, a flat upper-level ridge extending from the Lower Mississippi Valley eastward to the Mid-Atlantic and Southeast will aid in creating a major to extreme HeatRisk for the East part of the country. The developing heat has prompted Excessive Heat Warnings/Watches and Heat Advisories over parts of the Southern Plains to the Middle/Lower Mississippi Valley, Ohio/Tennessee Valleys, and Central Gulf Coast. The near-record temperatures and high humidity suggest Major to Extreme HeatRisk conditions for portions of the East, Tuesday and Wednesday. Extremely dangerous and potentially deadly heat, particularly for urban areas in the Southeast and East Coast, are forecast. Many daily record highs are possible for the East Coast, and numerous warm overnight lows will provide little relief from the heat overnight. Heat stress will build rapidly for those without adequate cooling or hydration. Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php