Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 345 PM EDT Thu Aug 29 2024 Valid 00Z Fri Aug 30 2024 - 00Z Sun Sep 01 2024 ...Record heat continues across the Ohio Valley into the Southern Appalachians through Friday, with relief on tap for the weekend... ...Much above average temperatures build across the Pacific Northwest, Northern Great Basin and into the Northern Rockies... ...Active thunderstorms expected along and ahead of a strong front pushing from the Upper to Mid Mississippi Valley into the Ohio Valley and across the Central to Southern Plains, producing heavy rains, flooding and severe weather... ...Heavy rains and isolated flooding possible along the Louisiana and upper Texas coasts... The recent period of much above average /record high temperatures from the Ohio Valley into the Southern Appalachians will be continuing through Friday. High temperatures are expected to be 10 to 15 degrees above average through Friday, supporting the potential for additional record high temperatures Thursday and Friday from southern Ohio into southern Indiana, much of Kentucky, eastern to central Tennessee and far western North Carolina. The combination of the hot temperatures and high humidity levels will produce major heat risks with maximum heat indices in the 100 to 110 degree range. The current record high temperature streak, will however, be coming to an end on Saturday when cooler temperatures are expected as cloud cover and precipitation move in ahead of a strong cold front. Much above average temperatures will also be building across the Pacific Northwest, Northern Great Basin into the Northern Rockies Friday and Saturday as a mid to upper level ridge strengthens across this region. These hot temps will likely continue into Sunday before cooling begins early next week. At the moment, however, it does not appear that these much above average temperatures will produce any record highs. The strong front bringing relief to record high temps over the Ohio Valley into the Southern Appalachians will first be pushing southeastward over the next two days from the Upper Mississippi Valley into the Great Lakes and southward into portions of the Central to Southern Plains. Active thunderstorms with heavy rains, localized flooding and severe weather are possible late Thursday afternoon into Thursday night/early Friday morning across the Upper to Mid Mississippi Valley into portions of the Central to Southern Plains along and ahead of this strong front. These active thunderstorms are then expected to flare again Friday into early Saturday across the Lower Great Lakes into the Ohio Valley with additional potential for heavy rains, localized flash flooding and severe weather. Heavy rains and localized flooding also possible across portions of the Central Appalachians into the Mid Atlantic Thursday afternoon into Thursday night along a stationary front across this region and then again late Saturday afternoon into Saturday night ahead of the above mentioned strong front moving southeastward from the Lower Lakes/Ohio Valley region. An area of much above average moisture values is expected to remain nearly stationary over the next few days across the western to central Gulf of Mexico. A weak mid to upper level disturbance embedded in this high moisture axis will likely produce heavy rainfall amounts along the Louisiana coast, westward to the Upper Texas coast. Rainfall totals of 3-5" possible over the next few days, with additional heavy rains into the end of the weekend and early next week also possible as the weak mid to upper level disturbance and axis of much above average moisture are not expected to move appreciably. Oravec Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php