Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
503 FXUS64 KMRX 291122 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 722 AM EDT Tue Sep 29 2026 ...New AVIATION... .KEY MESSAGES... Updated at 636 AM EDT Tue Sep 29 2026 - A notable warm up begins today and continues through Thursday, with temperatures rising into the mid to upper 80s by Wed and Thu across low elevation areas. - Low rain chances start to creep in by Friday but Saturday and Sunday have potential for heavy rain at times. && .DISCUSSION... Issued at 122 AM EDT Tue Sep 29 2026 In the upper levels, a ridge will be over the Tennessee and Ohio River Valleys. A trough remains over New England. A closed low over the Southwest is drifting eastward very slowly. At the surface, weak high pressure will be centered near the Carolinas. Ridging and high pressure through Thursday will bring dry, sunny weather along with a warming trend. Expect highs in the 80s for the rest of the workweek (around 90 degrees near Chattanooga). By Friday, a ridge will be centered near FL/GA/SC as a trough dips into the Ohio Valley. The position of the ridge and surface high to the southeast will supply deep layer moisture from the Gulf into the Tennessee Valley. Rain chances start to increase on Friday but higher chances are likely on Saturday as a slow moving cold front moves into the region. This boundary will likely linger over the region through Sunday before a shortwave finally pushes it through late Sunday. Confidence is increasing in heavy rain potential. Rain totals of 2 to 3 inches will be possible this weekend. Flooding potential will likely be low as dry as it has been but some minor issues cannot be ruled out. On Monday, rain chances will likely taper off as the system moves out and high pressure moves in from the north. Highs will be cooler in the 70s for Monday. && .AVIATION... (12Z TAFS) Issued at 636 AM EDT Tue Sep 29 2026 It will be a mostly persistence forecast. Brief fog to start at TRI, and fog looks likely again at the end of the period. Otherwise, will have a VFR forecast all sites. Winds will generally be light. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 86 57 90 62 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 84 56 87 59 / 0 0 0 0 Oak Ridge, TN 83 55 85 59 / 0 0 0 0 Tri Cities Airport, TN 79 54 83 56 / 0 0 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...McD AVIATION...99