


Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
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440 FXUS64 KMRX 292342 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 742 PM EDT Fri Aug 29 2025 ...New AVIATION... .DISCUSSION... Issued at 133 PM EDT Fri Aug 29 2025 Key Messages: 1. Slight moderation in temperatures this weekend before another cool down Monday into the rest of next week. 2. Mostly dry for valley locations through the weekend, with isolated to scattered activity focused along higher terrain, especially Sunday. 3. Scattered afternoon and evening precipitation chances return Monday through much of the upcoming week. Discussion: Currently we are situated underneath northwest flow on the western side of a trough axis extending from the eastern Great Lakes region to the mid Atlantic Seaboard. A dry continental air mass and surface high pressure will continue to promote mostly dry conditions through Saturday as a stationary boundary remains suppressed to the Gulf Coast. Isolated diurnal activity cannot be ruled out across higher terrain of SW NC or the E TN mountains Saturday afternoon, but valley locations will remain precip free. As we head into Sunday, a reinforcing shortwave will swing through the Ohio River Valley. Expect most valley locations to remain dry once again, but coverage of convection will be more scattered across the mountains and into SW VA(30-50% probabilities) owing to a vort max and jet coupling aloft. NAMBufr soundings depict MLCAPE less than 1000J/kg and PWAT values around 1.2", which is below the mean value for this time of the year per SPC sounding data out of KBNA. No sig weather is expected as a result. Though, if spending time in vicinity of the higher terrain for the holiday weekend be prepared for brief downpours and/or bouts of lightning to potentially interrupt outdoor activities. Saturday and Sunday will also experience temperatures a tad closer to seasonal norms. For Labor Day, an additional shortwave will be progressing into the Ozarks and broadening the troughing influence across the southeastern United States. A return of cooler temperatures and increasing chances of precipitation is expected areawide. This pattern will persist through much of the work week, with precipitation chances peaking during the afternoon and evening hours each day. The exact timing and coverage of activity may be dependent on how exactly shortwave impulses translate through mean flow aloft, with potential for a greater coverage of activity in the Wed/Thu timeframe associated with a more prominent shortwave and associated frontal passage. && .AVIATION... (00Z TAFS) Issued at 738 PM EDT Fri Aug 29 2025 VFR can be expected with mid to high clouds and light winds generally out of the north and northeast. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 61 88 62 85 / 0 0 0 10 Knoxville McGhee Tyson Airport, TN 60 85 61 84 / 0 0 0 10 Oak Ridge, TN 59 85 60 84 / 0 0 0 10 Tri Cities Airport, TN 55 82 57 80 / 0 0 0 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...KRS AVIATION...KS