Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
333 FXUS64 KMRX 051754 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 154 PM EDT Sun Oct 5 2025 ...New DISCUSSION... .KEY MESSAGES... Updated at 132 PM EDT Sun Oct 5 2025 - Dry weather will continue through Monday. A 40-70% chance for showers and a few storms make a return Tuesday and Wednesday. - Temperatures will begin the period unseasonably warm. Temperatures 5 to 10 degrees above normal. More seasonal conditions are anticipated by the latter half of the week. && .DISCUSSION... Issued at 132 PM EDT Sun Oct 5 2025 Currently, increasing moisture and isentropic lift is spreading cloud cover into southeast Tennessee, southern Plateau, and far east Tennessee mountains. HREF, REFS, and latest GFS show a chance of light showers or sprinkles over southeast Tennessee. Probabiliy of measurable precipitation is quite low. Otherwise, increasing clouds is expected. For tonight and Monday, upper and surface ridging will remain over the southern Appalachians. Easterly flow in much of the southern Appalachians will produce downslope into much of the region except for possibly the southeast. For Monday night through Wednesday, ensemble cluster analysis and deterministic models show ridging weakening and forced south as a series of short-waves and associated moves across the Ohio valley. As an upper trough moves into the northeast/mid-Atlantic states by Wednesday associated frontal boundary will move into the Tennessee valley and southern Appalachians. Jet dynamics, fronto-genetic forcing, and leading isentropic lift will produce an increasing chance of showers from Tuesday through Wednesday. Ensemble CAPE shows values of 500-700 so enough instability for a chance of thunderstorms. Environment is not supportive of strong to severe storms. Due to proximity of stronger forcing over the Ohio valley, the greatest QPF will be over southwest Virginia and northern sections of Tennessee where amounts of 0.50-0.75 inch expected. For areas along and south of interstate 40, 0.25-0.5 inch anticipated. For Thursday, an inverted surface trough is expected over the area with a chance showers mainly for areas along and south of interstate 40. Confidence is low. For Friday into next weekend, ensemble analysis and deterministic models are in disagreement and forecast confidence is low. Currently, greatest probability is for dry northwest and surface ridging producing dry conditions. && .AVIATION... (18Z TAFS) Issued at 110 PM EDT Sun Oct 5 2025 Southeast flow into the southern Appalachians is producing isentropic lift with increasing clouds and showers noted across northern Georgia. CHA and TYS could see a light shower or sprinkles through 00Z. Ceiling at CHA will lower to around 5kft this evening. Otherwise, VFR conditions anticipated at all TAF sites with a good deal of high and mid-level clouds. Winds will be brisk easterly between 5 to 10 kts through early this evening. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 65 82 67 84 / 10 10 10 20 Knoxville McGhee Tyson Airport, TN 60 83 64 83 / 10 10 10 20 Oak Ridge, TN 59 83 64 81 / 10 10 10 40 Tri Cities Airport, TN 56 82 58 80 / 0 10 10 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...DH AVIATION...DH