Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
406 FXUS64 KMRX 052350 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 750 PM EDT Tue Aug 5 2025 ...New AVIATION... .DISCUSSION... Issued at 138 PM EDT Tue Aug 5 2025 Key Messages: 1. A gradual warming trend into the weekend with more seasonal temperatures. 2. Isolate to scattered showers and thunderstorms expected through the forecast especially across the terrain. Discussion: Currently, strong surface ridging into the southern Appalachians. An upper trough over the Ohio and Tennessee valleys into the deep south is pulling sub-tropical moisture into the southeast and Carolinas. An area of rain and embedded heavier showers mainly east of the southern Appalachians. Some of these activity may move into the area through 24 hours. Overall, below normal temperatures continue through this evening with mostly cloudy sky. Ensemble cluster analysis shows a pattern change through the forecast period with troughing over the Tennessee valley/southern Appalachians/southeast United States slowly weakening the rest of this week replaced with building upper ridge this weekend and early next week. End result will be more normal temperatures for late summer. Isolated to scattered mainly afternoon and evening showers and thunderstorms are possible each day especially across the terrain features. Overall environment will not be conducive for severe storms as CAPES will mainly be in the 1500-2000 range, no shear, and limited DCAPE/Theta-E Difference values. PWs will be become near normal. As always for summer, can not rule out an isolated strong storms in the afternoon and early evening hours with gusty winds up to 40 mph and locally heavy rains producing runoff issues. && .AVIATION... (00Z TAFS) Issued at 740 PM EDT Tue Aug 5 2025 Radar trends continue to suggest shower chances are too low for any mention. Cloud cover will remain persistent, owing to isentropic ascent and strong low to mid level moisture advection. Latest NAMBufr soundings depict the potential for periods of MVFR or perhaps IFR conditions possible during Wednesday AM hours. Any impacts to flight categories should improve into the afternoon. Light winds less than 10kts through the TAF cycle. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 68 87 69 87 / 20 40 20 50 Knoxville McGhee Tyson Airport, TN 69 87 69 87 / 30 40 20 40 Oak Ridge, TN 68 87 68 87 / 20 40 20 40 Tri Cities Airport, TN 63 82 62 84 / 30 30 20 30 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...DH AVIATION...KRS