Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
515 FXUS64 KMRX 232339 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 739 PM EDT Sun Aug 23 2026 ...New AVIATION... .KEY MESSAGES... Updated at 732 PM EDT Sun Aug 23 2026 - Dry conditions with more comfortable humidity levels through Tuesday. - Shower and thunderstorm chances will return Wednesday and especially Thursday. && .DISCUSSION... Issued at 225 PM EDT Sun Aug 23 2026 Upper troughing will remain over the eastern US for the next few days as surface high pressure to our north and northwest drifts slowly east. This will provide us with a dry days and comfortably low relative humidity values each afternoon through Tuesday. Some patchy fog may develop in the late night hours tonight especially near rivers and lakes. By mid week the surface high will be off to our east and northeast, allowing low level flow to become more southwesterly and moisture to increase. Models suggest short wave energy moving across the area may have enough moisture to work with for a few showers and thunderstorms Wednesday, especially south and mountains. By Thursday into Thursday night, models show a stronger upper wave moving through the Great Lakes Region, dragging a weak cold front into our area. This will likely be the day with the highest coverage of showers and storms. We will have to wait until we get closer to see about the potential for any strong to severe storms, but right now the ensemble data joint probabilities for at least 500 J/kg of CAPE and > 30kt bulk shear are minimal at best and the chance for severe storms looks quite low. Lower confidence in the details further out, but models generally suggest high pressure will bring at least some drying behind the front for Friday into the weekend. The NBM still has some low chances for showers and storms for these days, especially over the mountains during the afternoon hours. High temperatures will generally not be far either side of normal for the entire forecast period. && .AVIATION... (00Z TAFS) Issued at 732 PM EDT Sun Aug 23 2026 Predominant VFR conditions and light winds less than 10kts are expected for the TAF cycle. Brief early morning fog/br cannot be ruled out at TRI as the forecast low is expected to near the crossover temperature of 55 degrees. Confidence is not high enough in fog potential to introduce anything less than MVFR conditions at this time. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 65 91 65 92 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 62 87 61 88 / 0 0 0 0 Oak Ridge, TN 61 87 61 88 / 0 0 0 0 Tri Cities Airport, TN 56 83 56 84 / 0 0 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...99 AVIATION...KRS