Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
198 FXUS64 KMRX 181124 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 624 AM EST Tue Nov 18 2025 ...New AVIATION... .KEY MESSAGES... Updated at 1258 AM EST Tue Nov 18 2025 - Low relative humidity again today with increasing winds. This will lead to enhanced fire danger. - Warmer weather to return Tuesday through Friday, with significant warm weather Knoxville and south Wednesday and Thursday. - Light rainfall Tuesday night with potential for a few thunderstorms. Rain chances will begin to increase again Thursday, with additional rain likely Friday into Saturday. && .DISCUSSION... Issued at 1258 AM EST Tue Nov 18 2025 Winds will begin to increase today and the flow will turn more southerly ahead of an approaching upper level short wave. However, moisture will be slow to increase and it will be quite warm this afternoon. This will allow for another day of low relative humidity values across the region. The low relative humidity and uptick in winds will bring another day of Enhanced Fire Danger across the entire area. Rain showers will move into the area tonight as the short wave moves across. There will be more precipitation north than south, but overall amounts will be on the light side with most areas expected to see less than a quarter of an inch even across the north. Soundings show some limited elevated instability, so a few rumbles of thunder cannot be ruled out as well. Models show no strong drying for Wednesday, so a few showers may linger along with quite a bit of cloud cover. Despite the cloud cover, it will be quite warm Wednesday as upper ridging will be building in from the south and west, and these abnormally high temperatures will continue into Friday. Highs will be around 10 to 15 degrees above normal on both Wednesday and Thursday, and the daily record high at CHA may be threatened both days (Current records at CHA: 11-19 77(1985), 11-20 78(1942)). For Thursday and beyond, the pattern becomes more active as a deep trough moves across the western U.S. and another trough moves across the Great Lakes region and northeast U.S. Models have been all over the place for these periods and uncertainty is still high on the impacts for our area. Confidence is moderate to high that at some point another system, or multiple systems, will move across our area bringing more rain. However, the details are still murky. As of right now, the best chance appears to be Friday into Saturday followed by some drying and then an uptick in rain chances again Tuesday as another wave approaches. Stay tuned. && .AVIATION... (12Z TAFS) Issued at 533 AM EST Tue Nov 18 2025 Will see some rain showers moving tonight with an increase in clouds, and cigs will likely drop to low VFR/MVFR by the end of the period with MVFR conditions the most likely at TRI. Winds at 2kft above the surface will be increasing tonight as well, and it looks like TRI will reach LLWS criteria for several hours. AT TYS and CHA it looks borderline for LLWS, so plan to leave it out there for now although it may need to be added as we get closer. A rumble of thunder cannot be ruled out at any given site tonight as well, but the probability looks too low to include at this time. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 72 58 77 55 / 0 40 10 10 Knoxville McGhee Tyson Airport, TN 69 56 72 54 / 10 70 10 10 Oak Ridge, TN 66 54 70 52 / 10 80 20 10 Tri Cities Airport, TN 64 48 64 51 / 10 80 20 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...99 AVIATION...99