Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
936 FXUS64 KMRX 211731 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 1231 PM EST Fri Nov 21 2025 ...New DISCUSSION, AVIATION... .KEY MESSAGES... Updated at 1229 PM EST Fri Nov 21 2025 - Showers and a few thunderstorms tonight and early Saturday morning, with clearing skies Saturday afternoon. - Mild temperatures continue through the weekend and the first part of next week. - Another system brings rain to the area Tuesday/Wednesday, followed by colder temperatures for Thanksgiving. && .DISCUSSION... Issued at 1229 PM EST Fri Nov 21 2025 A warm front is located from SW KY across northern Middle TN to central East TN, just south of Knoxville at the moment. Low clouds persist to the north of the front. It is expected to slowly lift northward through the evening, but it is possible that the models are moving it too fast, and that current rainfall in NE TN will slow its progress. In any case, we should see precip gradually decreasing on the warm side of this front, with more scattered shower coverage as we go into the late afternoon and evening hours. Showers will likely increase again after midnight as QG forcing picks up in association with an upper jet streak and a shortwave trough, although the positive tilt of this trough will mean forcing will be fairly weak and convection will be disorganized. Some weak elevated instability (MUCAPE ~ 500-700 J/kg) will give a low/slight chance of thunderstorms, but the threat of severe storms will stay mainly to our south and west where CAPE/shear overlap will be more favorable. The CAMS that showed some strong storms with earlier runs have been backing off that scenario in their more recent runs. Scattered showers linger into Saturday morning, followed by a mainly dry afternoon with decreasing clouds behind the exiting shortwave trough. Ridging aloft will build across the area on Sunday, peaking on Monday morning. Sunday will be a nice day with highs in the 60s under sunny skies as surface high pressure moved along the OH Valley region. Clouds increase Monday ahead of the next system, which will bring rain chances back to the area on Monday night. There is an initial shortwave trough that brings the first round of showers Monday night/Tuesday morning, followed by the main upper trough/cold frontal passage Tuesday night/Wednesday. A colder air mass builds into the area for Thanksgiving, with highs in the upper 40s and 50s. && .AVIATION... (18Z TAFS) Issued at 1229 PM EST Fri Nov 21 2025 A warm front is lifting north across the area, It is currently located just south of TYS, and will continue a northward drift through the evening. On the southern side of the front, vis/cigs will lift to VFR, with LIFR/IFR cigs on the north side. It should be north of TYS in the next hour or two, and be near TRI around 00Z. Additional rain showers are expected to spread into the area later tonight, lowering vis and cigs to predominantly MVFR, but with IFR conditions and TS possible at times. Some lifting of vis cigs will occur in the last few hours of the TAF period. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 63 75 49 68 / 60 40 0 0 Knoxville McGhee Tyson Airport, TN 62 71 47 64 / 70 50 10 0 Oak Ridge, TN 61 70 44 64 / 80 50 10 0 Tri Cities Airport, TN 58 66 42 60 / 70 60 10 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...DGS AVIATION...DGS