Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
043 FXUS64 KMRX 212353 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 653 PM EST Fri Nov 21 2025 ...New AVIATION... .KEY MESSAGES... Updated at 643 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... (00Z TAFS) Issued at 643 PM EST Fri Nov 21 2025 A boundary and associated rain in vicinity of TRI will maintain low confidence of reduced visibility over the next few hours, all while a brief period of VFR conditions are expected at TYS/CHA. An additional front will progress towards the region overnight, with MVFR cigs and showers eventually making a return. IFR or lower cigs/vis and occasional thunder will be possible as the main axis of forcing swings through, generally just before sunrise. Cigs will gradually lift or scatter out around mid-day at TYS/CHA. However, MVFR cigs are expected to persist into the afternoon at TRI. && .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...KRS