Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
153 FXUS64 KMRX 231740 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 1240 PM EST Sun Nov 23 2025 ...New DISCUSSION, AVIATION... .KEY MESSAGES... Updated at 1235 PM EST Sun Nov 23 2025 - Mild temperatures continue through mid-week. - A system brings the potential for rain, wind, and a few storms across the area Monday night into Wednesday, followed by colder temperatures for Thanksgiving. - Temperatures moderate by the weekend, with another potential rain maker moving in by Sunday. && .DISCUSSION... Issued at 1235 PM EST Sun Nov 23 2025 Dry conditions will remain in place through Monday due to a ridge over the Southeast and high pressure centered overhead. Tomorrow will be the nicest day of the forecast period with plenty of sun and highs in the mid to upper 60s. By late tomorrow night, a shortwave moving through the Midwest and Ohio Valley will bring widespread showers and rain. On and off showers will persist through Wednesday until the cold front moves through the area. A few storms are possible at times on Tuesday and into Tuesday night. Instability continues to look elevated during the day on Tuesday but there is a possibility we see surface based convection Tuesday night if you believe the NAM soundings. SPC has our southern areas in a Day 3 Marginal Risk. We will continue to monitor. The probability for widespread rainfall to occur is moderate to high. NBM 48 hour rainfall probs show mid 90s probs for at least 0.5 inches of rainfall to occur from Chattanooga up through Knoxville. From Knoxville up into southwest VA the probs for 0.5 inches of rain drop to around 50%. Dropping the 48 hour rainfall criteria to 0.25 inches results in all areas at 80% probs and above. For now, the biggest impact will be in the form of gusty winds across the east TN mountains with potential gusts up to 40 mph. This is due to the increasing 850mb jet with this system. Peak winds will occur from late Monday night through Tuesday night. This system may still produce a period of mountain wave winds but stay tuned as more model data comes in. Rain will be tapering off by Wednesday afternoon as the cold front moves through. High pressure over the Central U.S. will move into the region by Thursday morning bringing cold, dry Canadian air as a deep trough sits over the Eastern U.S. Dry weather is expected for the Thanksgiving holiday and through most of the weekend. Highs will be mainly in the 40s on Thursday and Friday. The next system may approach late in the weekend, around Sunday, but uncertainty is high that far out. && .AVIATION... (18Z TAFS) Issued at 1235 PM EST Sun Nov 23 2025 High pressure will be moving across northern portions the area tonight, setting up favorable conditions for fog development, especially at TRI. Dewpoints today have not dropped much with daytime mixing, and are well above tonight`s forecast low temps. Confidence of fog is highest at TRI, so a TEMPO for IFR vis/LIFR cigs will be mentioned there. With less confidence at TYS, MVFR vis will be forecast. CHA appears the least likely to see fog tonight. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 44 71 58 69 / 0 0 60 90 Knoxville McGhee Tyson Airport, TN 41 66 53 67 / 0 0 40 90 Oak Ridge, TN 41 65 52 65 / 0 0 50 90 Tri Cities Airport, TN 37 65 47 64 / 0 0 20 80 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...99 AVIATION...DGS