Area Forecast Discussion
Issued by NWS Knoxville/Tri Cities, TN
Issued by NWS Knoxville/Tri Cities, TN
060 FXUS64 KMRX 190502 AFDMRX Area Forecast Discussion National Weather Service Morristown TN 1202 AM EST Wed Nov 19 2025 ...New DISCUSSION, AVIATION... .KEY MESSAGES... Updated at 1155 PM EST Tue Nov 18 2025 - Above normal temperatures expected through the weekend, with warmest days today through Friday. - Scattered showers with potential for a few thunderstorms during the overnight. Mostly dry for the PM hours today. Rain chances will begin to increase again Thursday evening, with more widespread rain coverage Friday night into Saturday. && .DISCUSSION... Issued at 1155 PM EST Tue Nov 18 2025 A shortwave will continue to progress through the Ohio Valley region tonight. A line of showers with a few embedded thunderstorms can be noted along a surface boundary moving through central Kentucky, while a few scattered showers can be noted within our CWA ahead of the main line. Latest SPC mesoanalysis keeps a surface CAPE gradient to our west, suggesting only elevated instability atop a strong surface inversion as this activity moves through our forecast area. Overall, the main concern will be some gusty winds between 30-40mph due to strong H85 flow near 40kts being transported to the surface. Even then, the sfc inversion should help limit that threat. Finally, Low freezing levels near 10kft could also lead to small hail with any embedded stronger cells. The upper-level impulse will eject eastward throughout the day and increasing H5 heights will lead to mostly dry conditions with well above normal temperatures. Temperatures across the southern valley are currently forecast to be just a few degrees shy of record daily values through the end of the week. For Thursday night, a shortwave lifting through the southern plains and into the mid-Mississippi River Valley will increase isentropic ascent and promote a return of precipitation chances. The highest probabilities will be along the northern Plateau and in vicinity of the KY/TN/VA border. Vorticity maxima associated with a more prominent H5 shortwave will traverse the region Friday night. Increasing surface cyclogenesis within the Ohio Valley region will allow shower and thunderstorm chances to become more widespread. This system will gradually depart the region throughout Saturday as we begin to dry out late Saturday into Sunday. Drier weather is forecast to continue into early next week ahead of a stronger low pressure system expected to develop across the Southern Great Plains and move our direction by the middle of next week. && .AVIATION... (06Z TAFS) Issued at 1155 PM EST Tue Nov 18 2025 Scattered showers will move through early in the period. There will likely be a few embedded thunderstorms but probability looks too low at any given site to include in TAFs at this time. Probability of MVFR cigs is greatest and most persistent at TYS and TRI, where MVFR conditions could linger through late morning and into the afternoon hours, but the probability has risen enough at CHA to include several hours of MVFR cigs there as well. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 71 58 76 55 / 0 50 10 0 Knoxville McGhee Tyson Airport, TN 70 56 72 53 / 0 50 20 10 Oak Ridge, TN 67 54 71 51 / 0 60 20 10 Tri Cities Airport, TN 65 49 64 51 / 10 70 20 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DISCUSSION...KRS AVIATION...99