textproduct: Morristown

KEY MESSAGES

Updated at 233 AM EDT Wed Sep 16 2026

- Above normal temperatures persist through the forecast period. Slight cooling into next week.

- Most areas will remain dry this week, however, increasing chances of showers each day in the higher terrain as we approach the weekend.

DISCUSSION

Issued at 233 AM EDT Wed Sep 16 2026

A near 600 dam upper high is almost stationary over the SE CONUS, bringing record heat for mid September. As we approach the weekend, the upper high will scoot back west and eventually weaken. Surface high pressure over the E and NE, will also weaken, leaving our area more susceptible to just enough instability for diurnal shower development. A slight outside chance of showers for the southern plateau and mountains of SW Virginia later today. Tomorrow may introduce some scattered development over the Southern Appalachians into SW Virginia. Precipitation chances for the afternoon and evening will persist into next week, possibly expanding in coverage.

The lower to mid (some upper) 90s are forecast through the weekend, before a slight turn downward towards the end of the forecast period or early next week. Upper 90s to low 100s heat indices will be possible from the southern valley up through the central valley. The highest heat indices may peak Friday. Though most of the area won't reach Heat Advisory criteria, that doesn't mean to let your guard down when it comes to to being outdoors, staying cool, and hydrated. Our daytime highs yesterday (before climate officially runs after this discussion), tied daily records at both Tri-Cities and Chattanooga. That makes Chattanooga's streak of 90 and above at 43 days and counting, with no break in sight.

AVIATION

(06Z TAFS) Issued at 101 AM EDT Wed Sep 16 2026

The main aviation impact into the early morning hours will be the forecast development of fog at TRI. Prevailing at MVFR and TEMPO IFR were maintained, but reductions to LIFR are certainly possible. There is an outside chance of fog at TYS but not enough for inclusion in the TAF. Some lower clouds are also possible at CHA but not enough for ceilings. Otherwise, morning fog and low clouds will lift in the hours after sunrise, leading to clearing conditions and light and variable winds through the day.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 96 72 98 72 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 93 70 94 71 / 0 0 0 0 Oak Ridge, TN 93 70 94 70 / 0 0 10 0 Tri Cities Airport, TN 90 66 90 67 / 0 0 20 10

MRX WATCHES/WARNINGS/ADVISORIES

NC...NONE. TN...NONE. VA...NONE.