textproduct: Morristown

KEY MESSAGES

Updated at 129 AM EDT Fri Sep 18 2026

- Well above normal temperatures to persist through early next week. Cooling towards normal by end of the forecast period mid to late week.

- Increasing rain chances for the higher terrain this weekend into early next week with the valley least likely to see rain, similar to a typical summer pattern.

DISCUSSION

Issued at 129 AM EDT Fri Sep 18 2026

The anomalous ridge axis is located near or just west of the Mississippi this morning. It will become centered over Ark-La-Tex before further weakening and suppression as we get later into the weekend. What this means for our area is we will return to a diurnally induced precipitation pattern under weak northwesterly flow. There will be a chance of isolated to scattered showers and storms during the afternoon and early evening hours the entirety of the forecast period. Like usual, chances will be best over the higher terrain of the Southern Appalachians, Cumberland Plateau and Mountains. No severe weather expected; the only hazards will be lightning, possible heavy rain, and wind gusts. As we approach the middle of the week next week, the upper level pattern may bring shortwave troughing close to the region possibly providing more widespread precipitation.

Temperature-wise, today appears will be the final "hottest" area- wide with mid to upper 90s from the central valley down to the GA border. Heat indices could reach the lower 100s range. Tomorrow, temperatures and heat indices will be a smidge less for some, mostly northeastern Tennessee into southwest Virginia. A touch less in temperatures and heat indices Sunday and Monday, however, the more notable drop possibly comes Tuesday. An approaching frontal system and slightly lower heights aloft will be the big reason for what might be noticeable relief early next week. Then, the relief further infiltrates with lower temperatures and dew points Wednesday and Thursday. Some valley locations may see upper 70s to lower 80s for highs, which would be more in line climatologically for the end of September. Until then, Chattanooga will continue to build onto their record streak of 90 degrees or higher, now sitting at 45 days. Also cannot go without mentioning that even though most of the area won't reach Heat Advisory criteria the next couple of days, that doesn't mean to let your guard down when it comes to being outdoors, staying cool, and hydrated.

AVIATION

(12Z TAFS) Issued at 654 AM EDT Fri Sep 18 2026

Morning fog will dissipate quickly after TAF issuance at TRI otherwise sites will be VFR through this evening. TRI maintains the PROB30 for -TSRA chances, hi-res guidance continues to advertise iso-sct TS/SHRA near TRI this afternoon. All sites light N winds around 5 knots. Fog likely develops again at TRI tonight.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 98 73 98 71 / 10 10 40 20 Knoxville McGhee Tyson Airport, TN 95 71 93 69 / 10 20 30 30 Oak Ridge, TN 95 70 93 69 / 20 20 30 20 Tri Cities Airport, TN 89 67 88 66 / 50 30 30 10

MRX WATCHES/WARNINGS/ADVISORIES

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