textproduct: Morristown

KEY MESSAGES

Updated at 715 PM EDT Tue Jun 30 2026

- Isolated to scattered showers and thunderstorms this afternoon in the mountains and adjacent foothills, some may be strong to severe.

- Very hot this week with high temperatures well into the 90s common. Afternoon heat index values will climb to around or above 100 degrees in in most valley locations multiple days.

- A shortwave may brings better chances for showers and thunderstorms early next week, tempering highs slightly.

DISCUSSION

Issued at 1211 PM EDT Tue Jun 30 2026

A large mid-level ridge is building across the eastern U.S., bringing hot conditions to East TN. For the rest of today, afternoon instability with minimal capping and steep lapse rates will offer isolated to scattered showers and storms (mainly across the mountains. Convection is expected to develop along the NC border and drift SW, with additional activity possible along outflow boundaries in the Tri-Cities area and the NE TN foothills. Some storms could be strong to severe, with the main impacts being the potential for strong winds. Tomorrow, the ridge axis shifts slightly eastward. This will limit convection primarily to SW N and SE TN where the cap may be a bit weaker, though ample instability could still support storms if triggered.

Highs will climb into the lower to mid 90s across valleys today, with mid to upper 90s possible Wednesday through at least Friday. Overnight lows will remain muggy in the low to mid 70s. Heat indices will frequently hit 100 or high in the valley locations, with some areas exceeding 105 mid-week. The Heat Advisory covers the impacts through Friday evening. Heat safety is critical, make sure to stay hydrated, limit outdoor activity during peak heating, and check on vulnerable populations.

Thursday through Sunday, the ridge remains dominant, promoting mostly dry and very hot weather. Isolated afternoon and evening showers/storms can't be ruled out, especially near the higher terrain, but coverage should be limited. That said, given the steep lapse rates and marginal sheer, any storms that do pop up, could become severe and produce strong winds. Highs in the mid 90s are likely, continuing the heat wave through the holiday weekend.

Monday through Tuesday a shortwave disturbance looks to approach from the west, increasing the chances for showers and storms. This could bring slightly lower temperatures and offer some relief from the heat, through details remain uncertain at this time.

AVIATION

(00Z TAFS) Issued at 715 PM EDT Tue Jun 30 2026

Fog at TRI will be the main impact this period. With clear/calm conditions expected, fog seems likely, but how low vis will go is uncertain. For this TAF issuance, will follow model guidance of IFR vis for a few hours in the morning. Lower conditions cannot be ruled out, as is usual for TRI.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 77 97 77 99 / 0 20 10 40 Knoxville McGhee Tyson Airport, TN 74 95 74 96 / 0 10 10 20 Oak Ridge, TN 75 95 75 97 / 0 10 10 10 Tri Cities Airport, TN 71 95 71 97 / 0 0 10 10

MRX WATCHES/WARNINGS/ADVISORIES

NC...Heat Advisory until 9 PM EDT Thursday for Cherokee-Clay.

TN...Heat Advisory until 9 PM EDT /8 PM CDT/ Thursday for Anderson- Bledsoe-Blount Smoky Mountains-Bradley-Campbell-Claiborne- Cocke Smoky Mountains-East Polk-Grainger-Hamblen-Hamilton- Hancock-Hawkins-Jefferson-Johnson-Knox-Loudon-Marion-McMinn- Meigs-Morgan-North Sevier-Northwest Blount-Northwest Carter- Northwest Cocke-Northwest Greene-Northwest Monroe-Rhea- Roane-Scott TN-Sequatchie-Sevier Smoky Mountains-Southeast Carter-Southeast Greene-Southeast Monroe-Sullivan-Unicoi- Union-Washington TN-West Polk.

VA...Heat Advisory until 9 PM EDT Thursday for Lee-Russell-Scott VA- Washington VA-Wise.