textproduct: Morristown

KEY MESSAGES

Updated at 1211 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

(12Z TAFS) Issued at 658 AM EDT Tue Jun 30 2026

Later today could possibly be a repeat of yesterday with showers and storms shifting down from the north, potentially impacting TRI, possibly TYS and CHA as well. In addition to PROB30 already at TRI, they've been added at TYS and CHA to include the possible chances there. Clear and calm tonight with fog in the forecast at TRI again. 3SM occurred there this morning for an hour.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN MMM MMM MMM MMM / MMM MMM MMM MMM Knoxville McGhee Tyson Airport, TN MMM MMM MMM MMM / MMM MMM MMM MMM Oak Ridge, TN MMM MMM MMM MMM / MMM MMM MMM MMM Tri Cities Airport, TN MMM MMM MMM MMM / MMM MMM MMM MMM

MRX WATCHES/WARNINGS/ADVISORIES

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