textproduct: Morristown

KEY MESSAGES

Updated at 744 AM EDT Sat Jun 27 2026

- Multiple rounds of showers and thunderstorms are expected this afternoon through Sunday, with a few strong to severe storms possible. Isolated flooding issues are probable wherever training occurs.

- Hot temperatures well into the 90s are likely next week. Heat indices may climb above 100 degrees in the Tennessee Valley especially by mid week.

DISCUSSION

Issued at 250 AM EDT Sat Jun 27 2026

In the upper levels, a ridge will build into the Central U.S. today and a trough will remain over the Eastern U.S. At the surface, low pressure is over the Northeast with a stationary boundary stretching back through the Ohio Valley and Midwest connecting to a low in the Rockies. The boundary will likely stay to our north but with northwest steering flow aloft, showers and storms forming along the boundary will move southeastward into the Tennessee Valley. A shortwave is also approaching this evening, therefore, widespread showers and thunderstorms are expected this afternoon and evening. A few storms may be strong to severe. The region is in a marginal risk for severe storms today and that seems appropriate. Instability will be increasing with dew points getting back into the 70s this afternoon. CAPE will be around 1000 to 2000 J/kg. Deep layer shear is low to moderate around 20 knots. If storms are able to organize, gusty winds will be the primary threat.

Most guidance keeps the stationary boundary to our north through Sunday. With a ridge just to our west, northwesterly steering flow will bring waves of showers and thunderstorms through Sunday. CAMs show the first couple of waves of showers and storms progressing through the region quickly, although heavy downpours may still lead to isolated flooding issues. There is a possibility of training storms late tonight through Sunday morning. PWAT values will be near 2 inches. A Flood Watch may be issued later this morning. Confidence is low to medium on flooding potential with a good possibility that the boundary will stay far enough north to send progressive waves of activity without significant training.

Showers and storms will slowly taper off late Sunday afternoon or evening. A strong ridge will be building into the region from the Southeast up to the Great Lakes Sunday afternoon/evening. Monday through Friday will be hot and mostly dry as a strong ridge stays anchored over the Eastern U.S. There will be low rain chances mainly in the higher terrain of the East Tennessee Mountains. Monday and Tuesday highs will be mainly in the lower to mid 90s in the Tennessee Valley. Wednesday through Friday will be even hotter with highs in the mid to upper 90s. Heat index around 100 degrees is likely in the Southern and Central Tennessee Valley Monday and Tuesday. Heat index will be climbing into the 100 to 105 range on Wednesday through Friday.

AVIATION

(12Z TAFS) Issued at 744 AM EDT Sat Jun 27 2026

Boundary to the north expected to bring multiple rounds of SHRA/TSRA to terminals later today and through the TAF period. CHA being further from the boundary, may mean lesser of a chance of precipitation there. Extended PROB30 through 12z. Expect category changes under heavier precip and CIG changes. SWly winds and gusts to near 20 KT possible at TYS and TRI later today.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 89 72 91 74 / 40 70 50 0 Knoxville McGhee Tyson Airport, TN 87 70 88 72 / 90 90 70 30 Oak Ridge, TN 86 70 89 72 / 90 80 60 30 Tri Cities Airport, TN 84 67 85 68 / 90 90 70 20

MRX WATCHES/WARNINGS/ADVISORIES

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