textproduct: Morristown

KEY MESSAGES

Updated at 738 PM EDT Wed Aug 5 2026

- Daily chances of showers and storms will continue each day through the forecast period, primarily favoring the afternoon and evening hours. A low chance for localized flooding exists each day.

- Low end chance for isolated flooding, with continuous afternoon thunderstorms, highest chances will be along the plateau and Appalachians where storms are most likely each afternoon.

DISCUSSION

Issued at 241 PM EDT Wed Aug 5 2026

The slow moving upper level low currently overhead will gradually dissipate and be absorbed into the mean flow over the next couple of days. During this transition, steady August moisture and daytime heating will allow scattered to numerous showers and thunderstorms to fire off each afternoon. Mesoanalysis and forecast soundings indicate a relatively moist airmass with dewpoints in the upper 60s to low 70s helping to increase MLCAPE values, generally ranging from 1000 to 2000 J/kg. Given weak steering flow of generally 10 knots or less, slow moving storms will have the potential to drop a quick couple of inches of rain over a short period. 1-hour flash flood guidance ranges from 1.5 to 2 inches across the foothills and East Tennessee mountains, and 1.5 to 2.5 inches in southeast Tennessee and southwest North Carolina. Slow moving storms tracking over already saturated soils or anchoring to terrain features will present an isolated flash flood threat. Additionally, deep profiles and high freezing levels will support a mix of gusty winds, frequent lightning, and brief small hail with the stronger core structures.

As the upper low feature dampens out to end the week, orographically forced convection will become increasingly dominant over broader valley based heating elements, though any lingering outflow boundaries could still spark secondary valley development. High temperatures will hover near seasonal normals, generally in the middle to upper 80s for lower elevations.

Heading into the weekend and early next week, the remnants of the upper low phase completely into the mean flow aloft, while a northern stream trough drops into the Great Lakes region. This setup will maintain weak upper level divergence across the southern Appalachians. Diurnal heating combined with continuous deep layer moisture will maintain daily chances of afternoon/evening convection. By early next week, deterministic models diverge regarding synoptic details and low level jet enhancements with the GFS remaining more bullish on coverage compared to the drier ECMWF. NBM paints a broad 40-50% PoPs for much of the area in response. CIPS analogs suggest that any enhanced severe weather threat will remain displaced to our north and east closer to stronger synoptic forcing and deep-layer shear, leaving our area locked into typical late summer diurnal pulse activity with heavy downpours as the primary hazard.

AVIATION

(00Z TAFS) Issued at 738 PM EDT Wed Aug 5 2026

A few isolated TS remaining in the region, but not expecting additional impacts to TAF sites this evening. Patchy fog again possible overnight, most likely at KTRI. Tomorrow another day of scattered showers and TS, beginning around 19z to 20z for the valley TAF locations. Outside of a direct TS impact, winds will remain light.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 72 88 72 89 / 20 60 20 40 Knoxville McGhee Tyson Airport, TN 71 87 71 88 / 10 60 10 50 Oak Ridge, TN 70 87 70 88 / 10 60 10 50 Tri Cities Airport, TN 67 85 67 85 / 10 50 30 50

MRX WATCHES/WARNINGS/ADVISORIES

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