textproduct: Morristown

KEY MESSAGES

Updated at 229 PM EDT Sat Aug 8 2026

- Showers and thunderstorms will be around each day through next Saturday, with the afternoons generally the period of most activity.

- There will be potential for a few storms to become strong to severe each afternoon at least through Tuesday (and possibly beyond), with damaging winds and localized flooding the main threats.

- Temperatures will be generally not be far either side of normal for this time of year.

DISCUSSION

Issued at 229 PM EDT Sat Aug 8 2026

A weak mid/upper level circulation near the AR/TN border is drifting slowly east. A weak midlevel deformation zone out ahead of it is enhancing shower and thunderstorm activity over our area today. Flow is weak and PWAT values high, and like recent days these slow-moving storms can produce locally heavy rainfall/flooding and strong gusty winds. Sunday looks similar as the weak mid/upper low transitions to an open wave and continues to drift east. Weak flow, PWAT values in the 1.8 to 2 inch range and MLCAPE values generally in the 1000-1500 J/kg range point to another day with a potential for a few storms to become strong to marginally severe, with strong winds the primary threat along with localized flooding.

Models have not been consistent on how quickly the trough will exit east, but the trend has it moving east more quickly leading to the pattern becoming more northwesterly aloft for Monday and Tuesday with a broad upper trough centered to our east and a broad high pressure ridge to our west. This brings slightly drier air aloft to the area, steeper mid-level lapse rates, and afternoon MLCAPE values more in the 1500 to 2000 J/kg range. Shear still generally looks weak, but given the better thermodynamic profile storms Monday and Tuesday could pose a slightly higher threat of becoming strong to severe with damaging winds still the primary threat.

Models diverge for the later periods with cluster analysis showing one camp of ensemble members keeping us in more of a northwest flow aloft while another camp builds the ridge east with the jet displaced further north, thus confidence on the details is low. Convective coverage will be influenced by which camp is more correct as well as any short waves moving through the flow. Ensembles suggest at least a slight uptick in shear especially north by mid- week which is more consistent with the northwest flow camp of which some (including the latest runs of the operational GFS) bring a significant wave and a cold front into and through the area late in the work week. Overall, daily chances for showers and storms can be expected, but specifics on timing and severe/flooding potential will have to wait until we get closer.

AVIATION

(18Z TAFS) Issued at 104 PM EDT Sat Aug 8 2026

Scattered showers and thunderstorms around this afternoon will be included as prob30 thunder groups all sites. Fog/low cig development potential tonight will be influenced by the as yet unknown details of rain occurrence/timing/amounts at each site, but will carry a tempo group for MVFR vsby in fog at CHA for late tonight where the ensemble data suggests the highest chance. Other than with the fog and any showers/storms, VFR conditions are expected.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 72 91 73 91 / 20 40 10 70 Knoxville McGhee Tyson Airport, TN 71 90 72 90 / 20 30 10 40 Oak Ridge, TN 71 89 72 90 / 20 30 10 40 Tri Cities Airport, TN 68 87 69 88 / 20 20 20 30

MRX WATCHES/WARNINGS/ADVISORIES

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