textproduct: Morristown

KEY MESSAGES

Updated at 215 PM EDT Fri Jul 31 2026

- One last dry day today with seasonable temperatures and relatively comfortable humidity.

- A low chance for a few strong storms tomorrow afternoon into the later hours of the night. Damaging winds the main threat with localized flooding also possible. A tornado also cannot be ruled out, especially near the plateau.

- The wet pattern that begins tomorrow will persist into next week. Temperatures warm up towards next weekend.

DISCUSSION

Issued at 215 PM EDT Fri Jul 31 2026

One last dry day today with a bit of an increase in humidity under shortwave ridging aloft and surface high pressure situated over the Appalachians. A fairly stout closed upper low will arrive from the Northern Plains tomorrow vertically stacked above a surface low. Around Sunday, the trough axis and cut off low seemingly parks right over us, for the most part. There's still some uncertainty about how this will play out because of model discrepancies. It's not until Wednesday that the next trough rolls in and absorbs the aforementioned low. Thereafter until the end of the forecast period, weak steering develops, and daily chances of showers and storms continue with temperatures pushing above 90 again. Precipitation chances later in the week will be best over the higher terrain.

Tomorrow will present a chance of strong to possibly a severe storm, as well as isolated flooding. There will be a couple of rounds of storms tomorrow with the first between 7 am and 3 pm ET and 4 pm until possibly after midnight for the second. Null surface instability amid a low level inversion, will prevent the early day round from getting strong. There may be some thunderstorms, but it'll be mostly rain. The area with the greatest threat of stronger storms will be the plateau/west of I-40, where SPC has the area under a slight risk. A slim marginal area to the east of that and then no severe for much of northeast TN and southwest VA. This makes sense as southerly flow over the terrain is trying to pull what we'd typically see in winter; downsloping eradicating precipitation or just keeping it at bay. The strongest winds over the higher terrain will be later in the day tomorrow, but quickly dropping off into the overnight hours, so not like how true winter mountain wave events behave. Southerly flow develops in the afternoon and turns out of the SW close to midnight and after, which is why the downsloping shouldn't persist overnight.

The strong to severe threat for later tomorrow will surely need monitored with CAPE pushing 2000 J/Kg, deep layer shear around 35 kt, PWATs nearing 2 inches, and DCAPE over 700. Tornadic activity also cannot be ruled out when surface winds will be at their most "southerly". 18z HRRR forecast soundings around the plateau area depict southerly or slightly backed winds at the surface, increased SRH, 0-1 shear over 20 kt, and 3CAPE around 70 or higher. This threat will only be limited to western parts of the forecast area (plateau), as the entirety of threats is forecast to drop off as it moves east, possibly being choked off by the downslope flow. Mainly, damaging wind gusts will be the concern with possible flooding tomorrow.

AVIATION

(18Z TAFS) Issued at 142 PM EDT Fri Jul 31 2026

Predominant VFR conditions and light winds continue this afternoon. Increasing mid to low level VFR clouds and the chance for showers and storms will increase mid to late morning at CHA and TYS. This activity is associated with an approaching warm front and could lead to periods of MVFR conditions under the heaviest convection. Less confidence in precipitation making it to TRI due to expected downslope drying in northeast TN. Winds will shift to a southerly direction behind the morning warm-front.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 72 86 72 87 / 20 90 90 40 Knoxville McGhee Tyson Airport, TN 69 86 72 86 / 10 60 90 50 Oak Ridge, TN 69 84 70 85 / 10 70 90 60 Tri Cities Airport, TN 64 84 69 83 / 0 30 60 80

MRX WATCHES/WARNINGS/ADVISORIES

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