textproduct: Morristown

KEY MESSAGES

Updated at 729 PM EDT Sun Aug 30 2026 - Hot and humid conditions will continue with highs well into the 90s and heat index reaching or exceeding 100 for most by mid-week.

- Other than isolated storms in the mountains today or tomorrow, rain chances do not return until late in the week into the weekend.

DISCUSSION

Issued at 231 PM EDT Sun Aug 30 2026

Currently, a shortwave/low pressure system is moving into the northern Great Plains with a near 5,950m ridge centered to our west. Surface high pressure remains largely in place across the eastern U.S. This will lead to another hot and largely dry day across the region. With PWAT values sitting around 1.3 to 1.5 inches, moisture is sufficient for isolated showers or storms along the higher terrain, but most places will stay dry. By Monday, the upper high will strengthen and shift slightly east, leading to a further increase in temperatures into the 90s. Isolated rain chances continue along the higher terrain, but this will remain limited. By Tuesday and Wednesday, the 500mb high will remain near 5,950m and centered directly over the region, promoting widespread 90-degree temperatures. With similar moisture in place, heat index values will reach or exceed 100 degrees across most of the area, potentially 105 degrees in the southern Valley. The upper high begins to shift further south on Thursday, with an increase in moisture leading to a return of rain chances.

Friday and Saturday, a closed low will move into New England, leading to further suppression of high pressure and northwesterly flow aloft. With sufficient moisture in place, chances for diurnal showers and storms will increase above Thursday, also leading to some reduction in temperatures as well. With heating and moisture, a few stronger storms are possible, but we are certainly in a climatologically less favorable time of year.

AVIATION

(00Z TAFS) Issued at 729 PM EDT Sun Aug 30 2026

Going with a persistence forecast for the 00z TAF package, which will feature light and variable winds at all sites along with FEW040-050. Took the fog at TRI out for this issuance. Guidance has been consistently showing fog there the last few days and while fog formation has occurred in sheltered valleys in far southwest Virginia and northeast Tennessee the last few days, it hasn't impacted KTRI. Furthermore, today was another day of warm temperatures and dry conditions. So I believe they will stay P6SM and trended the TAF that direction.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 72 95 73 97 / 0 0 0 0 Knoxville McGhee Tyson Airport, TN 71 93 72 95 / 0 0 0 0 Oak Ridge, TN 71 93 72 95 / 0 10 0 0 Tri Cities Airport, TN 67 90 68 92 / 0 10 0 0

MRX WATCHES/WARNINGS/ADVISORIES

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