textproduct: Morristown

KEY MESSAGES

Updated at 133 PM EDT Sun Sep 20 2026

- Well above normal temperatures to persist into early this week. But relief is on the way, with a pattern change expected mid-week and much cooler temperatures to follow.

- Expect isolated to scattered showers today, with increasing coverage Monday through Wednesday.

- A few strong to severe storm with damaging winds could occur today and Monday, with damaging winds being the primary threat. Localized flooding will be possible each day through Wednesday as well.

DISCUSSION

Issued at 133 PM EDT Sun Sep 20 2026

Currently another hot day with highs once again expected to top out in the upper 80's to lower 90's across the eastern Tennessee Valley. While there are a few showers out there as of early this afternoon the coverage and intensity should both be lower than what we experienced yesterday with weaker synoptic forcing and lower PWAT values across the region. Similar conditions expected tomorrow and Tuesday with more hot days expected. We'll see more afternoon showers and thunderstorms once again... Forecast soundings suggest more instability on Monday and Tuesday leading to more vigorous afternoon convection. We could see a few severe thunderstorms with damaging straight line winds possible in the strongest storms. With the multiple days of storms and very little movement in the mean flow indicates the storms could sit over the same area for a while leading to isolated flooding.

By the middle of the week we will FINALLY see a large scale pattern change and usher in the first inklings of fall. Ridge builds in over Canada and a trough sets up closer to home that will slowly meander it's way through the eastern half o the United States for the rest of the week and into the weekend. This will much cooler temperatures starting Wednesday and by Thursday through the weekend we should see highs topping out only in the 70's for every except southeast TN where they may squeak across the 80 degree mark. This pattern will also be fairly dry with a more Canadian airmass moving in.

Looks like we'll finally get to open the windows this weekend!

AVIATION

(18Z TAFS) Issued at 133 PM EDT Sun Sep 20 2026

Less coverage of afternoon thunderstorms is expected today, with TRI having the highest chance of seeing storms. Once again fog is expected at TRI, but a lot will depend on if they get a storm this afternoon.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 72 95 70 92 / 10 40 50 70 Knoxville McGhee Tyson Airport, TN 70 93 69 88 / 10 40 60 90 Oak Ridge, TN 70 92 68 87 / 10 40 50 90 Tri Cities Airport, TN 66 88 65 83 / 10 30 60 90

MRX WATCHES/WARNINGS/ADVISORIES

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