textproduct: Morristown

KEY MESSAGES

Updated at 725 PM EDT Thu Aug 13 2026

- Periods of showers and storms continue this afternoon and Friday. The threat of severe weather is low, but there is potential for localized flooding and isolated damaging wind gusts.

- A warming trend is expected Friday into the weekend. Saturday through Monday look to be the most hot and humid days. Heat Advisory products may eventually be needed.

DISCUSSION

Issued at 151 PM EDT Thu Aug 13 2026

Today and Tonight...The regional radar mosaic reveals scattered showers and storms along the instability gradient from E TN and SW VA back toward W KY. Hi-res guidance has continued to struggle with this pattern largely due to the uncertainties at the mesoscale level. If we look further north, another MCS is tracking through Illinois this afternoon. This MCS should continue moving east- southeast and remain off to the north of NE TN and SW VA. However, additional scattered storms may develop this afternoon and evening. Visible satellite imagery highlights bubbly Cu forming across much of the area. Forecast soundings support the potential given moderate instability, high PWs, and sufficient bulk wind shear across our area. This could support the development of a few strong to severe storms. Today's threat of severe weather is low, but a few storms may be capable of producing damaging winds, primarily across SW VA and NE TN. These storms will also be capable of producing heavy rain and localized flooding impacts, but overall our flash flood threat will continue to decrease heading into Friday.

Friday through Early Next Week... An intensifying ridge axis will continue to build into the Tennessee Valley ahead of the weekend. This should limit any additional MCS impacts through the weekend, but more typical Summer diurnally driven storm chances remain in place. The ridge will support a warming trend through early next week. Our temperatures should warm well into the 90s in the valleys. Heat indices will approach Heat Advisory-level across our southeastern TN counties on Friday. There is some uncertainty with how high the surface dew points will go Friday afternoon. Some guidance keeps them in the low 70s while others warm them into the upper 70s. A Heat Advisory appears more likely Saturday and Sunday, especially across SE TN, where heat indices will warm into the mid to upper 100s. This heat will peak Sunday & Monday before the ridging responsible is suppressed further west toward the SW CONUS. Temperatures cool back toward normal values after Monday as mid- level troughing sets up over the Great Lakes and NE CONUS. This will allow for northwestern flow aloft to return with better daily shower & storm chances mid-week.

AVIATION

(00Z TAFS) Issued at 725 PM EDT Thu Aug 13 2026

Showers and storms are starting to dissipate. The overnight period will likely be quiet. Some patchy fog is possible near TRI. Dense fog is not expected since none of the terminals got rain today. Showers and storms will be isolated to scattered Friday afternoon and early evening.

PRELIMINARY POINT TEMPS/POPS

Chattanooga Airport, TN 75 96 77 97 / 10 20 10 20 Knoxville McGhee Tyson Airport, TN 74 93 75 94 / 10 20 10 20 Oak Ridge, TN 74 93 75 94 / 10 20 10 20 Tri Cities Airport, TN 70 89 71 90 / 10 30 10 60

MRX WATCHES/WARNINGS/ADVISORIES

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