Area Forecast Discussion

KEY MESSAGES

Updated at 738 PM CDT Tue Jul 21 2026

- There is a slight risk (level 2/5) for severe weather through tonight. Main impacts are damaging winds and flash flooding.

- Cooler and drier conditions arrive Wednesday and continue through the end of the week.

UPDATE

Issued at 738 PM CDT Tue Jul 21 2026

Quick update for this evening revolves around current thunderstorms now moving into our northern Middle TN counties. These storms will continue to move southward over the next several hours and present a damaging wind gust threat of 60+ mph and heavy rainfall leading to flash flooding in several areas. While the tornado threat has diminished, please don't sleep on these storms. Radar is suggesting wind speeds capable of dropping large trees and limbs which can cause plenty of damage -- as well as rainfall rates on the order of 3 to 4 inches an hour. If you go under a severe thunderstorm warning, please treat it as you would a tornado warning and take proper shelter.

Storm threat should end by midnight leaving light to moderate rain across our southern counties into the early morning hours. Flash flood watch continues until 7 am for many of our mid-state counties.

SHORT TERM

(Rest of today through Wednesday Night) Issued at 1113 AM CDT Tue Jul 21 2026

A surface front is moving south through Missouri into central Illinois this morning ahead of a shortwave in the northwest upper flow. The combination of lift and the ample instability and moisture at the surface will allow storms to fire across southern Indiana and Ohio over the next couple of hours. Some activity is already bubbling across our northeastern counties and some heavy downpours can't be ruled out this afternoon, but the main severe concern will be with the activity coming out of Kentucky this evening as bulk shear increases. Damaging winds will be the main severe storm threat this evening and into early Wednesday along with a very low risk of a tornado along the TN/KY state line. Instability and storm organization will decrease the further storms move south and the deeper we get into the overnight hours. The window of greatest severe potential looks like 7 PM to around 1 AM.

In addition to the severe threat, some instances of flash flooding will be a threat. PWAT values are around 1.9-2" across Middle Tennessee, so very high rain rates can be expected with storms today and tonight. HREF and associated CAMs show pockets of 2" of rain with 90th percentile values showing the potential for over 4" in isolated areas. With the wet July we've had so far, this would be sufficient for flash flooding in those areas. The HREF shows the higher probabilities of over 2" and higher 90th percentile values along and east of I-65. A Flood Watch is in effect through 12z Wednesday.

By 12z Wednesday, the surface front will be draped across the area from SW to NE. South of the surface front, additional showers and storms will be possible Wednesday afternoon along the plateau. Shear will be lower than tonight, so I don't expect any severe activity Wednesday afternoon. Behind the front, lower dew points will filter in from the northwest through the day and into Wednesday night. The surface front will be through the entire area by Wednesday night which will usher in a very pleasant night with low dropping into the low to mid 60s.

LONG TERM

(Thursday through next Tuesday) Issued at 1113 AM CDT Tue Jul 21 2026

To start the long term period, we will be in the nicest airmass we've had so far this summer. Dew points on Thursday will be in the low to mid 60s with highs in the low to mid 80s. Friday will be similar but a couple degrees warmer. A shortwave will ride northwest upper flow and approach the area Friday night into Saturday which will reintroduce some low to medium rain chances. Temperatures will creep up over the weekend with the possibility of a couple more shortwaves bringing additional storm storms chances going into early next week. There is some uncertainty of how far east ridging influences pushes which will affect our rain chances and temperatures next week.

AVIATION

(00Z TAFS) Issued at 618 PM CDT Tue Jul 21 2026

The first 6 hours of this TAF cycle will be riddled with TS and gusty winds as a broken line of thunderstorms moves into TN from the north. These should come to an end for all terminals by 05-06Z this evening and while cats will improve after the storms for CKV/BNA/MQY, MVFR cigs will return around sunrise Wednesday at BNA/MQY. CSV/SRB will bear the brunt of longer MVFR cigs through the night and sticking around after storms until lunchtime on Wednesday. Winds outside of storms will be light and we will see a shift to the northwest/north after storms pass. With storms, winds may be gusty at times with northwest to north gusts of 30 to 40 kts.

PRELIMINARY POINT TEMPS/POPS

OHX WATCHES / WARNINGS / ADVISORIES

Flood Watch until 7 AM CDT Wednesday for TNZ008>011-024>034- 056>066-075-077-078-080-093>095.