textproduct: Huntsville

KEY MESSAGES

Updated at 241 PM CDT Wed Jul 1 2026

- A Severe Thunderstorm Watch is in effect until 8 PM CDT for all of our Alabama and Tennessee counties.

- An Extreme Heat Warning remains in effect for all of northern AL and southern Middle TN through 7 PM on Thursday due to a combination of afternoon temperatures in the mid-upper 90s and heat indices up to 113F. A Heat Advisory is in effect from 7 PM on Thursday through 7 PM on Friday.

- Low to medium (30-50%) afternoon/evening thunderstorm chances exist this afternoon before dissipating early this evening. Some of these could be severe producing high end damaging microbursts. A very isolated large hail threat exists as well.

- Lower coverage of afternoon/evening thunderstorms exist on Friday and Saturday. Conditions will be favorable for a few strong to severe storms, with damaging winds being the primary threat.

NEAR TERM

(Tonight) Issued at 241 PM CDT Wed Jul 1 2026

Scattered strong to severe storms have been developing near and south of a boundary that extends from NW GA WSW into central Alabama. With a very unstable airmass (4000 to 6000 J/KG SBCAPE), steep 2-6 km lapse rates (7.5 to 8.0 degrees/km). Forecast soundings continue to show 30 to 35 degree theta E difference in this airmass through the afternoon hours. A very primed setup for high end severe downburst winds.

Thus, a Severe Thunderstorm Watch was issued until 8 PM CDT for all of our Alabama and Tennessee counties. Some storms have already produced large hail up to quarter size and damaging winds. Very sure scattered storms will continue to move primarily to the WSW. There is some question how far northward this development will occur, but the atmosphere is very primed in those areas. Thus, outflow boundaries could allow additional cells to develop further northward into our Tennessee counties before this activity should dissipate early this evening.

Despite convection heat index values have already hit the 105 to 114 degree range in some areas such as the Huntsville Airport, Muscle Shoals Regional Airport, Scottsboro area, etc. These heat index values will be possible through the afternoon hours in other locations, especially north of the Tennessee River.

SHORT TERM

(Thursday through Saturday) Issued at 1224 PM CDT Wed Jul 1 2026

Models do not show as much convection on Thursday afternoon. However, the boundary looks in guidance (though very weak and hard to discern) to remain over or near northern Alabama. The center of the upper ridge doesn't move much and remains centered over western Virginia and North Carolina. Lower shower and thunderstorm chances are expected (20-30%). This should allow highs to climb into the 94 to 99 degree range for much of the area. Though some mixing will occur in the afternoon, the position of the weak boundary over or near the area will likely help keep dewpoints high enough to warrant heat index values climbing over 110 degree at times in the afternoon. Thus, extending Extreme Heat Warning through Thursday at 7 PM. This may need to be extended later into the week, but more widespread shower and thunderstorm activity if it develops could impact that, so only extending a Extreme Heat Warning for now past Thursday evening.

Friday and Saturday shower and thunderstorm chances will diminish to lower chances (10-30 percent). Strong to severe microbursts still look possible. A Heat Advisory was extended through Friday at 7 PM. More cloud cover and lower daytime highs could keep heat index values too low and not widespread enough for an additional Heat Advisory on Saturday.

LONG TERM

(Saturday night through Wednesday) Issued at 1224 PM CDT Wed Jul 1 2026

More pronounced relief in the form of widespread showers and thunderstorms is expected into the weekend again, especially Sunday into early next week. A decent longwave trough axis pushes southeast into the area and maybe followed by a weakening upper low. Shear is very weak with these systems, but they should help focus stronger forcing over the area. With a humid and unstable airmass continuing to remain over the area, some heavier rainfall is expected into early next week and some slightly cooler temperatures with highs mainly between 90 and 95 degrees. Lows will not modify much though, staying in the lower 70s. This should keep heat index values much lower, mainly between 100 and 106 degrees in most locations. Widespread Heat Advisory conditions given possible cloud impacts and higher precipitation chances look less certain. Thus, only extending the Heat Advisory through Friday at 7 PM for now.

AVIATION

(00Z TAFS) Issued at 607 PM CDT Wed Jul 1 2026

Thunderstorm activity has begun to die down this evening over the TN Valley though a low chance will linger through sunset. The main concern overnight will be the potential for fog development given the recent rainfall and expected clear skies. Winds will remain light and variable overnight, also increasing the confidence for fog. Additional low chances for thunderstorms are in the forecast Thursday afternoon but were not included in the TAFs at this time given low confidence.

HUN WATCHES/WARNINGS/ADVISORIES

AL...Extreme Heat Warning until 7 PM CDT Thursday for ALZ001>010-016.

Heat Advisory from 7 PM Thursday to 7 PM CDT Friday for ALZ001>010-016.

TN...Extreme Heat Warning until 7 PM CDT Thursday for TNZ076-096-097.

Heat Advisory from 7 PM Thursday to 7 PM CDT Friday for TNZ076- 096-097.