textproduct: Huntsville

KEY MESSAGES

Updated at 912 AM CDT Sat Jul 18 2026

- Moderate (Level 2/4) to Major (Level 3/4) Heat Risk will build into the Tennessee Valley this weekend through the middle of next week, with peak heat index values between 100 to 105 degrees likely, and potentially between 105-109 degrees in some locations Monday and Tuesday.

- Daily thunderstorm chances will continue over the weekend into early next week. Strong gusty winds, frequent lightning and very heavy rainfall causing localized flooding may occur. A few storms could become strong to marginally severe, with gusty/damaging winds and heavy downpours the main threats.

- Slightly cooler and less humid air is expected in the middle and latter portions of next week.

NEAR TERM

(Rest of Today and Tonight) Issued at 912 AM CDT Sat Jul 18 2026

Some areas of low stratus that developed across the region overnight have been slow to dissipate this morning thanks to a stout inversion. These clouds will eventually scatter out and a mostly sunny sky will redevelop by the late morning and early afternoon. Ample heating will again allow high temperatures to reach the low to mid 90s -- and with dewpoints in the 70s, peak heat index values will reach the 100-105 degree range in most locations. NWS Heat Risk highlights a Moderate (Level 2/4) Heat risk across the entire Tennessee Valley this afternoon. Heat will be dangerous for those who are sensitive to heat as well as those who are without proper heating and hydration. Remember to look before you lock and stay weather aware if you have outdoor plans today!

Additionally, a low-medium chance (20-40%) of diurnally driven afternoon showers and thunderstorms will exist, with the focus being along preexisting outflow boundaries (one notably over NE Alabama along the AL/GA border). A few storms may become strong to marginally severe with gusty/damaging winds and heavy downpours the main threat. This activity will wane after sunset, with tranquil conditions again forecast overnight (save for some patchy fog in areas that receive rainfall).

SHORT TERM

(Sunday through Tuesday) Issued at 912 AM CDT Sat Jul 18 2026

A Moderate (Level 2/4) to Major (level 3/4) Heat Risk will be the main concern in the forecast early next week with high pressure building in and a tropical-like air mass in place under the ridge. This will create daytime highs in the low to mid 90s each day, with heat index values between 100-105 degrees across the entire Tennessee Valley (and several locations that reach the 105-109 degree range by Monday and especially Tuesday). Heat products may be needed by early next week and we will continue to monitor forecast trends. Regardless, it will be important to practice heat safety next week, especially if you have outdoor plans!

Daily thunderstorm chances will exist each afternoon, thanks to diurnal heating and residual outflow boundaries in place. The greatest coverage will likely occur on Sunday as a weak shortwave clips the northeast edge of the ridge, with medium-high (30-70%) chances for showers/storms. As the ridge builds east, PoPs will lower to 20-40% on Monday and 10-30% on Tuesday thanks to stronger subsidence and a lack of forcing. Each day there will be a low chance of a few storms becoming locally strong to marginally severe, with gusty/damaging winds and heavy downpours the main threat.

LONG TERM

(Monday night through Friday) Issued at 858 PM CDT Fri Jul 17 2026

The weather pattern during the day 4-7 period will involve a strong trough developing over the Great Lakes into the mid Atlantic and New England states and an upper ridge building over the southern Plains. A low level thermal ridge (850 mb temps of 20-23C) will arrive on Tuesday, making for a hot and humid day. Heat Risk will reach the Major category (3 out of 4) for much of the TN valley. High temperatures in the lower to middle 90s, heat index values of 100 to ~105F and WBGTs in the middle to upper 80s are expected. A shortwave trough axis and cool front will drop southeast toward the TN Valley through the TN Valley on Wednesday, bringing a low chance of thunderstorms. Behind the front, slightly cooler air with highs in the upper 80s to lower 90s are expected Wednesday, with middle to upper 80s on Thursday after morning lows in the middle to upper 60s. Another Friday morning lows in the 60s, afternoon highs will be near normal and in the upper 80s to around 90. And even better, dew points will drop into the middle to upper 60s Friday.

AVIATION

(18Z TAFS) Issued at 1142 AM CDT Sat Jul 18 2026

VFR conditions will be the predominant flight category at each terminal through the period, with light winds. A few TSRA will develop across the TN Valley this afternoon, but confidence was too low in coverage to mention in the TAF at this time. However, any storms that do develop will dissipate by 00-01z, with VFR conditions prevailing through the remainder of the period.

HUN WATCHES/WARNINGS/ADVISORIES

AL...None. TN...None.