textproduct: Huntsville

KEY MESSAGES

Updated at 858 PM CDT Fri Jul 17 2026

- Daily rounds of scattered storms will continue over the weekend into early next week. Strong gusty winds, frequent lightning and very heavy rainfall causing localized flooding may occur. There is a marginal risk of severe storms across far northeast Alabama and adjacent southern middle Tennessee Cumberland Plateau Sunday.

- Heat indices will reach the low 100s for many areas west of the Cumberland Plateau into early next week. Tuesday will be the hottest day of the period with heat indices nearing or exceeding 105 degrees for much of the area.

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

NEAR TERM

(Rest of tonight and Saturday) Issued at 858 PM CDT Fri Jul 17 2026

Upper level ridging remained in place across much of the Lower-48. A mostly zonal flow pattern continued from the Northern Rockies to across the Mid Atlantic. A moist airmass was in place over much of the CONUS. Precipitable water amounts over this region ranged from 1.8" to 2.1". Daytime heating and resultant higher instability earlier had yielded scattered to numerous showers and thunderstorms across parts of the Tennessee Valley. Local rainfall amounts ranged from a trace, to over 1.7" in the Bankhead National Forest of southern Lawrence County Alabama.

Shower activity has ended over the forecast area for the time being. However in a still unstable environment and the presence of many outflow boundaries interacting, we cannot rule out additional development as we go into the overnight. Otherwise with mainly mid and high altitude residual clouds, a muggy night is expected, as low temperatures only cool into the lower 70s. Some patchy fog cannot be ruled out in those area better subject to it forming, especially if wetting (0.10" or more) rainfall recently occurred.

We should have another round of showers and thunderstorms Saturday (mainly in the afternoon). Shower coverage appears will be isolated to scattered, thanks to slightly drier air. As is usually the case, the stronger storms could produce strong gusty winds, frequent lightning, and torrential downpours. Strong heating will push high temperatures into the low/mid 90s, with corresponding heat index values from the upper 90s to 105 degrees. The upper end of this is sufficient for a Heat Advisory; however areal coverage of the hottest values is too isolated to justify putting an Advisory at this time.

SHORT TERM

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

Isolated shower/thunderstorm activity should continue Saturday evening. Away from shower activity (most of the area) otherwise will have another muggy, humid night with lows only in the low/mid 70s. A return of higher amounts of moisture, and more strong daytime heating will produce scattered to numerous showers and thunderstorms. Similar conditions are forecast with highs into the lower 90s (with a few mid 90s), and heat index from the upper 90s to 105 degrees. Area coverage of the hottest values may not be sufficient for a Heat Advisory; something we will closely monitor. Shower activity should wind down Sunday night as lows fall into the low/mid 70s. Slightly drier air will reduce rain chances to isolated on Monday. Similar high temperatures should heat again into the low/mid 90s, and lows Monday night in the low/mid 70s. The duration of the heat could become a problem to some, even if conditions do not "officially" reach Advisory criteria. Area residents are urged to exercise caution while outdoors; not limited to drinking plenty of water, limiting your time outside, and trying to stay in the shade as much as possible.

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

(06Z TAFS) Issued at 1244 AM CDT Sat Jul 18 2026

Rain has come to an end across the area and patchy fog will be the main concern through the morning hours. Current satellite shows high clouds overspreading the area that may mitigate a larger fog concern, but trends will be monitored through the morning hours. Low chances for showers and thunderstorms are in the forecast today with the best chances in the afternoon. Reductions to MVFR conditions or lower will occur during any heavier showers/storms.

HUN WATCHES/WARNINGS/ADVISORIES

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