textproduct: Huntsville

KEY MESSAGES

Updated at 1054 AM CDT Mon Jun 29 2026

- A heat wave will occur this week with a Heat Risk value of 3 out of 4 (Major category) to 4 out of 4 (Extreme category). Afternoon highs in the mid to upper 90s will be common, with peak heat index values between 105 to 110 degrees

- A Heat Advisory is currently in effect through 7 PM Thursday for the entire Tennessee Valley.

NEAR TERM

(Tonight) Issued at 234 PM CDT Mon Jun 29 2026

Ridging has made its presence known with the second day of our first heat wave of the summer. As of 2 PM CT, temperatures had exceeded 90 degrees and on track for the mid 90s for high temps. Dew points were in the low to mid 70s, resulting in heat index values of 100-105. With several more hours of heating as cloud cover disperses, expect the heat to become more oppressive for the rest of the afternoon. Please limit outdoor activities and if unavoidable, take frequent water breaks. Despite mostly clear skies this evening and overnight, the higher dew points will only allow us to cool off into the mid to upper 70s. The heat advisory will continue overnight and through most of the workweek.

SHORT TERM

(Tuesday through Thursday) Issued at 1054 AM CDT Mon Jun 29 2026

We remain entrenched under ridging this week as 500 mb heights increase to near 596 over the TN Valley. Ambient temperatures will range from the mid 90s and could make a run at triple digits, especially Wednesday and Thursday. Oppressive moisture overnight will keep lows in the upper 70s. Due to continued high confidence in this pattern and the heat, the heat advisory was extended all the way through Thursday afternoon and evening to advertise the prolonged nature of this heat wave.

The only fly in the ointment here is that the ridge shifts northward, allowing ripples of inverted shortwave troughs to progress over the TN Valley from the east. These will be primarily diurnally enhanced, and as is common for these types of summertime patterns, most areas will reach heat advisory criteria before the showers and storms. Looking at forecast soundings, melting levels are very high but low-level lapse rates will be very impressive. A few stronger storms could produce wind gusts up to 40-50 mph. For now, we aren't expecting the potential for severe downbursts, but this will be a portion of the forecast to monitor closely.

LONG TERM

(Thursday night through Sunday) Issued at 1022 PM CDT Sun Jun 28 2026

The upper ridge will slowly make its way towards the eastern seaboard through Friday. By Saturday, ripples of shortwaves will traverse the Mississippi Valley into the Ohio and Tennessee valleys for the weekend, further weakening the influence of the ridge. At the surface, high pressure will maintain its hold over the Appalachians and into the Southeastern states through Sunday. Guidance indicates that moisture levels increase a bit more by late in the weekend as well (PWATs generally between 1.7-2.0 inches). Overall, expect a diurnal pattern to emerge by late week with daily chances of showers and storms, with generally low to medium chances (20-50%) each day. Severe weather is not anticipated at this time; however, with such warm and humid conditions, would not be surprised if the downburst potential increased by the weekend. Even with increasing shower and storm chances that may dampen the heat a bit, these will be our usual brief, summertime pop up thunderstorms and not every location will see rain.

Ultimately, the hot conditions will continue through Saturday at least until increased rain chances result in a slight cooldown for Sunday. Highs are forecast to remain in the mid to upper 90s with lows in the lower to mid 70s across north Alabama and southern middle Tennessee through Saturday. With elevated moisture, heat indices range between 100-109 degrees. NWS HeatRisk will also remain in the Major to Extreme categories (Levels 3 and 4 of 4) which are due in part to the compounding heat from earlier in the week. Lastly, forecast WBGTs generally range in the 87-90 degree range during the afternoons each day through Saturday. Therefore, heat products will likely be needed through late week. Make sure to take precautions for the dangerous heat! Wear light- colored, loose- fitting clothing, stay hydrated, and take frequent breaks in the shade if you work outside or have outdoor activities! Look before you lock - never leave people or pets in vehicles!

AVIATION

(00Z TAFS) Issued at 630 PM CDT Mon Jun 29 2026

VFR conditions expected at KHSV and KMSL TAF sites over the next 24 hours.

HUN WATCHES/WARNINGS/ADVISORIES

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

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