textproduct: Huntsville

KEY MESSAGES

Updated at 1141 AM CDT Mon Jul 27 2026

- Heat Advisory and Extreme Heat Warning in effect for portions of the TN Valley through 7PM Tuesday.

- A cold front will bring additional thunderstorms to the region Tuesday night/Wednesday morning, with coverage highest in the east. A a few strong- severe storms may occur during this timeframe.

- A drier airmass will encompass the region from Wednesday- Friday, but chances for showers and some thunderstorms will increase once again this weekend.

NEAR TERM

(Tonight) Issued at 357 PM CDT Mon Jul 27 2026

So far this afternoon the skies have remained mostly clear with only a few developing cu over north central and northeast AL. The main concern for the remainder of the day continues to be the dangerous heat as current heat indices range from the mid 90s to near 105 degrees. An Extreme Heat Warning is in effect for far NW AL and a Heat Advisory is in effect for remaining areas until 7pm tomorrow. Rain and thunderstorm chances will be below 20% through the overnight period. With light winds and mostly clear skies expected overnight, patchy dense fog was added to the forecast through the early morning hours. Otherwise, no major adjustments were made to the near term forecast.

Previous discussion: Showers and thunderstorms have moved out of the TN Valley leaving us with mostly sunny to partly cloudy skies at this hour. This will give way to temperatures running up into the mid 90s in NW AL and the lower 90s in NE AL. With plenty of moisture in place, heat index values will climb to 103-112 degrees across the TN Valley. Current forecast trends and observations led us to expand the Heat Advisory eastward to include NE AL and upgrade portions of NW AL (Lauderdale, Colbert, and Franklin Co) to an Extreme Heat Warning. These products will go through 7pm Tuesday, however the Extreme Heat Warning may need to be expanded eastward to the I-65 corridor for Tuesday afternoon if trends persist.

There may be a shower or two today, due to the heat and moisture in place, but we don't have any good lifting mechanisms in place. The MCS that will dive southward out of the Midwest today is forecasted to miss us to the NE tonight, however will not rule out some showers and thunderstorms brushing Southern Middle TN, maybe into NE AL if it can make it. For this, SPC has a Marginal Risk out for Southern Middle TN to accommodate the threat for strong winds in some of the stronger storms.

SHORT TERM

(Tuesday through Wednesday) Issued at 357 PM CDT Mon Jul 27 2026

Northerly to northwest flow will persist aloft as a strong upper ridge sits over the central CONUS and H85 height rises result in continued above normal heat. With the better forcing for rain and thunderstorms to our northeast tomorrow, the heat will once again be the main concern as forecast heat indices climb over 110 degrees over portions of NW AL tomorrow afternoon. This will result in a major risk for heat related illness, especially for those spending time outdoors without proper heat resistant clothing and hydration. As always, remember to look before you lock and never leave people or pets unattended in vehicles!

An upper wave will approach from the north as we head into Wednesday morning and will bring a frontal boundary to the area that will provide some relief from the intense humidity we have felt lately. As this happens, we do expect a cluster or complex of thunderstorms to move into the area either ahead of or right along the front. We will maintain medium rain and thunderstorms chances for early Wednesday morning as there is still some uncertainty on how widespread and intense the rainfall may be. The front is progged to exit the area by early Wednesday afternoon, and cooler highs (in the upper 80s/lower 90s) will follow.

LONG TERM

(Wednesday night through Sunday) Issued at 1109 PM CDT Sun Jul 26 2026

Extended range guidance from the lastest suite of global models continues to indicate that our forecast area will remain under the influence of moderately strong NNW flow aloft and dry northerly flow at the surface from Wednesday night-Friday. With dewpoints falling into the 60s, overnight lows will respond by dropping to more comfortable levels (m-u 60s), with afternoon highs remaining in the u80s-l90s. However, it appears as if deep-layer moisture will quickly return to the region at some point Friday night/Saturday morning as a compact surface low shifts eastward from the southern Plains into the Lower-MS Valley. Although strong low-level warm/moist advection ahead of the low will contribute to an increase in the coverage of convection across our region, current thinking is that instability will remain low (at least compared to the past couple of weeks) and should limit the overall coverage of thunderstorms. That said, the low-level jet will likely increase considerably ahead of this system, and may yield at least a limited risk for storm organization on Friday night/Saturday. By Sunday, the surface low is expected to weaken and transition into a broad trough across the Gulf Coast states, which should lead to a gradual decrease in the coverage of precipitation across our region.

AVIATION

(00Z TAFS) Issued at 602 PM CDT Mon Jul 27 2026

VFR conditions are forecast through the TAF period at both KMSL and KHSV.

HUN WATCHES/WARNINGS/ADVISORIES

AL...Extreme Heat Warning until 7 PM CDT Tuesday for ALZ001>003.

Heat Advisory until 7 PM CDT Tuesday for ALZ004>010-016.

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