textproduct: Huntsville

KEY MESSAGES

Updated at 244 PM CDT Tue Sep 15 2026

- A Heat Advisory is in effect through 8 PM Wednesday for much of the forecast area.

- Moderate (Level 2/4) NWS HeatRisk values are expected for the majority of the forecast period. However, Major (Level 3/4) values are expected across parts of northwest and north-central AL (as well as southern Middle TN) through Friday.

NEAR TERM

(Tonight) Issued at 244 PM CDT Tue Sep 15 2026

A troughing west and ridging east pattern continued over the Lower-48. Strong upper level ridging was present over the Deep South and Southern Appalachians, with 500mb maximum heights around 598 decameters. This ridge should strengthen to ~600 decameters during the overnight into Wed night. Surface high pressure off of the New England coast was providing a southerly flow across the area. 2 PM temperatures have risen into the mid 90s. Dewpoints have mixed even more than earlier anticipated, from the low/mid 70s earlier this morning into the mid/upper 60s. This has decreased heat index values into upper 90s to 103 degrees. The area will be close to, if not over heat advisory levels into the late afternoon.

Daytime heating produced clouds should fade as we go into the evening. Night time lows should cool into the upper 60s northeast Alabama to low/mid 70s near large bodies of water. Patchy fog late tonight cannot be ruled out, but am not forecasting it given low confidence.

SHORT TERM

(Wednesday through Thursday night) Issued at 909 AM CDT Tue Sep 15 2026

The aformentioned upper ridge will slowly build towards the SW as we go through the midweek. Thus similar temperatures are expected, with highs in the mid/upper 90s. Dewpoints should again mix to around 70 degrees, which should keep heat index values just below Advisory threshold of 105 degrees. We will evaluate this thinking, if the new NBM coming in in the next couple of hours trend warmer, we will extend the Heat Advisory into Wednesday. An otherwise repeat forecast with lows mainly in the 70s Wed night. Another hot and dry day is forecast for Thu with highs in the mid/upper 90s, and dewpoints mixing down into the upper 60s to around 70, which would keep apparent temperatures just below advisory criteria. Even though we may not have official advisories active, area residents should still practice heat alleviation tactics, like avoiding direct sun exposure for as much as possible, drinking plenty of water, and taking frequent breaks.

LONG TERM

(Friday through Monday) Issued at 1031 PM CDT Mon Sep 14 2026

Late this week the anchored ridge across the Southeast will continue to retrograde and weaken as a cut off low moves westward across Florida. What remains of the ridge will keep around warmer than normal temps in place with highs in the mid to upper 90s and heat index values around 100 degrees Friday and Saturday.

This weekend, the low will continue to slide westward. However, models are now not as certain on what the path and trajectory of the low will be as it is suggesting it slows down the westward progression on Sunday and stalls it out to our south through Monday. This pattern leads to a greater assumption that the front well to our north that drapes over into the OH Valley and Mid Atlantic will not make it through the TN Valley. The persistent sfc high along the east coast will cause it to become more of a wedge front for us on Sunday into Monday. Temps and POPs on Sunday and Monday will depend a lot on the pattern than ends up taking shape. However, there should be a downward temp trend with models favoring highs "only" in the 80s on Monday as medium rain chances (40-60%) move in.

AVIATION

(18Z TAFS) Issued at 1232 PM CDT Tue Sep 15 2026

Surface high pressure off of the New England coast, along with strong upper ridging aloft, will help maintain VFR conditions across the TN Valley. Southerly winds of 5-10kt this afternoon should back to the SE around 5kt tonight. SE winds of 5-10kt are expected shortly after daybreak Wed. Strong daytime heating will produce fair weather CU and maybe a few TCU during the time of peak heating.

HUN WATCHES/WARNINGS/ADVISORIES

AL...Heat Advisory until 8 PM CDT Wednesday for ALZ001>009.

TN...Heat Advisory until 8 PM CDT Wednesday for TNZ076-096-097.