textproduct: Huntsville

KEY MESSAGES

Updated at 1056 PM CDT Sat Jun 27 2026

- A heat wave builds in on Sunday and continues through much of the week with a Heat Risk value of 3 out of 4 (Major category) to 4 out of 4 (Extreme category) across the entire Tennessee Valley.

- A Heat Advisory is in effect for the entire Tennessee Valley from 12 PM today through 7 PM Tuesday.

NEAR TERM

(Today) Issued at 258 AM CDT Sun Jun 28 2026

Fairly tranquil conditions early this morning with just some passing mid to high clouds from remnant convection to the north and west. A strong area of high pressure over Texas will continue to build into the Tennessee Valley. Strong subsidence from the ridge will suppress most cloud cover and rain chances (though a low chance (20-30%) does clip our southern middle Tennessee counties in the afternoon). The main weather concern will be a building heatwave that will begin today and continue through much of the week. Underneath this ridge is a dome of very warm and humid air. Combined with ample sunshine and southerly winds, temperatures will climb into the low to mid 90s this afternoon, with heat index values above 100 degrees (and in some locations above 105 degrees). The heat today is the beginning of a week long heatwave that will intensify through the week with limited to no relief at night. As such a Heat Advisory has been issued for the entire Tennessee Valley and it will going into effect at Noon this afternoon through 7 PM Tuesday (though it will likely be extended later this week). Make sure to take precautions for the dangerous heat!

SHORT TERM

(Sunday night through Tuesday night) Issued at 1056 PM CDT Sat Jun 27 2026

The heat wave will be fueled by a persistent 594dam high aloft, leading to the warmest conditions we have seen so far this year. This high will be anchored over the OH Valley down through the TN Valley through much of the work week and will likely keep heat related advisories in place over multiple days. The heat threat will come from the combination of temps in the 90s (upper 90s some afternoons) and dewpoints in the low to mid 70s that will bring heat indices to the 100-109 degree range. Unfortunately recent guidance has trended warmer over the past day or so for Monday and Tuesday, with heat indices approaching 110 degrees each afternoon. This would put us closer to Extreme Heat Warning criteria, so this trend will have to be monitored closely over the next 24 hours. In addition, overnight lows in the mid to upper 70s will provide very little relief from the warm and humid conditions during the day, keeping us in a Major to Extreme HeatRisk through the short term period. While the forecast looks relatively dry during this period, there are low (10-20%) chances for a pop up thunderstorm Tuesday afternoon. Please keep up with the latest forecast as we head into next week. Those with outdoor plans should prioritize heat safety by staying hydrated, wearing light colored clothing, taking frequent breaks in the shade or A/C, using sunscreen, and never leaving people or pets behind in vehicles.

LONG TERM

(Wednesday through Saturday) Issued at 1056 PM CDT Sat Jun 27 2026

By midweek, the upper ridge will shift from being centered over the Tennessee Valley to the Appalachians. Even so, this feature will largely maintain its hold over the Southeast through the work week. Global models then show it shifting eastward and flattening a bit by the weekend as a series of shortwaves ripple over the Great Lakes region. At the surface, high pressure persists over the Appalachians and Southeastern states through the early part of next weekend. While a very low chance of a few showers/storms is suggested by the NBM for Wednesday and Thursday, the aforementioned pattern indicates that most areas are more likely to remain dry. Although, by late in the week, as the upper ridge shifts a bit more east and flattens, perhaps the return flow would be enough to increase shower and storm chances (20-30%) and bring a more summertime, diurnal pattern to the region.

Overall, the main concern will be the continued dangerous heat. Highs are forecast to remain steady in the mid 90s, with some spots potentially reaching the upper 90s (especially over NW AL) each day. Heat indices generally range between 102-110 degrees during this time as well. In addition, NWS HeatRisk is slated to be Major to Extreme (Levels 3 and 4 out of 4) Wednesday through Saturday. This is likely due in part to low temperatures not cooling off much at night, with values forecast to merely drop into the mid to upper 70s each night. WBGTs are also in the upper 80s to around 90 degrees. Therefore, not much relief is in sight, at least through next Saturday. Heat Advisories will likely be issued to account for this heat wave.

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

(06Z TAFS) Issued at 1237 AM CDT Sun Jun 28 2026

VFR conditions will prevail at each terminal through the period with light winds and a mostly clear sky.

CLIMATE

Issued at 552 PM CDT Sat Jun 27 2026

Moderate Risk for Much Above Normal Temperatures:

The Climate Prediction Center has included the Tennessee Valley in a Moderate Risk for Much Above Normal Temperatures on July 5. This means that there is a medium chance (40-60%) for temperatures to reach or exceed 91-94 degrees with heat indices above 105 degrees during this period.

More information on the CPC U.S. Hazards Outlook can be found at:

https://www.cpc.ncep.noaa.gov/products/predictions/threats/threats.php

HUN WATCHES/WARNINGS/ADVISORIES

AL...Heat Advisory from noon today to 7 PM CDT Tuesday for ALZ001>010- 016.

TN...Heat Advisory from noon today to 7 PM CDT Tuesday for TNZ076-096- 097.