textproduct: Huntsville

KEY MESSAGES

Updated at 1047 AM CDT Sat Jun 13 2026

- Heat Risk is moderate to major today with heat index values of 95-103 F.

- Low chances for thunderstorms this afternoon and evening. A few could be strong with gusty winds and heavy downpours.

- Additional rounds of showers and thunderstorms are forecast Sunday and Monday with a risk of strong gusty outflow wind gusts and locally heavy rainfall/flooding.

NEAR TERM

(Rest of Today and Tonight) Issued at 1047 AM CDT Sat Jun 13 2026

This afternoon brings high temperatures in the upper 80s to lower 90s with heat indices in the upper 90s to around 100 degrees. Light winds and mostly sunny skies will prevent much relief from this heat for those outdoors. Much of the area is in a Moderate Heat Risk with localized areas of Major Heat Risk. In turn, heat will affect those sensitive to heat as well as those without adequate cooling/hydration. Be sure to practice heat safety by staying hydrated and seeking shade this afternoon if outdoors.

Diurnal heating this afternoon will contribute to a low chance (30% or less) of a few pop up thunderstorms throughout the area. While shear remains weak throughout the area, CAPE of ~3000 J/kg as well as sufficient low level lapse rates will allow a gusty to damaging wind threat. Additionally, the potential for backbuilding/training exists with slow-moving thunderstorms. This will allow a low flash flood threat in areas where thunderstorms form and train over the same area.

The primary concern in the near term will be a shortwave shifting southward and a subsequent potential MCS that shifts southeastward towards the Tennessee Valley late tonight into early Sunday. Models have had quite a bit of disagreement with the evolution of said MCS, with some having it fully decay before reaching NW AL. However, recent trends look more favorable for the system to make it to NW AL before gradually weakening as it approaches I-65. Current timing for arrival of thunderstorms in NW is 06-08Z. Slow Corfidi upshear vectors in addition to high PWATs (~1.9-2.1") will support a medium threat for flash flooding as the system progresses southeastward. Instability will support at least a gusty wind threat with CAPE values around ~800-1000 J/kg. Shear and lapse rates continue to look weak along with strong backing aloft, so tornadoes and widespread damaging wind remain off the table for this system at this time. Have kept PoPs around 50% due to continued uncertainty in the evolution.

SHORT TERM

(Sunday through Tuesday) Issued at 1047 AM CDT Sat Jun 13 2026

A sfc high in the Gulf/Florida region will keep southerly flow in place for the TN Valley through Sunday, contributing to high PWATs and a potential for flash flooding as a cold front pushes southward through the area. Recent HIRES guidance indicates PoPs primarily bring in NE AL and southern middle TN as the front pushes through, keeping rainfall scattered spatially in nature. Have kept in 30-60% PoPs throughout the area Sunday afternoon into the evening hours before decreasing overnight. With similar environmental conditions to this afternoon (but better forcing), any storms that form along the frontal boundary will be capable of at least a gusty wind threat as well as heavy downpours. The good news is that storms along the boundary will be generally quick- moving and a widespread flash flooding threat will be unlikely. The Weather Prediction Center has all of northern AL and southern middle TN in a Marginal Risk (level 1 of 4) for excessive rainfall Sunday. Despite not being outlooked by SPC at this time, a low chance of a severe storm or two with the threat of damaging winds exists.

Post-frontal conditions should be relatively dry through the rest of the short term as sfc high pressure works into the area from the west. However, as the aforementioned front stalls along the Gulf, lingering showers and thunderstorms have a low chance of hanging out over the southern portions of our area (primarily Cullman). On the bright side, clouds associated with the frontal boundary will keep us relatively cooler as highs warm into the upper 70s to lower 80s throughout the TN Valley.

LONG TERM

(Monday night through Friday) Issued at 1033 PM CDT Fri Jun 12 2026

The TN Valley will be on the northern side of a cold front as we head into the long term period, bringing a temporary but much welcomed break from the heat and humidity. In fact, temps will fall to the low to mid 60s Tuesday morning with highs in the upper 70s/low 80s in the afternoon. Upper troughing will shift east through the eastern CONUS, pushing high pressure and dry conditions into the area on Tuesday before a return to southerly flow brings low chances for mainly diurnal showers and storms Wednesday. Temps will be on the rise during the mid-week period as well with highs approaching the upper 80s to lower 90s Wednesday and Thursday. Higher rain chances (60-80%) toward late next week as another upper wave and associated cold front approaches the area.

The forecast for next week still remains of lower confidence given model discrepancies at this range, but the threat for flash flooding early next week appears lower than in previous days.

AVIATION

(18Z TAFS) Issued at 1228 PM CDT Sat Jun 13 2026

VFR conditions are forecast to continue this afternoon. While a few thunderstorms have a low chance of popping up this afternoon, confidence is too low in this affecting the terminals to officially include this in the TAF. Amendments may be needed. Overnight into early Sunday, a PROB30 group was added to both KMSL and KHSV for MVFR conditions as a thunderstorm complex shifts into NW AL and gradually weakens eastward. VFR conditions return during the late morning and will remain in place through the afternoon before another low chance of thunderstorms pushes into NE AL (potentially affecting KHSV).

HUN WATCHES/WARNINGS/ADVISORIES

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