textproduct: Huntsville

KEY MESSAGES

Updated at 1050 AM CDT Fri Jun 26 2026

- On Saturday, a medium chance (40-60%) of thunderstorms in southern middle TN and northeastern AL that have a low threat of damaging wind gusts and hail in stronger storms.

- The first big heat wave of the summer moves in Sunday and continues through all of next week. HeatRisk values of Major and Extreme (Levels 3 and 4 out of 4) indicate impactful heat all week, coupled with Heat Index values of 100-109 F.

NEAR TERM

(Rest of Today and Tonight) Issued at 1050 AM CDT Fri Jun 26 2026

This morning, a remnant outflow boundary is pushing eastward through middle TN and northern AL producing a weakening band of showers with a few embedded thunderstorms. Several areas of residual outflow boundaries from stronger activity in the Central Plains will track eastward today and generate thunderstorms, but most are expected to remain north of our CWA. Any convection we see today, if any, would be diurnally driven pulse storms capable of heavy downpours and brief gusty winds. Otherwise, look for high temps to peak in the upper 80s to low 90s today.

Despite clouds pushing in from the west as a few shortwave troughs ripple through the primarily zonal flow, we should cool into the upper 60s to low 70s tonight. This will be our last night where lows may dip into the 60s for at least a week, in all likelihood.

SHORT TERM

(Saturday through Sunday) Issued at 1050 AM CDT Fri Jun 26 2026

The wetter pattern holds on for one more day as a stronger shortwave trough progresses through the Ohio Valley Saturday. This will overspread a favorable thermodynamic profile with low level lapse rates near 9 C/km and MLCAPE near 1500 J/kg. The stronger dynamic lift will be for northeastern AL and southern middle TN, allowing for a low-end severe threat to develop for damaging wind gusts and hail. The greatest likelihood of severe weather is northeast of the TN Valley, but a 30-60% rain chance exists for all areas north of the TN river, which may put a damper on any outdoor weekend plans.

Sunday begins the pivot with a large ridge building in from the northern Gulf. A surge of moisture will push northward, bringing dew points in the mid 70s that will persist over the next week and keep overnight lows about 10 degrees above average (66 for both HSV and MSL). High temperatures on Sunday reach the low to mid 90s with a Major HeatRisk (Level 3 out of 4) and heat indices of 100-105 F.

LONG TERM

(Sunday night through Thursday) Issued at 1050 AM CDT Thu Jun 25 2026

As a quick update with the morning guidance, the ridge looks to be a little "dirtier" with coverage and likelihood of diurnal thunderstorms increasing. This presents a tricky scenario for heat products, as those who see a shower or thunderstorm may not reach criteria for heat products, but the many more who do not see any convective activity will have oppressive heat.

Previous Discussion...

The global models are in general agreement that a broad ridge will hold sway across the OH/TN Valley region throughout next week as an Omega block appears to take shape across portions of North America. This will lead to a rather oppressive heat event with daily temperatures likely reaching the mid/upr 90s each day amid ongoing high dew points/humidity. Adding to this, insolation will tend to be high each day with light winds only exacerbating the situation. Heat-related products will probably be needed through the period. For those of you with outdoor activities or work next week, plan accordingly.

AVIATION

(18Z TAFS) Issued at 1259 PM CDT Fri Jun 26 2026

VFR conditions prevail through the TAF period. Sparse shower coverage is handled with a TEMPO group for the afternoon hours. Winds may approach 10 kts at times from the south-southwest this afternoon, weaken overnight, and then approach 10 kts again in the afternoon tomorrow.

CLIMATE

Issued at 605 PM CDT Thu Jun 25 2026

Moderate to High Risk for Much Above Normal Temperatures:

The Climate Prediction Center has included the Tennessee Valley in a High Risk for Much Above Normal Temperatures for July 3. Therefore, there is a 60-80% chance for temperatures above above the mid 90s and Heat Index values above 105 degrees F during this period.

The Climate Prediction Center has included the Tennessee Valley in a Moderate Risk for Much Above Normal Temperatures for July 4. Therefore, there is a 40-60% chance for temperatures above above the mid 90s and Heat Index values above 105 degrees F 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...None. TN...None.