textproduct: Huntsville

KEY MESSAGES

Updated at 1037 AM CDT Thu Jun 11 2026

- Strong to severe thunderstorms may develop from the late morning into the evening, with damaging wind gusts and localized flash flooding the primary threats.

- Heat index values of 95 to 103 degree range today.

- Additional rounds of showers and thunderstorms are forecast Saturday through Tuesday. Strong gusty outflow wind gusts, and locally heavy rainfall and flash flooding will continue to be a concern during this timeframe.

NEAR TERM

(Rest of Today and Tonight) Issued at 1037 AM CDT Fri Jun 12 2026

A generally zonal (west to east) mid and upper level flow pattern was in place across the greater Tennessee Valley. This flow in part was rounding the southern half of an upper low over Ontario. This setup should continue as we go into the weekend. A frontal boundary was located from north of Lake Erie, across the Ohio Valley to western Kentucky, to across the Ozarks and TX/OK Red River Valley. That boundary should move southward, becoming stationary across and near the forecast area over the weekend.

Of more concern is an area of convection moving to the ESE across western and middle Tennessee. This convection, that was part of a mesoscale convective system that impacted the western Ohio Valley last night. This convection was moving mainly to the east, but also building southward, forming over and north of a southward moving outflow boundary. This makes for difficult attempt in determining timing on how quickly (or slowly) will they move to the SE. Adding to that complexity is when development could occur along and south of the boundary from daytime heating and resultant higher instability.

Before the showers arrive, heating along with an increase in environmental instability will create conditions favorable for scattered to at times numerous showers and thunderstorms. At the moment, our latest timing has the showers reaching our NW Alabama and Middle Tennessee group in the next hour or two. More convection is likely in the afternoon. The recent 12Z sounding from Nashville shows a modestly unstable environment, with surface CAPE and DCAPE of 1200 and 1100 J/kg respectively, precipitable water amounts of 1.7" and bulk shear of ~20kt and 0-3 helicity ~100. This would support storms producing strong to severe outflow wind gusts. Sounding freezing levels at 14kft and locally over 15kft make hail unlikely. Locally heavy rainfall, with a risk that excessive rainfall and flooding cannot be ruled out. In locations before shower activity begins, high temperatures should rise into the upper 80s to lower 90s, with corresponding heat index values of 96 to 103 degrees.

Convection that forms should fade quickly in the early evening with a loss of daytime heating. Lows should cool to around 70. We cannot rule out patchy fog development in the late night, mainly in and near areas that receive earlier wetting rain (1/10 of an inch or greater).

SHORT TERM

(Saturday through Sunday) Issued at 1037 AM CDT Fri Jun 12 2026

The above mentioned frontal boundary should move a bit more to our south over the weekend. The presence of that boundary, along with passing upper level disturbances will keep some chance of showers and thunderstorms in the forecast Saturday into Sunday. A first round of convection should occur in the afternoon to the early evening. Before shower activity, expect another very warm to hot day with highs rising into the upper 80s to lower 90s, and corresponding heat index values in the mid 90s to 103 degrees. A thunderstorm complex moving late Saturday night could impact the Tennessee Valley before daybreak Sunday. This next complex coming in from the WNW could bring strong winds gusts and heavy downpours for Sunday morning. Otherwise after lows Sunday morning in the lower 70s, highs later in the day should be a tad cooler, mainly in the mid/upper 80s.

LONG TERM

(Sunday night through Thursday) Issued at 957 PM CDT Thu Jun 11 2026

The primary concern for early to mid next week will be a continued risk of flash flooding due to antecedent rainfall and subsequent saturated soils. Multiple days of rainfall are forecast as a series of shortwaves traverse eastward over the TN Valley. Models continue to indicate there will be plenty of moisture to work with over the area as southerly flow will bring PWATs around 1.8-2.2", which is above the 90th percentile per BMX climatology. Therefore, these storms will be efficient rainfall producers. There continues to be model disagreement in the long term period, which greatly influences how widespread rainfall is as well as if there's a risk for stronger storms. Currently, instability continues to look unimpressive with relatively weak shear and poor lapse rates. However, depending on frontal placement/timing, this could easily change over the weekend. For now, have continued with blended guidance and urge everyone with outdoor interests to check back in for forecast updates.

AVIATION

(18Z TAFS) Issued at 1240 PM CDT Fri Jun 12 2026

An area of showers and thunderstorms from a decaying MCS were progressing mainly eastward across the TN Valley, while an outflow boundary from previous convection heads southward. Locally strong outflow winds gusting to 40kt could occur with storms that form this afternoon, with CIG/VSBY reductions to MVFR. Shower coverage should end this evening with a loss of daytime heating. Patchy fog development cannot be ruled out in the late night, primarily in/near where heavier rainfall recently fell. Not enough confidence to add it to the TAF given uncertainty with future rain coverage. Low chances for shower/thunderstorm development returns by early Sat afternoon; chances however are too low for inclusion in the TAF.

HUN WATCHES/WARNINGS/ADVISORIES

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