textproduct: Huntsville

KEY MESSAGES

Updated at 952 AM CDT Sat Jul 11 2026 - A more organized threat for severe thunderstorms will exist this afternoon and evening. Damaging winds and localized flash flooding will be the primary concerns.

- Another low chance of severe storms will exist on Sunday, with localized damaging winds and heavy rainfall the primary concerns. - Heavy rainfall and a low risk for flash flooding will continue into the first half of the work week.

NEAR TERM

(Tonight) Issued at 120 PM CDT Sat Jul 11 2026

Clusters of showers and thunderstorms have developed within the past couple of hours across the Tennessee Valley along a remnant outflow boundary. An additional weak outflow boundary moving north looks as it it will collide with another boundary across western and middle Tennessee. Hi-Res guidance shows another broken line and/or cluster of storms developing along these colliding boundaries around 19z and pushing ESE/SE through the Tennessee Valley during the late afternoon and evening hours (2-10 PM) window.

A glance at environmental parameters shows that we are primed for strong to severe thunderstorms with MLCAPE values around 2000-2500 J/kg, DCAPE values up to 1000 J/kg, and low-level lapse rates around 8.5 to 9 C/km. Additionally, model soundings exhibit an inverted v profile (dewpoint depressions of 20-25 degrees) and mid-level dry air. This will favor damaging winds/downbursts from any storms that develop (especially those that can organize into line segments or multicellular clusters). Bulk shear around 20 kts will limit how much storms organize, but regardless a very pronounced downburst threat remains and SPC has outlooked the entire CWA in a Slight Risk (Level 2/5) for this reason. Should convection to northwest move in a little later (22-01z), the severe threat may linger through the late evening hours to around Midnight.

Corfidi upshear vectors are around 300 degrees 10 kts, meaning some backbuilding will likely occur (especially with convection that anchors itself to an outflow boundary). Thus, localized heavy rainfall and flash flooding threat will be a concern, especially as we head into the evening hours as deeper convection may train over the same locations. For this reason, WPC has placed the entire CWA in a Slight Risk (Level 2 of 4) for excessive rainfall. Convection will wane after 03-06z, with only a few elevated storms potentially persisting overnight as the outflow boundary should make it just south of the area. Should any partial clearing occur, some patchy fog may develop around daybreak. Overnight lows in the lower 70s will be common.

SHORT TERM

(Sunday through Monday) Issued at 952 AM CDT Sat Jul 11 2026

With a remnant outflow across or just south of the area on Sunday, another low risk of strong to severe storms is forecast again during the afternoon and evening. Additional support for convection may arise from a passing shortwave/MCV feature noted on some of the Hi-Res guidance. This activity will be diurnally driven and pulse-like in nature with localized damaging winds being the main convective threat. However, locally heavy rainfall/flash flooding may also rise to the forefront, depending on how much rainfall occurs today and where the strongest storms track/backbuild. A pretty similar day is forecast on Monday, with potentially an even higher coverage of showers and storms. Lower instability may hinder the severe threat somewhat, but hydro concerns will still exist due to the high PWATs, slow storm motions, and wet soils. PoPs for both Sunday and Monday will be medium to high (60-90%). The cloud cover and higher rain chances will lower temperatures, with highs peaking in the low to mid 80s both days.

LONG TERM

(Monday night through Friday) Issued at 952 PM CDT Fri Jul 10 2026

Several synoptic models meander the upper low into southern middle Tennessee or northern Alabama into Monday evening. This should keep moderate to high rain chances in the forecast through the late evening hours. Some thunderstorms may occur more in the early evening that could produce some lightning and heavy downpours before instability is lost. Rain chances drop significantly and become more isolated after midnight, as the upper low moves WSW into northern Mississippi. The cloud cover (after midnight coverage of showers will be very isolated) will likely keep low temperatures in the upper 60s to around 70 degrees.

During the day on Tuesday, the upper low moves NW into Missouri in most guidance. It pulls a weak warm front northward with it at the same time. This should increase rain/storm chances on Tuesday (especially in the afternoon) significantly. High temperatures hindered by persistent cloud cover and higher precipitation chances will be below normal, only climbing into the lower to mid 80s. By the evening hours on Tuesday, a strong upper ridge pivots SE towards the Tennessee Valley. Strong subsidence pushes into the area as a result. The center of this ridge looks to remain concentrated over the Ohio Valley and the Carolinas through the end of the week. This should increase subsidence over the area and limit convective coverage along a warm front through northern Alabama to an low to medium range.

Through the end of the week, as the center of the upper ridge continues to move SE into the Carolinas, at least isolated to scattered showers and thunderstorm activity looks likely along the weak warm front (which looks to be situated across north central Alabama into eastern Missouri). Shear continues to look very weak, but good afternoon/evening instability is shown by models. Some stronger downburst potential cannot be ruled out. Though the area will be on the western edge of the strong upper ridge, this warm front should keep us from getting really hot again. However, temperatures should warm back into the upper 80s to lower 90s and it will remain very humid. Thus, heat index values will be higher (Mainly 96 to 104 degrees) Thursday through the end of next week.

AVIATION

(18Z TAFS) Issued at 1148 AM CDT Sat Jul 11 2026

VFR conditions will be the predominant flight category this afternoon and evening. However, clusters of strong to severe thunderstorms will develop along a over a weak boundary to the north this afternoon and evening and have added a TEMPO group to handle this through 22-23z where localized MVFR conditions may occur. Additional storms may develop through the evening and have handled this with a PROB30 through 04-05z. AWWs and amendments may be needed during this broad timeframe. Thereafter, MVFR conditions due to low stratus will likely persist through the remainder of the night.

HUN WATCHES/WARNINGS/ADVISORIES

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