Area Forecast Discussion
Issued by NWS Huntsville, AL
Issued by NWS Huntsville, AL
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645 FXUS64 KHUN 221133 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 633 AM CDT Wed Jul 22 2026 ...New AVIATION... .KEY MESSAGES... Updated at 633 AM CDT Tue Jul 22 2026 - Unsettled weather will continue for the remainder of the week, with daily chances of showers and thunderstorms, as a frontal boundary remains stationary south of the Tennessee Valley. - Into the late week, locally heavy rainfall could occur near and south of the Tennessee River, as well as near and east of Interstate 65 corridor. && .NEAR TERM... (Today) Issued at 100 AM CDT Wed Jul 22 2026 The line of strong to severe storms moving south from central Tennessee continues to overall weaken, except where it is pushing into more abundant CAPE in SW Tennessee and northern Mississippi SBCAPE in those areas still 2500 to 4000 J/KG). Newest mesoscale models continue this trend as well. That being said, wind shear over 30 knots is mainly in place near the TN/AL border and further north. SBCAPE over northern Alabama and southern middle Tennessee is still around 1500 J/KG to 2000 J/KG (Mainly NW AL for higher SBCAPE). So, parameters are still in place over southern middle Tennessee such that a low chance severe threat is still in place. This threat in most guidance shifts east with time and dissipates towards or before daybreak on Wednesday as we lose more instability. We may have to watch Lincoln, Moore, and Franklin counties in TN for possible flash flooding through daybreak given potentially high rainfall rates that could be realized with some training of stronger storms possible over those areas. Lows tonight will be on the warm side only dropping into the lower to mid 70s. We should see a lower coverage of showers and storms (30-40%) after daybreak in southern middle Tennessee Wednesday morning before increasing in coverage to between 40 and 60 percent in the afternoon and early evening hours (especially east of the I-65 corridor. Given very high PWAT values through the day well over 2 inches, some flash flooding could occur in southern middle Tennessee and some areas east of the I-65 corridor into the early evening hours. However, as we lose stronger shear this morning, no additional severe thunderstorm development is expected. && .SHORT TERM... (Wednesday night through Friday) Issued at 933 PM CDT Tue Jul 21 2026 Slightly cooler air north of the front should filter across the area Wed night, with lows a bit more comfortable from the mid 60s to around 70. The aformentioned frontal boundary will become stationary south of the Tennessee Valley from Thu into the upcoming weekend. The presence of this front will keep medium to high chances of showers/thunderstorms, mainly for areas south of the Tennessee River and east of I-65. Low to medium rain chances are expected elsewhere. Some of the showers more to our south and east could be locally heavy. High enough rainfall amounts will be sufficient to warrant low chances of excessive rainfall and the potential for flash flooding. Cooler conditions will be noted Thu with highs in the mid/upper 80s. More comfortable lows will continue as well Thu night with lows in the mid 60s to around 70. A tad warmer Fri with highs in the mid 80s to around 90. && .LONG TERM... (Friday night through Tuesday) Issued at 933 PM CDT Tue Jul 21 2026 The long term period will largely be influenced by an upper level ridge and subsequent sfc high pressure system looming over the Deep South and slowly shifting eastward into the lower Mississippi Valley. A few features to watch will be how remnants of Tropical Storm Bertha interact with a cold front south of our area. How these two features interact will largely dominate the forecast for Friday into Sunday. We currently have low to medium rainfall chances through that time period and are outlooked for a Marginal risk (level 1 of 4) for flash flooding from the Weather Prediction Center. If the front shifts over the area and stalls, the flooding threat will increase. However, there is still too much uncertainty to dive into details as it is several days out. If you have outdoor plans early this weekend, it`s highly encouraged to check back in for updates. Otherwise, as the aforementioned ridge shifts eastward, dry weather should return to the area early next week along with a warming pattern as highs begin to climb back into the mid to upper 90s. Additional heat products will likely need to be considered if trends continue. && .AVIATION... (12Z TAFS) Issued at 632 AM CDT Wed Jul 22 2026 Predominantly VFR conditions should continue at both terminals through 17Z. A PROB30 group was included though to account for possible -TSRA impacting the terminals between 13Z and 17Z as a front approaches the area. Expect CIGS to break up around 17Z, with another prob30 group for -TSRA and MVFR CIGS/VSBYS. Guidance seems to oscillate the front back to the north this evening. This should bring higher PoP back into the KHSV terminal in particular. For now, added a tempo group to account for this between 23/03Z and 23/07Z. Lower rainfall chances are possible further west at KMSL, so only a PROB30 group to -TSRA activity and MVFR CIGS/VSBYS was added there between 08Z and 12Z. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...KTW SHORT TERM....RSB LONG TERM....HC AVIATION...KTW