Area Forecast Discussion
Issued by NWS Huntsville, AL
Issued by NWS Huntsville, AL
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089 FXUS64 KHUN 251137 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 637 AM CDT Wed Sep 25 2024 ...New AVIATION... .NEAR TERM... (Today) Issued at 233 AM CDT Wed Sep 25 2024 Weak cold front continues to drift eastward closer to NW AL this early Wed morning, as an upper low/trough axis drops into the Midwest region. Some light rain/showers are occurring ahead of the front across parts of north central/NE AL. This activity will increase though along/ahead of the front with the onset of the daytime period, as the front crosses into NW AL. Scattered to perhaps numerous showers/few tstms are expected for areas S/E of the front going more into the daytime hrs, as the upper low drops more into the Mid South area. Little in the way of instability should offset the prob for any stronger storms today, with mainly just some locally heavy rainfall possible with the activity later today. Rainfall amounts up to an inch are possible today, mainly along/east of I-65. Given the cloud cover/rainfall, highs will struggle to surpass the mid/upper 70s for most of the area. && .SHORT TERM... (Tonight through Friday night) Issued at 233 AM CDT Wed Sep 25 2024 The front will drift more to the east closer to the I-65 corridor tonight, with rainfall diminishing with the loss of weak buoyant energy. Weak convergence along the front may still allow for some shower/tstms overnight, mainly east of I-65. The influx of cooler air will at least translate into lows tonight in the lower/mid 60s. The pattern will then change considerably starting Thu, as Tropical Storm Helene in the western Caribbean lifts northward and strengthens into a hurricane. Outer rain bands/squalls associated with Helene will begin to spread northward into the eastern half of the region. Periods of moderate/heavy rainfall can be expected into Thu night, as the hurricane makes landfall along the FL Big Bend region and then lifts to the NNE. Additional rainfall amounts around 2-4 inches are possible Thu/Thu night, especially east of I-65 and a Flood Watch will likely be needed for the eastern half of the area during this time frame. Wind gusts east of I-65 could also be around 20-30 MPH into Thu night. These speeds are just below Wind Advisory criteria, although any change in the track of Helene to the west once inland could result in higher winds/gusts. The threat for localized/flash flooding could extend into Fri morning for areas east of I-65, as the remnants of Helene begin to lift N/E of the area and the upper low to the west drifts into the lower MS Valley. Going more into the day Fri, the better moisture convergence axis between these two systems will lift northward into TN, allowing for a diminishing trend in the rainfall over much of the area. This pattern continues into Fri night, as the remnants of Helene begin to be absorbed into the upper low to the west. Given the continued cloud cover/rainfall, highs Thu/Fri will likely trend in the lower/mid 70s, with lows into early Sat predom in the mid 60s/near 60F. && .LONG TERM... (Saturday trough Tuesday) Issued at 233 AM CDT Wed Sep 25 2024 The upper low will then begin to lift N/E of the central TN Valley this weekend, providing for a low chance of showers (20-30%) both Sat/Sun with some decreasing cloud cover. Minimal rain chances are expected into the first half of the work week as well, as a reinforcing cold front out of the NW sweeps thru the region. With the decrease in cloud cover/rainfall, highs this weekend will be more in the mid/upper 70s, before climbing into the upper 70s/near 80F Mon/Tue. Overnight lows thru the latter half of the forecast period also look to remain in the mid 60s/near 60F. && .AVIATION... (12Z TAFS) Issued at 637 AM CDT Wed Sep 25 2024 Cigs are just above 3K ft heading into the morning hrs this Wed, as a weak cold front crosses into NW AL. MVFR cigs near 3K ft are expected to develop ahead of the front closer to the KHSV airfield later this morning. Sct shra are also expected to form along/ahead of the front late this morning and a TEMPO group has been included for KHSV around 17-21Z to account for any reduced cig/vis. PROB30 groups were then maintained later this afternoon for both main terminals to account for any additional shra. Precip is then expected to diminish this evening, with VFR conds prevailing into early Thu morning. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...09 SHORT TERM....09 LONG TERM....09 AVIATION...09