textproduct: Huntsville

KEY MESSAGES

Updated at 1056 AM CDT Tue Aug 4 2026

- Chances for showers and thunderstorms will range from 10-20% (west) to 50-60% (east) from today-Thursday. Lightning, heavy rainfall and brief strong wind gusts will be the greatest impacts from the storms.

- Mainly afternoon/evening showers and storms will continue each day from Friday-Tuesday, with rain chances in the 20-40% range (40-60% range on Saturday).

- NWS Heat Risk highlights Moderate (Level 2 of 4) heat impacts across the Tennessee Valley beginning Thursday. These values will increase to Major (Level 3 of 4) for parts of the area on Monday/Tuesday.

NEAR TERM

(Rest of Today and Tonight) Issued at 1056 AM CDT Tue Aug 4 2026

An area of low pressure at the surface will travel westward across southern portions of GA/AL/MS today and tonight, as the parent cutoff upper cyclone drifts northward across GA and gradually weakens. As this occurs, a well-defined surface trough/streamline confluence axis (extending northward off the low) will enter northeastern AL later this morning, before progressing very slowly westward for the remainder of the day and night. In the presence of an otherwise unfavorable environment for lift aloft, low-level convergence in the vicinity of the trough (and in the presence of a moist boundary layer warming into the m-u 80s), combined with MLCAPE of 1000-2000 J/kg will be sufficient for the development of both showers and thunderstorms, initially beginning in the east between 15-17Z. With deep-layer NNE flow of 10-20 knots expected to persist in the circulation around the cutoff low, convective cells will be moving south- southwestward at a decent pace and this should limit the overall risk for flash flooding. However, lightning and heavy rainfall can be expected, along with brief strong wind gusts up to 40 MPH.

In similar fashion to yesterday evening, isolated showers and thunderstorms are expected to continue for a short period after 0Z (especially in the vicinity of the surface trough), but should dissipate between 2-4Z. As skies clear late this evening, conditions will once again become favorable for the development of patchy fog (some of which could be locally dense in locations that experience wetting rainfall later today). Overnight lows will be similar to those observed the past couple of nights (u60s-l70s).

SHORT TERM

(Wednesday through Thursday night) Issued at 1056 AM CDT Tue Aug 4 2026

Over the course of the short term period, a cutoff upper low (initially situated to the immediate east of the CWFA) will open into a highly sheared trough as the northern portion of the wave becomes absorbed in the polar westerlies while the southern portion lingers across the central/southern Appalachians. In the low-levels, an increasingly diffuse surface trough/wind shift axis will exist across the central or western portion of the forecast area on Wednesday, and should once again initiate development of deep/moist convection by late morning (with additional showers and thunderstorms focused along convective outflow boundaries and in preferred regions of orographic ascent across northeast AL/southern Middle TN later in the afternoon). Shear will remain very weak tomorrow, and with similar values of MLCAPE (1000-2000 J/kg) and PWAT (1.8-2"), we expect lightning, locally heavy rainfall and brief strong winds to be the greatest impacts. However, due to the decaying nature of the cutoff low, steering flow will back to the NW and diminish, resulting in slower cell motions to the southeast. Present indications are that this activity will dissipate by 2-4Z, with patchy fog expected during the early morning hours Thursday as temps fall into the u60s-l70s.

During the timeframe from Thursday-Thursday night, environmental conditions will become less conducive for convection as a mid- level ridge builds across much of the Gulf Coast and a Bermuda high expands southwestward in the low-levels (resulting in a light prevailing flow from the SSE). Nevertheless, at least widely scattered afternoon thunderstorms are expected in our region on Thursday (perhaps most concentrated in the elevated terrain of the east), but overall coverage should be lower (especially as slightly drier air may spill southwestward from the Appalachians). Due to a lower coverage of afternoon clouds/precipitation, highs will return to the u80s-l90s, with overnight lows rising into the l-m 70s Friday morning.

LONG TERM

(Friday through Monday) Issued at 930 PM CDT Mon Aug 3 2026

On Friday, the ridge to our west will expand and provide an increase in heat concerns that will persist through the weekend. Otherwise, there's a low to medium chances (20-40%) for diurnal showers and thunderstorms with the greatest coverage east of I-65. This weekend, moisture will wrap around the western side of the subtropical ridge out in the Atlantic and bring an increase in rainfall, low to medium (30-60%) chances Saturday through Monday. Highest coverage will again be east of I-65. Highs will be in the upper 80s to lower 90s Friday through Monday but heat index values will push above 100 degrees. At this time, values remain just below Heat Advisory criteria however trends will be monitored. Regardless, practice heat safety!

AVIATION

(12Z TAFS) Issued at 547 AM CDT Tue Aug 4 2026

VFR conditions are forecast to prevail through the TAF period. However, a low chance of showers exists at KHSV this afternoon through the evening which has been continued as a PROB30 group. Additionally, a low chance of patchy fog exists tonight, but confidence is too low to include this in the official TAF package.

HUN WATCHES/WARNINGS/ADVISORIES

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