textproduct: Huntsville

KEY MESSAGES

Updated at 356 PM CDT Sat Jul 4 2026

- A Heat Advisory remains in effect through 7 PM today, with some heat index values reaching up to 106F.

- After lower coverage of showers and thunderstorms today (30-50%), afternoon/evening showers and storms will increase to 40-80% from Sunday-Friday (highest on Monday/Tuesday).

- Some storms on Sunday could be strong to severe producing damaging winds.

- A low risk of flash flooding or river flooding may develop next week.

NEAR TERM

(Tonight) Issued at 356 PM CDT Sat Jul 4 2026

Isolated showers are beginning to develop over NW Alabama near the MS/AL border. The better coverage of shower and thunderstorms is occurring in Arkansas into northern Mississippi. Cloud cover today has kept northern Alabama a bit more stable. However, enough sunshine has occurred to push SBCAPE values into the 2500 to 3500 J/KG range. SPC analysis does show DCAPE values around 1300 J/KG over the area. Lapse rate (especially mid level) are not that good, but low level lapse rates have steepened to around 7.5 degrees/km. Forecast soundings do not show impressive theta E differences this afternoon and evening (15-20 generally).

Forcing may not really move into NW Alabama to help promote more robust thunderstorm activity until this evening, when instability and DCAPE values may start to wane. That being said some scattered showers and thunderstorms could develop between now and 8 PM in northwestern Alabama. This should push east this evening, but coverage of activity is not clear. For now, kept with 30 to 50 percent coverage of showers and thunderstorms. At this time, not expecting organized severe thunderstorm activity, though a few could be strong producing gusty winds to 50 mph, frequent lightning, and heavy rainfall.

Models continue to be divided on whether additional storms form and push southeast tonight after midnight. For now, kept with guidance, which dissipates chances after 1 AM. However, this may have to be adjusted in future shifts.

SHORT TERM

(Sunday through Monday night) Issued at 356 PM CDT Sat Jul 4 2026

The fairly amplified longwave trough axis pushes further east into the Ohio Valley southwest into eastern Arkansas/extreme western TN Sunday into Monday. This should focus strong lift over the area starting in the early morning hours on Sunday. Shear remains extremely weak. However, there may be just enough dry air and ample instability ahead of the longwave trough axis to produce some strong to severe microburst potential Sunday afternoon and evening. It should be cooler again with highs only reaching the upper 80s to lower 90s. However, afternoon SBCAPE could climb to between 2000 and 4000 J/KG again. Main threat would be damaging microburst winds with this activity. The main window for this activity is between 1 PM and 8 PM. Expect this activity to become isolated to scattered overnight and lose it intensity.

This trough axis does not move very quickly eastward through Monday night. This will keep scattered to numerous showers and thunderstorms in the forecast during that period. However, they are not expected to be severe at this time. Highest precipitation chances will be in the midday to early evening period mostly with more scattered chances in the overnight period. High PWATS will be in place, so flash flooding risk will increase during that period. Some minor river flooding may be possible. This wet pattern will keep highs much more pleasant (upper 80s to lower 90s). Though it will still be humid, so heat index values will remain in the 96 to 103 degree range mostly. So make sure to remain hydrated if working outside, even though high temperatures will be much lower.

LONG TERM

(Tuesday night through Saturday) Issued at 356 PM CDT Sat Jul 4 2026

The warm and humid airmass will continue into next week as an upper trough axis exits to the east and upper ridging builds over the area toward the mid-late week period. Fortunately this ridge looks to be a little weaker therefore temps and heat indices won't be quite as hot as we have seen this past week. An axis of higher moisture will be positioned over the TN Valley over much of the long term period and will lead to medium chances (40-60%) for rain and thunderstorms each day, peaking during the afternoon hours. PWATS will climb back to the 2-2.2" range and will bring an increased risk for localized flooding, especially over areas that receive consecutive days of heavy rainfall. For now, organized severe weather is not anticipated but some thunderstorms could be strong to marginally severe given afternoon instability. Daily highs will top out in the upper 80s/lower 90s with heat indices reaching the mid 90s to low 100s.

AVIATION

(00Z TAFS) Issued at 447 PM CDT Sat Jul 4 2026

VFR conditions are expected for most of the period. There is a low chance of a SHRA or TSRA through 06Z. The chance is a bit higher at KMSL so have included VCSH as a few -SHRA have already attempted to develop in this area. Patchy BR or FG is expected from 09-12Z, with a TEMPO forecast of 5SM BR (MVFR) at KHSV and KMSL. Scattered SHRA and TSRA are forecast again by 05/18Z, and have included PROB 30 groups for both KHSV and KMSL.

HUN WATCHES/WARNINGS/ADVISORIES

AL...Heat Advisory until 7 PM CDT this evening for ALZ001>010-016.

TN...Heat Advisory until 7 PM CDT this evening for TNZ076-096-097.