textproduct: Huntsville

KEY MESSAGES

Issued at 157 AM CDT Thu May 21 2026

- High chances (70-90%) of showers and thunderstorms are forecast each day through Tuesday of next week.

- Locally heavy downpours and lightning will be the primary hazards, but brief gusty winds will also occur with the stronger thunderstorms.

NEAR TERM

(Today) Issued at 157 PM CDT Thu May 21 2026

A few clusters of rain showers will continue in the predawn hours across the Tennessee valley -- with perhaps a rumble of thunder or two at times. This activity will temporarily wane around sunrise, but low stratus will remain into the mid to late morning hours. Temperatures will be tricky to forecast today and will be highly dependent on how many breaks in the cloud cover that can develop heading into the afternoon hours. Still think that some partial heating will take place, leading to highs reaching the upper 70s to lower 80s. Ample destabilization of the boundary layer, coupled with a weak shortwave moving NE into the area during the 15-18z, will generate additional clusters of showers and thunderstorms during the afternoon hours. PWATs around 1.6"-1.7" (90th percentile per BMX sounding climo) will make this activity efficient rainfall producers. Thus, locally heavy downpours/rainfall will be a threat with this activity along with frequent lightning and brief, gusty winds. Convection will regenerate/continue into the evening hours, before eventually dissipating late tonight.

SHORT TERM

(Tonight through Saturday) Issued at 754 PM CDT Wed May 20 2026

A similar pattern will remain in place through Saturday with additional shortwaves arriving Thursday night into early Friday, and again Friday night into early Saturday. These waves may have stronger low to mid level flow of 30-40kt at times, which may amplify the risk of gusty winds with the stronger storms. Lower PWs and drier air may follow behind the wave Saturday morning, but the blend of models still includes medium to high PoPs through the afternoon as well. This is something we may need to modify in future forecasts. High temperatures will remain in the upper 70s to lower 80s with lows in the lower to middle 60s.

LONG TERM

(Saturday night through Wednesday) Issued at 754 PM CDT Wed May 20 2026

A fairly stagnant weather pattern will remain in place late this weekend into the middle of next week. A 5h ridge will be anchored over the southwest Atlantic into GA and FL northwest into the Upper MS valley as a cutoff low in the southern Plains slowly moves northward through the week. The medium range models shows a similar low developing over the southern Plains by mid to late week. However, there is disagreement in the ridge position, the ECMWF is favored here due to its persistence this week. In either case, the pattern will keep persistent deep layer southerly flow in play for the TN valley during this period. This results in medium to high chances of showers and a few thunderstorms will persist Sunday and Monday lowering to low to medium Tuesday and Wednesday, with greatest PoPs during the daytime heating hours into the early evening.

AVIATION

(12Z TAFS) Issued at 539 AM CDT Thu May 21 2026

Stratiform rain will continue this morning, promoting low-end VFR to MVFR conditions due to reduced visibilities and low stratus. Another round of SHRA/TSRA will redevelop late this morning and into the afternoon/evening. Have included a TEMPO in the afternoon between 20-00z to highlight the period of highest confidence for TSRA. AWWs and Amendments may be needed during this timeframe. After sunset, MVFR stratus will build back into the region through the remainder of the period.

HUN WATCHES/WARNINGS/ADVISORIES

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