textproduct: Huntsville

KEY MESSAGES

Issued at 1014 AM CDT Tue May 19 2026

- Low to medium chances (20-40%) of showers and thunderstorms return tonight.

- Medium to high chances (50-90%) of showers and thunderstorms then persist each day from Wednesday through early next week. No severe weather is forecast.

NEAR TERM

(Rest of tonight and Wednesday) Issued at 1034 PM CDT Tue May 19 2026

Showers and thunderstorms continue to develop ahead of a trough axis that extends from a surface low over southeastern Canada through northern Indiana into southeast Missouri and eastern Arkansas. Fairly strong forcing aloft at 500 mb is seen along this trough axis. Further east in Mississippi and southeastern Arkansas, the strongest forcing is concentrated around 700 mb with 500 to 1500 J/KG of SBCAPE shown in SPC meso-analysis. Shear is very weak.

The main question is how deep the stronger forcing will be and how much instability we will have towards 1 AM into the early morning hours on Wednesday this far east. Most guidance weakens forcing around 700 mb significantly during that period, but strong vorticity develops in several models towards daybreak on Wednesday that pivots from NE Mississippi into NW Alabama. Models hold onto between 300 and 800 J/KG of SBCAPE in NW Alabama. Shear remains weak, but does increase to around 25 knots towards daybreak.

Expect the current activity over NW Mississippi to push more to the NNE overall. Though, models do show additional convection moving into NW Alabama maybe as early 4 AM. Confidence is low in the forecast, but given the strength of the forcing around 500 mb by models moving into NW Alabama between 4 AM and 7 AM, thinking that coverage in NW Alabama at least will increase significantly. Though at this time, think this will be general thunderstorm activity.

Expect this activity to continue to increase in coverage as it moves east during the day on Wednesday. Guidance develops between 1500 and 2000 J/KG of SBCAPE over the area as the surface front is slow to moves southeast through the area. This will make for a cloudy and rainy day on Wednesday with some areas receiving between 1/4 and 3/4 of an inch of rainfall with some locally higher amounts possible. This will provide a break from the hotter temperatures we have been seeing the last few days. Highs will likely only reach the lower to mid 80s.

SHORT TERM

(Wednesday night through Friday night) Issued at 1035 PM CDT Tue May 19 2026

With weak shear remaining over the area near the front on Wednesday night and the loss of daytime heating, coverage should drop off significantly to low to medium coverage (20-50%). However, we will remain in a humid airmass, as the front moves north again into Thursday. This will keep overnight lows on the warm side Wednesday night, only dropping into the lower to mid 60s.

As the front moves northward again on Thursday, additional shortwaves move along it. Combined with building instability as the front moves back over the area, widespread showers and thunderstorms are expected to develop (especially in the afternoon). Shear remains weak in most model output (less than 25 knots). That is a good thing given instability shown by guidance (1500-3000 J/KG). PWATS increase again though, so heavy downpours and frequent lightning will be fairly common. We will need to monitor for minor flash flooding issues Thursday afternoon.

Things don't change through Friday, as the front doesn't move much and additional disturbances move along it through the area. This will keep highs Friday afternoon in the lower to mid 80s. There might be a bit stronger shear (0-3 km ~ 30 knots) Friday afternoon along with instability between 1000 and 3000 J/KG, just enough shear to have to worry about strong to marginally severe thunderstorm activity. Some minor flash flooding could occur on Friday as well. Overnight lows Thursday night will push higher into the mid to upper 60s.

LONG TERM

(Saturday through Tuesday) Issued at 1035 PM CDT Tue May 19 2026

Southwesterly flow will largely persist aloft through the long term period. In addition, a series of shortwaves looks to ripple across the Southeast during the weekend and into early next week. At the surface, a cold front is slated to slowly make its way towards the Southeast through the weekend, but stall over the mid-Mississippi Valley and into the lower Ohio Valley early next week. This pattern will maintain low-level southerly flow over the region as well the continued advection of moisture up from the Gulf. Therefore, the rainy and summertime-like pattern is expected to continue through at least early next week, with daily chances (50-80%) of showers and thunderstorms. Highs will be temperated a bit by the higher rain chances each day; but, highs are forecast to generally reach the lower to mid 80s with lows in the 60s.

Model PWATs generally remain between 1.6-1.8 inches throughout the period, which are over the 90th percentile when compared with Sounding Climatology from Birmingham (~1.6 inches) for May 23rd through 26th. Showers/storms will therefore be efficient rainfall producers, so we'll need to monitor for the increased risk of localized flooding for areas that receive rainfall repeatedly. As for the potential for any severe weather, guidance suggests that bulk shear values may reach around 30 knots periodically this weekend and into early next week. Therefore, there is a non-zero chance of a stronger storm or two, but confidence is low at this point. Regardless, if you have outdoor plans, make sure to stay weather aware, as lightning is dangerous whether or not a storm is severe! In addition, if you encounter any flooded roads, remember to Turn Around, Don't Drown!

AVIATION

(06Z TAFS) Issued at 1216 AM CDT Wed May 20 2026

VFR conditions will prevail through much of the early/mid morning hours, but cloud cover will increase and ceilings will drop to around 4 kft by daybreak. A weak front will move into the Tennessee Valley today, bringing low to medium chances for SHRA/TSRA during the afternoon and evening hours. Confidence in timing is still very low so have handled with a 20-02z timeframe for now. Thereafter, lower clouds will build in and some light fog may develop in the late evening due to moist boundary layer conditions.

HUN WATCHES/WARNINGS/ADVISORIES

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