textproduct: Huntsville

KEY MESSAGES

Updated at 1126 AM CDT Fri May 22 2026

- There is a low chance for a few strong to severe thunderstorms today. The primary convective hazards will be gusty to damaging winds and a tornado or two.

- The risk for flash, areal and river flooding will continue to increase today and tonight, and a Flash Flood Watch is in effect for portions of the forecast area.

- A wet weather pattern will continue for the next seven days with an additional 2.5-4 inches of rain expected. Thus, the risk for flooding will continue through much of next week.

NEAR TERM

(Rest of Today and Tonight) Issued at 258 PM CDT Fri May 22 2026

Overall, there have been no significant changes in near term forecast reasoning this afternoon. At the present time, the western edge of a broad axis of rain and embedded thunderstorms (which has shifted slowly eastward across AL over the course of the day) extends from Franklin county, TN southward into Marshall county, AL. The greatest near term risk for strong-severe winds associated with this band will be with the previously severe- warned cell in Jackson county, and flash flooding will also remain a concern from Cullman county into northeast AL. In the wake of this activity, we will also need to monitor the progression of more widely-dispersed convective cells from northern MS into west- central AL, as low-level shear will remain favorable for mesocyclone and brief tornado development through early this evening. However, this activity may only impact a small part of northwest AL, as the thermodynamic environment should become less favorable with eastward extent. It still appears as if convection will quickly diminish in coverage after 0Z, but redevelopment of showers and thunderstorms may occur in the vicinity of a subtle low-level confluence axis shortly before sunrise tomorrow.

Previous Discussion: Embedded within prevailing southwesterly flow aloft (between a subtropical ridge to our southeast and a developing mid/upper low across southern SK/MB), a weak but negatively-tilted shortwave trough will progress from the Arklatex into the Lower Great Lakes by 12Z Saturday. In the low-levels, an increasingly compact area of low pressure will lift northeastward from southern AR into western TN/KY this afternoon before advancing into central IN tonight, resulting in a modest increase in SSE flow across the warm sector.

Present indications are that an extensive band of rain and thunderstorms within the cyclone's warm conveyor belt will continue to spread slowly eastward across much of AL this morning and into the early afternoon, as the SSW low-level jet strengthens to 30-40 knots. Although hodographs suggest that both 0-3km and 0-1km shear will support development of mesocyclones and brief tornadoes with stronger updrafts, the strongest cells appear as if they will be most concentrated across the southern half of the state (where SBCAPE is already in excess of 2500-3000 J/kg). Later this afternoon, a separate axis of convection may evolve within a low-level confluence axis extending southward from the primary low into central MS. This activity should track eastward into northwest AL after 21Z, and may also feature a similar risk for mesocyclones and brief tornadoes (especially if clouds partially scatter in this region, enabling CAPE to reach 1000-1250 J/kg). Otherwise, heavy rainfall and localized flash flooding will be the most significant concern today and tonight, given PWAT values in the 1.6-1.8" range. A Flash Flood Watch has been issued for the portion of the CWFA that has experienced the heaviest rainfall recently, and thus has the lowest 1-hour FFG values.

Although afternoon convection will likely last for a couple of hours beyond sunset this evening before dissipating, a brief period of drier conditions is expected from late this evening into the early morning hours Saturday. However, there is some concern that a subtle prefrontal confluence axis may drift southeastward into the region and initiate new showers and thunderstorms in the 10-12Z timeframe. As overcast low stratus clouds return in earnest this evening, overnight lows will be rather mild and in the l-m 60s.

SHORT TERM

(Saturday through Sunday night) Issued at 1126 AM CDT Fri May 22 2026

Scattered showers and thunderstorms (which may develop along a prefrontal confluence axis shortly before sunrise) will tend to spread southeastward with time and should exit our region by early afternoon. And, with mid-level height rises and broad scale subsidence predicted to strengthen in the wake of a departing shortwave trough, redevelopment of convection along remnant mesoscale boundaries tomorrow afternoon is uncertain. Regardless, a few thunderstorms will likely materialize over the course of the afternoon as temps warm into the u70s-l80s and these would be within an environment of higher CAPE (1500-2000 J/kg) but much weaker low-level shear compared to today. Thus, in spite of lower storm coverage, conditions appear slightly more favorable for damaging downburst winds tomorrow afternoon. In similar fashion to today, diurnal convection will dissipate within a couple of hours of sunset Saturday evening, with dry but warm/humid conditions anticipated through early Sunday morning.

During the timeframe from Sunday-Sunday night, chances for showers and thunderstorms will quickly increase once again as a southerly low-level jet strengthens to the east of a developing cutoff upper low in the subtropical jet (across eastern TX). Although deep-layer wind fields appear too weak to support storm organization, precipitable water values will remain rather high. Thus, the primary impacts from storms during this period will be lightning and locally heavy rainfall/flooding. Highs on Sunday will once again reach the u70s-l80s, with overnight lows remaining in the l-m 60s.

LONG TERM

(Monday through Thursday) Issued at 950 PM CDT Thu May 21 2026

The relief from the roller coaster of showers and thunderstorms you are looking for won't be found in the Long Term. We will be in a stagnate pattern that will keep medium to high rain chances in through mid week next week. As of right now, no severe weather is expected during this time. With the persistent rounds of rainfall, the potential for flooding will be closely monitored. WPC has at least some part of the forecast area in a Marginal ERO through Tuesday. From a drought perspective, we really needed the rain, but I think we are all ready for the return of some sunshine. High and low temperatures won't fluctuate much, with highs in the lower 80s, and lows in the low to mid 60s throughout the Long Term.

AVIATION

(18Z TAFS) Issued at 117 PM CDT Fri May 22 2026

A broken band of mod-hvy SHRA will continue to shift eastward and away from HSV early in the period, with TEMPO groups for MVFR vsby reductions included at this terminal thru 22Z. However, additional convective cells will enter NW AL from northern MS, with a similar TEMPO group included for MSL from 20-24Z. The heavier cores will be capable of producing wind gusts in excess of 25 kts, potentially warranting AWWs. Showers should dissipate shortly after sunset, with a brief clearing trend expected early this evening prior to redevelopment of MVFR stratus by 2Z. However, there are some indications that a slow-moving sfc trough may initiate redevelopment of both SHRA and TSRA by 10Z, with PROB30 groups for TSRA and MVFR vsby/IFR cig included at both terminals btwn 10-16Z. Conditions will gradually begin to improve as this activity spreads southeastward and out of the region late in the TAF period.

HUN WATCHES/WARNINGS/ADVISORIES

AL...Flood Watch through Saturday morning for ALZ008>010-016.

TN...None.