textproduct: Huntsville

KEY MESSAGES

Updated at 339 PM CDT Sat May 17 2026

- A significant warming trend into early next week with highs in the upper 80s to lower 90s.

- Low chances (15-30%) for a few thunderstorms in far northeast Alabama today and on Monday afternoons.

- Low to medium chances (20-50%) for showers and thunderstorms returning late Tuesday afternoon into Tuesday evening. Then medium to high (40-80%) chances for showers and thunderstorms Wednesday through Friday.

NEAR TERM

(Tonight) Issued at 339 PM CDT Sun May 17 2026

So far showers and thunderstorm activity has remained over southeastern and west central Georgia this afternoon. This makes sense given the location of the upper level trough axis over northwestern Georgia. Its axis extends southward through the area where the convection is occurring at this time. Expect that to continue into the evening hours, before dissipating. The cumulus field over northern Alabama looks fairly muted despite having a very unstable airmass in place, likely due to the subsidence in place behind the trough axis aloft itself. At least partly cloudy conditions will mainly continue this afternoon before dissipating early this evening. Some brief mostly cloudy conditions could occur near and east of I-65 this afternoon or early this evening, but not expecting convection development west of the AL/GA border.

If we do get any initiation (very low chance...less than 15%), the atmosphere is setup for severe downburst development. This would occur mainly right along or just west of the AL/GA border if it does. However, not expecting that to occur at this time.

Abundant sunshine has allowed temperatures to climb into the 87 to 92 degree range so far this afternoon. We could still see a high in the 92 to 94 degree range before sunset. It is not quite as humid as it was earlier due to some mixing of drier air aloft this afternoon, but still a bit muggy out there with dewpoints in the 61 to 66 degree range. So make sure to hydrate if playing sports or working outdoors.

Low level flow will remain southerly to southeasterly tonight. This will continue to advect more moist air into the area. Winds should be a just a little stronger tonight (around 5 mph) than previous nights (calm/variable). These winds and weak moisture advection will keep lows from dropping much below the lower to mid 60s tonight. Some fog in the sheltered valley locations of NE Alabama is expected, but this is not expected to be widespread.

SHORT TERM

(Monday through Wednesday) Issued at 1133 AM CDT Sun May 17 2026

A strong longwave trough axis for this time of year will push east from the desert southwest into the central Plains area on Monday. The upper ridge over the area continues to hold strong though over the southeast. However, low level moisture advection will continue and areas west of I-65 will likely see a lot of sunshine. This should allow highs to climb back into the upper 80s and lower 90s again on Monday. Further east, models hint at a weak low level moisture convergence boundary setting up over far eastern Alabama formed from convection the day before in Georgia. This could be a focus a low chance (20-30 percent coverage) of convective development in the afternoon/early evening before dissipating. SBCAPE is not bad (800 to 1500 J/KG) in most guidance (a bit higher in some). However, shear continues to be weak and lapse rate around closer to 6.5 degree/km in the afternoon. This looks like general thunderstorm parameters. If SBCAPE climbs to between 2000 and 3000 J/KG in future models runs or lapse rates steepen, then a marginal severe downburst threat could materialize.

By Monday night, southwesterly flow deepens. This should help to bring even higher dewpoints into the area and keep lows from dropping below the 65 to 70 degree range in most areas (exception being the valley areas of NE Alabama).

Most guidance keeps convection west of the area on Tuesday (except the ECMWF suite) due to the continuing strength of the upper level ridge over the Southeast. We will have more cloud cover around though, keeping highs from climbing back into the 89 to 93 degree range. Highs still climb into the 85 to 90 degree range given the warm 925 mb temperatures shown in guidance. Only kept a low chance (20-30%) of showers and thunderstorms in the forecast in NW Alabama in the afternoon on Tuesday.

Models seem to converge on showing the upper ridging really weakening and sliding further east Tuesday night into Wednesday. Low to medium chances (20-50%) of showers and thunderstorms push into the area as a result. Shear remains weak in guidance, but fairly unstable conditions (SBCAPE 1000 to 2000 J/KG) builds over the area during the day on Wednesday. Given instability parameters and shear climbing to between 20 and 25 knots, a marginal threat of strong to severe thunderstorms could develop, but confidence in that is very low.

LONG TERM

(Wednesday night through Sunday) Issued at 1045 PM CDT Sat May 16 2026

Upper level zonal flow on Wednesday looks to eventually turn into southwest flow aloft through late week. In addition, a series of shortwaves are shown by guidance to move along this flow pattern over the Southeast from mid to late week. Meanwhile, a surface cold front will approach the Tennessee Valley on Wednesday, passing just to our south by Thursday, then stall over the Southeast through Saturday. Overall, expect a wet pattern from Wednesday through Saturday! Looking at the potential for storms, while instability is sufficient for development, bulk shear values (particularly on Wednesday) are low. Values on Wednesday are generally around 10 kts or less. Guidance then suggests bulk shear values will be less than 30 knots through at least Friday. Therefore, not anticipating severe storms at this time.

Even with low confidence in the potential for any severe weather, model PWATs on Wednesday generally range between 1.6-1.8 inches by Wednesday and this looks to persist into the weekend. When compared with BMX Sounding Climatology (in the afternoon), this range is over the 90th percentile. Therefore, showers and storms will be efficient rainfall producers. In addition, model soundings show low corfidi downshear values on Wednesday, indicative of slow-moving showers/storms as well as the potential for backbuilding/training storms (increasing the potential flood threat). Furthermore, with several days of elevated moisture and medium to high chances of showers/storms, we'll need to continue to keep an eye on the potential for flash flooding by late week, especially for areas that see consistent and heavier rainfall during this time. It has been fairly dry recently, but please remember flood safety next week! If you encounter flooded roads: Turn Around Don't Drown!

As for temperatures, these will be tempered a bit by the higher rain chances (especially Thursday through Saturday), with highs generally in the upper 70s to lower 80s each day and lows in the lower to mid 60s each night.

AVIATION

(18Z TAFS) Issued at 1221 PM CDT Sun May 17 2026

Southerly winds around 10 knots gusting to around 15 knots are expected this afternoon at both terminals. VFR CIGS are expected at KHSV at times through 22Z, before dissipating. We will have to watch to see if isolated -TSRA could come close to the KHSV terminal, but that is not expected at this time. Less cloud cover is expected at the KMSL terminal. Winds will become lighter around 5 knots early this evening. Winds should keep fog at bay at the terminals. Southerly winds will pick up to around 10 knots gusting up to 18 knots after 18/15Z.

HUN WATCHES/WARNINGS/ADVISORIES

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