textproduct: Huntsville

KEY MESSAGES

Updated at 1023 AM CDT Tue Sep 8 2026

- Low chances (20-30%) for a shower/storm developing across the area this afternoon.

- Better chances (20-40%) of showers and storms Thursday and Friday along and North of the TN River as a front sags south toward the CWA.

- NWS Heat Risk will remain in the Minor to Moderate Category throughout the forecast period.

NEAR TERM

(Tonight) Issued at 1242 PM CDT Tue Sep 8 2026

Only minor changes were made to the current forecast, as a few more (than originally anticipated) showers have bubbled up across the CWFA. These are mainly along the I-65 corridor, as well as a few now developing in far NW AL. As such, have increased the PoPs slightly for the remainder of the afternoon. Aside from a few orographically-induced showers well E on the TN/GA border, am not anticipating too much coverage in NE AL with the ridging to the E providing subsidence there (though PoPs were nudged up a few percent given radar trends in the mountains/east).

Otherwise, the forecast is in great shape and no additional changes were warranted.

SHORT TERM

(Wednesday through Friday) Issued at 1023 AM CDT Tue Sep 8 2026

High pressure aloft and at the sfc will keep a dry forecast on tap for Wednesday for the area, with daytime highs topping out 2-3 degrees warmer than today. Highs Wednesday range from the lower 90s east to the middle 90s west, but Heat Index values still remain below 100F (which is a far cry from this time last week).

A pattern change is in the works for Thursday/Thursday night as ridging shifts eastward aloft, and at the same time, an upper low traverses the Srn Canadian provinces. This will send a front southward, and with it, clusters of showers and storms along the boundary. Locations along and N of the TN River have the best shot at seeing rain Thursday, but chances decrease significantly the farther south you go in the CWA. Rain chances for us are highest in Srn Middle TN (20-30%) and are upwards of 60-70% over Metro Nashville. Locally, in Cullman County, rain chances are less than 5%. As with this past weekend, gusty winds 30-40mph, frequent lightning, and locally heavy rainfall due to slow movement will be the primary threats. Lows Thursday night will be mild and in the lower/middle 70s, with daytime highs Friday will top out in the lower to middle 90s ahead of medium chances (~40%) for developing showers and storms.

LONG TERM

(Friday through Monday) Issued at 1105 PM CDT Mon Sep 7 2026

Extended range model data suggests that a subtle low-level streamline confluence axis (initially positioned across the TN Valley) will lift northward into the OH Valley and lose definition during the period from Friday-Saturday night, in response to surface pressure falls across the southern High Plains. This, along with SW flow aloft (provided by a weak mid- level trough drifting eastward over the Lower MS Valley), will force PWAT values back into the 1.8-2" range, leading to a general increase in the coverage of showers and thunderstorms both days. With no clear evidence of synoptic scale forcing for ascent, subtle deep- layer warm/moist advection and mesoscale boundaries will likely be the source of unorganized convection (largely tied to the diurnal warming cycle, but with some potential for convection to persist at night, as well).

On Sunday and Monday, there are indications that the Atlantic subtropical ridge will begin to strengthen as it retrogrades westward into the southeastern CONUS. Although this could potentially have a negative influence on the overall coverage of afternoon convection, low-level moisture return will improve as southerly flow becomes established within the warm sector of a low tracking northeastward into the Upper MS Valley. With dewpoints returning to the l-m 70s, PWAT values will continue to rise above 2" and this coupled with collapsing steering currents aloft may enhance the risk for locally heavy rainfall and flooding during this period. Due to increased rain chances, highs will fall back into the u80s-l90s, as overnight lows remain in the u60s-l70s.

AVIATION

(18Z TAFS) Issued at 1225 PM CDT Tue Sep 8 2026

Isolated showers continue to bubble up in the vicinity of KHSV, with one very nearly atop the site right now. With the 18Z TAF issuance, VCSH was introduced into the TAFs, with a TEMPO group for any direct impacts causing MVFR conds briefly at both sites thru late this afternoon. Showers will dissipate shortly after sunset this evening, with SCT clouds and VFR conds lingering overnight.

HUN WATCHES/WARNINGS/ADVISORIES

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