textproduct: Huntsville

KEY MESSAGES

Updated at 307 AM CDT Tue Sep 8 2026

- Low chances for showers and thunderstorms will return to the northern part of the forecast area Thursday and Thursday night.

- As a moist airmass returns to the region, chances for showers and thunderstorms will increase to 40-60% on Friday/Saturday afternoons, before falling into the 20-40% range Sunday/Monday. Lightning and heavy rainfall will be the main impacts from the storms.

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

NEAR TERM

(Today) Issued at 307 AM CDT Tue Sep 8 2026

A frontal boundary that moved southward across the area a couple of days ago has moved even further to the south, now extending from the central Great Plains, to the MS/AL coast and across central Florida. Broad high pressure situated over the Mid Atlantic was the otherwise controlling the area's general weather. A SE flow rounding this high was bringing low/mid level moisture across the region. This was noted well from the old long- short image, and nighttime microphysics satellite products. This was producing scattered low/mid altitude clouds across the area. A generally SE flow has returned across the area, as the high slowly builds more off shore the next couple of days. Otherwise, temperatures were in the 70s with SE winds of 5-10 mph.

The above noted moisture being lifted along with daytime heating produced instability could result in a few showers mainly this afternoon. Will stay with 20 percent or less rain chances. With a cooler airmass in place, high temperatures should be similar to what occurred on Labor day, ranging from the upper 80s to lower 90s. Expect SE winds of 5-15 mph this morning and afternoon, decreasing below 5 mph after sunset.

SHORT TERM

(Tonight through Thursday night) Issued at 1105 PM CDT Mon Sep 7 2026

Short range model consensus suggests that the TN Valley will remain under the influence of a strong 500-mb ridge during the period from Tuesday night-Wednesday night, as its center migrates slowly eastward into the southeastern Atlantic Coast. At the surface, a weakening dome of high pressure will shift slowly eastward off the Mid-Atlantic Coast, but should provide sufficient influence to sustain light SSE winds and a plume of relatively lower dewpoints across our region. This will translate to a continuation of dry weather, with morning lows in the u60s-l70s (perhaps a few degrees cooler in the sheltered valleys of northeast AL/southern TN) as afternoon highs rise back into the l-m 90s (with less morning cloud cover).

By Thursday and Thursday night, the subtropical ridge is predicted to weaken and shift eastward into the southwestern North Atlantic, allowing a light WSW flow to develop aloft. As this occurs, light SW flow will become established in the low-levels ahead of a cold front (attached to an occluding cyclone across northern Quebec) that will initially extend from eastern CO northeastward into southeastern Quebec. Although the front will exhibit very little (if any) movement, a prefrontal wind shift axis will focus the development of widespread convection (well to our north) on Wednesday night and Thursday, which should force the prefrontal wind shift axis to drift southeastward with time. This feature will likely initiate new clusters of showers and thunderstorms as it slowly approaches our CWFA, but with a very low probability that it will actually enter our region, we will only include a 20-30% POP (generally focused across northwest AL/southern TN). Due to the lingering presence of a drier (but gradually modifying) continental airmass across our region, CAPE will be on the low side (but certainly adequate for development of some thunderstorms). This, coupled with weak vertical wind shear, suggest that any storms will be unorganized and lightning should be the primary impact. Highs will remain in the l-m 90s on Thursday, with overnight lows once again in the u60s-l70s.

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

(12Z TAFS) Issued at 643 AM CDT Tue Sep 8 2026

A lower level moisture return has resulted in scattered to broken lower clouds across the TN Valley. These clouds had cloud bases of 2500-8000ft AGL. Daytime heating producing a more unstable environment supports the formation of isolated showers mainly in the afternoon. Confidence on timing and coverage of shower activity is too low for inclusion in the TAF. Otherwise, light SE winds should increase to 5-15kt this morning and early afternoon, before subsiding to around 5kt tonight.

HUN WATCHES/WARNINGS/ADVISORIES

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