textproduct: Huntsville

KEY MESSAGES

Updated at 945 AM CDT Sat Jun 20 2026

- Low to medium chances for showers and thunderstorms are forecast this afternoon/evening and again Sunday afternoon and evening.

- Additional rounds of rain and storms are forecast with medium to high (60-90%) chances Monday and Tuesday. A few storms may become severe on Monday, with damaging winds and localized flash flooding being the main concern.

- Low chances for showers and thunderstorms will continue Tuesday night-Friday, but storm coverage across our region will depend on the location of a weak stationary front.

NEAR TERM

(Rest of Today and Tonight) Issued at 945 AM CDT Sat Jun 20 2026

Mid-level clouds and some light rain/virga continue to linger across the Tennessee Valley this morning, which has helped to limit sunshine/heating. Recent satellite trends indicate at least some partial clearing will take place by 18z, which will allow our temperatures to reach the low to mid 80s by the afternoon. A stalled front to the south and west of the area will again serve as a focus for showers and storms this afternoon. There will be a sharp gradient of PoPs from southwest to northeast across the region, with medium to high chances (50-80%) of showers and storms across northwest Alabama and Cullman County and low to medium chances (10-40%) across much of north central Alabama, northeast Alabama, and southern middle Tennessee. The main threats with this activity will be heavy downpours, lightning, and localized gusty winds.

Convection will wane by late this evening, with partly cloudy and muggy conditions continuing overnight. In areas where clearing can occur, patchy fog will be a concern due to the moist boundary layer. Overnight lows in the mid to upper 60s will be common.

SHORT TERM

(Sunday through Monday night) Issued at 945 AM CDT Sat Jun 20 2026

On Sunday, the Tennessee Valley will again be wedged between a stalled frontal boundary to the south and a stronger cold front to the north over the Ohio Valley, Mid South, and Ozarks. The end result should be more sunshine for Father's Day and potentially some elevated heat concerns as highs rise to the mid to upper 80s and heat index values reach the mid to upper 90s -- with a few spots exceeding the 100 degree mark. Those with outdoor plans should ensure they observe common sense, heat safety practices and rules. Once again, convection to the south of the area will develop along the front and move northeastward into the region, generating low to medium (30-50%) chances for showers and storms in the afternoon.

A stronger shortwave over the Ohio Valley will finally force the cold front to our north into the region during the day on Monday. A line/broken line of convection may develop along this boundary as it sinks southward, moving into the Tennessee Valley during this afternoon and evening hours. The shear profile and thermodynamics do favor some organized, strong to severe storms with damaging winds being the main threat -- along with perhaps some marginally severe hail. Storm motions will be quite slow, which may favor backbuilding and subsequently a slightly higher heavy rainfall and localized flash flooding threat. WPC has already highlighted most of our area in a Slight Risk (level 2 of 4) for Excessive Rainfall on Monday. Again, it will be important for those with outdoor plans to monitor the forecast and make sure they have multiple ways to get warnings. The initial front will push southward into central Alabama and stall Monday night, resulting in at least low to medium (30-50%) chance for showers and elevated storms for the remainder of the night. However, the severe threat will come to end by the late evening.

LONG TERM

(Tuesday through Friday) Issued at 954 PM CDT Fri Jun 19 2026

Extended range model data suggests that a flat mid-level ridge will extend from subtropical portions of the eastern North Pacific eastward across the Gulf and into the central North Atlantic for much of the period. To our north, a longwave trough will remain intact across eastern Canada and adjacent portions of the northern Plains, Great Lakes and northeastern CONUS, with subtle amplification of the broader trough expected at times. This configuration will maintain NW flow aloft of 15-25 knots across the TN Valley, with at least a couple of convectively-enhanced disturbances predicted to strengthen large scale ascent. In the low-levels, an initial surface low will deepen as it lifts northeastward off the coast of New England and into Nova Scotia on Tuesday/Tuesday night, with the southward progression of the trailing cold front into our region expected to be retarded by a weaker surface low diving southeastward into the Upper MS Valley. A moist/unstable but weakly sheared airmass (featuring PWAT values of 1.8-2" and CAPE in the 1500-2000 J/kg range) will exist south of the front and should support numerous thunderstorm clusters on Tuesday that will progress southeastward across the region within prevailing NW flow aloft.

Beginning Tuesday night and continuing through Thursday night, there is a high degree of uncertainty regarding precisely how far south the frontal boundary (and intrusion of drier continental air) will reside, and this will have a large impact on thunderstorm coverage during this timeframe. However, it does appear as if a developing lee cyclone across the southern High Plains will send the front northward once again on Friday, allowing chances for showers and storms to increase once again. Temperatures will change very little over the course of the period, with afternoon highs in the l-m 80s, and overnight lows in the m-u 60s.

AVIATION

(12Z TAFS) Issued at 642 AM CDT Sat Jun 20 2026

Mainly virga still occurring over northwestern Alabama north of a stalled frontal boundary. Some isolated light drizzle or rain is showing up in an observation or two, but expect virga to continue for a couple of hours more. Thus, at KMSL only included a PROB30 for SHRA at this time. Expect -SHRA to become predominant at KMSL after 15Z. As instability builds late this morning, expect -TSRA to develop mainly between 18Z and 22Z at KMSL. Due to uncertainty of more predominant -SHRA and -TSRA at KHSV, only included a PROB30 for -TSRA between 18Z and 22Z at that terminal. This may need to be adjusted if more widespread development occurs that far east. Expect this activity to dissipate earlier at KHSV (~ 21/00Z) and later at KMSL (21/04Z). Light southerly winds are expected the remainder of the TAF period. Fog may need to be added depending on cloud cover trends in models.

HUN WATCHES/WARNINGS/ADVISORIES

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