textproduct: Huntsville

KEY MESSAGES

Updated at 955 AM CDT Sun Jun 21 2026

- A Marginal Risk for strong to severe storms exists tomorrow morning with the primary threats being damaging winds and heavy rainfall.

- Low to medium chances of general showers and thunderstorms remain in the forecast through Wednesday with frequent lightning and heavy rainfall being the primary threats.

NEAR TERM

(Rest of Today and Tonight) Issued at 955 AM CDT Sun Jun 21 2026

With sunrise, fog and low clouds have begun to lift as temperatures slowly increase. Additional clearing is forecast through the morning with partly cloudy skies likely by midday. The decrease in cloud cover will allow for temps to quickly heat up with highs soaring into the upper 80s. Dew points will remain elevated, in the high 60s to low 70s, due to continual southerly surface flow. As such, heat indices will make it into the mid to high 90s. Make sure to take proper precautions if spending time outdoors.

Models have maintained their lower rain chances for this afternoon with the main focal point being a boundary that looks to lift north through central AL this afternoon. Highest rain chances (20-30%) will be confined to our SW areas that could see slightly higher coverage of general showers and thunderstorms. Elsewhere rain chances will remain low. Rain chances will drop off after sunset. Our attention will then shift to an approaching MCS that is discussed below.

SHORT TERM

(Monday through Wednesday) Issued at 955 AM CDT Sun Jun 21 2026

Through the short term we will be in zonal flow aloft that will allow several embedded shortwaves to pass through the TN Valley, the first of which arrives on Monday. Early Monday morning an MCS will be ongoing to our NW associated with a weak surface cyclone. Through the morning this feature will push SE and move through the TN Valley. While a stray shower or storm may develop during the early morning hours, the main MCS looks to enter NW AL just after sunrise and move from NW to SE through the morning. Models indicate a decent amount of surface instability (+1000 J/KG) will be present. Paired with an okay amount of bulk shear (25-35 KTS), a few strong to severe storms certainly look possible with damaging winds being the main severe threat. This is supported by SPC with the whole area being under a Marginal Risk (1/5). Unfortunately our tropical airmass will still be in place with high dew points and PWATS, making heavy rainfall again a concern. Low corfidi up shear values raise concerns for training convection and potential flash flooding. As such, WPC has place most of the area in a Slight Risk (2/4) for Excessive Rainfall.

The MCS looks to weaken as it pushes south but model guidance does push it all the way through our area by early afternoon. Brief clearing may occur, yet without much change in the airmass, low to medium (20-40%) chances for general showers and thunderstorms will remain in the forecast late Monday afternoon through Wednesday afternoon. While no severe weather is forecast, all storms will remain capable of efficient rainfall production through midweek, making heavy rainfall and localized flooding the main concern. With an active weather pattern for the entire short term forecast, make sure to remain weather aware and have multiple ways to get warnings.

LONG TERM

(Tuesday night through Saturday) Issued at 958 PM CDT Sat Jun 20 2026

For the first couple of days of the extended period (Wednesday/Thursday), our forecast area will remain beneath a light (10-20 knot) NW flow aloft between a strong subtropical high centered across southern AZ/southern NM/northern Mexico and an amplifying northern stream shortwave trough digging southeastward into the Great Lakes. In the low-levels, high pressure (initially across the central Appalachians) will shift quickly eastward off the Mid- Atlantic Coast as a slow-moving area of low pressure drifts southeastward across the Upper MS Valley/Great Lakes. This will yield light SSW return flow across our region (perhaps as early as Wednesday, but more likely by Wednesday night) which will contribute to an increase in the coverage of showers/thunderstorms once again. Present indications are that storm coverage will remain fairly high on Thursday to the south of a weak cold front trailing southwestward off the low to our north, but deep-layer flow and shear appear too weak to warrant concern for organized convection. Nevertheless, a moist/unstable airmass featuring PWAT values of 1.6-1.8" and CAPE of 1500-2500 J/kg could result in a risk for strong downburst winds.

During the timeframe from Friday-Saturday, global models suggest that the mid-level high over the southwestern deserts will begin to weaken as the central North Atlantic subtropical ridge strengthens and retrogrades westward across the FL Peninsula and into the eastern Gulf. With our region likely to become increasingly influenced by minor height rises aloft and drying profiles, we expect the coverage of showers and thunderstorms to gradually decrease from Friday into Saturday (although with a lingering front/convergence axis likely to lie somewhere in the vicinity of the TN Valley, rain chances will certainly be non-zero). Highs will progressively warm from the l-m 80s into the m-u 80s by Saturday, as overnight lows rise from the m-u 60s into the u60s-l70s.

AVIATION

(18Z TAFS) Issued at 1148 AM CDT Sun Jun 21 2026

VFR conditions will prevail through the first half of the TAF period. Early tomorrow morning lower ceilings and gusty SW winds will build in ahead of an approaching line of storms. Ceilings look to drop just before sunrise, around 10Z, with rain and storms moving in from NW to SE. Highest confidence in impacts beginning at MSL around 11Z and around 15Z at HSV. Conditions will likely be lower than currently forecast while the storms move through with subsequent TAF issuances refining timing and intensity as the timeframe draws closer.

HUN WATCHES/WARNINGS/ADVISORIES

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