textproduct: Huntsville

KEY MESSAGES

Updated at 958 PM CDT Sat Jun 20 2026

- Low chances (30% or less) of showers are forecast Sunday afternoon into the evening - Medium-high chances (60-90%) of thunderstorms are forecast Monday and Tuesday- peaking during the afternoon hours. A few storms have a low chance of becoming severe on Monday, with damaging winds and localized flash flooding being the main concerns

- Low-medium chances (40% or less) for showers and thunderstorms will continue Tuesday night-Saturday, but storm coverage across our region will depend on the location of a weak stationary front

NEAR TERM

(Rest of tonight and Sunday) Issued at 958 PM CDT Sat Jun 20 2026

Despite not seeing widespread rain today, at least patchy fog development will be likely overnight as low level moisture coexists with light winds and mostly clear skies. Confidence in widespread fog is not high enough to issue a Dense Fog Advisory at this time, however, there is a low chance one could be issued overnight/early Sunday if fog development spatially exceeds expectations. Otherwise, dry conditions are forecast tonight as a sfc front pushes northeast out of our area and into the Appalachian region. It is then forecast to stall, lingering just east of our forecast area through Sunday. Low chances (30% or less) of showers are forecast Sunday afternoon as a brief upper level shortwave shifts eastward into the area. Coverage and rain chances have decreased in recent model trends, however, CAMs indicate a couple showers along the I-65 corridor during the afternoon with a low chance of producing lightning. The primary concern Sunday will be heat as highs rise into the upper 80s (reaching 90 in some locations) along with heat index values in the upper 90s to near 100 degrees. If you have outdoor plans, abide by heat safety by drinking plenty of water and seeking shade when able to prevent heat related illness.

SHORT TERM

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

Rain chances increase Sunday night into Monday morning (30-50%) as an upper level shortwave shifts east into the area once again. Simultaneously, an approaching cold front stemming from low pressure centered over the OH River Valley will force high chances (70-90%) of thunderstorms by Monday afternoon. Model soundings indicate PWATs reaching around 1.9-2.2", which is above the 90th percentile per BMX and OHX sounding climatology. Therefore, thunderstorms will be efficient rainfall producers. Additionally, Corfidi upshear values indicate the potential for backbuilding/training of relatively slow moving storms, increasing the overall flash flood threat. The Weather Prediction Center has outlooked our area in a Slight (risk level 2 of 4) outlook for Excessive Rainfall Monday morning through Tuesday morning. A secondary threat will be damaging winds as both instability as well as shear will support some organized convection. The Storm Prediction Center has outlooked the entire Tennessee Valley in a Marginal Risk (level 1 of 5) for severe weather. Be sure to have multiple ways to get warnings Monday as multiple threats are on the table. Another heat threat also exists Monday afternoon as highs are forecast to reach the upper 80s once again with heat indices in the upper 90s to around 100, however, we will be monitoring how thunderstorms and subsequent cloud cover affects these temperatures as they will likely be cooler than currently forecast. While rain chances decrease overnight, medium rain chances (40-60%) return Tuesday afternoon as a boundary stalls to our south. This will continue a low flooding threat in NW AL, where the Weather Prediction Center currently has us outlooked in a Marginal Risk (level 1 of 4) for Excessive Rainfall. We encourage everyone with plans early in the week to remain weather aware and check back in for updates.

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

(00Z TAFS) Issued at 602 PM CDT Sat Jun 20 2026

VFR conditions are forecast through this evening, however, lowered ceilings (and potential fog formation) will bring MVFR conditions late tonight into early Sunday. By the afternoon, VFR conditions return along with a low chance (PROB30 group) of thunderstorms with subsequent MVFR conditions.

HUN WATCHES/WARNINGS/ADVISORIES

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