textproduct: Huntsville

KEY MESSAGES

Updated at 1030 AM CDT Mon Apr 20 2026

- An unsettled pattern will develop this weekend bringing chances (50-70%) for rain and storms.

NEAR TERM

(Tonight) Issued at 132 PM CDT Mon Apr 20 2026

Tonight, a upper level trough continues moving eastward across eastern Canada and northeastern U.S., followed by upper level ridging that will encompass the TN Valley. As a result of upper level ridging and subsequent sfc high pressure, mostly clear skies and light winds will allow for radiational cooling as low temperatures drop into the mid 40s to low 50s (which is around 5 degrees warmer compared to the previous night's lows). Due to mostly clear skies, low-level moisture, and calm winds there is also a low chance (20%) of some patchy fog along large bodies of water. Any fog that does form will dissipate by late Tuesday morning.

SHORT TERM

(Tuesday through Wednesday night) Issued at 1030 AM CDT Mon Apr 20 2026

Short range model consensus suggests that a 500-mb shortwave ridge will translate eastward across the TN Valley tomorrow, with a weak trough expected to dig from the southern Plains into the north FL from Tuesday into Wednesday night. In the low-levels, we will remain under the influence of a weakening area of high pressure drifting southeastward off the Mid-Atlantic Coast for much of the short term period, as the western periphery of the surface ridge is predicted to remain intact across the central Gulf Coast states. Thus, although light southwesterly return flow will contribute to progressively warmer temperatures (highs returning to the u70s-l80s and lows returning to the l-m 50s), dewpoints will only gradually climb into the u40s-l50s by Wednesday and Wednesday night. Present indications are that rain and thunderstorms related to elevated warm/moist advection on the western edge of the low-level ridge will remain focused across TX today and tonight, before this regime gradually begins to spread eastward through the Lower MS Valley and perhaps into the central Gulf Coast states during the short term period. Although solutions from some of the CAMs (most notably the RRFS-EMC) indicate that weak cellular convection may impact portions of MS/AL/GA on Wednesday afternoon/evening, this would most likely occur across the southern portions of these states (where dewpoints will be a bit higher), and we will maintain a dry forecast for our CWFA at this time.

LONG TERM

(Thursday through Sunday) Issued at 856 PM CDT Sun Apr 19 2026

Upper level ridging begins to move into the Southeast during the second half of the work week. With sfc high pressure located across GA/SC, southerly flow will advect in a warm and moist airmass into the Tennessee Valley. Locally, this results in a gradual warming trend in temperatures, but also a much more noticeable increase in dewpoints. Afternoon highs Thursday and Friday rise into the mid 80s with dewpoints increasing from the lower 50s on Thursday to lower 60s by Friday evening. The dry pattern comes to an end by this weekend as troughing to our west shifts eastward allowing for several shortwaves to ripple through the local forecast area. The first of these disturbances arrives Friday evening/Saturday morning, which will bring a medium chance (45-65%) of showers and thunderstorms to the area. A more substantial system moves through this weekend and will be something to keep an eye on for severe storms. Joint probabilities of shear greater than 30 knots and CAPE exceeding 1000 J/kg have increased to around 30 percent. Various machine learning algorithms also show low probabilities of severe storms. At this time it is too early to pin down an exact timeframe of the most likely period for showers and thunderstorms will be 6-7 days out. However, it is April and this is typically one of our most active months for severe storms. Check back for updates as details for the weekend become more clear.

AVIATION

(18Z TAFS) Issued at 1145 AM CDT Mon Apr 20 2026

VFR conditions are forecast through the TAF period.

HUN WATCHES/WARNINGS/ADVISORIES

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