textproduct: NWS Birmingham

KEY MESSAGES

Issued at 621 AM CDT FRI AUG 21 2026

- Heat: Major HeatRisk will continue today, with heat indices forecast between 105 to 109 degrees. Heat Advisory remains in effect.

- Thunderstorms: Severe storms are expected this afternoon across southern Central Alabama, with damaging winds and heavy rain remaining the main concerns.

DISCUSSION

(Today through Thursday) Issued at 105 AM CDT FRI AUG 21 2026

Latest radar trends have increased forecast confidence through the morning and into the afternoon as models are now resolving the weather pattern more clearly. The current complex of storms in the northeast will slide east while sagging south, clearing before sunrise. While the severe potential has relaxed for the remainder of the evening, isolated flooding remains a concern, particularly in terrain-influenced areas. Activity developed as a shortwave tracked along the stalled frontal boundary to our northwest.

Another round of storms is likely from late morning into the afternoon as a stronger northern front pushes the stationary boundary through, aided by an additional shortwave. Scattered showers and storms will develop south of this slow-moving boundary, with the highest confidence for precipitation across our southern areas. Primary threats with any marginally severe storms will be damaging winds and locally heavy rainfall.

Upper-level ridging will attempt to build in over the weekend. Increased subsidence and drier air will lower rain chances through the weekend, though precipitation looks to return early next week as a series of shortwaves rotates through with the northwest flow aloft.

High temperatures will continue in the low to mid-90s over the coming days. Persistent humidity will promote daily heat indices in the 105-109 degree range today. I have extended the Heat Advisory for a large portion of the area through early this evening. Drier air arriving this weekend will help keep heat indices in check, generally in the 100-104 range.

16

AVIATION

(12Z TAFS) Issued at 621 AM CDT FRI AUG 21 2026

Through the morning hours, BHM and EET should experience VFR conditions with low potential for shower and storm activity, followed by chances increasing during the afternoon into the evening hours. TCL may experience showers with some thunderstorms through now through the afternoon. For MGM and AUO, conditions are good through 13Z then these sites may experience showers and storms from the developing line as it continues southeast. Overall, a 30-40% chance of isolated showers and storms is forecast with chances decreasing across the north after 21Z and the south after 03Z.

Note: AMD NOT SKED for AUO due to a weather observation outage.

05

FIRE WEATHER

Relative humidity will generally remain elevated today, with lingering moisture across the area. Low to moderate rain chances will persist through today before a drying trend takes hold this weekend. Drier air filtering into the area on Saturday will result in a decrease in relative humidity (35 to 45%) for most locations. However, wind speeds are expected to remain light, which should negate any significant fire weather concerns during this period.

PRELIMINARY POINT TEMPS/POPS

Gadsden 94 70 93 69 / 20 0 0 0 Anniston 92 70 91 69 / 30 10 0 0 Birmingham 93 72 92 71 / 30 10 0 0 Tuscaloosa 96 73 97 72 / 30 10 0 10 Calera 94 72 93 71 / 30 10 0 0 Auburn 90 72 90 72 / 50 30 0 0 Montgomery 95 73 96 72 / 50 20 0 0 Troy 94 71 94 70 / 60 50 10 0

BMX WATCHES/WARNINGS/ADVISORIES

Heat Advisory until 9 PM CDT this evening for the following counties: Autauga-Barbour-Bibb-Bullock-Chilton-Dallas-Elmore- Fayette-Greene-Hale-Jefferson-Lamar-Lowndes-Macon-Marengo-Marion- Montgomery-Perry-Pickens-Pike-Russell-Shelby-St. Clair-Sumter- Tuscaloosa-Walker.