textproduct: NWS Birmingham

KEY MESSAGES

Issued at 555 AM CDT TUE AUG 18 2026

- Heat: Major HeatRisk is expected to persist through the middle of the workweek. Heat indices are forecast between 103 to 109 degrees. A Heat Advisory is now in effect for portions of central Alabama on Tuesday.

- Thunderstorms: Isolated afternoon thunderstorms will remain in the forecast through Thursday, especially south of I-20. More organized rain chances will increase closer to the weekend, as a series of disturbances moves through the region.

DISCUSSION

(Tuesday through next Monday) Issued at 1122 PM CDT MON AUG 17 2026

Over the next several days, the upper-level ridge that has dominated the forecast will finally begin to slide west. While this won't have an immediate effect on our afternoon highs temperatures, it will allow for the region to come under the influence of a deep trough over the Midwest. Afternoon highs will generally start to decrease a degree or two here and there, with dew points slightly decreasing as well. Expect portions of the region to remain in Heat Advisory criteria through at least Wednesday, before heat index values drop once more into Friday.

It's during this timeframe that a few weak shortwaves should start to clip this region, as the trough over the Midwest continues to deepen. More organized rain chances are possible Friday, and into the weekend, but confidence is currently low regarding overall coverage and rainfall amounts. With that being said, this deepening trough should allow for dry air to filter back into the region, dropping our peak heat index values well below heat advisory criteria through the weekend. However, afternoon highs will continue to reach the low to mid-90s, and will likely stay here into early next week.

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AVIATION

(12Z TAFS) Issued at 555 AM CDT TUE AUG 18 2026

There is high confidence for VFR conditions to prevail today with scattered cumulus development by late morning and through the afternoon and into at least early evening. Some shower and thunderstorm activity is expected to develop from midday through the afternoon and persist into the evening hours with best chances southwest, but potential remains too low to mention at TCL and MGM for this issuance.

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

05

FIRE WEATHER

Dry conditions will continue, with MinRH values dropping into the 35 to 45 percent across western and southwestern counties. Winds will remain light through the period, with isolated afternoon showers and thunderstorms expected the next several days. Fire weather concerns will remain low over the next five days, but will begin to increase if rain-free conditions persist.

PRELIMINARY POINT TEMPS/POPS

Gadsden 94 69 97 72 / 0 0 0 0 Anniston 93 69 95 71 / 0 10 0 0 Birmingham 93 73 96 74 / 10 20 0 0 Tuscaloosa 98 75 99 75 / 20 20 10 10 Calera 95 73 97 73 / 10 20 0 0 Auburn 92 73 92 74 / 10 10 0 0 Montgomery 99 75 99 74 / 20 20 10 0 Troy 98 74 97 72 / 30 20 20 0

BMX WATCHES/WARNINGS/ADVISORIES

Heat Advisory until 9 PM CDT this evening for the following counties: Autauga-Barbour-Bibb-Bullock-Chilton-Dallas-Elmore- Greene-Hale-Lee-Lowndes-Macon-Marengo-Montgomery-Perry-Pickens- Pike-Russell-Sumter-Tuscaloosa.