textproduct: NWS Birmingham

KEY MESSAGES

Issued at 620 PM CDT THU MAY 21 2026

- A daily scattering of showers and thunderstorms is expected through next week.

- There is a level 1 out of 5 risk for severe weather on Friday, May 22nd from late morning to early evening. Threats include a brief tornado and damaging wind gusts.

DISCUSSION

(This afternoon through Wednesday) Issued at 150 PM CDT THU MAY 21 2026

We'll be in a relatively persistent weather pattern from now into next week. Deep south to southwesterly flow will sustain a warm and humid air mass along with repeated shortwave troughs aloft. This'll promote a daily scattering of showers and thunderstorms with bouts of widespread activity due to the presence of a nearby surface front and modest mid-level flow, plus influence from thunderstorm outflow.

Of short-term intrigue is the passage of a shortwave trough tomorrow/Friday. This feature is shown to bring bulk shear near 25 knots along with a low-level wind field exhibiting some curvature per forecast soundings and hodographs, just within range of the parameter space for updraft rotation. Additionally, models show the development of at least weak surface-based instability (HREF is between 1,000 to 2,000 J/kg). This could support a few showers or thunderstorms with rotation. Based on the overall setup, the longevity of any strong/rotating cell should be brief as updraft strength will be hampered by relatively weak lapse rates. On that same note, daytime heating will be the lifeline of this sort of activity, so the threat window looks to be from late morning to early evening. We'll have to keep an eye on any isolated cells or cells on the edge of shower/storm clusters for the potential of a brief, low-end tornado or damaging wind gusts. This is a low (level 1 out of 5) risk.

Otherwise, rounds of showers and thunderstorms will offer much- needed rainfall across central Alabama. Locations that receive multiple rounds of any heavy activity could total as much as two to four inches.

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AVIATION

(00Z TAFS) Issued at 620 PM CDT THU MAY 21 2026

Cloudiness continues through the next 24 hours, with periods of showers and thunderstorms associated with a stalled front. VFR to MVFR ceilings and visibility are forecast this evening outside of potential for rain/thunderstorms. PROB30 for TSRA maintained through 4z-5z this evening with ongoing scattered convection. Ceilings will fall to at least MVFR early in the morning, with a medium to high chance for IFR. Patchy MVFR visibility may also occur overnight due to patchy fog. MVFR ceilings hold on for most of the rest of Thursday, with further PROB30 for TSRA during the afternoon

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FIRE WEATHER

A persistent weather pattern will produce a daily scattering of showers and thunderstorms through next week. Bouts of precipitation and lack of low RH will keep fire weather conditions at bay.

PRELIMINARY POINT TEMPS/POPS

Gadsden 63 80 63 82 / 60 80 90 90 Anniston 64 80 64 81 / 60 70 80 90 Birmingham 66 80 65 82 / 60 90 80 80 Tuscaloosa 67 79 66 84 / 60 90 80 80 Calera 66 81 65 84 / 60 90 80 90 Auburn 68 84 67 81 / 20 50 70 90 Montgomery 68 82 67 83 / 30 60 60 90 Troy 67 84 68 83 / 10 50 50 90

BMX WATCHES/WARNINGS/ADVISORIES

None.