902
FXUS64 KBMX 300154
AFDBMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
854 PM CDT WED APR 29 2026
..NEW MESOSCALE UPDATE
KEY MESSAGES
ISSUED AT 854 PM CDT WED APR 29 2026
- A MARGINAL TO SLIGHT RISK (LEVEL 1 TO 2 OF 5) REMAINS IN EFFECT
THROUGH THIS EVENING. DAMAGING WINDS AND HAIL ARE THE MAIN
THREATS WITH ANY SEVERE ACTIVITY.
- THE NEXT CHANCE OF RAIN WILL BE FRIDAY AND SATURDAY, WITH
SHOWERS AND A FEW THUNDERSTORMS EXPECTED.
MESOSCALE UPDATE FOR THUNDERSTORMS THIS EVENING
ISSUED AT 854 PM CDT WED APR 29 2026
THE SURFACE COLD FRONT EXTENDS FROM ACROSS SOUTHERN LAMAR COUNTY
EXTENDING EAST-NORTHEAST TO NEAR GADSDEN. OVER THE PAST FEW
HOURS, SHOWER AND THUNDERSTORM ACTIVITY HAS INCREASED NEAR AND
JUST SOUTH OF THE BOUNDARY ACROSS OUR WEST AND CENTRAL COUNTIES
WHERE OUTFLOWS FROM CONVECTION TO THE SOUTH ADVANCED NORTHWARD
TOWARD THE SURFACE FRONT AND INTERACTED WITH INCREASED LOW-LEVEL
CONVERGENCE.
RAP 13 KM MESOSCALE ANALYSIS DATA SHOWS A 300 MB 100 KT JET
MOVING EAST OVER OUR CENTRAL COUNTIES AT THIS TIME, WHICH IS
HELPING TO FURTHER ENHANCE CONVECTIVE ACTIVITY FROM
NORTHERN/EASTERN TUSCALOOSA COUNTY EASTWARD INTO NORTHERN
JEFFERSON AND NORTHERN ST. CLAIR COUNTIES. THE 30/00Z BMX
OBSERVED SOUNDING REVEALED STEEPENING MID-LEVEL LAPSE RATES DUE
TO A SLUG OF DRIER AIR THAT HAS MOVED IN FROM 800-500 MB.
SUFFICIENT INSTABILITY WILL PERSIST THROUGH LATE EVENING ACROSS
THIS AREA WHILE BULK SHEAR VALUES AREAWIDE REMAIN SUFFICIENT FOR
CONTINUED ORGANIZED CONVECTION OVERNIGHT.
PREVIOUS CONVECTION ACROSS OUR FAR SOUTHWEST COUNTIES AND ITS
ASSOCIATED COLD POOL OUTFLOW HAS EXHAUSTED AVAILABLE INSTABILITY
SO THE WATCH WAS ABLE TO BE CANCELLED EARLIER. WE WILL CONTINUE
TO MONITOR TRENDS WITH GREATEST POTENTIAL FOR STRONG TO SEVERE
STORMS ALONG WITH A HEAVY RAINFALL/POTENTIAL URBAN FLASH FLOOD
RISK FOR PORTIONS OF TUSCALOOSA/JEFFERSON/ST. CLAIR COUNTIES
THROUGH 10 PM.
MESOSCALE UPDATE FOR THUNDERSTORMS THIS EVENING
ISSUED AT 852 PM CDT WED APR 29 2026
SURFACE COLD FRONT EXTENDS FROM ACROSS SOUTHERN LAMAR COUNTY
EXTENDING EAST-NORTHEAST TO NEAR GADSDEN. OVER THE PAST FEW
HOURS, SHOWER AND THUNDERSTORM ACTIVITY HAS INCREASED NEAR AND
JUST SOUTH OF THE BOUNDARY ACROSS OUR WEST AND CENTRAL COUNTIES
WHERE OUTFLOWS FROM CONVECTION TO THE SOUTH ADVANCED NORTHWARD
TOWARD THE SURFACE FRONT AND INTERACTED WITH INCREASED LOW-LEVEL
CONVERGENCE. RAP 13 KM MESOSCALE ANALYSIS DATA SHOWS A 300 MB
100 KT JET MOVING EAST OVER OUR CENTRAL COUNTIES AT THIS TIME,
WHICH IS HELPING TO FURTHER ENHANCE CONVECTIVE ACTIVITY FROM
NORTHERN/EASTERN TUSCALOOSA COUNTY EASTWARD INTO NORTHERN
JEFFERSON AND NORTHERN ST. CLAIR COUNTIES.
PREVIOUS CONVECTION ACROSS OUR FAR SOUTHWEST COUNTIES AND ITS
ASSOCIATED COLD POOL OUTFLOW HAS EXHAUSTED AVAILABLE INSTABILITY
SO THE WATCH WAS ABLE TO BECANCELLEDBUT THE WATCH WILL REMAIN IN
PLACE FURTHER EAST WHERE INSTABILITY PERSISTS, THOUGH THE
GREATEST RISK IN THE NEAR TERM FOR HAIL AND WINDS IS ACROSS
NORTHERN PICKENS, SOUTHERN LAMAR, SOUTHERN FAYETTE AND TUSCALOOSA
COUNTIES.
30/00Z BMX OBSERVED SOUNDING SHOWS A SLUG OF DRIER AIR HAS MOVED
IN FROM 800-500 MB, RESULTING IN STEEPING LAPSE RATES ALOFT. RAP
13 KM MESOANALYSIS DATA SHOWS SBCAPE VALUES AROUND 2500 J/KG WITH
0-6 KM BULK SHEAR VALUES AT OR OVER 40 KTS ACROSS THE WEST-
CENTRAL AND SOUTHWEST COUNTIES SO CONDITIONS REMAIN SUPPORTIVE
FOR ORGANIZED CONVECTION AND A SEVERE STORM OR TWO AT LEAST
THROUGH 9 PM. MOST HIGH-RES GUIDANCE DEPICTS INCREASING SHOWER
AND THUNDERSTORM ACTIVITY INTO THE OVERNIGHT, THOUGH INTENSITY IS
EXPECTED TO WANE THROUGH THE NIGHT WITH GRADUALLY DECREASING
INSTABILITY, WHILE SHEAR PROFILES WILL REMAIN SUFFICIENT FOR
PERSISTENT, ORGANIZED CONVECTION.
05
DISCUSSION
(THIS EVENING THROUGH TUESDAY)
ISSUED AT 308 PM CDT WED APR 29 2026
THIS AFTERNOON A FRONTAL BOUNDARY EXTENDED FROM WRN PA SWWD TO NW
AL AND BACK TOWARD TX. ALONG AND AHEAD OF THIS BOUNDARY,
CONVECTION IS ALREADY DEVELOPING OVER MS. THIS CONVECTION WILL
SPREAD EWD ACROSS C AL THIS AFTERNOON INTO THU. THERE IS EXPECTED
TO BE SUFFICIENT FORCING AND INSTABILITY FOR STRONG TO MARGINALLY
SEVERE STORMS TO DEVELOP THROUGH THIS EVENING AHEAD OF IT.
DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN THREAT. NRLY FLOW
WILL HELP TO GIVE US A RAIN BREAK BEHIND THE FRONT FOR THU
AFTERNOON AND EVENING. AN UPPER SHORTWAVE WILL ALLOW FOR RAIN
CHANCES TO RETURN FOR FRI AND SAT. HOWEVER, TEMPERATURES AND DEW
POINTS WILL BE MUCH LOWER BEHIND THE FRONT AS THIS WAVE MOVES
THROUGH. LOOK FOR MAINLY RAIN SHOWERS WITH LOW PROBABILITY OF
THUNDERSTORMS WITH THE ACTIVITY FOR FRI AND SAT.
DRY WEATHER RETURNS ON SUN BEHIND THE UPPER SYSTEM WITH A LARGE
SURFACE RIDGE EXTENDING FROM TX, ACROSS THE DEEP SOUTH AND INTO
THE CAROLINAS. COOL AND PLEASANT SPRING CONDITIONS ARE EXPECTED.
RAIN-FREE WEATHER WILL CONTINUE UNDER THE INFLUENCE OF RIDGING
THROUGH THE END OF OUR EXTENDED FORECAST ON TUE. LOOK FOR A
WARMING TREND AS WE MOVE INTO MON AND TUE ACROSS AL AS OUR AIRMASS
MODERATES AND THE SURFACE RIDGE WEAKENS.
08
AVIATION
(00Z TAFS)
ISSUED AT 646 PM CDT WED APR 29 2026
A SURFACE COLD FRONT IS APPROACHING THE INTERSTATE 59 CORRIDOR
FROM THE NORTHWEST WHILE A FEW MID-LEVEL SHORTWAVES ARE MOVING
EAST OVER THE WESTERN COUNTIES EARLY THIS EVENING. MODERATE
CONFIDENCE FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TO
AFFECT TCL, BHM, AND EET THROUGH MID TO LATE EVENING, FOLLOWED BY
IMPROVING CONDITIONS OVERNIGHT. MODERATE CONFIDENCE FOR SHOWERS
AND A FEW THUNDERSTORMS AFFECTING MGM/AUB LATER IN THE NIGHT
THROUGH EARLY THURSDAY MORNING. EXPECT SOME LOW CLOUDS TO PERSIST
EVEN AFTER SHOWERS AND STORMS MOVE OUT THROUGH MID THURSDAY
MORNING BEFORE BEFORE VFR CONDITIONS ARE EXPECTED TO RETURN
AREAWIDE TOWARD MIDDAY, FOR WHICH THERE IS HIGH CONFIDENCE.
AMD NOT SKED WILL CONTINUE FOR TCL DUE TO INTERMITTENT
OBSERVATIONS.
05
FIRE WEATHER
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED FOR LATE
THIS AFTERNOON THROUGH THURSDAY MORNING AHEAD OF A COLD FRONT.
DRIER AIR BEHIND THE FRONT WILL DROP RHS BACK INTO THE 30-40%
RANGE ACROSS THE NORTHERN COUNTIES ON THURSDAY AFTERNOON, BEFORE
REBOUNDING AS RAIN CHANCES RETURN FOR FRIDAY AND SATURDAY. DRIER
CONDITIONS RETURN AGAIN FOR SUNDAY THROUGH TUESDAY.
PRELIMINARY POINT TEMPS/POPS
GADSDEN 51 72 47 69 / 60 10 10 20
ANNISTON 56 73 50 70 / 70 20 10 30
BIRMINGHAM 56 72 52 69 / 80 20 10 30
TUSCALOOSA 56 74 52 70 / 80 20 10 50
CALERA 56 75 52 71 / 80 30 10 40
AUBURN 61 74 55 69 / 90 30 10 40
MONTGOMERY 61 75 54 66 / 90 30 20 50
TROY 61 76 54 68 / 90 40 20 40
BMX WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...05
AVIATION...05
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