857
FXUS64 KBMX 050957
AFDBMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
457 AM CDT TUE MAY 5 2026
..NEW AVIATION
KEY MESSAGES
ISSUED AT 456 AM CDT TUE MAY 5 2026
- A SLIGHT RISK (LEVELS 2 OUT OF 5) FOR SEVERE THUNDERSTORMS IS IN
EFFECT FOR LATE WEDNESDAY INTO EARLY THURSDAY. THREATS INCLUDE
ISOLATED, BRIEF TORNADOES AND DAMAGING WIND GUSTS.
- VERY BENEFICIAL RAINFALL IS EXPECTED TO FALL THROUGH THURSDAY
EVENING, WITH MOST LOCATIONS SEEING 2 PLUS INCHES OF RAIN DURING
THIS TIMEFRAME.
DISCUSSION
(TUESDAY THROUGH NEXT MONDAY)
ISSUED AT 1145 PM CDT MON MAY 4 2026
THE WEATHER STORY FOR THIS FORECAST PERIOD REMAINS THE TROUGH AND
COLD FRONT EXPECTED TO MOVE THROUGH INTO WEDNESDAY, BRINGING WITH
IT HEAVY RAINFALL AND THE THREAT FOR SEVERE WEATHER. IF YOU
REMEMBER MY DISCUSSION FROM LAST NIGHT, I HIGHLIGHTED SOME OF THE
"FAILURE" MODES THAT COULD OCCUR WITH THIS SYSTEM WEDNESDAY
NIGHT. SOME OF THESE FAILURE MODES STILL EXIST (STRONG CAPPING),
BUT SOME OF THE OTHER FAILURE MODES ARE BEGINNING TO RESOLVE
THEMSELVES. THE MAIN ONE IS FORECAST INSTABILITY VALUES. GUIDANCE
HAS STARTED TO COME AROUND TO INSTABILITY VALUES INCREASING
DURING THE DAY ON WEDNESDAY, SETTLING ANYWHERE FROM 1000 TO
2000 J/KG OF INSTABILITY. THESE NUMBERS ARE MORE THAN SUPPORTIVE
FOR ORGANIZED SEVERE WEATHER, WHICH IS WHY THE STORM PREDICTION
CENTER MAINTAINED THE SLIGHT RISK (LEVEL 2 OF 5) FOR LATE
WEDNESDAY EVENING, AND INTO WEDNESDAY NIGHT. GIVEN THE PARAMETER
SPACE, ALL MODES OF SEVERE WEATHER WOULD BE POSSIBLE, WITH THE
HAIL THREAT DIMINISHING ONCE STORMS BECOME LINEAR.
AS UPSCALE GROWTH BEGINS SOMETIME WEDNESDAY EVENING, THESE STORMS
WILL QUICKLY BECOME VERY EFFICIENT RAINFALL PRODUCERS GIVEN VERY
HIGH PRECIPITABLE WATER VALUES. BECAUSE OF THIS, HEAVY RAIN IS
ALSO EXPECTED WITH THESE STORMS, AND CONFIDENCE IS HIGH THAT MOST
LOCATIONS WILL SEE BETWEEN 2 AND 3 INCHES OF RAINFALL. EVENING
GUIDANCE HAS THESE STORMS BRIEFLY STALLING AT SOME POINT
OVERNIGHT, AND GIVEN THE HIGH RAINFALL RATES, 4+ INCHES WOULDN'T
BE OUT OF THE QUESTION IN A FEW AREAS. HOWEVER, CONFIDENCE IN
WHERE THESE STORMS WILL STALL IS LOW, AND WILL CONTINUE TO BE
EVALUATED THE NEXT TWO DAYS.
RAIN CHANCES WILL TAPER OFF INTO THE WEEKEND, WITH TEMPERATURES
FALLING TO A BELOW AVERAGE FEEL BEHIND THE COLD FRONT. HOWEVER, A
SURFACE RIDGE WILL QUICKLY SET IN, ALLOWING TEMPERATURES TO
REBOUND BACK INTO THE 80S COME SUNDAY. THANKFULLY, ANOTHER
REINFORCING TROUGH AND COLD FRONT WILL MOVE THROUGH THE REGION
SOMETIME TO START THE NEW WORKWEEK, INCREASING RAIN CHANCES ONCE
MORE, AND DROPPING TEMPERATURES BACK DOWN TO A MORE SEASONABLE
FEEL.
/44/
AVIATION
(12Z TAFS)
ISSUED AT 456 AM CDT TUE MAY 5 2026
THERE IS HIGH CONFIDENCE IN VFR CONDITIONS THROUGHOUT THE TAF
PERIOD. A SUB-TROPICAL JET ATOP THE REGION WILL RESULT IN BOUTS
OF HIGH-LEVEL CLOUDS. WINDS BECOME SOUTHERLY AROUND 10 KNOTS FROM
~15Z ONWARD. WE'LL KEEP AN EYE ON THE WIND FIELD TUESDAY
EVENING/NIGHT, AS A STRENGTHENING LOW-LEVEL JET ACROSS THE
TENNESSEE VALLEY MAY RESULT IN OCCURRENCES OF LLWS.
AMD NOT SKED WILL CONTINUE FOR TCL DUE TO INTERMITTENT
OBSERVATIONS.
89^GSATTERWHITE
FIRE WEATHER
MINRH VALUES WILL LINGER IN THE 30-40% RANGE FOR THE NEXT TWO
DAYS, BEFORE REBOUNDING WEDNESDAY. HERE, THE NEXT ORGANIZED
SYSTEM WILL BEGIN WORKING INTO THE AREA. RIGHT NOW, THERE IS HIGH
CONFIDENCE IN ORGANIZED RAIN CHANCES WEDNESDAY INTO THURSDAY,
WITH SOME LOCATIONS SEEING 2 PLUS INCHES OF RAIN. GIVEN RECENT
RAINFALL, AND THE UPCOMING RAINFALL, THIS SHOULD KEEP FIRE
WEATHER CONCERNS LIMITED GIVEN SOME DAMP FUELS.
PRELIMINARY POINT TEMPS/POPS
GADSDEN 78 60 80 60 / 10 30 70 100
ANNISTON 79 61 82 63 / 10 20 60 90
BIRMINGHAM 79 64 81 64 / 10 20 70 90
TUSCALOOSA 81 64 83 64 / 10 10 70 90
CALERA 81 61 83 64 / 10 10 60 90
AUBURN 80 61 84 68 / 0 10 20 70
MONTGOMERY 82 61 88 68 / 10 10 30 70
TROY 81 60 87 67 / 0 0 20 50
BMX WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION.../44/
AVIATION...89^GSATTERWHITE
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