542
FXUS64 KBMX 071955
AFDBMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
255 PM CDT WED OCT 7 2026
..NEW DISCUSSION
KEY MESSAGES
ISSUED AT 250 PM CDT WED OCT 7 2026
- TROPICAL STORM ISAIAS IS FORECAST TO STRENGTHEN INTO A HURRICANE
BEFORE MAKING LANDFALL ON FRIDAY EVENING ALONG THE NORTHERN GULF
COAST.
- WINDS MAY GUST AS HIGH AS 40 TO 50 MPH LATE FRIDAY NIGHT THROUGH
SATURDAY, RESULTING IN THE POTENTIAL FOR SCATTERED TO NUMEROUS
DOWNED TREES AND POWER LINES.
- RAINFALL AMOUNTS OF 2 TO 4 INCHES WITH LOCALLY HIGHER AMOUNTS UP
TO 5 INCHES WILL RESULT IN THE POTENTIAL FOR FLASH FLOODING,
ESPECIALLY IN URBAN AND OTHER POOR DRAINAGE AREAS.
- A THREAT FOR ISOLATED TORNADOES MAY DEVELOP ALONG AND EAST OF
I-65 ON SATURDAY, WITH THE RELATIVELY HIGHEST POTENTIAL IN FAR
SOUTHEASTERN PORTIONS OF CENTRAL ALABAMA, BUT CONFIDENCE REMAINS
LOW AT THIS TIME.
DISCUSSION
(THIS AFTERNOON THROUGH TUESDAY)
ISSUED AT 250 PM CDT WED OCT 7 2026
TROPICAL STORM ISAIAS OVERVIEW:
TROPICAL STORM ISAIAS CONTINUES TO STRENGTHEN OVER THE
SOUTHWESTERN GULF TODAY. IT WILL MOVE SLOWLY NORTH-NORTHEASTWARD
THROUGH TOMORROW, BEFORE ACCELERATING TO THE NORTHEAST AND NORTH
THURSDAY NIGHT THROUGH LANDFALL ON THE NORTHERN GULF COAST FRIDAY
NIGHT AS IT PHASES WITH A SOUTHERN STREAM SHORTWAVE TROUGH.
MODELS ARE SLOWLY COMING INTO BETTER AGREEMENT, BUT THERE ARE
STILL SOME TYPICAL DIFFERENCES IN TRACK AND TIMING. IN GENERAL
THE AI MODELS REMAIN FURTHER EAST THAN SOME OF THE PHYSICAL
MODELS. SOME MODELS ARE ALSO STILL A FEW HOURS APART ON TIMING AS
WELL. IT'S IMPORTANT TO REMEMBER THAT THE CENTER OF THE STORM CAN
TRACK ANYWHERE INSIDE (OR EVEN JUST OUTSIDE) OF THE CONE, AND
THAT IMPACTS CAN OCCUR WELL OUTSIDE THE CONE ESPECIALLY AS THE
STORM WILL BE INCREASING IN SIZE DURING ITS EXTRATROPICAL
TRANSITION. GIVEN THE FAST-MOVING NATURE OF THE STORM, THE WIND
THREAT DOES APPEAR TO BE INCREASING. THE SPEED MAY DECREASE THE
FLASH FLOODING THREAT A BIT, THOUGH WITH THE POTENTIAL FOR BANDING
TO OCCUR THE THREAT FOR SOME FLASH FLOODING DOES REMAIN. THE
TORNADO THREAT REMAINS UNCERTAIN, BUT IS STILL WORTH KEEPING AN
EYE ON. BOTTOM LINE IS EVERYONE IN CENTRAL ALABAMA NEEDS TO BE
PREPARED FOR TROPICAL WEATHER IMPACTS.
GRADIENT/TROPICAL WINDS:
WHILE THE STORM'S CORE WILL LIKELY LOSE SOME ORGANIZATION AS IT
MOVES INTO THE AREA, LOW-LEVEL WIND FIELDS REMAIN STRONG WITH
925MB WINDS AROUND 60-70KTS, AND FAST-MOVING SYSTEMS ARE
TYPICALLY A BIGGER CONCERN FOR WINDS. WHILE A STABLE LAYER
ASSOCIATED WITH THE WEDGE WILL BE A LIMITING FACTOR FOR MIXING
DOWN THE HIGHER WINDS, FORECAST SOUNDINGS DO INDICATE THE
POTENTIAL FOR 40-50KT WINDS NOT TOO FAR OFF THE GROUND. THE HIGH
PRESSURE TO OUR NORTHEAST WILL ALSO ENHANCE THE PRESSURE
GRADIENT. THEREFORE, POTENTIAL WIND GUSTS LOOK TO BE IN THE 40-
50 MPH RANGE WITH POTENTIAL FOR LOCALLY HIGHER GUSTS ESPECIALLY
IN THE SOUTHERN COUNTIES AND ALSO AT HIGHER ELEVATIONS. THIS
WOULD RESULT IN SCATTERED TO NUMEROUS DOWNED TREES AND POWER
OUTAGES, WHICH COULD BE MORE WIDESPREAD IF THE STRONGER SOLUTIONS
VERIFY. WATCHES MAY BECOME NECESSARY AS EARLY AS TONIGHT.
HEAVY RAINFALL/FLASH FLOODING:
DROUGHT REMAINS ONGOING OVER THE AREA, BUT SOME AREAS DID RECEIVE
BENEFICIAL RAINFALL LAST WEEKEND, ESPECIALLY OUR FAR SOUTHWEST
AND FAR SOUTHEAST COUNTIES. STREAMFLOWS REMAIN BELOW NORMAL TO
WELL BELOW NORMAL FOR THIS TIME OF YEAR ACROSS WEST ALABAMA,
WHILE STREAMFLOWS ARE CLOSER TO NORMAL FOR THIS TIME OF YEAR
(THOUGH NORMAL IS FAIRLY LOW THIS TIME OF YEAR) ELSEWHERE. THIS
SHOULD MINIMIZE THE RISK OF WIDESPREAD MAIN STEM RIVER FLOODING.
STILL, WITH COPIOUS TROPICAL MOISTURE TRANSPORT THERE WILL BE A
THREAT FOR FLASH FLOODING, ESPECIALLY IN URBAN AND OTHER POOR
DRAINAGE AREAS. CURRENT FORECAST RAINFALL AMOUNTS RANGE FROM 2-4"
WITH LOCALLY HIGHER AMOUNTS OF 5". THERE MAY BE A BAND OF
RELATIVELY LOWER RAINFALL AMOUNTS DUE TO DRY SLOTTING SOMEWHERE
BETWEEN HIGHER AMOUNTS WEST WITH THE CORE OF THE SYSTEM AND
HIGHER AMOUNTS EAST WITH A NORTH-SOUTH FRONTAL BAND THAT SETS UP
SOUTH OF THE CENTER OF THE SYSTEM, BUT PLACEMENT OF THESE FEATURES
IS UNCERTAIN. A FLOOD WATCH MAY EVENTUALLY BE NEEDED FOR PORTIONS
OF THE AREA.
SEVERE WEATHER/TROPICAL TORNADOES:
UNSURPRISINGLY, LOW-LEVEL SHEAR AND HELICITY VALUES ARE HIGH AS
THE TROPICAL SYSTEM MOVES IN. MID-LEVEL WINDS/DEEP-LAYER SHEAR
VALUES ARE HIGHER THAN NORMAL FOR A TROPICAL SYSTEM DUE TO
PHASING WITH THE UPSTREAM SHORTWAVE TROUGH. THE MAIN LIMITING
FACTOR AS IT OFTEN IS AS WE MOVE INTO THE COOL SEASON IS
INSTABILITY. THE COLD AIR DAMMING WEDGE AND ASSOCIATED EASTERLY
WINDS RESULTING IN EVAPORATIVE COOLING FROM ISENTROPIC LIFT
DRIVEN RAINFALL WILL BE THE PRIMARY LIMITING FACTOR FOR SURFACE-
BASED INSTABILITY. AT THIS TIME, THE NORTHEAST QUADRANT OF THE
STORM LOOKS STABLE AS IT MOVES IN OVERNIGHT. STARTING POTENTIALLY
AS EARLY AS THE EARLY MORNING HOURS ON SATURDAY IN OUR FAR
SOUTHEAST COUNTIES, A NARROW CORRIDOR OF INSTABILITY MAY DEVELOP
AS THE WARM FRONT LIFTS NORTHWARD IN TANDEM WITH THE CENTER OF
THE SYSTEM WHILE A DEVELOPING OCCLUDED FRONT BEGINS TO MOVE
WESTWARD. INSTABILITY AND SHEAR PROFILES WOULD BE CONDUCIVE FOR A
POTENTIAL FOR ISOLATED, LIKELY BRIEF TORNADOES MAINLY ALONG AND
EAST OF I-65 (THOUGH IF WESTERN SOLUTIONS VERIFY THIS CORRIDOR
WOULD SHIFT WESTWARD) DURING THE DAY ON SATURDAY, WITH RELATIVELY
HIGHEST POTENTIAL IN OUR FAR SOUTHEAST COUNTIES. THIS WOULD BE
CONDITIONAL BASED ON PLACEMENT OF THE CONVECTIVE BAND, WITH THE
APPROACHING DRY SLOT BEING A POTENTIAL LIMITING FACTOR WHERE IT
SUPPRESSES CONVECTION. THIS THREAT WILL NEED TO BE CLOSELY
MONITORED AS WE GET CLOSER AND CAN ASSESS THE MESOSCALE TRENDS.
32/JDAVIS
AVIATION
(18Z TAFS)
ISSUED AT 1219 PM CDT WED OCT 7 2026
VFR CONDITIONS WILL PREVAIL THIS AFTERNOON AND OVERNIGHT. EXPECT
SOME HIGH CIRRUS CLOUDS TO MOVE OVER THE FAR SOUTH AND SOUTHEAST
LOCATIONS ON THURSDAY WHILE DRY CONDITIONS PERSIST. LOW-LEVEL WINDS
WILL BE FROM THE NORTHEAST TO EAST AT 4-8 KTS TODAY, BECOMING 2-4
KTS OVERNIGHT THEN BECOMING MORE EAST AT 5-10 KTS THURSDAY.
05
FIRE WEATHER
DRY CONDITIONS ARE EXPECTED THROUGH THURSDAY. RH VALUES WILL
GENERALLY BE IN THE 25 TO 35 PERCENT RANGE THURSDAY AFTERNOON.
RAIN CHANCES AND HUMIDITY BEGIN TO INCREASE ACROSS SOUTHEAST
PORTIONS OF THE AREA FRIDAY, WHILE AREAS FURTHER TO THE NORTHWEST
WILL HAVE RH VALUES IN THE 30 TO 40 PERCENT RANGE. FIRE DANGER
FOR WESTERN AND NORTHWESTERN AREAS FRIDAY AS WINDS BEGIN TO PICK
UP AHEAD OF AN APPROACHING TROPICAL SYSTEM. WIDESPREAD RAIN AND
HIGH WINDS ARE EXPECTED FRIDAY NIGHT AND SATURDAY AS TROPICAL
STORM ISAIAS MOVES THROUGH THE AREA.
PRELIMINARY POINT TEMPS/POPS
GADSDEN 52 89 58 84 / 0 0 0 0
ANNISTON 53 88 59 83 / 0 0 0 10
BIRMINGHAM 57 90 63 85 / 0 0 0 10
TUSCALOOSA 57 93 62 89 / 0 0 0 10
CALERA 56 90 61 84 / 0 0 0 20
AUBURN 59 86 63 79 / 0 0 0 30
MONTGOMERY 57 88 61 83 / 0 0 0 40
TROY 58 86 61 79 / 0 0 0 50
BMX WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...32/JDAVIS
AVIATION...05
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