313
FXUS64 KHUN 100347
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1047 PM CDT TUE SEP 9 2025
..NEW NEAR TERM, SHORT TERM, LONG TERM
NEAR TERM
(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 1047 PM CDT TUE SEP 9 2025
LIGHT (5-15 KNOT) SOUTH-SOUTHWEST FLOW ALOFT WILL CONTINUE ACROSS
THE TN VALLEY THIS EVENING, BEFORE BEGINNING TO VEER TO THE WEST
SHORTLY BEFORE SUNRISE AS A MID-LEVEL TROUGH OVER THE MS VALLEY
SHIFTS EASTWARD. IN THE LOW-LEVELS, OUR FORECAST AREA WILL REMAIN
UNDER THE INFLUENCE OF A HIGH AS IS TRACKS EAST-NORTHEASTWARD FROM
NEW ENGLAND INTO THE NORTHWESTERN ATLANTIC, WITH RIDGING IN THE
LEE OF THE APPALACHIANS EXPECTED TO SUPPORT A VERY LIGHT SE WIND
OVERNIGHT. SURFACE OBSERVATIONS INDICATE THAT THE BOUNDARY LAYER
AIRMASS HAS GRADUALLY MODIFIED OVER THE PAST 24 HOURS, WITH
DEWPOINTS NOW IN THE U50S-L60S, BUT GIVEN THE WEAK NATURE OF THE
APPROACHING MID-LEVEL TROUGH, WE ANTICIPATE NO IMPACTS ON SENSIBLE
WEATHER. HOWEVER, LOWS WILL BE A FEW DEGREES WARMER TONIGHT AND
SHOULD RANGE FROM THE MID 50S IN THE COOLER VALLEYS OF NORTHEAST
AL TO THE U50S-L60S ELSEWHERE. WITH THE SUBTLE INCREASE IN LOW-
LEVEL MOISTURE, CONDITIONS WILL BE SLIGHTLY MORE FAVORABLE FOR
DEVELOPMENT OF PATCHY MIST/FOG AROUND SUNRISE IN VALLEYS AND NEAR
LARGE BODIES OF WATER.
THE AXIS OF THE 500-MB TROUGH (NOTED ABOVE) IS PREDICTED TO CROSS
THE REGION LATE TOMORROW MORNING, WITH WINDS ALOFT VEERING TO NW
IN ITS WAKE AND STRENGTHENING INTO THE 15-25 KNOT RANGE BY
TOMORROW AFTERNOON. AT THE SURFACE, THE LOCAL PRESSURE GRADIENT
WILL RELAX AS A HIGH OVER THE NORTHWESTERN ATLANTIC MOVES FURTHER
AWAY FROM THE REGION AND PROGRESSIVELY LIGHTER WINDS THROUGHOUT
THE DAY. WITH ONLY A FEW HIGH- BASED CU EXPECTED, MOSTLY SUNNY
SKIES AND DRY CONDITIONS WILL LEAD TO AFTERNOON TEMPERATURES A FEW
DEGREES WARMER COMPARED TO TODAY (U70S-L80S IN ELEVATED TERRAIN
TO M-U 80S IN THE VALLEY).
SHORT TERM
(WEDNESDAY NIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 1047 PM CDT TUE SEP 9 2025
LATEST SHORT RANGE MODEL DATA SUGGESTS THAT A MID-LEVEL VORT MAX
(IN THE WAKE OF THE BROADER TROUGH TO ITS EAST) WILL DIVE
SOUTHEASTWARD INTO CENTRAL IL DURING THE DAY TOMORROW BEFORE
ADVANCING INTO THE OH VALLEY WEDNESDAY NIGHT. ALTHOUGH THIS
FEATURE MAY INSTIGATE THE DEVELOPMENT OF WEAK CONVECTION (IN THE
FORM OF SHOWERS AND A FEW THUNDERSTORMS) BEGINNING LATE TOMORROW
EVENING AS IT INTERACTS WITH A DIFFUSE WARM FRONT EXTENDING FROM
THE CENTRAL PLAINS INTO THE OH VALLEY, THIS ACTIVITY WILL LIKELY
NOT SURVIVE AS FAR SOUTH AS OUR FORECAST AREA. HOWEVER, WITH NNW
WINDS ALOFT PREDICTED TO INCREASE FURTHER INTO THE 25-30 KNOT
RANGE OVERNIGHT, IT IS AT LEAST SOMETHING TO MONITOR. A SLIGHTLY
HIGHER CHANCE FOR A COUPLE OF SHOWERS AND PERHAPS A THUNDERSTORM
WILL OCCUR ON THURSDAY AFTERNOON/EARLY EVENING AS THE VORT MAX
DIGS SOUTHEASTWARD INTO THE SOUTHERN APPALACHIANS. ALTHOUGH
DEWPOINTS IN THE M50S-L60S WILL SUPPORT CAPE OF 1000-1500 J/KG
(WITH AFTERNOON HIGHS IN THE M80S-L90S), A MID-LEVEL SUBSIDENCE
INVERSION SHOULD INHIBIT THE VERTICAL GROWTH OF UPDRAFTS AND
OVERALL POTENTIAL FOR LIGHTNING/THUNDER.
DURING THE PERIOD FROM FRIDAY-FRIDAY NIGHT, THE VORT MAX IS
PREDICTED TO DEEPEN INTO A PARTIALLY CLOSED LOW ACROSS COASTAL
PORTIONS OF NC/SC, INDUCING DRY NORTHERLY FLOW ALOFT ACROSS OUR
FORECAST AREA. IN THE LOW-LEVELS, A LIGHT NE WIND WILL RESUME
ALONG THE SOUTHERN PERIPHERY OF ANOTHER HIGH SHIFTING EASTWARD
ACROSS SOUTHEASTERN CANADA, AND THIS WILL YIELD A DRY FORECAST.
UNFORTUNATELY, THE RETURN OF NORTHEASTERLY WINDS WILL HAVE LITTLE
IMPACT ON TEMPERATURES AT OUR LATITUDE, WITH HIGHS CONTINUING IN
THE M80S-L90S THROUGH FRIDAY. OVERNIGHT LOWS WILL REMAIN IN THE
U50S-L60S, BUT MAY BE A FEW DEGREES COOLER FRIDAY NIGHT IF DRIER
AIR MANAGES TO WORK ITS WAY INTO THE REGION FROM THE NORTHEAST.
LONG TERM
(SATURDAY THROUGH TUESDAY)
ISSUED AT 1047 PM CDT TUE SEP 9 2025
THE UPPER RIDGE/HIGH WILL CONTINUE TO BE THE DOMINATING FACTOR ON
WEATHER HERE LOCALLY WITH A MUCH WARMER AIRMASS PERSISTING INTO
NEXT WEEK. WITH LARGE SCALE SUBSIDENCE IN PLACE, WE WILL MAINTAIN
A DRY FORECAST THROUGH THE EXTENDED PERIOD AND THE MAIN IMPACT
WILL TRANSITION MORE TO THE DRY HEAT. THANKFULLY, THE BETTER
MOISTURE WILL BE SUPPRESSED TO OUR SOUTH WHICH WILL HELP LIMIT
HEAT INDICES BELOW THE 100 DEGREE MARK. OVERNIGHT LOWS WILL BE ON
THE WARMER SIDE TOO, DROPPING TO THE MID TO UPPER 60S BUT
THANKFULLY NOT AS BAD AS THE HOT, MUGGY NIGHTS WE SAW NEARLY A
MONTH AGO. SO HANG IN THERE, SUMMER IS NOT OVER YET! REMEMBER TO
PRACTICE HEAT SAFETY AS WE HEAD THROUGH THE REMAINDER OF THE WEEK
AND WEEKEND AND NEVER LEAVE PEOPLE OR PETS UNATTENDED IN VEHICLES!
AVIATION
(00Z TAFS)
ISSUED AT 653 PM CDT TUE SEP 9 2025
CONDITIONS WILL REMAIN VFR AT THE HSV/MSL TERMINALS, WITH A FEW
HIGH-LVL CI POSSIBLE THROUGHOUT THE TAF PERIOD AND DEVELOPMENT OF
A FEW HIGH-BASED CU DURING THE PEAK OF THE DIURNAL WARMING CYCLE
TOMORROW. ALTHOUGH PATCHY BR/FG MAY DEVELOP IN LOCAL VALLEYS AND
NEAR LARGE BODIES OF WATER AROUND SUNRISE (ESPECIALLY WITH
DEWPOINTS NOW IN THE M-U 50S), CONFIDENCE IS NOT HIGH IN VSBY
REDUCTIONS AT EITHER AIRPORT. A LIGHT SE WIND WILL CONTINUE
OVERNIGHT, BEFORE BECOMING LGT/VRBL LATE IN THE PERIOD.
HUN WATCHES/WARNINGS/ADVISORIES
AL...NONE.
TN...NONE.
NEAR TERM...70/DD
SHORT TERM...70/DD
LONG TERM...25
AVIATION...70/DD
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