918
FXUS64 KHUN 222257
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
557 PM CDT TUE SEP 22 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 1110 AM CDT TUE SEP 22 2026
- THERE IS A LOW RISK FOR STRONG TO SEVERE THUNDERSTORMS THIS
AFTERNOON ACROSS THE SOUTHEASTERN HALF OF THE FORECAST AREA.
DAMAGING WIND GUSTS, SMALL HAIL, AND FREQUENT LIGHTNING WILL BE
THE MAIN THREATS WITH THIS ACTIVITY.
- A SLIGHTLY COOLER AND DRIER AIRMASS WILL BEGIN TO ARRIVE ON
WEDNESDAY NIGHT. HIGHS WILL FALL BACK INTO THE LOWER-MID 80S
FROM THURSDAY-MONDAY, WITH LOWS IN THE MID 50S-LOWER 60S.
NEAR TERM
(REST OF TODAY AND TONIGHT)
ISSUED AT 223 PM CDT TUE SEP 22 2026
THERE HAVE BEEN NO SIGNIFICANT CHANGES TO NEAR TERM FORECAST
REASONING SINCE THE UPDATE EARLIER THIS MORNING. SCATTERED
THUNDERSTORMS (WHICH INITIALLY DEVELOPED IN THE VICINITY OF A
STATIONARY SURFACE TROUGH BISECTING THE CWFA) WILL CONTINUE TO
SPREAD SOUTHEASTWARD THIS AFTERNOON. WITH SPC MESOANALYSIS
INDICATING SBCAPE IN THE 2500-3000 J/KG RANGE, STRENGTHENING W-NW
FLOW ALOFT WILL SUPPORT A MINOR DEGREE OF STORM ORGANIZATION INTO
MULTICELL CLUSTERS, WITH LOCALLY DAMAGING DOWNBURST WINDS AND
FREQUENT LIGHTNING EXPECTED TO BE THE PRIMARY CONVECTIVE IMPACTS.
LATEST HIGH-RESOLUTION MODEL GUIDANCE STILL SUGGESTS THAT BOTH
STORM COVERAGE AND INTENSITY SHOULD DECREASE SUBSTANTIALLY BETWEEN
23-1Z, FOLLOWED BY PARTIAL CLEARING THIS EVENING. HOWEVER, A
BROKEN-OVERCAST LAYER OF LOW STRATUS CLOUDS IS LIKELY TO DEVELOP
WITHIN THE MOIST BOUNDARY LAYER AIRMASS SHORTLY AFTER MIDNIGHT,
AND A FEW SPRINKLES OF RAIN OR LOW-TOPPED SHOWERS MAY OCCUR
BENEATH THIS CLOUD DECK. OVERNIGHT LOWS WILL BE IN THE MID 60S.
PREVIOUS DISCUSSION:
A MID-LEVEL SUBTROPICAL HIGH WILL MIGRATE SLOWLY EASTWARD ACROSS
SOUTH TX OVER THE COURSE OF THE NEAR TERM PERIOD, AS A WEAK CLOSED
CYCLONE TRAVELS SOUTHEASTWARD FROM EASTERN IA INTO IN. THIS
CONFIGURATION WILL FORCE LIGHT W-NW FLOW ALOFT (10-20 KNOTS) TO
GRADUALLY STRENGTHEN INTO THE 25-35 KNOT RANGE BY THE END OF THE
PERIOD. AT THE SURFACE, A TROUGH OF LOW PRESSURE CURRENTLY EXTENDS
FROM THE ARKLAMISS REGION NORTHEASTWARD THROUGH NORTHWEST
AL/MIDDLE TN AND INTO WV. THIS FEATURE WILL PROVIDE THE LOW-LEVEL
LIFT FOR CONVECTIVE DEVELOPMENT WITHIN THE SEASONABLY MOIST AND
UNSTABLE AIRMASS (FEATURING PWAT OF 1.6-1.7" AND MLCAPE OF
1000-2000 J/KG) IN AN ENVIRONMENT OTHERWISE LACKING SYNOPTIC SCALE
FORCING FOR ASCENT. WITH DEVELOPMENT OF A FEW CONVECTIVE CELLS
ALREADY IN PROGRESS ACROSS CENTRAL PARTS OF THE CWFA, WE
ANTICIPATE THAT STORM COVERAGE WILL CONTINUE TO INCREASE THROUGH
DAY (PEAKING DURING THE MID-AFTERNOON AND THEN BEGINNING TO
DIMINISH RAPIDLY BETWEEN 23-1Z). GIVEN THE CURRENT
POSITION/ORIENTATION OF THE BOUNDARY AND A MODEST INCREASE IN
STEERING FLOW THROUGHOUT THE DAY, CELLS SHOULD SPREAD EAST-
SOUTHEASTWARD WITH TIME, WITH HIGHEST COVERAGE ANTICIPATED ACROSS
OUR SOUTHEASTERN FORECAST ZONES. WITH AFTERNOON TEMPERATURES
EXPECTED TO RANGE FROM THE M-U 80S IN THE EAST TO THE L90S IN THE
WEST, LOW-LEVEL LAPSE RATES WILL REMAIN SUFFICIENTLY STEEP TO
SUPPORT BRIEF STRONG WIND GUSTS (UP TO 40-50 MPH). HOWEVER,
PARAMETERS FOR SEVERE DOWNBURST WINDS APPEAR GENERALLY LESS
FAVORABLE TODAY (COMPARED TO YESTERDAY).
OVERNIGHT, SURFACE PRESSURES WILL RISE WITHIN A LARGE ANTICYCLONE
CENTERED ACROSS SOUTHERN QUEBEC. THIS WILL EFFECTIVELY RESULT IN
A COLD AIR DAMMING SCENARIO TO THE EAST OF THE CENTRAL/SOUTHERN
APPALACHIANS, AND SHOULD FORCE THE LOW-LEVEL CONFLUENCE AXIS
(BISECTING OUR FORECAST AREA) TO REMAIN NEARLY STATIONARY.
ALTHOUGH A FEW LOW-TOPPED SHOWERS WILL BE POSSIBLE AT TIMES
(PARTICULARLY IN THE VICINITY OF THE TROUGH AXIS), BOTH POPS AND
THE RISK FOR LIGHTNING/THUNDER WILL BE VERY LOW DUE TO NOCTURNAL
STABILIZATION OF THE BOUNDARY LAYER. AN ABUNDANCE OF LOW STRATUS
CLOUDS APPEARS LIKELY TO EVOLVE DURING THE EARLY MORNING HOURS
WEDNESDAY, AND SHOULD KEEP OVERNIGHT LOWS FROM FALLING BELOW THE
M-U 60S.
SHORT TERM
(WEDNESDAY THROUGH THURSDAY NIGHT)
ISSUED AT 1110 AM CDT TUE SEP 22 2026
OVER THE COURSE OF THE SHORT TERM PERIOD, A SUBTROPICAL HIGH
(CENTERED ALONG THE NORTHWEST GULF COAST) IS PREDICTED TO
STRENGTHEN AND AMPLIFY NORTHWARD THROUGH THE GREAT PLAINS, AS A
MID/UPPER-LEVEL CYCLONE TRACKS SOUTHEASTWARD FROM IN TO A POSITION
OFF THE COAST OF NC/SC. AS THIS OCCURS, WINDS ALOFT ACROSS THE
LOCAL AREA WILL PROGRESSIVELY VEER TO N-NW AND STRENGTHEN TO 35-45
KNOTS, WITH DRY ADVECTION IN THE MID/UPPER-LEVELS CONTRIBUTING TO
A RAPID DROP IN ATMOSPHERIC MOISTURE CONTENT BEGINNING LATE
WEDNESDAY AFTERNOON. IN THE LOW-LEVELS, THE SURFACE TROUGH
BISECTING OUR CWFA WILL REMAIN NEARLY STATIONARY ON WEDNESDAY, BUT
SHOULD BEGIN TO DRIFT WESTWARD WEDNESDAY NIGHT AS THE MAGNITUDE
OF COLD AIR DAMMING WILL BE MAXIMIZED ACROSS WESTERN VA/NC DURING
THIS TIMEFRAME. THE BOUNDARY WILL LIKELY FOCUS THE DEVELOPMENT OF
CONVECTION ONCE AGAIN FROM LATE WEDNESDAY MORNING INTO THE
AFTERNOON HOURS, AND GIVEN THE ANTICIPATED ORIENTATION OF THIS
FEATURE AND STRENGTHENING NW STEERING FLOW, HIGHEST COVERAGE WILL
BE ACROSS THE SOUTHEASTERN PORTION OF THE FORECAST AREA. IN SPITE
OF STRONGER FLOW/SHEAR, CAPE WILL LIMITED AS MORNING STRATUS
CLOUDS SHOULD BE SLOW TO MIX OUT AND WILL KEEP AFTERNOON TEMPS IN
THE 85-90F RANGE. THUS, THE RISK FOR STRONG DOWNBURST WINDS WILL
BE EVEN LOWER (COMPARED TO TODAY). NEVERTHELESS, A FEW
THUNDERSTORMS WILL BE POSSIBLE (PARTICULARLY IN THE SOUTHEAST).
DUE TO EXPECTATIONS THAT THE TROUGH WILL BEGIN DRIFTING WESTWARD
WEDNESDAY NIGHT, A FEW LOW-TOPPED SHOWERS WILL BE POSSIBLE REGION-
WIDE DURING THE OVERNIGHT HOURS.
DURING THE TIMEFRAME FROM THURSDAY-THURSDAY NIGHT, THE SURFACE
TROUGH WILL CONTINUE TO ADVANCE NORTHWESTWARD AND AWAY FROM THE
REGION, WITH LIGHT E-SE FLOW AT THE SURFACE ADVECTING A
COOLER/DRIER AIRMASS INTO THE REGION FROM THE RIDGE TO OUR EAST.
THUS, WE EXPECT RAIN CHANCES TO DROP CONSIDERABLY DURING THIS
PERIOD, WITH ONLY A FEW SHOWERS POSSIBLE (BOTH IN THE VICINITY OF
THE TROUGH AND IN THE HIGHER TERRAIN TO OUR NORTHEAST) THURSDAY
AFTERNOON. TEMPERATURES WILL BE NOTABLY COOLER ON THURSDAY
AFTERNOON, WITH HIGHS RANGING FROM THE M-U 70S IN THE ELEVATED
TERRAIN OF NORTHEAST AL/SOUTHERN MIDDLE TN TO THE M80S IN THE
WEST. OVERNIGHT LOWS WILL FALL INTO THE M50S-L60S BY FRIDAY
MORNING.
LONG TERM
(FRIDAY THROUGH MONDAY)
ISSUED AT 923 PM CDT MON SEP 21 2026
A FALL-LIKE WEATHER PATTERN WILL PERSIST THROUGH THE LONG TERM
PERIOD AS THE TENNESSEE VALLEY SITS UNDERNEATH NORTHWEST FLOW THAT
WILL CONTINUE TO USHER IN A COOLER AIRMASS. DRY CONDITIONS
CONTINUE WITH AFTERNOON HIGHS IN THE LOW TO MID 80S WITH OVERNIGHT
LOWS IN THE MID TO UPPER 50S. AS WE HEAD INTO NEXT WEEK, A WEAK
MID LEVEL RIDGE BEGINS TO SHIFT INTO THE SOUTHEAST. THIS SHOULD
WARM TEMPERATURES UP A FEW DEGREES INTO THE MID TO UPPER 80S. AT
THE SAME TIME A SHORTWAVE IS FORECAST TO DIG SOUTHEAST ACROSS THE
PLAINS. THIS WOULD BRING A LOW CHANCE OF PRECIP DURING THE DAY ON
MONDAY. HOWEVER, THIS IS QUITE FAR OUT AND AT THIS TIME THERE IS
LOW CONFIDENCE IN THIS OCCURRING. THEREFORE, KEPT THE NBM VERY LOW
CHANCE (5-15%) OF SHOWERS ON MONDAY.
AVIATION
(00Z TAFS)
ISSUED AT 557 PM CDT TUE SEP 22 2026
VFR CONDITIONS ARE EXPECTED FOR MOST OF THE NIGHT WITH A LOWER
MVFR CLOUD DECK MOVING IN AROUND SUNRISE TOMORROW. LOWER MVFR
CLOUDS LOOK TO HOLD ON FOR MOST OF THE MORNING BEFORE LIFTING BACK
TO VFR TO MIDDAY. THERE REMAINS A LOW CHANCE FOR SCATTERED SHOWERS
AND THUNDERSTORMS TOMORROW AFTERNOON HOWEVER CONFIDENCE IN TIMING
AND LOCATION IS CURRENTLY TOO LOW TO INCLUDE IN THE TAF.
HUN WATCHES/WARNINGS/ADVISORIES
AL...NONE.
TN...NONE.
NEAR TERM...70
SHORT TERM....70
LONG TERM....GH
AVIATION...RAD
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