399
FXUS64 KHUN 281215
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
715 AM CDT WED MAY 28 2025
..NEW AVIATION
NEAR TERM
(TODAY)
ISSUED AT 445 AM CDT WED MAY 28 2025
A DISTINCT MID-LEVEL SHORTWAVE TROUGH WILL SPREAD EAST-
NORTHEASTWARD FROM EASTERN OK/WESTERN AR INTO THE CUMBERLAND
PLATEAU VICINITY BY 12Z WEDNESDAY, WITHIN THE CIRCULATION AROUND A
STATIONARY UPPER-LEVEL LOW OVER SOUTHWESTERN MN. IN RESPONSE TO
THIS, A WEAK SURFACE WAVE WILL LIFT NORTHEASTWARD FROM
WESTERN/MIDDLE TN INTO CENTRAL KY BY SUNRISE, WITH A SLOW-MOVING
TROUGH AXIS EXTENDING SOUTHWESTWARD FROM THE LOW FORCING A SOLID
BAND OF MODERATE-HEAVY SHOWERS (AND A FEW RUMBLES OF THUNDER)
ACROSS CULLMAN/MARSHALL/DEKALB COUNTIES. ALTHOUGH VERY WEAK LOW-
LEVEL ROTATION HAS BEEN NOTED THROUGHOUT THE EARLY MORNING HOURS
WITH EMBEDDED SUPERCELLULAR STRUCTURES IN REFLECTIVITY DATA FROM
BOTH KHTX AND ARMOR, THE OVERALL STORM ENVIRONMENT IS NOT
SUPPORTIVE OF EVEN BRIEF TORNADOES AT THIS HOUR. HOWEVER, ECHO
TRAINING AND HIGH RAINFALL RATES HAVE COMBINED TO RESULT IN A
LOCALIZED RISK FOR MINOR FLOODING AND PONDING OF WATER ACROSS THE
SAME REGION, AND AN SPS WILL BE CONTINUED TO ADDRESS THIS RISK.
ACROSS THE REMAINDER OF THE CWFA, MOIST BOUNDARY LAYER CONDITIONS
AND CALM TO LIGHT WNW FLOW HAS SUPPORTED THE DEVELOPMENT FOG (SOME
OF WHICH HAS BEEN LOCALLY DENSE).
PRESENT INDICATIONS ARE THAT THE SHORTWAVE TROUGH (INITIALLY
ACROSS THE CUMBERLAND PLATEAU) WILL ACCELERATE NORTHEASTWARD INTO
THE NORTHERN MID-ATLANTIC STATES TOMORROW, AS THE PRIMARY UPPER
LOW SPREADS SOUTHEASTWARD INTO SOUTHERN WI. AS THIS OCCURS, MID-
LEVEL SW FLOW OF 35-45 KNOTS WILL VEER TO THE WEST AND DROP INTO
THE 20-30 KNOT RANGE, AND WITH PREVAILING LIGHT WNW FLOW AT THE
SURFACE (LACK OF LOW-LEVEL CONVERGENCE), WE EXPECT A MUCH LOWER
COVERAGE OF PRECIPITATION COMPARED TO PREVIOUS DAYS. NEVERTHELESS,
AS THE SURFACE LOW TRAVELS FURTHER NORTHEASTWARD INTO OH, A
SECONDARY SURFACE TROUGH MAY INITIATE THE DEVELOPMENT OF A FEW
SHOWERS AND STORMS THIS AFTERNOON (MAINLY ACROSS THE NORTHEASTERN
CORNER OF THE CWFA) AS TEMPS WARM INTO THE M-U 70S AND CAPE
INCREASES INTO THE 1000-1500 J/KG RANGE. WITH DEEP-LAYER FLOW AND
SHEAR PREDICTED TO WEAKEN WITH TIME, ORGANIZED/SEVERE CONVECTION
IS NOT ANTICIPATED.
SHORT TERM
(TONIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 445 AM CDT WED MAY 28 2025
ALTHOUGH LIGHT NORTHERLY FLOW AND DRY CONDITIONS WILL PERSIST
ACROSS THE REGION ON WEDNESDAY EVENING, SHOWERS AND ELEVATED
THUNDERSTORMS WILL SPREAD NORTHWARD INTO THE REGION FROM THE
NORTHWESTERN/CENTRAL GULF COAST BY EARLY THURSDAY MORNING AS
ELEVATED WARM ADVECTION STRENGTHENS DOWNSTREAM FROM A DEVELOPING
AREA OF LOW PRESSURE ACROSS CENTRAL TX. THIS TREND WILL CONTINUE
THROUGHOUT THE LATE MORNING HOURS, WITH A POTENTIAL INCREASE IN
COVERAGE/INTENSITY POSSIBLE DURING THE AFTERNOON AS THE SURFACE
WAVE SHIFTS INTO THE MID-SOUTH AND WINDS RETURN TO THE SOUTH
(ADVECTING A MOIST/UNSTABLE BOUNDARY LAYER NORTHWARD ONCE AGAIN).
PRESENT INDICATIONS ARE THAT THE LOW WILL BEGIN TO DEEPEN AT A
MORE CONSIDERABLE RATE FROM LATE THURSDAY AFTERNOON THROUGH FRIDAY
MORNING AS IT LIFTS NORTHEASTWARD INTO EASTERN KY AND INTERACTS
WITH A RATHER INTENSE 500-MB SHORTWAVE TROUGH DIGGING
SOUTHEASTWARD ACROSS THE MID-MS VALLEY. STRENGTHENING MID-LEVEL
FLOW AND DEEP-LAYER ASCENT PROVIDED BY THIS WAVE WILL SUPPORT
DEVELOPMENT OF A BROKEN QLCS ALONG THE LOW'S TRAILING COLD FRONT,
WITH THIS FEATURE EXPECTED TO SHIFT RAPIDLY SOUTHEASTWARD ACROSS
THE CWFA EARLY FRIDAY MORNING (EXITING OUR SOUTHEASTERN COUNTIES
BY 13-15Z FRIDAY). WITH OUR REGION LOCATED WELL WITHIN THE
MOIST/UNSTABLE WARM SECTOR OF THE LOW (PRIOR TO THE ARRIVAL OF THE
COLD FRONT), SHEAR AND INSTABILITY WILL SUPPORT A RISK OF
DAMAGING WIND/LARGE HAIL WITH THE MOST INTENSE CELLS BOTH WITHIN
THE QLCS AND POTENTIALLY ACROSS THE OPEN WARM SECTOR WELL AHEAD OF
THE FRONT ON THURSDAY AFTERNOON/EVENING. AT THIS POINT, THE RISK
FOR EVEN A BRIEF TORNADO APPEARS RATHER LOW (COMPARED TO THE PAST
COUPLE OF DAYS) DUE TO THE UNFAVORABLE TIME OF DAY FOR FRONTAL
PASSAGE AND INDICATIONS THAT THE WSW LOW-LEVEL JET MAY ONLY REACH
20-30 KNOTS IN INTENSITY BY EARLY FRIDAY MORNING.
DEEP-LAYER NW FLOW IN THE WAKE OF THE DEPARTING TROUGH AND COLD
FRONT WILL ADVECT A COOLER/DRIER AIRMASS INTO THE REGION
FRIDAY/FRIDAY NIGHT, WITH SOME WRAP-AROUND CLOUDS AND LIGHT RAIN
POSSIBLE IN THE NORTHEASTERN CORNER OF THE CWFA DURING THE DAY ON
FRIDAY AND INTO FRIDAY EVENING.
LONG TERM
(SATURDAY THROUGH TUESDAY)
ISSUED AT 445 AM CDT WED MAY 28 2025
GLOBAL MODELS SUGGEST THAT DRY CONDITIONS WILL PERSIST ACROSS THE
TN VALLEY ON SATURDAY. HOWEVER, A BAND OF SHOWERS WILL LIKELY
EVOLVE TO OUR NORTH (FROM THE MID-MS VALLEY INTO THE SOUTHERN
APPALACHIANS) WITHIN A WEAK LOW-LEVEL CONFLUENCE ZONE PROVIDED BY
A REINFORCING/CONTINENTAL HIGH BUILDING SOUTHWARD FROM CANADA.
ALTHOUGH THIS ACTIVITY WILL BE LARGELY DRIVEN BY THE DIURNAL
WARMING CYCLE, AS THE HIGH MIGRATES FURTHER SOUTHEASTWARD INTO THE
CENTRAL APPALACHIANS LATE IN THE WEEKEND AND THE SURFACE
CONFLUENCE AXIS DRIFTS SOUTHWARD, THERE IS SOME CONCERN FOR
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS IN OUR REGION ON SUNDAY.
HOWEVER, THIS WILL ULTIMATELY DEPEND ON WHERE THE SURFACE BOUNDARY
LIES (AND THIS COULD BE TO OUR NORTHEAST). IN ANY EVENT,
INSTABILITY WILL BE FAIRLY LOW (BUT SUFFICIENT FOR
LIGHTNING/THUNDER) AND NW WINDS ALOFT WILL ONLY BE IN THE 20-25
KNOT RANGE, SO ORGANIZED SEVERE CONVECTION IS NOT ANTICIPATED AT
THIS POINT. WE MAY ALSO BE IMPACTED TO SOME EXTENT (ON SUNDAY
NIGHT) BY THE REMNANTS OF AN MCS DROPPING SOUTH-SOUTHEASTWARD
ACROSS THE CENTRAL PLAINS ON SATURDAY, BUT THIS ASPECT OF THE
FORECAST IS QUITE UNCERTAIN AT THIS POINT. CONDITIONS WILL REMAIN
DRY EARLY NEXT WEEK AS THE SURFACE HIGH SHIFTS EASTWARD OFF THE
SOUTHERN MID-ATLANTIC COAST AND A MID-LEVEL RIDGE BUILDS ACROSS
THE SOUTHEASTERN CONUS.
AVIATION
(12Z TAFS)
ISSUED AT 715 AM CDT WED MAY 28 2025
OVERALL, THERE HAVE BEEN NO SIGNIFICANT CHANGES TO AVIATION
FORECAST REASONING FOR THIS PARTICULAR PERIOD, AS LOW STRATUS/FOG
WILL DISSIPATE RATHER QUICKLY BY 15Z, WITH MOSTLY SUNNY SKIES AND
LGT NW WINDS EXPECTED THIS AFTN. ALTHOUGH A FEW SHRA/TSRA WILL BE
POSSIBLE, COVERAGE IS EXPECTED TO BE MUCH LOWER (COMPARED TO
PREVIOUS DAYS) AND WE WILL NOT MENTION IN THE TAFS AT THIS POINT.
DEVELOPMENT OF LIGHT BR/FG WILL BE POSSIBLE ONCE AGAIN THIS
EVENING, BUT WITH AN INCREASE IN HIGH CLOUDS EXPECTED PRIOR TO
MIDNIGHT WE WILL NOT MENTION IN THE FORECAST ATTM. CHANCES FOR
RAIN AND ELEVATED TSRA WILL INCREASE ONCE AGAIN TOWARD THE END OF
THE TAF PERIOD, BUT CONFIDENCE IN COVERAGE IS TOO LOW TO INCLUDE
PRECIPITATION AT THIS POINT.
HUN WATCHES/WARNINGS/ADVISORIES
AL...NONE.
TN...NONE.
NEAR TERM...70/DD
SHORT TERM...70/DD
LONG TERM...70/DD
AVIATION...70/DD
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