651
FXUS63 KLMK 051547
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
1147 AM EDT FRI SEP 5 2025
KEY MESSAGES
* COLD FRONT TO PUSH THROUGH THE REGION LATER TONIGHT AND SATURDAY
BRINGING ANOTHER ROUND OF BENEFICIAL RAINFALL TO THE REGION.
STRONG TO SEVERE STORMS WILL BE POSSIBLE OUT AHEAD OF THIS FRONT
THIS EVENING AND INTO THE OVERNIGHT HOURS.
* COOLER AND DRIER AIR WILL RETURN TO THE REGION LATE SATURDAY AND
INTO SUNDAY. OVERNIGHT LOWS SUNDAY AND MONDAY MORNING MAY BREAK
RECORD LOW TEMPS. PLEASANT WEATHER IS EXPECTED FOR NEXT WEEK.
UPDATE
ISSUED AT 1147 AM EDT FRI SEP 5 2025
SO FAR THIS MORNING, TEMPERATURES HAVE WARMED QUICKLY THANKS TO A
COMBINATION OF STRENGTHENING SW FLOW AND MOSTLY SUNNY SKIES. A
SURFACE COLD FRONT EXTENDS ALONG THE I-65 CORRIDOR ACROSS INDIANA,
BENDING BACK TO THE SOUTHWEST INTO WESTERN KENTUCKY. TO THE EAST OF
THE FRONT, TEMPERATURES HAVE WARMED QUICKLY THANKS TO A COMBINATION
OF SW WINDS AND MOSTLY SUNNY SKIES, WITH READINGS ALREADY REACHING
THE LOW-TO-MID 80S BY JUST AFTER 15Z. SFC DEWPOINTS ARE ALSO POOLED
AHEAD OF THE FRONT, WITH UPPER 60S AND LOW 70S ACROSS PORTIONS OF
CENTRAL AND SOUTHERN KY. IT IS ALSO WORTH NOTING THAT HIGH AMOUNTS
OF UPPER-LEVEL SMOKE WITH SOME HAZY CONDITIONS HAVE BEEN OBSERVED ON
SATELLITE AND IN SFC OBS SO FAR THIS MORNING. HRRR SMOKE GRIDS
SUGGEST THAT THIS SHOULD CONTINUE THROUGH THE DAY TODAY, WITH
CONDITIONS BECOMING LESS HAZY TONIGHT INTO TOMORROW.
AS FAR AS THE LATEST THINKING ON THIS AFTERNOON AND EVENING'S SEVERE
THREAT, THE 12Z HI-RES GUIDANCE CONTINUES TO SUGGEST THAT THE
AFOREMENTIONED COLD FRONT WILL CONTINUE TO SINK TO THE SOUTH AND
EAST THROUGH THE DAY TODAY, GRADUALLY BECOMING MORE WEST-TO-EAST
ORIENTED THROUGH THE DAY. BEHIND THE FRONT, FALLING DEWPOINTS WILL
LEAD TO A CUTOFF IN INSTABILITY, WITH 2000-3000 J/KG MLCAPE EXPECTED
ALONG AND AHEAD OF THE FRONT, MAINLY SOUTH OF THE OHIO RIVER. WITH
NEUTRAL TO SLIGHT INCREASES IN MID-LEVEL HEIGHTS EXPECTED THROUGH
MID-AFTERNOON AND THE SFC FRONT EXPECTED TO BECOME MORE DIFFUSE,
TRIGGERING FOR CONVECTION WILL LIKELY BE DELAYED UNTIL THE MID-TO-
LATE AFTERNOON HOURS. THE 12Z HRRR AND NAM NEST SOLUTIONS GENERALLY
SHOW CONVECTIVE INITIATION BETWEEN 21-23Z ALONG AND SOUTH OF THE
KENTUCKY PARKWAYS. INITIALLY, INVERTED-V SOUNDING PROFILES IN THE
LOW-LEVELS AND AMPLE INSTABILITY ACROSS SOUTHERN AND EASTERN KY
SHOULD SUPPORT A DAMAGING WIND AND NEAR-SEVERE HAIL THREAT WHERE
STORMS CAN DEVELOP. THIS THREAT SHOULD CONTINUE THROUGH 01-03Z, AT
WHICH POINT NEAR-SFC STABILITY SHOULD SET IN, ALTHOUGH ELEVATED
CONVECTION SHOULD CONTINUE OVERNIGHT. FARTHER TO THE NORTHWEST,
SHOWERS AND SUB-SEVERE THUNDERSTORMS SHOULD BRING ANYWHERE FROM 0.10-
0.50" TONIGHT INTO TOMORROW MORNING.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 339 AM EDT FRI SEP 5 2025
EARLY MORNING SATELLITE IMAGERY SHOWS PARTLY CLOUDY SKIES ACROSS THE
REGION. GOES NIGHT-TIME FOG PRODUCT REVEALS A DECENT AMOUNT OF FOG
IN THE RIVER VALLEYS. A STALLED OUT FRONTAL BOUNDARY HAS BECOME A
WARM FRONT AND IS LIFTING NORTHWARD ACROSS THE REGION THIS MORNING.
THE FRONTAL BOUNDARY IS ROUGHLY ALONG THE I-64 CORRIDOR. NORTH OF
THE FRONT, TEMPERATURES WERE IN THE LOWER 50S ACROSS SOUTHERN
INDIANA AND FAR NORTHERN KENTUCKY. SOUTH OF THE FRONT, TEMPERATURES
WERE MAINLY IN THE UPPER 50S TO THE LOWER 60S. A FEW MID 60S WERE
NOTED DOWN ALONG THE KY/TN BORDER.
FOR THE REMAINDER OF THE OVERNIGHT PERIOD, NO SIGNIFICANT WEATHER IS
EXPECTED. TEMPS TOWARD SUNRISE WILL BE IN THE MID-UPPER 50S ACROSS
THE NORTH WITH UPPER 50S/LOWER 60S DOWN ACROSS THE SOUTH.
FOR TODAY, AFOREMENTIONED SURFACE WARM FRONT WILL CONTINUE TO LIFT
NORTHWARD THIS MORNING. IN ITS WAKE, A BROAD SOUTHWEST FLOW REGIME
WILL SET UP ACROSS THE REGION. WE EXPECT PARTLY SUNNY SKIES WITH
BREEZY SOUTHWEST WINDS DEVELOPING BY MID-LATE MORNING AND CONTINUING
THROUGH THE AFTERNOON HOURS. STRONG DIURNAL HEATING IS EXPECTED AND
A GRADIENT OF TEMPERATURE WILL BE NOTED ACROSS THE REGION. AFTERNOON
HIGHS WILL TOP OUT IN THE LOW-MID 80S ACROSS SOUTHERN INDIANA AND
FAR NORTHERN KENTUCKY. ACROSS CENTRAL KENTUCKY, HIGHS SHOULD TOP
OUT IN THE MID-UPPER 80S WITH LOWER 90S POSSIBLE, MAINLY SOUTH OF
THE CUMBERLAND PARKWAY.
AS WE HEAD INTO THE LATE AFTERNOON HOURS, A COLD FRONT AND AN UPPER
LEVEL SHORTWAVE TROUGH AXIS WILL DROP INTO THE REGION FROM THE
NORTHWEST. LATEST MODEL RUNS SHOW THAT THE UPPER LEVEL HEIGHT FALLS
ARE NOT AS STRONG AS THEY HAVE BEEN IN THE PAST FEW DAYS.
ADDITIONALLY, CONVERGENCE ALONG THE FRONT WILL BE INITIALLY WEAK.
THEREFORE, MUCH OF THE DAY TODAY WILL FEATURE DRY CONDITIONS, BUT
SCATTERED CONVECTION WILL LIKELY DEVELOP TOWARD THE EVENING HOURS AS
CONVERGENCE ALONG THE FRONT STRENGTHENS.
MULTI-MODEL CONSENSUS SOUNDINGS CONTINUE TO SHOW A PLUME OF MODERATE
INSTABILITY DEVELOPING ACROSS THE REGION. MLCAPE VALUES WILL LIKELY
INCREASE INTO THE 1500-2500 J/KG RANGE. SHEAR PROFILES REMAIN
SUPPORTIVE OF ORGANIZED CONVECTION WITH 30-35KTS OF BULK SHEAR
AVAILABLE, ALTHOUGH THE PROFILE IS GENERALLY UNIDIRECTIONAL HERE.
WITHIN THIS ENVIRONMENT, SCATTERED DISCRETE CONVECTION WILL LIKELY
DEVELOP ACROSS PORTIONS OF WESTERN KY/TN. GIVEN THE INITIAL SHEAR
PROFILES, SOME SUPERCELLULAR STRUCTURES MAY BE SEEN WITH THE INITIAL
CONVECTION, ALONG WITH A FEW SPLITS. HOWEVER, GIVEN THAT MODEL
SOUNDINGS SHOW A RATHER LARGE T/TD SPREAD IN THE LOW-LEVELS
RESULTING IN INVERTED-V SOUNDINGS, UPSCALE GROWTH INTO SEVERAL MULTI-
CELLULAR CLUSTERS IS THE LIKELY CONVECTIVE EVOLUTION WITH THIS
SYSTEM.
AS WE MOVE INTO THE MID-LATE EVENING HOURS, FASTER MID-LEVEL FLOW
LAGGING BEHIND THE FRONTAL BOUNDARY WILL PUSH EASTWARD INTO THE
REGION. THE RIGHT ENTRANCE REGION OF THE UPPER LEVEL JET SHOULD
ARRIVE BY MID-LATE EVENING. GOOD SYNOPTIC SCALE LIFT WITH THIS
REGION AIDED BY AN INCREASE IN THE NOCTURNAL LOW-LEVEL JET SHOULD
SET THE STAGE FOR CONVECTION TO TRANSITION FROM SURFACE BASED TO
MORE OF AN ELEVATED NATURE. INDEED, MODEL SOUNDINGS SHOW A FAIR
AMOUNT OF ELEVATED INSTABILITY INTO THE OVERNIGHT HOURS WHICH SHOULD
RESULT IN WIDESPREAD CONVECTION FOR MUCH OF THE OVERNIGHT HOURS. AS
THE SURFACE FRONT PUSHES SOUTHWARD, THE FLOW ALONG THE FRONT WILL
BECOME MORE PARALLEL TO THE FLOW ALOFT, RESULTING IN SOME
BACKBUILDING OF CONVECTION. TRAINING OF CONVECTION MAY BECOME AN
ISSUE ACROSS SOUTHERN KY RESULTING IN SOME LOCALIZED HEAVY RAINFALL
SWATHS THAT MAY LEAD TO ISOLATED INSTANCES OF FLASH FLOODING.
IN TERMS OF CONVECTIVE HAZARDS, THERE APPEARS TO BE A SHORT WINDOW
OF OPPORTUNITY FOR SEVERE WEATHER TONIGHT. THE INITIAL CONVECTIVE
DEVELOPMENT OF DISCRETE CELLS MAY POSE A LOW RISK OF TORNADOES AND
LARGE HAIL WITH ANY SUSTAINED STRONG CORES. HOWEVER, THE MAIN
CONVECTIVE HAZARD WILL LIKELY BE DAMAGING WIND GUSTS, ESPECIALLY
WHERE CELLS TEND TO BOW OUT.
LOWS TONIGHT WILL DROP INTO THE LOW-MID 50S ACROSS SOUTHERN IN AND
FAR NORTHERN KY, WITH MID-UPPER 50S EXPECTED ACROSS MUCH OF
CENTRAL/SOUTHERN KY.
LONG TERM /SATURDAY THROUGH THURSDAY/
ISSUED AT 339 AM EDT FRI SEP 5 2025
SATURDAY THROUGH MONDAY NIGHT...
CURRENT DATA SUGGESTS THAT THE UPPER LEVEL TROUGH AXIS WILL SWING
THROUGH THE REGION SATURDAY MORNING. WIDESPREAD SHOWER AND EMBEDDED
THUNDERSTORMS ARE LIKELY TO BE ONGOING SATURDAY MORNING. HOWEVER,
THIS ACTIVITY SHOULD PUSH OFF TO THE SOUTH AND EAST DURING THE DAY
WITH IMPROVING CONDITIONS THROUGH THE AFTERNOON HOURS. DEPENDING ON
CLOUD COVER, TEMPERATURES WILL BE TRICKY TO FORECAST HERE. WITHIN
THE CLOUDS AND SHOWERS, TEMPERATURES WILL LIKELY HOLD IN THE UPPER
50S, BUT THEN RECOVER A BIT IN THE AFTERNOON. FOR NOW, PLAN ON
GOING WITH MID-UPPER 60S OVER THE EASTERN SECTIONS FOR HIGHS WITH
LOW-MID 70S OUT ACROSS THE WEST. COLD ADVECTION AND CLEARING SKIES
WILL ALLOW TEMPS TO DROP INTO THE MID-UPPER 40S SATURDAY NIGHT WHICH
MAY BREAK SOME RECORD LOWS TEMPS SUNDAY MORNING (MAINLY AT
LEXINGTON).
DRY AND COOLER CONDITIONS ARE EXPECTED FOR SUNDAY WITH DAYTIME HIGHS
IN THE LOW-MID 70S ACROSS SOUTHERN IN AND THE NORTHERN HALF OF KY,
MID-UPPER 70S WILL BE SEEN ACROSS SOUTHERN KY. SUNDAY NIGHT WILL
LIKELY FEATURE A GOOD RADIATIONAL COOLING NIGHT ACROSS THE REGION.
LOWS WILL LIKELY DIP INTO THE UPPER 30S/LOWER 40S IN OUR RADIATIONAL
COOLING SPOTS AND VALLEY LOCATIONS, WITH MID 40S ELSEWHERE. IF THIS
SCENARIO WORKS OUT, LOW TEMPERATURE RECORDS MAY BE SET ONCE AGAIN.
DRY AND PLEASANT WEATHER IS EXPECTED FOR MONDAY WITH HIGHS THE MID-
UPPER 70S AND OVERNIGHT LOWS IN THE UPPER 40S TO NEAR 50.
TUESDAY THROUGH THURSDAY...
BROAD TROUGHING IS LIKELY TO HOLD ACROSS THE EASTERN US THROUGH MUCH
OF NEXT WEEK WITH SOME RIDGING BUILDING INTO THE PLAINS AS A TROUGH
DEVELOPS ACROSS THE WESTERN CONUS. DRY CONDITIONS ARE EXPECTED
THROUGH THE PERIOD WITH MODERATING TEMPERATURES. HIGHS ON TUESDAY
WILL WARM INTO THE LOWER 80S WITH LOW-MID 80S EXPECTED FOR WEDNESDAY
AND THURSDAY.
AVIATION /12Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 643 AM EDT FRI SEP 5 2025
WILL SEE SOME PATCHY FOG OVER IN THE BLUEGRASS REGION EARLY IN THE
PERIOD, BUT THIS SHOULD MIX OUT BY 05/13Z. LOOK FOR SOUTHWEST WINDS
TO PICK UP LATER THIS MORNING AND CONTINUE THROUGH THE AFTERNOON
HOURS. SUSTAINED WINDS OF 8-10KTS WITH GUSTS TO 20-25KTS WILL BE
POSSIBLE. SURFACE COLD FRONT WILL PUSH INTO THE REGION THIS EVENING
WITH SCATTERED SHOWERS/STORMS FIRING OUT AHEAD OF IT. TIMING OF THE
STORMS HAS BEEN DELAYED BY A FEW HOURS AS NEW GUIDANCE SUGGESTS IT
MAY BE 05/23Z OR LATER BEFORE CONVECTION DEVELOPS ACROSS THE REGION.
CLUSTERS OF SHOWERS/STORMS WILL MOVE ACROSS THE REGION OVERNIGHT AND
INTO SATURDAY MORNING. CIGS LOOK TO REMAIN GENERALLY VFR THOUGH
SOME MVFR CIGS MAY DEVELOP BY SUNRISE SATURDAY.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
UPDATE...CSG
SHORT TERM...MJ
LONG TERM...MJ
AVIATION...MJ
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