382
FXUS63 KLMK 140205
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
1005 PM EDT TUE MAY 13 2025
KEY MESSAGES
* SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE
THIS AFTERNOON AND EVENING, BEFORE DIMINISHING AROUND SUNSET.
HEAVY RAINFALL, LIGHTNING, AND GUSTY WINDS ARE THE MAIN THREATS.
* A WARMING TREND IS EXPECTED LATER IN THE WEEK, WITH HIGHS WELL
INTO THE 80S THURSDAY AND FRIDAY. THE POTENTIAL FOR WAVES OF
STRONG, POSSIBLY SEVERE STORMS LATE THURSDAY THROUGH FRIDAY NIGHT
IS INCREASING.
UPDATE
ISSUED AT 1005 PM EDT TUE MAY 13 2025
THE LAST OF THE SHOWERS AND STORMS ARE NOW DISSIPATING. SCATTERED
CONVECTIVE DEBRIS CLOUDS WILL SLOWLY DISSIPATE OVER THE NEXT FEW
HOURS. WINDS ARE CURRENTLY LIGHT OUT OF THE SOUTH AND WILL BECOME
CALM TO LIGHT AND VARIABLE OVERNIGHT. PATCHY FOG HAS ALREADY BEGUN
TO DEVELOP AND WILL CONTINUE TO FILL IN. DUE TO THIS REASON, HAVE
INCREASED THE FOG COVERAGE IN THE GRIDS. OTHERWISE, THE FORECAST
REMAINS ON TRACK.
SHORT TERM /THROUGH WEDNESDAY NIGHT/
ISSUED AT 330 PM EDT TUE MAY 13 2025
WATER VAPOR IMAGERY CONTINUES TO SHOW BROAD MID- AND UPPER-LEVEL
CYCLONIC FLOW AS AN UPPER LOW SPINS ACROSS THE OHIO AND TENNESSEE
VALLEYS THIS AFTERNOON. EMBEDDED VORTICITY LOBES PINWHEELING AROUND
THE CENTER OF THE UPPER LOW ARE HELPING TO TRIGGER BANDS OF SHOWERS
AND THUNDERSTORMS ACROSS THE AREA, WITH THE MAIN AREA OF SHOWERS AND
STORMS DRAPED ACROSS THE I-64 CORRIDOR AT THIS HOUR. MLCAPE AROUND
700-1000 J/KG IS SUFFICIENT FOR SCATTERED STRONGER UPDRAFTS WHICH
ARE HELPING TO PRODUCE A FEW STORMS WITH PEA SIZED HAIL AND GUSTY
WINDS. WITH THE UPPER LOW ALMOST OVERHEAD, WEAK FLOW IS NOTED IN THE
MID- AND UPPER-LEVELS, RESULTING IN WEAK DEEP LAYER SHEAR (LESS THAN
20 KT) AND SLOW STORM MOTIONS. THIS IS LEADING TO MAINLY GARDEN-
VARIETY STORMS, WITH HEAVY RAINFALL AND LOCALIZED FLOODING BEING THE
MAIN HAZARDS WITH STORMS IN ADDITION TO GUSTY WINDS AND LIGHTNING.
AS WE LOSE DAYTIME HEATING THIS EVENING, THUNDERSTORMS WILL
GRADUALLY DISSIPATE WITH A FEW SHOWERS LINGERING INTO THE EARLY
OVERNIGHT HOURS. MOST OF THE NIGHT TONIGHT SHOULD BE DRY AND MILD AS
AMPLE LOW-LEVEL MOISTURE LIMITS NIGHTTIME COOLING. AS A SFC PRESSURE
TROUGH WILL BE DRAPED JUST NORTH OF THE REGION, A WEAK PRESSURE
GRADIENT IS EXPECTED TONIGHT, AND LIGHT AND VARIABLE WINDS ARE
EXPECTED. WHILE SCATTERED TO AT TIMES BROKEN CLOUDS ARE EXPECTED
TONIGHT INTO TOMORROW MORNING, AREAS WHICH SEE MORE CLEARING COULD
SEE ANOTHER ROUND OF PATCHY FOG WEDNESDAY MORNING, SOME OF WHICH MAY
BE DENSE. CONFIDENCE IN DENSE FOG IS STILL FAIRLY LOW, BUT IS
SOMEWHAT HIGHER ACROSS SOUTHERN KY WHICH HAS A BETTER CHANCE FOR
CLEARING.
ON WEDNESDAY, THE UPPER LOW WILL LIFT TO THE NORTH AND EAST OF THE
AREA AND BEGIN TO OPEN UP AS RIDGING BUILDS FROM THE SOUTHWEST.
THERE WILL LIKELY BE A PERIOD SIMILAR TO THIS MORNING WITH SCATTERED
OR BROKEN STRATOCUMULUS AS AMPLE MOISTURE NEAR THE SURFACE MIXES TO
THE TOP OF THE BOUNDARY LAYER. HOWEVER, MORE SUNSHINE IS EXPECTED ON
WEDNESDAY AS DRIER AIR WRAPS AROUND THE BACK SIDE OF THE LOW
PRESSURE SYSTEM. ANOTHER CHANCE FOR MORE ISOLATED SHOWERS AND
THUNDERSTORMS IS EXPECTED TOMORROW AFTERNOON. CAMS ARE GENERALLY
SUPPORTING TWO AREAS OF ENHANCED COVERAGE FOR TOMORROW AFTERNOON
EVENING -- ONE CLOSER TO THE CENTER OF THE UPPER LOW NORTH OF I-64
AND EAST OF I-65, AND ANOTHER WHICH WILL APPROACH FROM THE SOUTHWEST
TOMORROW AFTERNOON. WHILE INSTABILITY VALUES SHOULD BE SIMILAR TO
TODAY, SHEAR WILL BE SOMEWHAT STRONGER (20-25 KT); HOWEVER, WOULD
STILL EXPECT MAINLY GARDEN-VARIETY SHOWERS AND STORMS.
MOST SHOWERS SHOULD DIMINISH WEDNESDAY EVENING AS THE SUN SETS,
THOUGH ISOLATED SHOWERS MAY CONTINUE OVERNIGHT ALONG THE LEADING
EDGE OF A LOW-LEVEL THETA-E SURGE. TEMPERATURES WILL AGAIN REMAIN
MILD AS MID- AND UPPER-LEVEL HEIGHTS BUILD INTO THURSDAY MORNING,
WITH LOWS THURSDAY MORNING ONLY FALLING INTO THE 60S.
LONG TERM /THURSDAY THROUGH TUESDAY/
ISSUED AT 330 PM EDT TUE MAY 13 2025
THURSDAY - FRIDAY NIGHT...
THE CLOSED UPPER LOW THAT HAD PLAGUED US THROUGH MID WEEK WILL NOW
BE LIFTING WELL TO THE NE OVER NEW ENGLAND ON THURSDAY, AND WE'LL
SEE BRIEF/PROGRESSIVE UPPER RIDGING OVER THE OHIO VALLEY AHEAD OF A
STRONG NORTHERN PLAINS TROUGH. WE'LL BE THANKFUL FOR THE UPPER RIDGE
AS IT WILL PROVIDE NOTABLE CAPPING (10-11C AT H7) EVIDENT ON
FORECAST SOUNDINGS, WHICH WILL HOLD BACK A VERY STRONG POTENTIALLY
UNSTABLE ENVIRONMENT CHARACTERIZED BY ML CAPE VALUES IN THE 3000-
4000 J/KG RANGE. THESE IMPRESSIVE INSTABILITY VALUES WILL ALSO BE IN
THE PRESENCE OF STRONG DEEP LAYER SHEAR FOR THIS TIME OF YEAR. THE
END RESULT IS THAT IF SOMETHING WERE TO POP ON THURSDAY, LOOK OUT.
THE GOOD NEWS IS THAT IT DOESN'T APPEAR THAT WILL BE THE CASE, AT
LEAST DURING THE DAYTIME HOURS. LOOK FOR TEMPS IN THE MID TO UPPER
80S FOR MOST ON THURSDAY WITH DEW POINTS CLIMBING INTO THE 65 TO 70
DEGREE RANGE. PLAIN AND SIMPLE, THURSDAY WILL FEEL LIKE A SUMMER DAY.
AS WE MOVE INTO THURSDAY NIGHT, THE UPPER RIDGE AXIS SLIDES EAST OF
OUR AREA AS THE POTENT NORTHERN PLAINS SHORTWAVE MOVES TOWARD THE
UPPER MIDWEST. A WEAKENED COLD FRONT TRAILING FROM THE MN SURFACE
LOW WILL APPROACH OUR AREA FROM THE NW. MODELS SHOW SOME SCATTERED
CONVECTION TRYING TO GET GOING ACROSS OUR NORTHERN CWA ASSOCIATED
WITH THIS FEATURE. WE'LL STILL HAVE PLENTY OF AVAILABLE INSTABILITY
LEFT OVER, HOWEVER WILL LIKELY HAVE AT LEAST SOME LOW LEVEL
STABILITY WITH THE LOSS OF HEATING. THEREFORE, WOULD EXPECT HAIL
WOULD BE THE MAIN THREAT WITH ANY STRONGER STORMS, AND PERHAPS AN
ISOLATED WIND DAMAGE THREAT IF STRONG STORMS ARE ABLE TO OVERCOME
THE STABLE LAYER.
ASSUMING CONVECTION DOESN'T GO CRAZY THURSDAY/THURSDAY NIGHT (I.E,
COLD POOL WASHING OUT THE AIRMASS), THIS SETS THE STAGE FOR A BIGGER
SEVERE CONCERN FOR LATER FRIDAY INTO FRIDAY NIGHT. FORECAST
SOUNDINGS CONTINUE TO SHOW A CONCERNING SIGNAL FOR A STRONGLY
UNSTABLE AIRMASS IN THE PRESENCE OF PLENTY OF DEEP LAYER SHEAR FOR
LATER FRIDAY INTO FRIDAY NIGHT. VERY STEEP MID LEVEL LAPSE RATES
WILL ALLOW FOR LARGE POSITIVE AREA CAPABLE OF LARGE OR VERY LARGE
HAIL, AND DAMAGING WINDS. HODOGRAPHS ALSO SHOW ENOUGH LOW LEVEL
LOOPING FOR TORNADIC POTENTIAL AS WELL. FORECAST MODELS SUGGEST THAT
A SHORTWAVE EMBEDDED WITHIN THE PARENT CLOSED LOW COULD ROTATE INTO
THE MID MISSISSIPPI RIVER VALLEY, TRIGGERING UPSTREAM CONVECTION
WHICH WOULD THEN PROGRESS INTO OUR AREA FRIDAY EVENING, PERHAPS INTO
THE OVERNIGHT. EARLY INDICATIONS ARE THAT A WIND PRODUCING, COLD
POOL DRIVEN COMPLEX COULD RAKE ACROSS OUR REGION SOMETIME IN THIS
TIMEFRAME. ADDITIONAL CONCERNS WOULD ARISE WITH ANY
ISOLATED/SUPERCELLULAR CONVECTION AHEAD OF A COLD POOL DRIVEN
COMPLEX IN THE FORM OF VERY LARGE HAIL AND TORNADIC POTENTIAL. TOO
EARLY TO FOCUS SPECIFICALLY ON A GIVEN HAZARD, BUT RIGHT NOW, ALL
ARE IN PLAY WITH DAMAGING WIND BEING THE PRIMARY THREAT.
SATURDAY - SUNDAY NIGHT...
THE WEEKEND COULD SEE A BRIEF DRIER PERIOD AS WE ARE EXPECTING THE
COLD FRONT TO BE CONVECTIVELY REINFORCED (COLD POOL) WELL TO THE
SOUTH OF OUR CWA. WE'LL KEEP SOME CHANCES IN, ESPECIALLY ACROSS OUR
SOUTHERN CWA, BUT MUCH WILL DEPEND ON WHAT HAPPENS WITH LATE FRIDAY
CONVECTION. UPPER 70S AND LOW 80S SEEM REASONABLE BUT COULD VARY
DEPENDING ON THE FRIDAY OUTCOME.
MONDAY - TUESDAY...
UPPER RIDGING SHOULD START TO BUILD OVER OUR AREA BY EARLY NEXT WEEK
IN RESPONSE TO ANOTHER STRONG CENTRAL CONUS TROUGH. THE FRONTAL
BOUNDARY THAT HAD BEEN STALLED TO OUR SOUTH WILL TRY TO LIFT BACK
NORTH TOWARD OUR AREA AS A WARM FRONT. WILL KEEP CONVECTIVE CHANCES
IN HERE WITH TEMPS LIKELY WARMING BACK INTO THE LOW 80S BY TUESDAY.
CONCERN IS STARTING TO GROW FOR THE TUESDAY NIGHT/WEDNESDAY TIME
FRAME FOR PERHAPS ANOTHER ROUND OF STRONG TO SEVERE STORMS.
AVIATION /00Z TAFS THROUGH 06Z THURSDAY/
ISSUED AT 734 PM EDT TUE MAY 13 2025
THE SCATTERED SHOWERS AND THUNDERSTORMS ARE BEGINNING TO WANE
THIS EVENING AS DAYTIME HEATING REDUCES INSTABILITY. THERE IS A
CLUSTER OF STORMS BETWEEN LOUISVILLE AND E-TOWN REMAINING.
CONDITIONS WILL BECOME VFR AS THESE SHOWERS/STORMS DISSIPATE. LIGHT
WINDS AND PLENTY OF LOW-LEVEL MOISTURE OVERNIGHT WILL BRING ANOTHER
CHANCE FOR FOG AROUND SUNRISE WEDNESDAY, THOUGH CONFIDENCE IN THIS
REMAINS LOW DUE TO THE POTENTIAL FOR PASSING LOW-MID LEVEL CLOUDS.
AFTER SUNRISE WEDNESDAY, LOW-LEVEL MOISTURE SHOULD MIX INTO A
STRATUS LAYER, POTENTIALLY BRINGING ANOTHER ROUND OF MVFR/IFR
CEILINGS. BY MID-MORNING, THESE CLOUDS WILL LIFT AND WINDS WILL PICK
UP OUT OF THE SOUTH AROUND 6-9KTS.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
UPDATE...SRW
SHORT TERM...CSG
LONG TERM...BJS
AVIATION...SRW
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