340
FXUS63 KLMK 190211
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
1011 PM EDT MON MAY 18 2026
KEY MESSAGES
* TODAY THROUGH TUESDAY, TEMPERATURES ARE EXPECTED TO WARM INTO THE
MID 80S TO LOW 90S. SOME DAILY MAX TEMPERATURE RECORDS COULD BE
CHALLENGED.
* THIS AFTERNOON/EVENING, SHOWERS AND/OR THUNDERSTORMS ARRIVE,
ESPECIALLY FOR OUR NORTHWESTERN COUNTIES. THIS IS MAINLY A WIND
AND HAIL THREAT.
* A LINE OF STRONG TO SEVERE STORMS IS EXPECTED TO MOVE THROUGH
AHEAD OF A COLD FRONT ON TUESDAY, POSSIBLY BRINGING STRONG WINDS
AND HAIL. THE LINE WILL WEAKEN AS IT MOVES EAST OVER THE REGION.
* MORE ACTIVE WEATHER ARRIVE LATER THIS WEEK AS MULTIPLE ROUNDS OF
SHOWERS AND SCATTERED THUNDERSTORMS ARE POSSIBLE GOING
INTO MEMORIAL DAY WEEKEND.
MESOSCALE
ISSUED AT 1011 PM EDT MON MAY 18 2026
CONVECTION CONTINUES TO SLOWLY MOVE EASTWARD ACROSS SOUTHERN INDIANA
THIS EVENING. WE'RE WATCHING A SW-NE ORIENTED BAND OF VERY HEAVY
RAINFALL WITH SOME EMBEDDED THUNDERSTORMS THAT WILL TRAIN ACROSS
PORTIONS OF MEADE, HARRISON, CLARK, AND FLOYD COUNTIES IN SOUTHERN
INDIANA OVER THE NEXT FEW HOURS.
OVERALL, ATMOSPHERE IS MARGINALLY UNSTABLE WITH ABOUT 500-700 J/KG
OF MLCAPE AND ABOUT 30-35KT OF BULK SHEAR. THE ONGOING CONVECTION
RESIDES WITHIN AN ENHANCED PWAT PLUME WITH VALUES 1.6-1.9 INCHES.
WITH DEEP LAYER SHEAR LARGELY PARALLEL TO THE SYNOPTIC SCALE ASCENT
PATTERN, EXPECT THIS CONVECTION TO SLOWLY MOVE EASTWARD WITH TIME
WHILE WEAKENING. LATEST CAM GUIDANCE SUGGESTS THAT THIS ACTIVITY
WILL DIMINISH WITH TIME, LIKELY IN THE 12-2 AM EDT TIME FRAME.
WITHIN THIS BAND, A SOLID 1.5-2.5 INCHES OF RAINFALL IS EXPECTED.
AREAS EAST OF THE BAND ACROSS FAR NORTH-CENTRAL KY HAVE REMAINED
RAIN-FREE TODAY, SO THIS RAINFALL WILL BE WELCOMED AND WITH RATES
DIMINISHING WITH TIME, GOOD GROUND ABSORPTION WILL BE POSSIBLE,
EXCEPT IN THE URBAN AREAS.
COLD OUTFLOW FROM THIS CONVECTION HAS PUSHED SOUTHWARD AND DOWN
TOWARD THE WK/BG PARKWAY CORRIDOR. CURRENT EXPECTATIONS ARE FORE
THIS CONVECTION TO MAINLY STAY ON THE INDIANA SIDE OF THE OHIO
RIVER, THOUGH THE SOUTHWEST EDGE OF THE RAINFALL MAY MAKE IT INTO
THE LOUISVILLE METRO REGION OVER THE NEXT 1-3 HOURS.
SHORT TERM /THROUGH TUESDAY NIGHT/
ISSUED AT 241 PM EDT MON MAY 18 2026
CURRENT MESOANALYSIS SHOWS 2000-2500 J/KG OF UNINHIBITED SBCAPE,
ABOUT 20KTS OF DEEP LAYER SHEAR, AND STEEP LAPSE RATES. NOT SEEING
MUCH AGITATED CU OVER OUR CWA JUST YET, BUT JUST TO THE WEST, WE
HAVE SEEN SOME INITIATION. SHEAR WILL SLIGHTLY INCREASE AS THE MCS
APPROACHES THE CWA, WHICH WILL HELP STORMS TO BECOME SLIGHTLY MORE
ORGANIZED. OVER THE NEXT FEW HOURS DO EXPECT SOME SCATTERED STRONG
TO SEVERE STORMS, WITH A WIND AND HAIL THREAT. THE THREAT AREA WILL
BE SMALL, OVER SOUTHERN INDIANA AND JUST ALONG THE OHIO RIVER. MOST
OF THE REGION WILL BE SPARED OF ANY STORMS. ADDITIONALLY, PWATS NEAR
1.8-2.0 INCHES AND A SLOWLY MOVING LINE OF STORMS WILL ALLOW FOR
HEAVY RAINFALL. THIS LINE IS ALSO MOVING APRALLEL TO THE LLJ, WHICH
WILL ALLOW FOR TRAINING. DUE TO THIS, THERE IS ALSO A RISK FOR HEAVY
RAINFALL TO LEAD TO SOME MINOR FLOODING ISSUES OVER OUR FAR
NORTHWESTERN AREAS IN SOUTHERN INDIANA.
AS THE SUN SETS, WE WILL QUICKLY LOSE INSTABILITY. SHOWERS AND
STORMS ARE EXPECTED TO QUICKLY DISSIPATE. WITH BROKEN SKY COVER AND
LIGHT SOUTHERLY WINDS, NOT EXPECTING A GREAT RADIATIONAL COOLING
NIGHT. LOW TEMPERATURES WILL LIKELY REMAIN WARM IN THE UPPER 60S AND
LOW 70S. THIS WILL BE CLOSE TO WARM MINIMUM RECORDS FOR MAY 18.
AHEAD OF AN APPROACHING COLD FRONT, WAA WILL CONTINUE TO KEEP
TEMPERATURES IN THE UPPER 80S AND BRUSHING 90. THIS WILL HELP SBCAPE
TO INCREASE NEAR 3000J/KG. DEW POINTS WILL ALSO CREEP INTO THE UPPER
60S AND LOW 70S. THOUGH SHEAR WILL REMAIN LOW AROUND 20KTS. PULSE
SUMMERTIME THUNDERSTORMS WILL BE POSSIBLE IN THE AFTERNOON PRIOR TO
THE COLD FRONT AND ASSOCIATION LINE OF STORMS. WHEN THE COLD FRONT
APPROACHES, WE ARE EXPECTING A DECAYING LINE OF STORMS TO OUTRUN THE
BEST FORCING ALONG THE COLD FRONT. WIND AND HAIL WILL BE THE MAIN
THREAT ON TUESDAY OVER THE NORTHWESTERN 2/3RD OF THE CWA. THE COLD
FRONT WILL BEGIN TO SLOW ITS PROGRESSION SOUTHWARD TUESDAY NIGHT,
MAKING IT THROUGH MOST OF THE CWA BY WEDNESDAY MORNING.
LONG TERM /WEDNESDAY THROUGH MONDAY/
ISSUED AT 241 PM EDT MON MAY 18 2026
AS THE COLD FRONT SLOWLY SAGS THE THE SOUTH ON WEDNESDAY, WIDESPREAD
SHOWERS AND SCATTERED THUNDERSTORMS ARE EXPECTED, ESPECIALLY FOR THE
SOUTHERN HALF OF OUR AREA. RICH MOISTURE ALONG THE FRONT WILL HELP
FUEL THESE SHOWERS AND STORMS, WITH LREF PW VALUES RANGING FROM 1.4-
1.7" (>95TH PERCENTILE CLIMATOLOGICALLY). INSTABILITY TO THE SOUTH
OF THE FRONT WILL ALSO HELP FUEL THESE SHOWERS, WITH LREF MEAN
SBCAPE AROUND 750-1000 J/KG. THE WIND SHEAR PROFILE IS VERY MEAGER,
SO WE DON'T CURRENTLY EXPECT SEVERE WEATHER AT THIS STAGE. WITH THE
FRONT MOVING THROUGH, TEMPERATURES WILL MUCH CLOSER TO NORMAL FOR
THIS TIME OF YEAR, WITH HIGHS IN THE MID-TO-UPPER 70S NORTH OF THE
FRONT IN SOUTHERN INDIANA AND NORTHERN KENTUCKY, AND HIGHS IN THE
LOW 80S SOUTH OF THE FRONT IN SOUTH CENTRAL KENTUCKY.
THE FRONT STALLS OUT JUST SOUTH OF OUR AREA BY THURSDAY, BUT WITH
SOME MOISTURE STILL IN PLACE OVER OUR FAR SOUTHERN COUNTIES CHANCES
FOR SHOWERS WILL BE POSSIBLE (35-50%). WITH NORTHERLY FLOW AT THE
SURFACE, TEMPERATURES ACROSS THE REGION WILL BE SLIGHTLY COOLER THAN
WEDNESDAY, WITH HIGHS IN THE LOW-TO-MID 70S.
THOUGH AN AREA OF SURFACE HIGH PRESSURE TRIES TO BUILD IN OVER THE
GREAT LAKES AND OHIO VALLEY REGIONS THURSDAY, A BROAD UPPER LEVEL
TROUGH OVER THE WESTERN CONUS PUSHES EASTWARD AND DRIVES THE HIGH
OUT OF THE AREA. AHEAD OF THE TROUGH AXIS, A SERIES OF SHORTWAVES
SURGES NORTHEASTWARD, LIFTING THE FRONTAL BOUNDARY NORTHWARD THURSDAY
NIGHT. CONSIDERABLE SOUTHERLY FLOW AT THE SURFACE AND ALOFT WILL
ALLOW DEEP MOISTURE TO SURGE BACK NORTHWARD, HELPING SET UP A FEW
DECENT PERIODS OF SHOWERS AND SOME THUNDERSTORMS INTO MEMORIAL DAY
WEEKEND. THE SOUTHERLY FLOW WILL ALSO ALLOW TEMPERATURES TO RISE
BACK UP INTO THE 80S BY THE WEEKEND, BUT WITH DEW POINTS AGAIN IN
THE MID 60S, IT WILL ALSO FEEL RATHER MUGGY OUTSIDE. THE MORE
ACTIVE PATTERN FOR ROUNDS OF SHOWERS IS CURRENTLY EXPECTED TO LAST
THROUGH THE END OF THE FORECAST PERIOD, SO A LITTLE BIT OF DROUGHT
RELIEF MAY FINALLY BE ON THE WAY.
AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 739 PM EDT MON MAY 18 2026
A ROUND OF SHOWERS AND THUNDERSTORMS ARE CURRENTLY MOVING NE THROUGH
SOUTHERN IN CAUSING GUSTY/STRONG WINDS. RAIN CHANCES TO BE OUT OF
HNB AND SDF BY 05Z. A MARGINAL SIGNAL FOR LLWS AT HNB/SDF OVERNIGHT
(05-07Z) AS A LLJ SCRAPS ACROSS SOUTHERN IN. WINDS WILL ALSO TAKE A
SHIFT TO THE SW BY TOMORROW. A MID LEVEL CLOUD DECK WILL MOVE IN
TOMORROW BRINGING BKN/OVC100 TO ALL SITES. AHEAD OF A COLD FRONT, A
LINE OF SHOWERS AND STORMS WILL MOVE IN TOMORROW AFTERNOON/EVENING.
WIND GUSTS ARE EXPECTED TO INCREASE DURING THIS TIME WITH THE
POTENTIAL FOR LOWER VIS DURING PERIODS OF HEAVIER RAIN.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
MESOSCALE....MJ
SHORT TERM...SRW
LONG TERM....BEN
AVIATION.....CAL
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