244
FXUS63 KLMK 180909
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
509 AM 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.
* 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.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 509 AM EDT MON MAY 18 2026
TODAY, A CLOSED LOW WITHIN AN UPPER TROUGH IS LOCATED NEAR THE FOUR
CORNERS. EAST OF THE TROUGH, SOUTHWEST FLOW STRETCH OVER THE PLAINS
BEFORE MEETING AN UPPER RIDGE FLOWING THROUGH THE GREAT LAKES AND
NEW ENGLAND REGIONS. THE LOWER OHIO VALLEY SITS UNDER THIS RIDGE
WITH GUSTY (20-25 MPH) SOUTHERLY WINDS BEING DRIVEN BY A PRESSURE
GRADIENT BETWEEN A SURFACE HIGH OVER THE SOUTHEAST AND LOW PRESSURE
THAT STRETCHES FROM THE WESTERN PLAINS INTO THE MIDWEST. THIS SIT-UP
IS EXPECTED TO PROVIDE LOTS OF SUNSHINE AND WAA TO DRIVE HIGH
TEMPERATURES INTO THE MID 80S TO LOW 90S THROUGHOUT SOUTHERN INDIANA
AND CENTRAL KENTUCKY.
BY THIS AFTERNOON, THE SOUTHERN LOW LEVEL WINDS WILL NOT ONLY DRIVE
TEMPERATURES WARMER, BUT THEY WILL ALSO LIFT PRECIPITABLE WATER
VALUES TO 1.75-2" OVER WESTERN KENTUCKY NORTH INTO WESTERN INDIANA,
AND AS THE REMNANTS OF THE SYSTEM CURRENTLY OVER IOWA DRIFT
SOUTHEAST TOWARDS THE CWA, IT WILL HAVE THIS MOISTURE RICH UNSTABLE
ENVIRONMENT TO WORK WITH TO BRING SHOWERS AND THUNDERSTORM TO
SOUTHERN INDIANA. MOISTURE IS EXPECTED TO QUICKLY DROP OFF SOUTH OF
THE OHIO RIVER, SO MOST OF THE ACTIVITY IS EXPECTED TO REMAIN IN
SOUTHERN INDIANA, AND THE BEST CHANCES FOR STRONG TO SEVERE
THUNDERSTORMS WILL BE IN THE FAR NORTHWESTERN PARTS OF THE CWA,
INCLUDING DUBOIS COUNTY, WHERE THUNDERSTORMS COULD DEVELOP AHEAD OF
THE APPROACHING LINE.
WITH MLCAPE VALUES AROUND 1,600 J/KG, MUCAPE VALUES NEAR 2,300 J/KG,
AN INVERTED "V" SOUNDING WITH LCLS NEAR 1 KM, STRONG WINDS AND HAIL
COULD BE POSSIBLE. DEEP LAYER SHEAR IS WEAK AROUND 25 KNOTS, SO THIS
COULD POSSIBLY HELP SOME HAIL TO MELT AS IT FALL BACK THROUGH THE
COLUMN, REDUCING ITS SIZE. THE HIGH PWATS WILL ALSO LIKELY DRIVE
INTENSE RAINFALL WHICH COULD CAUSE PONDING OF WATER. THERE IS A
LIMITED WINDOW FOR ANY STRONGER STORMS AS INSTABILITY IS EXPECTED TO
QUICKLY DROP TO THE SOUTHEAST.
TONIGHT, ANY REMAINING SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DISSIPATE. CONTINUED WAA WITH SOME CLOUD COVER WILL HELP LIMIT
COOLING, KEEPING LOW TEMPERATURES IN THE UPPER 60S TO LOW 70S.
LONG TERM /TUESDAY THROUGH SUNDAY/
ISSUED AT 509 AM EDT MON MAY 18 2026
TOMORROW, AHEAD OF AN APPROACHING COLD FRONT, TEMPERATURES ARE
EXPECTED TO ONCE AGAIN CLIMB INTO THE UPPER 80S TO LOW 90S WITH
ANOTHER DAY OF GUSTY WAA. THIS IS EXPECTED TO DRIVE VERY HIGH
INSTABILITY IN THE AREA OF SPC'S "SLIGHT" RISK. SOME AREAS OVER
SOUTHERN INDIANA COULD SEE MLCAPE VALUES NEAR 2,500 J/KG AND MUCAPE
VALUES NEAR 3,000 J/KG. THIS WOULD HELP AN EXPECTED LINE OF
CONVECTION AHEAD OF THE FRONT TO GENERATE STRONG GUSTY WINDS AND
POSSIBLY LARGE HAIL BEFORE WEAKENING AS THE SYSTEM PUSHES OFF TO THE
EAST. CURRENT TIMING HAS THE LINE REACHING DUBOIS COUNTY DURING THE
EARLY AFTERNOON. IN THE FOLLOWING HOURS, THE LINE WOULD PUSH EAST
THROUGH SOUTHERN INDIANA AND CENTRAL KENTUCKY.
TUESDAY NIGHT, THE COLD FRONT IS EXPECTED TO REACH OUR SOUTHERN
INDIANA COUNTIES, BUT IT COULD BE SLOW GETTING THROUGH CENTRAL
KENTUCKY, NOT MAKING IT THROUGH THE CWA UNTIL SOMETIME ON WEDNESDAY.
THE FRONT WILL SLOWLY VEER WINDS TOWARDS THE NORTH. TEMPERATURES
WILL REMAIN MILD TUESDAY NIGHT FALLING INTO THE MID TO UPPER 60S,
BUT WEDNESDAY'S HIGHS CAN BE EXPECTED TO SEE SOME RELIEF ONLY MAKING
IT TO THE MID 70S NEAR JASPER, INDIANA TO THE MID 80S NEAR CLINTON
COUNTY. THIS WILL BE NEAR NORMAL FOR MANY ACROSS THE CWA. THE SLOW
MOVING FRONT WILL KEEP SHOWER AND THUNDERSTORM CHANCES ACROSS THE
CWA THROUGH WEDNESDAY, BUT STRONG STORMS AREN'T EXPECTED.
ON THURSDAY, HIGHS ARE EXPECTED TO BE SLIGHTLY BELOW NORMAL, IN THE
LOW TO MID 70S FOR MOST. FAR SOUTHERN KENTUCKY COULD SEE THE UPPER
70S. ENJOY IT BECAUSE TEMPERATURES BEGIN TO INCH BACK UP DAY BY DAY
INTO THE MID 80S BY SUNDAY. PRECIPITATION CHANCES REMAIN LOW BUT
REMAIN AS THE FRONT SITS SOUTH OF THE CWA. ANOTHER LOW PRESSURE
SYSTEM COULD SWING THROUGH ON FRIDAY, BRINING A BETTER CHANCE FOR
WIDESPREAD RAIN.
AVIATION /06Z TAFS THROUGH 12Z TUESDAY/
ISSUED AT 215 AM EDT MON MAY 18 2026
VFR CONDITIONS ARE EXPECTED TO REMAIN THROUGH THE PERIOD AT MOST
SITES, BUT HNB AND POSSIBLY SDF COULD SEE A LINE OF LATE
AFTERNOON/EVENING CONVECTION ARRIVE FROM THE NORTHWEST BEFORE
DISSIPATING. THIS COULD BRING HEAVY SHOWERS AND LOW VFR CEILINGS FOR
A LIMITED TIME. ALL AREA TAF SITES CAN EXPECT SOUTHERLY WINDS TO
BECOME GUSTY, GUSTING TO 20-25 KNOTS FOR MOST OF THE DAY BEFORE
EASING TONIGHT.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
SHORT TERM...KDW
LONG TERM...KDW
AVIATION...KDW
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