170
FXUS63 KLMK 202016
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
416 PM EDT SAT JUN 20 2026
KEY MESSAGES
* STRONG TO SEVERE STORMS WILL BE POSSIBLE LATER SUNDAY AFTERNOON
INTO LATE SUNDAY EVENING. ALL SEVERE HAZARDS COULD BE IN PLAY,
ESPECIALLY ALONG AND WEST OF I-65 AND NORTH OF THE WK/BG PARKWAYS.
* A SOMEWHAT UNSETTLED PATTERN IS EXPECTED THROUGH EARLY WEEK WITH
TEMPERATURES SLIGHTLY BELOW NORMAL AND OFF AND ON SHOWER AND STORM
CHANCES POSSIBLE, ESPECIALLY ACROSS SOUTHERN KY.
SHORT TERM /THROUGH SUNDAY/
ISSUED AT 416 PM EDT SAT JUN 20 2026
THROUGH THE REST OF THE EVENING AND INTO TONIGHT, NORTHWEST FLOW
WILL PUSH A WEAK COLD FRONT SOUTH THROUGH SOUTHERN INDIANA, AHEAD OF
A SMALL SURFACE HIGH, AND WITH PRECIPITABLE WATER VALUES BETWEEN 1.1
AND 1.3" AHEAD OF THE FRONT, ISOLATED TO SCATTERED SHOWERS WITH A
FEW THUNDERSTORMS WILL LIKELY DEVELOP. THIS ACTIVITY IS EXPECTED TO
BE LIMITED TO ALONG AND NORTH OF INTERSTATE 64 AND WILL FADE EARLY
TONIGHT.
THE SURFACE HIGH MOVING INTO THE LOWER OHIO VALLEY WILL CAUSE
WESTERLY WINDS TO BECOME LIGHT AND VARIABLE BEFORE BECOMING MORE
EASTERLY TOMORROW MORNING. SOME PASSING CLOUDS WILL REMAIN, BUT
CLEARING SKIES WILL LEAD TO SOME RADIATIVE COOLING. TEMPERATURES ARE
EXPECTED TO FALL INTO THE LOW TO MID 60S IN MANY PLACES WITH SOME
AREAS REACHING INTO THE 50S.
TOMORROW, WINDS BEGIN OUT OF THE EAST TO EAST-SOUTHEAST AS A SURFACE
LOW OVER THE WESTERN PLAINS GETS QUICKLY PUSHED EASTWARD BY ZONAL
FLOW. THE INCREASING PRESSURE GRADIENT OVER SOUTHERN INDIANA AND
CENTRAL KENTUCKY WILL CONTINUE VEERING WINDS TOWARDS THE SOUTH,
CARRYING WARM MOIST AIR FARTHER NORTHWARD AS A WARM FRONT. PARTLY TO
MOSTLY SUNNY SKIES WILL DRIVE INSTABILITY, POSSIBLY HELPING THE
FRONT DEVELOP ISOLATED CONVECTION THROUGHOUT THE AFTERNOON AND
EVENING HOURS AS TEMPERATURES REACH INTO THE MID TO UPPER 80S WITH
DEW POINTS IN THE MID 60S TO NEAR 70.
LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/
ISSUED AT 416 PM EDT SAT JUN 20 2026
HEADING INTO SUNDAY EVENING INTO THE OVERNIGHT, THE AFOREMENTIONED
SURFACE LOW THAT WAS OVER THE PLAINS GETS PUSHED TOWARDS SOUTHERN
INDIANA, WHERE IT'S EXPECTED TO ARRIVE AFTER MIDNIGHT. WHILE IT DOES
THIS, THE LOW DRAGS A COLD FRONT WITH IT. AHEAD OF THE FRONT, SOUTH
AND SOUTHWEST WINDS BEING DRIVEN BY A 35-40 MPH LOW LEVEL JET LIFT
DEW POINTS INTO THE UPPER 60S TO LOW 70S AS PRECIPITABLE WATER
VALUES CLIMB TO OVER 1.5", REACHING UP TO 2.25" ALONG THE FRONT.
THERE REMAINS A QUESTION OF HOW MUCH INSTABILITY THERE WILL BE FOR
THE APPROACHING FRONT AND EXPECTED CONVECTION TO WORK WITH. IF AREAS
ALONG AND NORTH OF THE OHIO RIVER REMAIN MORE CLOUDY, IT WILL REDUCE
INSTABILITY. THE LATEST MODEL RUNS HAVE REDUCED INSTABILITY VALUES
BUT HAVE AN EARLIER ARRIVAL TIME. SOME EARLIER RUNS HAVE INDICATED A
LATER ARRIVAL WITH HIGHER INSTABILITY AND HIGHER DCAPE VALUES, BUT
THE LATER RUNS ALSO DEVELOP A STABLE LAYER IN THE BOUNDARY LAYER.
BASICALLY, THERE REMAINS UNCERTAINTY IN THE THE TIMING. THE MAIN
THREAT CONTINUES TO HAVE A LINE OF CONVECTION LIKELY BOWING AS IT
MOVES THROUGH THE CWA. STRONG WINDS ARE EXPECTED, BUT THE AMOUNT OF
INSTABILITY AVAILABLE TO THE LINE AND THE TIME OF ARRIVE WILL
DETERMINE HOW STRONG THE LINE IS. IT COULD BE THE EARLIER ARRIVAL
WITH A DEVELOPED COLD POOL THAT BEGINS OUTRUNNING THE FRONT, OR THE
LINE COULD REMAIN CLOSER TO THE FRONT, PROVIDING FOR A LATER
ARRIVAL.
THERE IS A SMALL THREAT FOR A TORNADO. THE BEST CHANCE FOR THIS
WOULD BE EARLIER IN THE EVENING OVER SOUTHWEST INDIANA, IF
CONVECTION ARRIVES IN TIME. MODEL SOUNDINGS SHOW GOOD INSTABILITY IN
THE LOW AND MID LEVELS WITH STRONG 0-6 KM DEEP LAYER SHEAR OVER 50
KNOTS. HODOGRAPHS SHOW GOOD BACKING AT THE SURFACE. A COUPLE
LIMITING FACTORS ARE HIGH LCLS (OVER 1 KM) AND MARGINAL INSTABILITY,
POSSIBLY BEING ONLY AROUND 500 J/KG.
THE OTHER RISK TOMORROW EVENING/NIGHT WILL BE THE FLASH FLOODING
RISK. ANYTIME PRECIPITABLE WATER VALUES GET TO NEAR 2", RAIN CAN
PILE UP QUICK. AS LONG AS THE CONVECTION REMAINS GENERALLY NORTH AND
SOUTH ORIENTED AND QUICKLY PUSHES THROUGH PERPENDICULAR TO THE FLOW,
THE FLOODING THREAT WILL REMAIN FAIRLY LOW, BUT IF THE WEST TO EAST
PART OF THE LINE DOESN'T CONTINUE DROPPING SOUTH AND MOVES MORE TO
THE EAST AND WE HAVE TRAINING, THERE WILL LIKELY BE PROBLEMS. THE
BEST CHANCES FOR FLOODING CURRENTLY LOOK TO BE OVER INDIANA. THE
INDIANAPOLIS NWS OFFICE HAS ALREADY ISSUED A FLOOD WATCH. THIS COULD
BE EXPANDED SOUTH A ROW OR TWO OF COUNTIES INTO OUR CWA IN THE
FUTURE.
AS THE CONVECTION PUSHES OFF TO THE EAST AND SOUTH, IT'S EXPECTED TO
WEAKEN. BY MONDAY MORNING, THE MAIN CONVECTION IS EXPECTED TO BE OUT
OF KENTUCKY OR WEAKENED TO MOSTLY JUST SHOWERS BEFORE MOST ACTIVITY
COME TO AN END MONDAY AFTERNOON.
AVIATION /18Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 219 PM EDT SAT JUN 20 2026
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. WINDS OUT
OF THE WEST WILL BECOME LIGHT AND VARIABLE TONIGHT AS SURFACE HIGH
PRESSURE MOVES INTO THE REGION. TOMORROW, WINDS PICK BACK UP FROM
THE EAST-SOUTHEAST BEFORE VEERING TOWARDS THE SOUTH.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
SHORT TERM...KDW
LONG TERM...KDW
AVIATION...KDW
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