845
FXUS63 KLMK 170825
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
425 AM EDT THU SEP 17 2026
KEY MESSAGES
* HEAT ADVISORY REMAINS IN EFFECT THROUGH THIS EVENING.
* UNSEASONABLY HOT TEMPERATURES CONTINUE WITH HIGHS IN THE MID TO
UPPER 90S AND HEAT INDEX VALUES UP TO 105 DEGREES.
* WEAK FRONT BRINGS LOW END (30-40%) RAIN CHANCES ON FRIDAY
* BETTER CHANCES OF RAIN RETURN EARLY TO MID NEXT WEEK.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 337 AM EDT THU SEP 17 2026
TODAY, UPPER HIGH PRESSURE, CENTERED OVER THE MID-MISSISSIPPI
VALLEY, EXTENDS OVER THE LOWER OHIO VALLEY WITH ZONAL FLOW
STRETCHING FROM THE UPPER PLAINS EAST THROUGH THE GREAT LAKES AND
OFF INTO THE ATLANTIC. AT THE SURFACE, A WEST TO EAST ORIENTED FRONT
REMAINS TO OUR NORTH WITH HIGH PRESSURE NORTH OF THAT. ANOTHER AREA OF
HIGH PRESSURE REMAINS OVER THE SOUTHEAST, KEEPING LIGHT WAA AND HIGH
DEW POINTS IN PLACE OVER SOUTHERN INDIANA AND CENTRAL KENTUCKY,
SOUTH OF THE FRONT. HIGHS ARE ONCE AGAIN EXPECTED TO CLIMB INTO THE
MID TO UPPER 90S IN MOST AREAS. PARTS OF THE BLUEGRASS AND SOUTHEAST
INDIANA MAY ONLY SEE THE LOW 90S. WITH DEW POINTS IN THE LOW TO MID
70S, HEAT INDICES ARE EXPECTED TO REACH OVER 100 DEGREES TO AROUND
105 DEGREES AGAIN IN MANY AREAS ALONG AND WEST OF INTERSTATE 65.
THIS IS KEEPING THE HEAT ADVISORY IN PLACE THROUGH THE EVENING
HOURS. AN ISOLATED SHOWER OR THUNDERSTORM REMAINS POSSIBLE, BUT AS
WITH THE LAST COUPLE OF DAYS, MOST AREAS WILL REMAIN SUNNY AND DRY.
TONIGHT, WINDS CALM UNDER MOSTLY CLEAR SKIES EARLY IN THE NIGHT, BUT
AS THE COLD FRONT TO THE NORTH BEGINS TO DROP SOUTH, CLOUDS ARE
EXPECTED TO BEGIN INCREASING ACROSS SOUTHERN INDIANA CLOSER TO
FRIDAY MORNING. STILL A LITTLE RADIATIVE COOLING IS EXPECTED TO HELP
TEMPERATURES DROP INTO THE UPPER 60S IN SOME RURAL AREAS. THE URBAN
AREAS WILL REMAIN A LITTLE WARMER IN THE LOW TO MID 70S.
LONG TERM /FRIDAY THROUGH WEDNESDAY/
ISSUED AT 337 AM EDT THU SEP 17 2026
STALLED SFC BOUNDARY WILL DRIFT SOUTHWARD TOWARDS THE OHIO VALLEY
AND THE COMMONWEALTH THURSDAY NIGHT INTO FRIDAY MORNING. THIS WILL
INCREASE SHOWER/STORM CHANCES ACROSS THE CWA ESPECIALLY OVER
SOUTHERN IN, NORTH CENTRAL KY AND OVER THE BLUEGRASS REGION. CURRENT
FORECASTS CONTINUES TO SHOW A 20-30 PERCENT CHANCE OF POPS. THERE
REMAINS SOME UNCERTAINTY ON HOW FAR SOUTH THIS BOUNDARY WILL GO
ACROSS THE STATE OF KY. THE PLACEMENT OF THIS BOUNDARY WILL HAVE A
LARGE INFLUENCE ON NOT JUST POTENTIAL SHOWER AND STORM POTENTIAL BUT
ALSO ON OUR TEMPERATURES. THE IS SOME GUIDANCE THAT IS STARTING TO
SUGGEST THE BOUNDARY COULD GO AS FAR SOUTH AS THE KY/TN BORDER. IF
THIS SCENARIO PLAYS OUT WE WOULD NOT NEED TO CONTINUE THE HEAT
ADVISORY INTO FRIDAY. IF IT STOPS SHORT AND MAKES IT TO ONLY CENTRAL
KY THEN SOME OF OUR COUNTIES TO THE SOUTH AND WEST MAY NEED TO
CONTINUE THE HEAT ADVISORY FOR ANOTHER DAY. GIVEN THE LACK OF
CONFIDENCE, IT WAS DECIDED TO WAIT ON MORE DATA AND CONFIDENCE
BEFORE EXTENDING THE CURRENT HEAT ADVISORY FOR FRIDAY.
FRONT WILL LIFT NORTH AGAIN TO START THE WEEKEND BUT THE CENTER OF
THE UPPER RIDGE WILL BE FURTHER WEST. WHILE WE WILL SEE TEMPERATURES
BOTH SATURDAY AND SUNDAY RETURN TO THE LOW-MID 90S, HEAT INDEX
VALUES WILL NOT BE AS HOT. THE FORECAST CONTINUES TO LOOK MAINLY DRY
FOR THE WEEKEND.
PATTERN FLATTENS OUT AND BECOMES MORE ZONAL FOR EARLY NEXT WEEK WITH
A SERIES OF SYSTEMS WORKING THROUGH THE REGION WITH A COLD FRONT
PUSHING THROUGH DURING THE FIRST HALF OF THE WEEK. THIS SHOULD BRING
COOLER TEMPERATURES IN THE 80S BY THE MIDDLE OF NEXT WEEK WITH SOME
SHOWERS AND POSSIBLE STORMS.
AVIATION /06Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 126 AM EDT THU SEP 17 2026
HIGH PRESSURE IS KEEPING VFR CONDITIONS IN PLACE THROUGH THE
FORECAST PERIOD. WINDS REMAIN LIGHT BUT WILL VEER TOWARDS THE
NORTHWEST THROUGHOUT THE DAY.
LMK WATCHES/WARNINGS/ADVISORIES
KY...HEAT ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
KYZ023>034-038-045-046-053-054-061>065-070>077-081.
IN...HEAT ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
INZ076>079-083-084-089>092.
SHORT TERM...KDW
LONG TERM...KDW
AVIATION...KDW
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