471
FXUS63 KLMK 171757
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
157 PM EDT THU SEP 17 2026
..UPDATED AVIATION DISCUSSION
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 (20-30%) RAIN CHANCES ON FRIDAY
* BETTER CHANCES OF RAIN RETURN EARLY TO MID NEXT WEEK.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 430 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 430 AM EDT THU SEP 17 2026
HEADING INTO FRIDAY, THE UPPER HIGH SLIDES WEST TOWARDS TEXAS AS ITS
NEGATIVELY TILTED UPPER RIDGE ROTATES EAST THROUGH THE NORTHERN
PLAINS. NORTHWEST FLOW, AHEAD OF THE RIDGE, WILL PUSH A SURFACE HIGH
THROUGH EASTERN CANADA AS A THE COLD FRONT SOUTH OF THE HIGH DROPS
SOUTH INTERACTING WITH SHORTWAVES RIDING AROUND THE UPPER HIGH, NEAR
THE CWA. THIS IS EXPECTED TO INCREASE SHOWER AND THUNDERSTORM
CHANCES THAT ARE EXPECTED TO WORK THEIR WAY SOUTH THROUGH THE CWA.
NOT EXPECTING MUCH IN THE WAY OF TOTAL RAINFALL, BUT ADDITIONAL
CLOUD COVER AND A SHIFT TO NORTHERLY WINDS COULD HELP BRING RELIEF
FROM WARM TEMPERATURES. THE TIMING LOOKS DELAYED, SO AT LEAST PARTS
OF THE HEAT ADVISORY MAY NEED TO BE EXTENDED INTO FRIDAY.
SATURDAY, THE FRONT IS EXPECTED TO BEGIN MOVING BACK NORTH AS A WARM
FRONT. WAA WILL KEEP HIGH TEMPERATURES IN THE LOW TO MID 90S THROUGH
THE BEGINNING OF NEXT WEEK BEFORE WIDESPREAD 80S RETURN. THE OVERALL
PATTERN REMAINS A LITTLE MESSY WITH A GENERAL ZONAL FLOW OVER THE
LOWER OHIO VALLEY. A SURFACE LOW/FRONTAL SYSTEM IS EXPECTED TO BRING
INCREASED SHOWER AND THUNDERSTORMS CHANCES FOR THE BEGINNING AND
MIDDLE PARTS OF NEXT WEEK. OVERALL RAINFALL AMOUNTS REMAIN LOW.
AVIATION /18Z TAFS THROUGH 00Z SATURDAY/
ISSUED AT 156 PM EDT THU SEP 17 2026
VFR CONDITIONS ARE EXPECTED TO PREVAIL THIS FORECAST CYCLE WITH A
STEADY WNW TO W WIND TODAY ALONG WITH SOME HIGHER BASED SCT-BKN
CUMULUS CLOUDS. WINDS SLACKEN TONIGHT AND GO MORE SW. LOOK FOR LIGHT
AND VARIABLE WINDS TOMORROW WITH SOME REMNANT OUTFLOW AND A WEAK
FRONTAL BOUNDARY STALLING NEAR THE AREA. COULD SEE SOME AFTERNOON
AND EVENING SHOWERS OR A STORM ALONG AND NORTH OF I-64 AND PUT A
PROB30 AT KSDF TO ACCOUNT FOR THIS IN THE 24-30 HOUR PERIOD.
LMK WATCHES/WARNINGS/ADVISORIES
KY...HEAT ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
KYZ029>034-038-045-046-054-065-077.
HEAT ADVISORY UNTIL 8 PM EDT /7 PM CDT/ FRIDAY FOR KYZ023>028-
053-061>064-070>076-081.
IN...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR INZ076>079-
090>092.
HEAT ADVISORY UNTIL 8 PM EDT /7 PM CDT/ FRIDAY FOR INZ083-084-
089.
SHORT TERM...KDW
LONG TERM...KDW
AVIATION...BJS
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