396  
FXUS63 KLMK 140000  
AFDLMK  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LOUISVILLE KY  
800 PM EDT THU AUG 13 2026  
   
..UPDATED AVIATION DISCUSSION  
 
   
KEY MESSAGES  
 
* HOT AND HUMID CONDITIONS CONTINUE THIS AFTERNOON, WITH HEAT INDEX  
VALUES NEAR 100 FOR MOST. A FEW ISOLATED SHOWERS AND STORMS REMAIN  
POSSIBLE THROUGH THE AFTERNOON AND EVENING.  
 
* THUNDERSTORMS ARE MOST LIKELY ACROSS INDIANA AND OHIO TONIGHT, AND  
COULD SEE SOME STORMS SNEAK INTO OUR SOUTHERN IN AREAS TONIGHT AND  
TOMORROW MORNING. CONFIDENCE REMAINS LOW, AND OVERALL SEVERE RISK  
IS LOW FOR OUR AREA.  
 
* OUTSIDE OF STORMS, HEAT INDICES ARE LIKELY (60-80% CHANCE) TO  
SURPASS 100 DEGREES WEST OF I-75 AGAIN TOMORROW. THE HEAT AND  
HUMIDITY PEAKS SATURDAY AND SUNDAY, WHEN HEATRISK IS FORECAST TO  
REACH THE MAJOR CATEGORY AREA-WIDE.  
 
 
   
SHORT TERM /THROUGH FRIDAY NIGHT/  
 
ISSUED AT 336 PM EDT THU AUG 13 2026  
 
IT IS FAIRLY WARM AND MUGGY ACROSS THE REGION TODAY, WITH KY MESONET  
STATIONS SHOWING TEMPS REACHING THE UPPER 80S AND LOW 90S. THE HEAT  
ADVISORY STILL APPEARS TO BE WELL PLACED, WITH THE MORE CONSISTENT  
100+ HEAT INDICES IN OUR SOUTHWEST, THOUGH THERE ARE MANY LOCATIONS  
HOVERING RIGHT AROUND 100 THIS AFTERNOON. THE ADVISORY WILL CONTINUE  
AS IS AND IS PLANNED TO EXPIRE ON TIME AT 01Z THIS EVENING. DUE TO  
THE HEAT AND HUMIDITY IN PLACE, WE HAVE BEEN ABLE TO BECOME QUITE  
UNSTABLE TODAY, WITH SBCAPE UP TO 5000 J/KG ACCORDING TO SPC  
MESOANALYSIS. WE'LL CONTINUE TO SEE SOME ISOLATED SHOWERS AND STORMS  
THROUGH THE AFTERNOON, THOUGH WEAK SHEAR AND A LACK OF A TRIGGER  
MECHANISM FOR OUR AREA SHOULD KEEP CONVECTION ISOLATED AND SOMEWHAT  
UNORGANIZED.  
 
FOR TONIGHT, WILL BE KEEPING A CLOSE EYE ON THE CONVECTION MOVING  
ACROSS IL/IN AS IT PROGRESSES EASTWARD BY TOMORROW MORNING. THERE IS  
BETTER AGREEMENT FROM MOST CAMS THAT THE MAIN AXIS OF HEAVIEST  
CONVECTION AND PRECIP WILL BE ACROSS IN AND SOUTHWEST OH INTO  
TOMORROW MORNING, THOUGH SOME OF OUR NORTHEAST CWA COULD GET CLIPPED  
BY THIS. THE HREF LPMM SHOWS THIS AXIS OF PRECIP WELL, AND SHOWS THE  
MAIN AXIS STRETCHING FROM DAVENPORT, IA TO CINCINNATI, OH, REMAINING  
JUST TO OUR NORTH. FOR OUR AREA SPECIFICALLY, JEFFERSON COUNTY IN  
WOULD HAVE THE GREATEST CHANCE FOR ANY HYDRO ISSUES, BUT CURRENTLY  
NOT EXPECTING ENOUGH TO WARRANT A FLOOD WATCH AT THIS TIME. THIS  
COULD CHANGE WITH HOW THE EVENING EVOLVES, BUT THERE IS NOT ENOUGH  
CONFIDENCE WE WILL END UP SEEING THAT MUCH PRECIP. OUR FFG NUMBERS  
ARE LOWER, WITH 1-HR FFG AROUND 1.25" FOR AREAS EAST OF I-65. NOT  
GOING TO RULE OUT THE POSSIBILITY OF A FLOODING ISSUE TONIGHT, BUT  
AGAIN THE CONFIDENCE IS HIGHER TO OUR NORTHEAST. WE TALKED WITH WPC  
ABOUT THE MODERATE RISK IN THE D1 ERO, AND WE BOTH AGREED THAT IT  
SHOULD PROBABLY BE TRIMMED BACK FROM OUR AREA. HOWEVER, THEY ARE NOT  
PLANNING TO UPDATE THIS OUTLOOK AGAIN UNTIL THIS EVENING.  
 
HEAT AND HUMIDITY CONTINUE TO BUILD TOMORROW, WITH HIGHS IN THE MID-  
90S POSSIBLE, ALONG WITH UNCOMFORTABLE DEWPOINTS POTENTIALLY  
REACHING 80 IN SOME SPOTS. THIS SET UP WILL YIELD HEAT INDICES WELL  
ABOVE 100, POSSIBLY PEAKING OVER 110 IN SOME AREAS AS WELL. THE ONE  
CAVEAT TO THIS IS IF WE DO END UP SEEING MORE MORNING CONVECTION AND  
LINGERING CLOUD DEBRIS THAN FORECAST, THAT COULD POSSIBLY DERAIL THE  
TEMP/HEAT INDEX FORECAST TOMORROW. WE'LL LET THE CURRENT HEAT  
ADVISORY RUN AS IS THIS EVENING, BUT WILL LIKELY NEED TO ISSUE A NEW  
ONE FOR TOMORROW IF THE FORECAST REMAINS ON TRACK. TOMORROW'S  
POTENTIAL HEADLINE WILL NEED TO COVER MUCH MORE OF THE AREA TOO.  
 
A STATIONARY BOUNDARY WILL BE SITUATED ACROSS THE OHIO RIVER THROUGH  
TOMORROW, AND COULD BE THE FOCUS FOR REDEVELOPMENT TOMORROW  
AFTERNOON. WE'LL HAVE ANOTHER DAY OF VERY STRONG INSTABILITY, THOUGH  
SHEAR WILL LIKELY BE VERY WEAK.  
 
 
   
LONG TERM /SATURDAY THROUGH THURSDAY/  
 
ISSUED AT 336 PM EDT THU AUG 13 2026  
 
===== DRIER TREND THIS WEEKEND, BUT HOTTER TEMPERATURES =====  
 
UPPER RIDGING WILL BUILD ACROSS THE US OVER THE WEEKEND, LEADING TO  
A DRIER TREND FOR OUR AREA. HOWEVER, THIS WILL ALSO LEAD TO MUCH  
HOTTER TEMPS, WITH DAILY HIGHS IN THE 90S BOTH DAYS. WITH DEWPOINTS  
REACHING THE MID 70S, THAT WILL EASILY YIELD HEAT INDICES BETWEEN  
105-110 BOTH SATURDAY AND SUNDAY. THERE IS HIGH CONFIDENCE THAT  
WE'LL NEED A HEAT HEADLINE FOR THE WEEKEND.  
 
===== PRECIP CHANCES RETURN EARLY NEXT WEEK =====  
 
A FRONTAL BOUNDARY WILL SHIFT SOUTHWARD THROUGH THE OHIO VALLEY  
SUNDAY NIGHT AND INTO MONDAY, AND WILL LIKELY BRING A ROUND OF  
SHOWERS AND STORMS TO THE AREA. ANY OVERNIGHT CONVECTION SUNDAY  
NIGHT WILL BE ELEVATED, BUT REDEVELOPMENT MONDAY AFTERNOON WOULD BE  
SFC BASED IN A HIGHLY UNSTABLE AIRMASS. NOT A LOT OF SHEAR EXPECTED  
THEN TO LIMIT ORGANIZATION, BUT CERTAINLY COULD SEE SCATTERED  
THUNDERSTORMS ON MONDAY.  
 
TUESDAY AND WEDNESDAY APPEAR MOSTLY DRY, WITH MAINLY ISOLATED CHANCES  
EAST OF I-65 BOTH DAYS. SFC HIGH PRESSURE WILL BE CENTERED TO OUR  
NORTH THEN, SO NOT GOING TO EXPECT MUCH ACTIVITY FOR THE MID-WEEK.  
 
 
   
AVIATION /00Z TAFS THROUGH 06Z SATURDAY/  
 
ISSUED AT 759 PM EDT THU AUG 13 2026  
 
DEEP CONVECTION IS SAGGING SOUTHEAST OVER NORTHEASTERN AND EASTERN  
KY THIS EVENING. ONE STRONGER STORM FURTHER WEST IS MOVING OVER RGA  
AT THE START OF THE TAF PERIOD. OTHER THAN BRIEF TSRA IMPACTS AT  
RGA, THE REST OF THE OVERNIGHT PERIOD LOOKS MOSTLY DRY. WE COULD  
HAVE A COUPLE SHOWERS NORTH OF SDF LINGER FOR ANOTHER HOUR OR TWO  
BEFORE DIMINISHING.  
 
ON FRIDAY, WEAKENING CONVECTION DIVING SOUTHEAST ACROSS CENTRAL IN  
MAY SEND OUT AN OUTFLOW BOUNDARY INTO SOUTHERN IN BY MID-MORNING.  
SCATTERED SHOWERS AND STORMS APPEAR POSSIBLE, ESPECIALLY ALONG AND  
NORTH OF I-64, THROUGH THE MID TO LATE MORNING HOURS. HOWEVER,  
CONFIDENCE IS SOMEWHAT LOW IN THE CONVECTIVE EVOLUTION TOMORROW.  
 
 
   
LMK WATCHES/WARNINGS/ADVISORIES  
 
KY...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KYZ023-026-061-  
070>073.  
IN...NONE.  
 
 
 
 
 
SHORT TERM...CJP  
LONG TERM...CJP  
AVIATION...EBW  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab KY Page
The Nexlab IN Page
Main Text Page