382
FXUS63 KLMK 130517
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
117 AM EDT THU AUG 13 2026
KEY MESSAGES
* WAVES OF THUNDERSTORMS INTO TONIGHT COULD GENERATE SEVERE WEATHER,
WITH DAMAGING WINDS THE PRIMARY HAZARD AND A LOWER RISK FOR LARGE
HAIL.
* REPEATED ROUNDS OF HEAVY RAINFALL IN THUNDERSTORMS THROUGH THIS
EVENING COULD RESULT IN FLASH FLOODING. THERE IS A LEVEL 2 OF 4
(SLIGHT) RISK FOR EXCESSIVE RAINFALL AREA-WIDE, AND A LEVEL 3
(MODERATE) RISK FOR EXCESSIVE RAINFALL ACROSS SE INDIANA AND NORTH
CENTRAL KY.
* ADDITIONAL ROUNDS OF STORMS ARE POSSIBLE (20-40% CHANCE) BOTH
TOMORROW AND FRIDAY, BUT CONFIDENCE IS LOW ON SEVERE WEATHER AND
FLOODING POTENTIAL EACH DAY.
* OUTSIDE OF STORMS, HEAT INDICES ARE LIKELY (50-80% CHANCE) TO
SURPASS 100 DEGREES WEST OF I-65 EACH AFTERNOON THROUGH THURSDAY,
AND AREA-WIDE OVER THE WEEKEND.
UPDATE
ISSUED AT 345 PM EDT WED AUG 12 2026
SEVERE THUNDERSTORM WATCH 577 HAS BEEN ISSUED FOR ALL SOUTHERN IN
COUNTIES AND CENTRAL KY COUNTIES UNTIL 9PM EDT/ 8PM CDT. WE WILL
CONTINUE TO MONITOR THE DESTABILIZATION WITHIN THE AREA AHEAD OF THE
BROKEN LINE OF STORMS. MAIN HAZARD FOR STORMS WILL BE DAMAGING
WINDS, HOWEVER A BRIEF SPIN UP TORNADO CANNOT BE RULED OUT. FLASH
FLOODING WILL ALSO BE A THREAT THIS EVENING AND INTO THE EARLY
MORNING HOURS.
SHORT TERM /THROUGH FRIDAY/
ISSUED AT 228 PM EDT WED AUG 12 2026
THINGS HAVE QUIETED DOWN ACROSS THE CWA AT THIS HOUR, HOWEVER ANY
LULLS IN ACTIVITY WILL BE PRETTY SHORT-LIVED AS WE GEAR UP FOR THE
NEXT ROUND OF CONVECTION LATER THIS AFTERNOON THROUGH EVENING. THE
OUTFLOW BOUNDARY FROM THIS MORNING'S STORMS WAS ABLE TO PUSH
WESTWARD TO AN OWENSBORO, KY TO SCOTTSVILLE, KY LINE. AREAS TO THE
EAST OF THIS BOUNDARY HAVE REMAINED IN THE 70S THROUGH THE MORNING
AND EARLY AFTERNOON, AND HAVE ONLY RECENTLY BEGUN TO RISE INTO THE
LOW 80S, SIGNALING SOME RECOVERY (BUILDING INSTABILITY) OF THE
AIRMASS. TO BACK THAT UP, A RECENT ACARS SOUNDING OUT OF SDF SHOWS A
NOTABLE LOW LEVEL INVERSION IS PRESENT. TO THE WEST OF THE BOUNDARY,
TEMPERATURES ARE IN THE LOW 90S WITH DEW POINTS RANGING IN THE MID
TO UPPER 70S. COULD STILL SEE SOME HEAT INDICES IN THE 100 TO 105
DEGREE RANGE THIS AFTERNOON WEST OF THE BOUNDARY.
THE BIG QUESTION FOR THIS AFTERNOON AND EVENING WILL BE HOW MUCH WE
ARE ABLE TO DESTABILIZE/RECOVER THE AIRMASS AHEAD OF DEVELOPING
STORMS UPSTREAM? THE RAP DEPICTION OF SB CAPE RECOVERY ON THE SPC
MESOANALYSIS PAGE IS QUITE DRAMATIC WITH A QUICK RECOVERY, AND STILL
HAS OUR AREA DE-STABILIZING TO 4000-5000 J/KG BY LATE AFTERNOON.
THINKING THIS IS A LITTLE OVERDONE GIVEN WHERE WE ARE CURRENTLY, AND
LIKE THE 12/12Z HREF DEPICTION OF MORE AROUND 2000-2500 J/KG OF ML
CAPE BY LATE AFTERNOON. WE ARE CURRENTLY SEEING QUITE A BIT OF
HEATING WHERE THE CLOUDS HAVE CLEARED, HOWEVER THIS WINDOW MAY ALSO
BE PRETTY SHORTLIVED AS CONVECTIVE DEBRIS FROM THE UPSTREAM SYSTEM
WILL SOON BE OVERSPREADING THE AREA.
SOME OF THE LATEST RUNS OF THE HI-RES DATA DO SUGGEST THAT A
DEVELOPING CONVECTIVE COMPLEX WILL MAKE IT INTO OUR AREA, HOWEVER
THEY MAY BE A LITTLE OVERDONE ON INTENSITY IF WE AREN'T ABLE TO
FULLY RECOVER. IN CONTRAST, IF WE DO QUICKLY DESTABILIZE THEN WE
WILL BE IN PLAY FOR ANOTHER EVENING OF DAMAGING WIND THREATS,
ESPECIALLY IF A GOOD COLD POOL IS ABLE TO GET ESTABLISHED UPSTREAM
AHEAD OF TIME. SPC DID EXPAND THE SLIGHT RISK OVER OUR ENTIRE AREA,
WHICH SUGGESTS THE MORE UNSTABLE SOLUTION, AND RECENT COLLABORATION
WITH THEM HAS SUGGESTED THAT A SEVERE THUNDERSTORM WATCH IS
POSSIBLE, BUT WE ARE GOING TO WAIT AND SEE HOW WE DESTABILIZE.
TIMING STILL LOOKS PRETTY GOOD FOR STORM ARRIVAL AROUND 4 OR 5 PM
EDT ACROSS OUR NORTHERN CWA, PUSHING SOUTH THROUGH THE CWA INTO THE
EVENING, AND EXITING OUR SE AROUND 10 PM EDT OR SO. WE'LL ALSO HAVE
TO WATCH FOR ANY HEAVY RAINFALL TO DEVELOP INTO A FLASH FLOODING
CONCERN, PARTICULARLY ACROSS AREAS THAT SAW A LOT OF RAIN LAST NIGHT
AND THIS MORNING. ESSENTIALLY WHERE WPC HAS DRAWN THE MODERATE RISK.
AFTER THE EVENING WAVE PUSHES THROUGH WE DO EXPECT A BRIEF LULL IN
ACTIVITY. HOWEVER WE MAY SEE A SIMILAR SCENARIO SET UP THROUGH THE
OVERNIGHT TO WHAT OCCURRED LAST NIGHT. THE REMNANT CONVECTIVELY
REINFORCED OUTFLOW IS EXPECTED TO SET UP IN A MORE W-E FASHION
SOMEWHERE AROUND THE I-64 CORRIDOR. HERE, WE COULD GET REDEVELOPMENT
OF SHOWERS AND STORMS OVERNIGHT AS THE BOUNDARY STALLS ROUGHLY
PARALLEL TO THE UPPER FLOW AND THERE IS AT LEAST SOME MODEST LOW
LEVEL JET CONTRIBUTION TO MOISTURE TRANSPORT. MUCH LIKE LAST NIGHT,
THE 12/12Z HREF SUGGESTS SOME VERY IMPRESSIVE RAINFALL TOTALS FROM
THE MAX ENSEMBLE MEMBER, AND HAS SOME SUPPORT FROM THE PMM DATA AS
WELL. IN ADDITION, THE 12/12Z HRRR ALSO PEGGED A BULLSEYE OF 5+"
ACROSS SOUTHWEST IN IN A LOCALIZED AREA. FORECAST MODELS THIS
AFTERNOON CONTINUE TO SUGGEST SOME TRAINING OF STORMS IN THAT AREA
THROUGH THE OVERNIGHT, SO FELT IT PRUDENT TO EXTEND THE FLOOD WATCH
ACROSS SOUTHERN INDIANA THROUGH 12Z THURSDAY MORNING TO ACCOUNT FOR
THIS THREAT. NOT A SLAM DUNK, BUT ALSO COULD HAVE SOME LOCALIZED
HIGH END FLOODING IMPACTS LIKE WE SAW LAST NIGHT ACROSS EAST CENTRAL
IN. SAME SETUP, JUST A DIFFERENT ORIENTATION.
A LOT OF WHAT HAPPENS THIS EVENING AND TONIGHT COULD HAVE A BEARING
ON WHAT HAPPENS GOING INTO THURSDAY. WHEREVER THE REMNANT
BOUNDARY SETS UP WILL BE THE FOCUS FOR ADDITIONAL SHOWER AND
STORM ACTIVITY THROUGH THE AFTERNOON AND EVENING. THE NW FLOW
PATTERN ALOFT WILL CONTINUE ON THE NE PERIPHERY OF THE UPPER
RIDGE SO THIS SHOULD KEEP MOST OF THE CONVECTIVE ACTIVITY ACROSS
THE NORTHERN AND EASTERN PORTIONS OF THE CWA. ADDITIONAL
DAMAGING WIND THREATS MAY DEVELOP ALONG WITH A LINGERING FLOOD
THREAT, OR ENHANCED FLOOD THREAT IF IT IS STILL ONGOING FROM ANY
OVERNIGHT ACTIVITY. OUR SW CWA WOULD BE MOST LIKELY TO GET IN
ON A HEAT ADVISORY TOMORROW, BUT WILL AGAIN TAKE A WAIT AND SEE
APPROACH GIVE CONVECTIVE ACTIVITY AND THE POTENTIAL TO BUST A
TEMP FORECAST.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/
ISSUED AT 228 PM EDT WED AUG 12 2026
*** FRIDAY THROUGH MID NEXT WEEK ***
A WEAK SHORTWAVE TROUGH WILL BRING CHANCES FOR SOME RAIN SHOWERS ON
FRIDAY, HOWEVER CONFIDENCE IS LOW IN TIMING OR INTENSITY AT THIS
TIME. AN UPPER LEVEL RIDGE WILL BEGIN TO BUILD OVER THE REGION AT
THE END OF THE WEEK INTO THE WEEKEND. THIS WILL BRING IN A WARMER
AND SLIGHTLY DRIER AIR MASS TO THE OHIO VALLEY. MAXIMUM TEMPERATURES
FOR THE WEEKEND ARE EXPECTED TO BE IN THE MID TO UPPER 90S, WITH
HEAT INDICES POTENTIALLY REACHING TRIPLE DIGITS.
MOVING INTO EARLY NEXT WEEK, A FRONTAL BOUNDARY IS FORECASTED TO
MOVE THROUGH THE AREA FROM THE NW. THIS WILL BRING RAIN CHANCES BACK
INTO THE FORECAST AND POSSIBLY A BRIEF RELIEF IN TEMPERATURES.
HOWEVER, THIS IS NOT EXPECTED TO LAST LONG AS ANOTHER WARM AIRMASS
WILL MOVE BACK INTO FOR THE MIDDLE OF THE WEEK.
AVIATION /06Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 116 AM EDT THU AUG 13 2026
VFR CONDITIONS SHOULD BE PREDOMINANT THROUGHOUT THE FORECAST PERIOD,
THOUGH SCATTERED STORMS THROUGH AROUND 13Z COULD BRING VISIBILITY
REDUCTIONS IN MODERATE RAIN. A BREAK IN CONVECTIVE ACTIVITY SHOULD
OCCUR MID MORNING INTO LATE AFTERNOON, WHEN ADDITIONAL STORMS MAY
(30-40% CHANCE) MOVE IN FROM THE NORTHWEST. WINDS WILL BE LIGHT AND
VARIABLE OVERNIGHT, THEN PREDOMINANTLY FROM THE SOUTHWEST AT 6-8 KT
DURING THE DAY.
LMK WATCHES/WARNINGS/ADVISORIES
KY...FLOOD WATCH UNTIL 8 AM EDT THIS MORNING FOR KYZ025-029>043-
047>049-055>057-066-067.
IN...FLOOD WATCH UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING FOR
INZ076>079-083-084-089>092.
UPDATE...CAL
SHORT TERM...BJS
LONG TERM...CAL
AVIATION...JRB
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