448
FXUS63 KLMK 090656
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
256 AM EDT WED SEP 9 2026
KEY MESSAGES
* THE HOTTEST DAY OF THE WEEK WILL BE TODAY WITH HIGHS IN THE LOW TO
MID 90S AND PEAK HEAT INDICES IN THE LOW 100S ALONG AND WEST OF I-
65. A HEAT ADVISORY HAS BEEN ISSUED.
* A COLD FRONT ARRIVES THURSDAY MORNING WITH 80-90% CHANCE OF
SHOWERS AND A FEW STORMS POSSIBLE. FAIRLY WIDESPREAD RAINFALL
BETWEEN .5" - 1" IS EXPECTED WITH LOCALLY HIGHER AMOUNTS OVER 1.5"
POSSIBLE, ESPECIALLY ALONG AND NORTH OF I-64.
* THIS WEEKEND IS EXPECTED TO REMAIN ACTIVE WITH OFF AND ON ISOLATED
TO SCATTERED SHOWERS AND STORMS.
SHORT TERM /THROUGH THURSDAY NIGHT/
ISSUED AT 256 AM EDT WED SEP 9 2026
THINGS START OFF QUIET TODAY WITH A STEADILY TIGHTENING PRESSURE
GRADIENT (20-25 MPH GUSTS TODAY) OVER THE REGION BETWEEN HIGH
PRESSURE OFF THE MID-ATLANTIC COAST, AND STRONG SURFACE LOW PRESSURE
OVER EASTERN CANADA. THE COMBINATION OF BEING ON THE NORTHERN
PERIPHERY OF A STRONG SOUTHERN CONUS RIDGE, AND THE FAIRLY
IMPRESSIVE WARM ADVECTION COMPONENT ON THE LOW LEVEL SW FLOW WILL
ALLOW FOR A WARM DAY WITH MAX TEMPS IN THE LOW AND MID 90S. IN
ADDITION TO THE HOT TEMPERATURES, SOME LOW AND MID 70S DEW POINTS
ARE LIKELY TO POOL ACROSS OUR NW CWA AHEAD OF THE APPROACHING COLD
FRONT THAT WILL BE TRAILING FROM THE AFOREMENTIONED EASTERN CANADA
LOW. THIS SHOULD YIELD MAX HEAT INDEX VALUES IN AROUND 105 IN OUR
FAR W/NW CWA WHERE DEW POINTS ARE HIGHEST. HEAT INDICES IN THE LOW
100S WILL BE MORE LIKELY AS FAR EAST AS THE I-65 CORRIDOR. THERE IS
SOME CONCERN THAT INCREASING MID TO UPPER SKY COVER FROM UPSTREAM
CONVECTION COULD KNOCK TEMPS AND OVERALL HEAT INDICES DOWN A BIT, SO
THERE IS SOME BUST POTENTIAL HERE. SOME HI-RES GUIDANCE ALSO
SUGGESTS A FEW SHOWERS AND STORMS COULD DEVELOP ON REMNANT OUTFLOW AS
EARLY AS MID AFTERNOON ACROSS OUR NW. BOTH OF THESE FACTORS HURT
CONFIDENCE, BUT STILL ENOUGH EVIDENCE TO SUGGEST SOME PERIODS OF
~105F ARE POSSIBLE. NOT SURE WE'LL HIT WIDESPREAD 105F READINGS AS
FAR EAST AS THE I-65 CORRIDOR, BUT IT WILL BE CLOSE ENOUGH TO LEAVE
CURRENT HEADLINE AS IS.
AS WE GET DEEPER INTO THE EVENING AND OVERNIGHT, SHOWER AND STORM
CHANCES WILL CONTINUE TO INCREASE THANKS TO BETTER FORCING AND
MOISTURE TRANSPORT BROUGHT ON BY AN IMPRESSIVE MID TO UPPER LEVEL
JET STRUCTURE OVER THE GREAT LAKES REGION. DEEP LAYER FLOW WILL BE
NEARLY PARALLEL TO THE STALLING FRONTAL BOUNDARY THAT WILL APPROACH
FROM THE NW WHICH WILL ALLOW FOR SOME TRAINING OF ROUNDS OF SHOWERS
AND STORMS LATER TONIGHT THROUGH THURSDAY. THERE DOES CONTINUE TO BE
A MARGINAL RISK OF A FEW ISOLATED DAMAGING WIND INSTANCES FOR AREAS
ALONG AND NORTH OF THE WESTERN KENTUCKY AND BLUEGRASS PARKWAYS. IN
ADDITION, WPC IS CARRYING A MARGINAL RISK OF EXCESSIVE RAINFALL WITH
THIS SYSTEM. BASIN AVERAGE QPF IS EXPECTED TO BE MOSTLY IN THE .5"
TO .75" RANGE ACROSS THE AREA, HOWEVER THERE HAS BEEN A PRETTY
CONSISTENT SIGNAL FOR LOCALIZED AMOUNTS OVER 2-3" IN SPOTS,
ESPECIALLY ALONG AND NORTH OF THE I-64 CORRIDOR. LREF PROBS OF OVER
1" CONTINUE TO TREND UPWARD, AND NOW EXCEED 40-50% IN SPOTS ACROSS
OUR NORTHERN CWA. THE 09/00Z HREF ALSO SUGGEST POCKETS OF 2-3"+
THROUGH LATE THURSDAY, WHICH IS ALSO BACKED UP BY THE 48 HR PMM
DATA. IF THESE VALUES STAY SPREAD OUT OVER THE 48 HOUR PERIOD THEN
WE SHOULD BE ABLE TO HANDLE IT PRETTY WELL GIVEN HOW DRY WE HAVE
BEEN. HOWEVER, IF WE GET MOST OF THE RAIN WITH ONE OR TWO QUICK
HITTING ROUNDS, ESPECIALLY LATER TONIGHT INTO THURSDAY, THEN COULD
SEE US NEEDING A FEW FLOOD ADVISORIES OR WARNINGS. CONFIDENCE AND
EXPECTED COVERAGE OF ANY FLOOD CONCERNS AREN'T HIGH ENOUGH TO
WARRANT ANY HEADLINES AT THE MOMENT, BUT WILL CONTINUE TO MONITOR
TRENDS.
THE FRONT WILL STALL ACROSS THE AREA THROUGH THURSDAY WITH CONTINUED
ROUNDS OF W-E SHOWERS AND STORMS MOVING THROUGH. THE OVERALL DEEP
LAYER SHEAR STARTS TO WEAKEN BY THURSDAY, SO THE LOW END SEVERE
THREAT DOES NOT TRANSLATE INTO THE DAY ON THURSDAY, HOWEVER THE
THREAT FOR A FEW LOCALIZED FLOOD CONCERNS WILL.
WILL MAKE NOTE OF A FAIRLY IMPRESSIVE TEMP GRADIENT ACROSS THE AREA
ON THURSDAY THANKS TO THE STALLED FRONTAL BOUNDARY. LOOKING FOR LOW
80S ACROSS SOUTHERN IN, AND STILL HANGING ONTO THE LOW 90S ACROSS
SOUTHERN KY.
LONG TERM /FRIDAY THROUGH TUESDAY/
ISSUED AT 256 AM EDT WED SEP 9 2026
FRIDAY - SATURDAY...
THE SURFACE COLD FRONT WILL BE STALLED NEAR THE KY/TN BORDER BY
FRIDAY MORNING. MEANWHILE, A POSITIVELY TILTED SHORTWAVE TROUGH WILL
APPROACH AND SLOWLY MOVE THROUGH THE REGION. EXPECT LINGERING
SHOWERS AND A FEW STORM CHANCES ON FRIDAY AHEAD OF THIS TROUGH AXIS,
MAINLY CONFINED TO CENTRAL AND SOUTHERN KY. OVERALL, DEEP LAYER
SHEAR WILL BE PRETTY WEAK BY THIS POINT, SO NOT EXPECTING ANY
ORGANIZED UPDRAFTS. TEMPERATURES BEHIND THE FRONT WILL BE NOTABLY
COOLER WITH HIGHS ON FRIDAY IN THE LOW AND MID 80S.
LOOKS LIKE MAINLY DIURNALLY DRIVEN SHOWERS OR A STORM CHANCE
CONTINUES INTO SATURDAY AS ANOTHER SLOW MOVING SHORTWAVE PASSES
THROUGH THE ZONAL FLOW ALOFT. TEMPS LOOK TO RECOVER BACK TO THE 85
TO 90 DEGREE RANGE AS WE ENTER THE HEART OF THE WEEKEND.
SUNDAY - TUESDAY...
THE CENTER OF THE UPPER RIDGE LOOKS TO RETROGRADE SLIGHTLY BACK INTO
THE CAROLINAS LATE WEEKEND INTO EARLY NEXT WEEK, HELPING TO PUSH THE
STRONGER BELT OF WESTERLIES FARTHER NORTH. THE INCREASED UPPER
RIDGING WILL COME WITH TEMPERATURES LIKELY HOLDING ABOVE NORMAL IN
THE UPPER 80S AND LOW 90S. LOOKS TO BE A SOMEWHAT "DIRTY" RIDGE WITH
NOT MUCH OF A SUBSIDENCE INVERSION TO KEEP VERTICAL DEVELOPMENT IN
CHECK. WON'T BE A LOT OF TRIGGERING MECHANISMS EITHER, OUTSIDE OF
DIURNAL HEATING, SO WILL ONLY EXPECT SOME ISOLATED AFTERNOON AND
EVENING SHOWER OR STORM ACTIVITY EACH DAY. VERTICAL SHEAR WILL BE
WEAK SO ANY STORM MODES WOULD BE PULSE IN NATURE.
AVIATION /06Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 132 AM EDT WED SEP 9 2026
QUIET NIGHT ONGOING WITH ONLY A FEW MID AND UPPER LEVEL CLOUDS.
LIGHT SSW WINDS WILL CONTINUE THROUGH SUNRISE WITH A BIT MORE UPPER
SKY COVER STARTING TO OVERSPREAD THE REGION BY THEN. LOOK FOR
STRONGER SW WINDS TO TAKE HOLD BY LATE MORNING IN THE 10 TO 15 MPH
RANGE ALONG WITH SOME GUSTS IN THE 20-25 MPH RANGE. THESE GUSTS
SUBSIDE IN THE EVENING WITH SCT-BKN MID LEVEL CLOUDS CONTINUING. A
FEW SHOWERS OR A STORM COULD DEVELOP ALONG REMNANT OUTFLOW LATER
THIS EVENING ACROSS THE HNB/SDF TAF SITES, BUT CONFIDENCE IS LOW.
LMK WATCHES/WARNINGS/ADVISORIES
KY...HEAT ADVISORY FROM NOON EDT /11 AM CDT/ TODAY TO 8 PM EDT /7
PM CDT/ THIS EVENING FOR KYZ023>032-061-062-070>072.
IN...HEAT ADVISORY FROM NOON EDT /11 AM CDT/ TODAY TO 8 PM EDT /7
PM CDT/ THIS EVENING FOR INZ076>079-083-084-089>092.
SHORT TERM...BJS
LONG TERM...BJS
AVIATION...BJS
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