731
FXUS63 KLMK 080543
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
143 AM EDT MON JUN 8 2026
..UPDATED AVIATION DISCUSSION
KEY MESSAGES
* ISOLATED SHOWERS AND STORMS ARE POSSIBLE TODAY, MAINLY ACROSS
SOUTHERN INDIANA AND SOUTHERN KENTUCKY. CENTRAL KENTUCKY SHOULD
STAY WARM AND DRY.
* UNSETTLED WEATHER WITH LOCALIZED AREAS OF HEAVY RAINFALL AND FLASH
FLOODING ARE POSSIBLE IN KY AND SOUTHERN IN MONDAY - TUESDAY
MIDDAY. LOCALIZED AMOUNTS OF 3-6" OF RAIN WILL BE POSSIBLE IN THE
HEAVIEST SWATHS.
* HOT AND HUMID WEDNESDAY AND THURSDAY, WITH PEAK AFTERNOON HEAT
INDEX VALUES BETWEEN 90-100.
* ADDITIONAL SHOWERS AND THUNDERSTORMS POSSIBLE IN THE MEDIUM RANGE,
ESPECIALLY WEDNESDAY MORNING AND AGAIN THURSDAY EVENING INTO
FRIDAY. SOME STRONG STORMS AND LOCALLY HEAVY RAINFALL WILL BE
POSSIBLE.
SHORT TERM /THROUGH TUESDAY NIGHT/
ISSUED AT 339 PM EDT SUN JUN 7 2026
THIS EVENING AND THIS EVENING...
WARM AND HUMID CONDITIONS ARE PRESENT ACROSS THE REGION THIS
AFTERNOON, WITH TEMPERATURES MAINLY IN THE MID 80S ACROSS THE AREA.
DEWPOINT TEMPERATURES RANGE ARE IN THE UPPER 60S AND LOW 70S ACROSS
TWO SEPARATE AREAS: ONE GENERALLY NORTH OF I-64 AND ANOTHER ONE
ALONG THE KY/TN BORDER. THERE IS A RELATIVE MINIMUM IN NEAR-SFC
MOISTURE ACROSS THE MIDDLE OF THE CWA. VARIATIONS IN SFC HEATING AND
HUMIDITY CAN BE SEEN IN SATELLITE IMAGERY BASED ON THE AMOUNT OF
CUMULUS PRESENT. JUST TO THE NORTH OF THE AREA, THIS DIURNAL
CONVECTION HAS COMBINED WITH ENOUGH RESIDUAL CONVERGENCE ALONG A
WASHED OUT FRONT FOR SHOWERS AND A FEW STORMS TO DEVELOP. THROUGH
THE MID-EVENING HOURS TONIGHT, AN ISOLATED SHOWER, POSSIBLY A STORM
MAY BE ABLE TO FORM NORTH OF I-64 AND ALONG THE KY/TN BORDER WHERE
THERE IS BETTER MOISTURE; HOWEVER, MOST AREAS SHOULD REMAIN DRY
THROUGH EARLY MONDAY MORNING. TEMPERATURES ARE EXPECTED TO TOP OUT
IN THE MID-TO-UPPER 80S BEFORE DROPPING SLOWLY THROUGH THE 80S AND
INTO THE 70S TONIGHT.
LATE TONIGHT THROUGH MONDAY NIGHT...
LATE TONIGHT INTO MONDAY MORNING, A CORRIDOR OF SLIGHTLY STRONGER
LOW-TO-MID LEVEL SW FLOW IS EXPECTED TO LIFT FROM SW TO NE ACROSS
THE LOWER OHIO VALLEY, BRINGING A SURGE OF GREATER MOISTURE WITH IT.
THIS WILL BE ASSOCIATED WITH A MID-LEVEL SHORTWAVE DISTURBANCE THAT
IS EXPECTED TO MOVE FROM THE SOUTHERN PLAINS TODAY ACROSS THE MID-
MISS. VALLEY ON MONDAY AND INTO THE LOWER GREAT LAKES BY TUESDAY.
THE SURGE OF MOISTURE WHICH IS EXPECTED TO MOVE ACROSS THE AREA WITH
THIS SYSTEM IS QUITE ANOMALOUS, WITH PRECIPITABLE WATER VALUES
EXPECTED TO EXCEED 2", OR ROUGHLY THE 99TH PERCENTILE OF MODEL
CLIMATOLOGY, MONDAY INTO MONDAY NIGHT. THIS SURGE OF MOISTURE SHOULD
INITIALLY MANIFEST AS INCREASING CLOUDS, BUT BY MONDAY MORNING,
SCATTERED SHOWERS AND STORMS ARE EXPECTED TO LIFT IN WAVES FROM SW
TO NE ACROSS CENTRAL KY AND SOUTHERN IN. AS HAS BEEN MENTIONED OVER
SEVERAL DISCUSSIONS, SOUNDING PROFILES ARE QUITE FAVORABLE FOR
EFFICIENT HEAVY RAIN PRODUCTION, WITH HREF MEAN INSTABILITY AMOUNTS
OF 1000-1500 J/KG SPREAD ACROSS A DEEP LAYER. WITH THE UPPER RIDGE
AXIS CLOSE TO THE AREA, CLOUD LAYER WINDS ARE EXPECTED TO BE MODEST,
ON THE ORDER OF 15 MPH, RESULTING IN RELATIVELY SLOW STORM MOTIONS.
THE COMBINATION OF INGREDIENTS REFERENCED ABOVE SHOULD SUPPORT
SWATHS OF MODERATE TO HEAVY RAINFALL AMOUNTS MONDAY AFTERNOON AND
EVENING, WITH BASIN AVERAGE AMOUNTS OF 1 TO 2.5" LIKELY, ESPECIALLY
ACROSS THE WESTERN TWO-THIRDS OF THE CWA. WHAT IS OF GREATER CONCERN
IS THE POTENTIAL FOR ISOLATED HIGHER TOTALS, WITH THE 12Z HREF
SHOWING 6-HR LPMM RAINFALL SWATHS OF 3-6" ACROSS PORTIONS OF THE
AREA. THESE AMOUNTS, IF REALIZED, WOULD LEAD TO FLASH FLOODING, AS
EXHIBITED IN THE WPC DAY 2 EXCESSIVE RAINFALL OUTLOOK. AT THE SAME
TIME, THE COVERAGE OF THESE HEAVIER SWATHS IS STILL UNCERTAIN, AND
BECAUSE OF THIS, WHILE A FLOOD WATCH MAY BE NEEDED FOR PORTIONS OF
THE AREA, WE WILL HOLD OFF ON HEADLINES FOR NOW.
WITH SCATTERED TO NUMEROUS SHOWERS AND STORMS IN THE FORECAST, IT IS
ALSO IMPORTANT TO MENTION THAT WHILE LIGHTNING AND GUSTY WINDS WILL
BE POSSIBLE IN STRONGER CONVECTIVE CORES, ORGANIZED SEVERE WEATHER
STILL APPEARS TO BE UNLIKELY MONDAY AFTERNOON AND EVENING AS DEEP-
LAYER SHEAR SHOULD BE FAIRLY WEAK (GENERALLY 15 KT OR LESS).
SHOWERS AND STORMS SHOULD DIMINISH IN COVERAGE AFTER SUNSET MONDAY,
WITH MOST AREAS REMAINING DRY INTO TUESDAY MORNING. HOWEVER, A
SECONDARY WAVE OF SHOWERS AND STORMS IS PROGGED TO DEVELOP IN SOME
HI-RES OUTPUTS EARLY TUESDAY MORNING AS ANOTHER 20-25 KT LLJ NOSES
INTO THE REGION FROM SOUTHERN IL.
TEMPERATURE RANGES MONDAY INTO MONDAY NIGHT SHOULD BE SUPPRESSED DUE
TO AMPLE MOISTURE, WITH HIGHS ONLY EXPECTED IN THE UPPER 70S AND LOW
80S, AND LOWS ONLY FALLING INTO THE UPPER 60S AND LOW 70S.
TUESDAY AND TUESDAY NIGHT...
BY TUESDAY MORNING, THE MAIN MID- AND UPPER-LEVEL SHORTWAVE AXIS IS
EXPECTED TO BE LIFTING ACROSS MICHIGAN AND THE GREAT LAKES, WITH A
NEW UPPER RIDGE AXIS DEVELOPING OVER THE SOUTHERN PLAINS AND
MISSISSIPPI VALLEY. WITH SHOWERS AND STORMS POTENTIALLY ONGOING
TUESDAY MORNING ACROSS PORTIONS OF THE AREA, MANY ASPECTS OF
TUESDAY'S FORECAST ARE UNCERTAIN. THE GENERAL TREND SHOULD BE TOWARD
LESS SHOWER/STORM ACTIVITY AS WE GET LATER INTO THE DAY ON TUESDAY
AND INTO TUESDAY NIGHT DUE TO THE GRADUAL LOSS OF BETTER SYNOPTIC
FORCING ALOFT. HOWEVER, THE RESIDUAL AIR MASS WITH AMPLE LOW-LEVEL
MOISTURE WOULD SUPPORT ADDITIONAL SHOWER/STORM DEVELOPMENT DEPENDING
ON MESOSCALE FEATURES SUCH AS DIFFERENTIAL HEATING BOUNDARIES OR
CONVECTIVE OUTFLOW BOUNDARIES WHICH WILL BE DIFFICULT TO RESOLVE
MORE THAN 6-12 HOURS OUT. AS A RESULT, WE'LL KEEP HIGH POPS (80-90%)
IN THE FORECAST INTO TUESDAY. TEMPERATURES SIMILAR, IF NOT SLIGHTLY
WARMER THAN PERSISTENCE DURING THE DAY ON TUESDAY, WITH HIGHS MOST
LIKELY IN THE LOW-TO-MID 80S.
WHILE THE OVERALL RISK FOR SEVERE WEATHER IS NOT PARTICULARLY
CONCERNING TUESDAY INTO TUESDAY NIGHT, AI/ML GUIDANCE DOES SHOW A
SIGNAL FOR SOME SEVERE CONVECTION, PARTICULARLY TUESDAY NIGHT, WITH
A SETUP THAT COULD BE FAVORABLE. WITH THE LOWER OHIO VALLEY EXPECTED
TO BE ON THE NE SIDE OF AN EMERGING RIDGE, WITH A POOL OF HIGHER
INSTABILITY LOCATED TO THE NORTHWEST OF THE REGION, IT IS POSSIBLE
THAT WE COULD GET AN MCS TO DROP FROM NW TO SE INTO THE AREA, WITH
SEVERAL DETERMINISTIC MODELS SHOWING A SIGNAL FOR THIS TUESDAY NIGHT
INTO WEDNESDAY MORNING. WHILE CONFIDENCE IN THIS OCCURRING IS STILL
LOW-TO-MEDIUM, IF THIS OCCURRED, THERE WOULD BE A DAMAGING WIND
POTENTIAL FOR OUR AREA. FOR NOW, WE'LL CONTINUE TO MONITOR THIS
POTENTIAL, WITH HI-RES GUIDANCE OVER THE NEXT 24-48 HOURS HOPEFULLY
ADDING CONFIDENCE IN WHETHER OR NOT THIS MAY OCCUR.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
ISSUED AT 339 PM EDT SUN JUN 7 2026
WEDNESDAY - WEDNESDAY NIGHT...
WE START OFF THE MEDIUM RANGE WITH A WARM, MOIST AIRMASS IN PLACE:
MEAN PW VALUES NEAR 1.8 INCHES AND SFC DEWPOINTS IN THE LOW TO MID
70S. A MID AND UPPER LEVEL RIDGE CENTERED OVER MEXICO AND TEXAS WILL
EXTEND NORTHEAST OVER THE LOWER MS VALLEY, NOSING EAST OVER THE TN
AND LOWER OH VALLEYS. THE LATEST 12Z DETERMINISTIC GFS/ECMWF SEEM TO
HINT AT POSSIBLE MCS ACTIVITY RIDING THE MID-LEVEL RIDGE AXIS BEFORE
DROPPING SOUTHEAST FROM CENTRAL IL/IN TUESDAY NIGHT INTO WEDNESDAY
MORNING. SO IT'S POSSIBLE WE MAY HAVE SOME CONVECTION ONGOING
WEDNESDAY MORNING, BUT FORECAST CONFIDENCE REMAINS LOWER ON THE
DETAILED EVOLUTION OF ANY CONVECTION THAT FAR OUT. HOWEVER, A
MAJORITY OF LREF MEMBERS (70%) SUPPORT THE IDEA OF SOME ACCUMULATING
RAINFALL WEDNESDAY MORNING.
MID-LEVEL SUBSIDENCE, ESPECIALLY IN THE WAKE OF ANY MORNING
SHOWERS/STORMS, WOULD LIKELY LEAD TO DRIER CONDITIONS LATER IN THE
AFTERNOON AND EVENING. ENSEMBLE MEAN GUIDANCE POINTS TO A MINIMUM IN
PRECIPITABLE WATER WEDNESDAY NIGHT INTO EARLY THURSDAY (1.6-1.7
INCHES). AND WITH A LACK OF FORCING, WEDNESDAY NIGHT SHOULD REMAIN
DRY.
THE ONLY OTHER CONCERN ON WEDNESDAY WILL BE VERY WARM AND
UNCOMFORTABLY HUMID CONDITIONS. 850 MB TEMPERATURES ARE FORECAST TO
RISE TO 19-20 C BY WEDNESDAY AND THURSDAY, WHICH IS AROUND THE
CLIMATOLOGICAL 98TH PERCENTILE. IF CONDITIONS INDEED MOSTLY DRY OUT
DURING THE SECOND HALF OF WEDNESDAY, TEMPERATURES WILL LIKELY TOP
OUT IN THE MID 80S TO AROUND 90. LOW TO MID 70S DEWPOINTS WILL
CONTRIBUTE TO HEAT INDICES PEAKING BETWEEN 90-100 WEDNESDAY
AFTERNOON AND EVENING. SFC TEMPERATURES WILL ONLY FALL INTO THE
LOWER 70S FOR LOWS WEDNESDAY NIGHT.
THURSDAY - FRIDAY...
A POTENT UPPER LEVEL TROUGH AND MID-LEVEL VORTICITY MAXIMUM ARE
FORECAST TO ROTATE NORTHEAST OVER THE UPPER MIDWEST AND GREAT LAKES
THURSDAY INTO FRIDAY. THIS SYSTEM SHOULD FEATURE A PARENT SFC
CYCLONE NEAR HUDSON BAY, WITH SECONDARY CYCLOGENESIS LIKELY FROM THE
GREAT LAKES INTO PORTIONS OF EASTERN CANADA. VERY WARM, MOIST LOW-
LEVEL SW FLOW WILL REMAIN IN PLACE AHEAD OF A COLD FRONT DROPPING
THROUGH THE MIDWEST. IT APPEARS WE COULD SEE SOME SPOTTY CONVECTION
IN THE WARM SECTOR ON THURSDAY, BUT OTHERWISE WE CAN EXPECT A HOT
AND HUMID DAY WITH HIGHS IN THE UPPER 80S AND LOWER 90S. PEAK HEAT
INDEX VALUES LOOK TO REACH THE MID 90S TO LOW 100S THURSDAY
AFTERNOON AND EVENING.
THE POTENTIAL FOR SHOWERS AND THUNDERSTORMS WILL LIKELY BE MAXIMIZED
ALONG THE COLD FRONT THURSDAY NIGHT INTO FRIDAY. MEDIUM RANGE AI
SEVERE CONVECTIVE GUIDANCE SUGGESTS SOME POTENTIAL FOR STRONG STORMS
12Z THU - 12Z FRI, WITH HIGHER PROBABILITIES (15+ PERCENT) EAST OF
OUR AREA AFTER 12Z FRIDAY. OVERALL, THE SEVERE WEATHER SIGNAL IS
RELATIVELY MODEST AND THIS MAY BE PARTLY DUE TO AN ILL-TIMED COLD
FRONT LATE THURSDAY NIGHT OR EARLY FRIDAY. WE WILL HAVE SOME
POTENTIAL FOR LOCALLY TORRENTIAL RAINFALL, GUSTY WINDS, AND
LIGHTNING, HOWEVER. FORECAST CONFIDENCE IS CONSIDERABLY LOWER BEYOND
FRIDAY.
AVIATION /06Z TAFS THROUGH 12Z TUESDAY/
ISSUED AT 142 AM EDT MON JUN 8 2026
VFR CONDITIONS TO START THIS FORECAST PERIOD, BUT EXPECT CONDITIONS
TO DETERIORATE TO LOW-END MVFR AND IFR LATER THIS MORNING INTO THE
AFTERNOON. RICH MOISTURE WILL SURGE IN FROM THE SOUTH JUST AHEAD OF
A MID-LEVEL SHORTWAVE TROUGH LIFTING NORTHEAST OVER THE MIDWEST.
NUMEROUS SHRA AND SCATTERED TSRA WILL DEVELOP ACROSS THE REGION
MONDAY MORNING AND AFTERNOON, WITH OCCASIONAL ROUNDS INTO TONIGHT AS
WELL. ANY SHOWER OR STORM COULD HAVE LOCALLY INTENSE RAIN, SO COULD
SEE SOME BRIEF VIS REDUCTION INTO THE IFR RANGE. SOME IMPROVEMENT
BACK TO VFR IS EXPECTED LATER THIS AFTERNOON INTO THE EVENING, BUT
OVERALL CONFIDENCE IN CEILINGS IS LOW ONCE THE UPPER LOW APPROACHES
THE AREA. LIGHT SSE - S WINDS BETWEEN 5 AND 10 KNOTS ARE EXPECTED
THROUGH THE PERIOD.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
SHORT TERM...CSG
LONG TERM...EBW
AVIATION...BJS
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