582
FXUS63 KLMK 200541
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
141 AM EDT MON JUL 20 2026
..UPDATED AVIATION DISCUSSION
KEY MESSAGES
* SCATTERED THUNDERSTORMS WILL BRING HEAVY RAINFALL, LIGHTNING, AND
GUSTY WINDS TO SOUTH-CENTRAL KENTUCKY THIS AFTERNOON AND EVENING.
* STRONG TO SEVERE THUNDERSTORMS ARE LIKELY ON TUESDAY. DAMAGING
WINDS AND TORNADOES ARE THE MAIN THREATS. HEAT INDICES WILL BE IN
THE 100-110 DEGREE RANGE OUTSIDE OF STORMS TUESDAY AFTERNOON.
* CALM WEATHER MOVES IN WITH COOLER THAN AVERAGE HIGHS FOR WEDNESDAY
THROUGH FRIDAY THIS WEEK.
SHORT TERM /THROUGH TUESDAY/
ISSUED AT 352 PM EDT SUN JUL 19 2026
A STRONG MID/UPPER LEVEL RIDGE REMAINS CENTERED OVER THE ROCKIES,
WITH WEAK NW FLOW ALOFT OVER THE LOWER OH VALLEY. SFC HIGH PRESSURE
IS SHIFTING ACROSS THE GREAT LAKES, AND A WEAK COLD FRONT HAS PUSHED
THROUGH SOUTHERN IN AND NORTHERN KY. A VERY WARM, MOIST AIRMASS
REMAINS IN PLACE SOUTH OF THE BOUNDARY. SCATTERED WEAK CONVECTION
HAS BEGUN TO DEVELOP THIS AFTERNOON, MAINLY ACROSS SOUTH-CENTRAL KY
WHERE PW VALUES SLIGHTLY EXCEED 2 INCHES. MLCAPE IS PEAKING AROUND
2000-2500 J/KG SOUTH OF I-64 THIS AFTERNOON, BUT EFFECTIVE DEEP
SHEAR IS VERY WEAK AT 15-20 KTS. THE MOISTURE-RICH, MODERATELY
UNSTABLE ENVIRONMENT WILL SUPPORT PULSE CONVECTION CAPABLE OF
LOCALLY TORRENTIAL DOWNPOURS AND GUSTY WINDS. THOUGH THE RISK FOR
ORGANIZED SEVERE WEATHER IS VERY LOW, PRECIPITATION LOADING COULD
ENHANCED DOWNWARD MOMENTUM AND PRODUCE AN ISOLATED WET MICROBURST.
SCATTERED CONVECTION WILL CONTINUE THROUGH SUNSET BEFORE GRADUALLY
DIMINISHING.
TEMPERATURES HAVE RISEN INTO THE MID 80S TO NEAR 90 THIS AFTERNOON.
CONDITIONS WILL DRY OUT TONIGHT, WITH TEMPERATURES SETTLING INTO THE
MID 60S (NORTH) TO LOWER 70S (SOUTH) EARLY MONDAY. ON MONDAY, A
POTENT LOW PRESSURE SYSTEM WILL DEVELOP EAST ACROSS ONTARIO AND THE
UPPER MIDWEST. WE'LL STILL HAVE THE WEAK, STALLED FRONTAL BOUNDARY
IN THE VICINITY OF SOUTH-CENTRAL KY. ISOLATED PULSE CONVECTION
APPEARS POSSIBLE MONDAY AFTERNOON. COVERAGE SHOULD BE MUCH LESS THAN
SATURDAY AND EVEN TODAY.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/
ISSUED AT 352 PM EDT SUN JUL 19 2026
===== SEVERE STORMS LIKELY TUESDAY =====
A RATHER INTERESTING PATTERN FOR LATE JULY IS SET TO BRING A ROUND
(OR TWO) OF STRONG TO SEVERE STORMS ON TUESDAY. WHILE CONFIDENCE IN
DETAILED TIMING IS LOW, FORECAST CONFIDENCE IN SEVERE WEATHER IS
HIGH. A POTENT UPPER LEVEL TROUGH AND MID/UPPER LEVEL SPEED MAX WILL
STREAM SOUTHEAST OVER THE UPPER MIDWEST AND GREAT LAKES ON TUESDAY.
A SUB-995 MB SFC LOW IS FORECAST TO SPIN ACROSS THE ON/QC BORDER
TUESDAY MORNING, WITH A TRAILING COLD FRONT PUSHING SOUTHEAST
THROUGH THE MIDWEST. RECENT MODEL GUIDANCE HAS INCREASED CONFIDENCE
THAT WE'LL LIKELY HAVE AN MCS ONGOING ACROSS PORTIONS OF IL/IN AT
12Z TUESDAY, AND THIS ACTIVITY COULD PUSH INTO PORTIONS OF SOUTHERN
IN AND CENTRAL KY BETWEEN 12-18Z TUESDAY. ONE OR MORE LINE SEGMENTS
APPEAR POSSIBLE, WHICH COULD BE CAPABLE OF HEAVY RAINFALL AND GUSTY
WINDS.
ANY AREAS THAT SEE MORNING CONVECTION WILL LIKELY NEED A LITTLE
EXTRA TIME TO DESTABILIZE, BUT THIS SHOULDN'T TAKE LONG TUESDAY
AFTERNOON WITH A HOT, HUMID AIRMASS IN PLACE. LOW-LEVEL SW FLOW WILL
STEADILY ADVECT WARM, MOIST AIR INTO THE REGION AHEAD OF THE
SEASONALLY STRONG COLD FRONT. THE MID-LEVEL TROUGH AXIS PIVOTS
SOUTHEAST ACROSS THE GREAT LAKES TUE EVENING AND OVERNIGHT, WITH 45
KT MID-LEVEL NW WINDS OVER THE OH VALLEY. LOW-LEVEL WSW FLOW
PRODUCES SOME VEERING, WITH EFFECTIVE BULK SHEAR MORE THAN
SUFFICIENT FOR ORGANIZED CONVECTION AND ROTATING UPDRAFTS. IT
APPEARS ORGANIZED MULTICELLS OR SUPERCELLS COULD DEVELOP AHEAD OF
ONE MORE LINE SEGMENTS TUE EVENING AND OVERNIGHT. SCATTERED TO
NUMEROUS THUNDERSTORMS ARE POSSIBLE TUESDAY AFTERNOON INTO TUESDAY
NIGHT, AND THE MAIN THREAT IS DAMAGING WINDS. GIVEN THE SHEAR
PROFILE AND POTENTIAL FOR SUPERCELLS, TORNADOES AND ISOLATED LARGE
HAIL ARE ALSO ON THE TABLE. AND DEPENDING ON LINE ORIENTATION OF ANY
LINEAR FEATURES, 0-3 KM SHEAR WILL LIKELY BE SUFFICIENT FOR EMBEDDED
MESOVORTICES.
CONVECTIVE EVOLUTION ON TUESDAY REMAINS FAIRLY UNCERTAIN AT THIS
TIME RANGE, AND WILL DEPEND ON MONDAY NIGHT ACTIVITY. OUTSIDE OF
THUNDERSTORM ACTIVITY, TEMPERATURES WILL HAVE AN OPPORTUNITY TO
SURGE INTO THE LOWER 90S TUESDAY AFTERNOON. HEAT INDEX VALUES MAY
EXCEED 100-105 FOR A SHORT TIME, AND A HEAT ADVISORY MAY BE NEEDED
ONCE THE CONVECTIVE AND SKY COVER FORECASTS BECOME MORE CLEAR.
THE SFC COLD FRONT WILL PUSH THROUGH CENTRAL KY TUESDAY NIGHT, WITH
THE OVERALL SEVERE WEATHER RISK DIMINISHING SUBSTANTIALLY BY
WEDNESDAY MORNING.
BEYOND TUESDAY, SURFACE HIGH PRESSURE BUILDS IN WITH A PREDOMINANT
NW FLOW AT HIGHER LEVELS BRINGING IN COOLER AND DRIER AIR FOR
WEDNESDAY THROUGH FRIDAY. HIGHS WILL BE IN THE LOW 80S WITH THE
COOLEST DAY BEING THURSDAY. SOME PLACES MAY NOT REACH 80 DEGREES AT
ALL IN THE AFTERNOON THEN. EVENTUALLY, BY FRIDAY AFTERNOON AND INTO
SATURDAY, SW FLOW ON THE BACKSIDE OF THE SURFACE HIGH RETURNS WITH
SEEMINGLY TYPICAL AFTERNOON CONVECTION ON SATURDAY AFTERNOON, HIGHS
REACHING THE UPPER 80S AND LOW 90S ONCE AGAIN.
AVIATION /06Z TAFS THROUGH 12Z TUESDAY/
ISSUED AT 141 AM EDT MON JUL 20 2026
FOR THE REST OF THE NIGHT, WE ARE EXPECTING DRY CONDITIONS, BUT
EARLIER RAINFALL IS EXPECTED TO LEAD TO LOW STRATUS AND FOGGING OVER
SOUTH CENTRAL KENTUCKY, AFFECTING BWG. BELIEVE CONDITIONS WILL BE
BETTER AT SDF, HNB, LEX, AND RGA. TYPICAL SHALLOW FOG COULD IMPACT
HNB. RGA COULD ALSO BE CLOSE TO THE NORTHERN EDGE OF THE LOW
CEILINGS. DURING THE DAY, ISOLATED SHOWERS AND THUNDERSTORM REMAIN
POSSIBLE, BUT THE CHANCE OF ANYTHING HITTING A TAF SITE IS SO LOW,
IT WAS LEFT OUT OF THE TAFS.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
SHORT TERM...EBW
LONG TERM...EBW
AVIATION...KDW
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