610
FXUS63 KLMK 052334
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
734 PM EDT SUN JUL 5 2026
KEY MESSAGES
* ISOLATED/SCATTERED SHOWERS AND STORMS ARE POSSIBLE THROUGH
AROUND 11PM. A FEW STRONG STORMS CAN'T BE RULED OUT WITH
GUSTY WINDS, INTENSE LIGHTNING, AND TORRENTIAL RAINFALL.
* SEASONABLE TEMPERATURES (MID-UPPER 80S) AND DAILY CHANCES (20-40%)
FOR AFTERNOON-EVENING THUNDERSTORMS ARE FORECAST THROUGHOUT THE
UPCOMING WORK WEEK. THE RISK FOR SEVERE WEATHER APPEARS LOW
THROUGH AT LEAST WEDNESDAY.
SHORT TERM /THROUGH MONDAY NIGHT/
ISSUED AT 306 PM EDT SUN JUL 5 2026
AFTERNOON SATELLITE IMAGERY SHOWS MOSTLY SUNNY SKIES ACROSS MUCH OF
THE REGION. THE EXCEPTION WOULD BE OVER FAR SOUTHERN KY WHERE SOME
HIGHER CONVECTIVE CLOUD TOP DEBRIS HAS SPREAD NORTHWARD.
TEMPERATURES AT MID-AFTERNOON WERE IN THE MIDDLE 80S ACROSS THE
REGION. WE'LL LIKELY SEE TEMPS TOP OUT IN THE 84-88 DEGREE RANGE
THIS AFTERNOON BEFORE TEMPS SETTLE BACK INTO THE UPPER 70S THIS
EVENING.
RADAR HAS BEEN RATHER QUIET THIS AFTERNOON. HOWEVER, WE
EXPECT ISOLATED TO SCATTERED STORMS TO DEVELOP IN THE NEXT FEW HOURS
AS WE HIT CONVECTIVE TEMPS, WHICH ARE AROUND 87 TO 88 DEGREES.
INITIALLY, BEST CHANCES OF PRECIPITATION WILL BE ACROSS OUR FAR
NORTHERN ROW OF INDIANA COUNTIES, WHERE A SMALL AREA OF SURFACE
CONVERGENCE WAS LOCATED. A BAND OF LIGHT TO MODERATE SHOWERS HAS
DEVELOPED JUST NORTH OF THE CWA. IF CURRENT CONVECTIVE TRENDS
CONTINUE, THE SHOWERS WILL MOVE INTO PORTIONS OF SCOTT/JEFFERSON
COUNTIES IN INDIANA IN THE NEXT FEW HOURS. ADDITIONAL
ISOLATED/SCATTERED CONVECTION MAY DEVELOP ACROSS THE REMAINDER OF
THE REGION LATER THIS AFTERNOON. LATEST SUITE OF CAMS WANTS TO
FURTHER DEVELOP CONVECTION OVER CENTRAL TN AND PUSH IT NORTH.
CONVECTIVE CLOUD DEBRIS SPREADING NORTHWARD INTO SOUTHERN KY MAY
LIMIT ADDITIONAL HEATING IN THE LAKE CUMBERLAND REGION. IT IS
POSSIBLE THAT THE MORE FAVORED CONVECTIVE REGION MAY END UP ONCE
AGAIN IN THE I-165 CORRIDOR IF THE HRRR IS CORRECT. MODEL
SOUNDINGS STILL SHOW SKINNY CAPE PROFILES WITH WEAK SHEAR AND
PWATS UP AROUND 1.8-1.9 INCHES. STILL THINK MAIN THREATS WOULD
BE GUSTY WINDS, INTENSE CG LIGHTNING AND TORRENTIAL RAINFALL
WITH ANY STORMS THAT DEVELOP.
CONVECTION SHOULD DECREASE IN THE MID-LATE EVENING WITH THE LOSS OF
HEATING. A FEW SHOWERS MAY PERSIST INTO THE LATE NIGHT HOURS.
COMBINATION OF CLEARING SKIES, LIGHT WINDS, AND AMPLE MOISTURE MAY
RESULT IN FOG FORMATION IN THE LOW-LYING AND TYPICAL FOG PRONE
AREAS. LOWS WILL COOL INTO THE UPPER 60S AND LOWER 70S.
FOR MONDAY, UPPER TROUGH AXIS WILL HANG OVER THE OHIO VALLEY DURING
THE PERIOD WITH A WEAK FRONTAL BOUNDARY DROPPING SOUTHWARD INTO THE
REGION. A RATHER STAGNANT, BUT MOIST AIRMASS WILL REMAIN ACROSS THE
REGION. MODEL SOUNDINGS FOR MONDAY AFTERNOON CONTINUE TO EXHIBIT
SKINNY CAPE PROFILES WITH WEAK VERTICAL WIND SHEAR. TYPICAL
SUMMERTIME PULSE-DRIVEN CONVECTION LOOKS TO BE THE CONVECTIVE MODE
OF THE DAY WITH A 30-40% COVERAGE AREA. HIGHS ON THE DAY WILL BE A
LITTLE COOLER WITH HIGHS IN THE 83-88 DEGREE RANGE WITH MONDAY NIGHT
LOWS DROPPING INTO THE UPPER 60S/LOWER 70S.
LONG TERM /TUESDAY THROUGH SUNDAY/
ISSUED AT 306 PM EDT SUN JUL 5 2026
AT THE BEGINNING OF THE FORECAST PERIOD (TUESDAY MORNING), A
POSITIVELY TILTED TROUGH WILL STRETCH FROM THE LOWER MISSISSIPPI
RIVER VALLEY TO NEW ENGLAND, FOSTERING WEAK CYCLONIC FLOW OVER THE
LOCAL AREA. THIS, COMBINED WITH MODEST (1000-2000 J/KG SBCAPE)
DIURNALLY DRIVEN INSTABILITY, SHOULD BE SUFFICIENT TO SUPPORT A
COUPLE SCATTERED (20-40% COVERAGE) AFTERNOON-EVENING SHOWERS AND
STORMS. DEEP LAYER WIND SHEAR SHOULD BE WEAK (REFS ENSEMBLE MAX IS
15-20 KT), SUGGESTING THE PROBABILITY OF SEVERE/SUSTAINED STORMS IS
LOW, BUT WITH THE EPS ENSEMBLE MEAN MAINTAINING PWATS OF 1.7-1.9
INCHES AND FORECAST SOUNDINGS DEPICTING A DEEP (~12KFT) WARM CLOUD
LAYER, ANY SHOWERS AND STORMS WILL PROVE EFFICIENT RAIN-PRODUCERS.
BOTH THE NAMNEST AND RRFS ADVERTISE VERY LOCALIZED POCKETS OF HOURLY
RAINFALL OVER 1.5 INCHES BENEATH THE HEAVIEST CELLS, WHICH IS
APPROACHING FLASH FLOOD GUIDANCE (FFG) - THE THRESHOLD AROUND WHICH
WE BECOME CONCERNED ABOUT HYDROLOGICAL PROBLEMS. OUTSIDE OF STORMS,
IT'LL BE A SEASONABLY WARM AND HUMID DAY WITH HIGH TEMPERATURES IN
THE MID 80S AND DEWPOINTS IN THE LOW 70S.
GLOBAL MODELS DON'T AGREE ON PRECISELY WHEN THAT TROUGH WILL SHIFT
OFF TO THE EAST, BUT FORECAST EXPERIENCE WOULD MAKE ONE LEAN TOWARDS
A LATER DEPARTURE, WHICH SUGGESTS WEDNESDAY WILL BE VIRTUALLY A
REPEAT OF TUESDAY - SEASONABLY WARM AND HUMID WITH POP-UP (20-40%
COVERAGE) AFTERNOON-EVENING STORMS THAT COULD DUMP VERY LOCALIZED
HEAVY RAINFALL BUT POSE LITTLE RISK FOR SEVERE WEATHER. EVENTUALLY,
THE GFS, ECMWF, AND CMC AGREE THAT A MORE PRONOUNCED FEATURE WILL
PASS THROUGH THE MIDWEST/LOWER GREAT LAKES REGIONS, POTENTIALLY
SERVING AS A FOCUS FOR ORGANIZED CONVECTION, THOUGH THEY DISAGREE ON
DETAILS SUCH AS PRECISE TRACK, STRENGTH, AND ESPECIALLY TIMING. AT
THIS POINT, THE BEST OVERLAP BETWEEN SHEAR AND INSTABILITY AMONG THE
LONG-RANGE ENSEMBLES IS THURSDAY NIGHT INTO FRIDAY, WHEN THE LOW
RESOLUTION ENSEMBLE FORECAST (LREF) SYSTEM GIVES A 20-35% JOINT
PROBABILITY FOR 0-6KM WIND SHEAR > 25 KT AND MUCAPE > 1000 J/KG;
THIS CORRESPONDS TO OUR HIGHEST (60-80%) PROBABILITIES OF
PRECIPITATION (POPS) IN THE 7-DAY FORECAST.
THEREAFTER, EMPIRICAL ORTHOGONAL FUNCTIONS (EOFS) OF 500MB HEIGHTS
SUGGEST UNCERTAINTY INCREASES IN THE SYNOPTIC PATTERN, WITH A DIPOLE
IN EOF1 SUGGESTING THIS IS DRIVEN MAINLY BY POSITION UNCERTAINTY IN
RIDGING OVER THE INTERMOUNTAIN WEST/GREAT PLAINS AND TROUGHING OVER
THE NORTHEAST/GREAT LAKES. "HOW DOES THIS INFLUENCE OUR LOCAL
WEATHER?", ONE MAY ASK. A MORE EXPANSIVE UPPER LEVEL TROUGH OVER THE
NORTHEAST/GREAT LAKES (40% CHANCE) WOULD RESULT IN LESS WARM AND
HUMID CONDITIONS, ALONG WITH CONTINUED DIURNALLY DRIVEN SHOWERS AND
THUNDERSTORMS; MEANWHILE, A RIDGE THAT BUILDS FURTHER EAST INTO THE
OHIO VALLEY (60% CHANCE) WOULD FAVOR INCREASINGLY WARM AND MUGGY
CONDITIONS WITH LOW DAILY RAIN CHANCES BY NEXT SUNDAY (7/12).
AVIATION /00Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 732 PM EDT SUN JUL 5 2026
VFR CONDITIONS SHOULD BE PREDOMINANT THROUGHOUT THE FORECAST PERIOD,
THOUGH AN AREA OF SLOWLY-WEAKENING THUNDERSTORMS NEAR/WEST OF BWG
WILL POSE A 30% CHANCE OF LIGHTNING THERE THE NEXT 1-2 HOURS. HIGH
RESOLUTION MODEL GUIDANCE (FROM THE HREF) SHOWS A 20-40% PROBABILITY
OF VISIBILITY REDUCTIONS TO UNDER A HALF MILE IN PATCHY FOG TONIGHT,
WITH THE HIGHEST CHANCES AT HNB, BWG, AND RGA DURING THE 08-12Z
TIMEFRAME. WINDS WILL GO LIGHT AND FICKLE TONIGHT, THEN BLOW
PREDOMINANTLY FROM THE WEST BY MID TO LATE AFTERNOON MONDAY.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
SHORT TERM...MJ
LONG TERM...JRB
AVIATION...MJ/JRB
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