652
FXUS63 KLMK 050705
AFDLMK
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOUISVILLE KY
305 AM EDT WED AUG 5 2026
KEY MESSAGES
* PATCHY FOG IS LIKELY THIS MORNING, WITH SOME POCKETS OF DENSE FOG
POSSIBLE.
* ISOLATED TO SCATTERED SLOW MOVING SHOWERS AND STORMS (20-40%
COVERAGE) ARE POSSIBLE EAST OF I-65 ON WEDNESDAY, AND ACROSS MOST
OF THE AREA THURSDAY. MOST LOCATIONS WILL REMAIN DRY.
* BETTER SHOWER AND STORM CHANCES, ALONG WITH SUMMER WARMTH AND
HUMIDITY, WILL RETURN LATER THIS WEEK, PEAKING AT 40-60% FRIDAY
INTO SATURDAY.
SHORT TERM /THROUGH THURSDAY NIGHT/
ISSUED AT 305 AM EDT WED AUG 5 2026
THIS MORNING THROUGH TONIGHT...
ACROSS THE AREA THIS MORNING, GREATER LOW-LEVEL MOISTURE IS STARTING
TO CREEP TO THE NORTH AND WEST AS A CUT-OFF LOW LIFTS SLOWLY OUT OF
THE SOUTHERN APPALACHIANS. THIS MOISTURE RETURN HAS ALLOWED HIGHER
SFC DEWPOINTS AND MORE CLOUD COVER TO MOVE BACK INTO THE AREA, WITH
SCATTERED 5K FT STRATUS SHOWING UP ON NIGHTTIME MICROPHYSICS
SATELLITE IMAGERY. A FEW SHOWERS HAVE EVEN DEVELOPED OVER EASTERN
KY; HOWEVER, MOST HI-RES GUIDANCE SUGGESTS THIS SHOULD DISSIPATE
OVER THE NEXT FEW HOURS. BETWEEN NOW AND SUNRISE, PATCHY FOG WILL
TRY TO DEVELOP IF WE CAN GET ENOUGH BREAKS IN THE STRATUS DECK.
THERE IS A ROUGHLY 20% CHANCE OF SUB 1 MILE VISIBILITIES ALONG AND
EAST OF A GLASGOW-WINCHESTER LINE PER THE 00Z HREF, WITH THE
GREATEST CHANCES FOR FOG IN THE SHELTERED RIVER VALLEYS.
TODAY, OUR AREA WILL BE SANDWICHED BETWEEN APPROACHING BROAD
TROUGHING FROM THE NW AND THE AFOREMENTIONED CUTOFF LOW TO THE SE.
IN BETWEEN THESE FEATURES, MID-LEVEL RIDGING IS EXPECTED TO EXTEND
FROM WESTERN KY INTO SOUTHWEST IN. THE COMBINATION OF HIGHER SFC
DEWPOINTS AND COOLER MID-LEVEL TEMPERATURES ALONG AND EAST OF I-65
SHOULD SUPPORT A GRADIENT IN INSTABILITY ACROSS THE AREA, WITH
AROUND 1500-2000 J/KG MLCAPE EXPECTED TO EXTEND FROM LAKE CUMBERLAND
UP INTO THE BLUEGRASS THIS AFTERNOON. IT IS IN THESE AREAS WHERE
THERE WILL BE BETTER CHANCES FOR POP-UP SHOWERS AND STORMS, WITH
WEAK FORCING ALOFT PROBABLY LIMITING COVERAGE TO ISOLATED OR WIDELY
SCATTERED AT BEST. DEEP-LAYER SHEAR AROUND 10 KNOTS SHOULD RESULT IN
SLOW-MOVING GARDEN-VARIETY SHOWERS AND STORMS, AND SEVERE WEATHER IS
NOT EXPECTED. HIGH TEMPERATURES THIS AFTERNOON SHOULD BE FAIRLY
SEASONABLE FOR EARLY AUGUST, GENERALLY RANGING FROM 86-91 ACROSS THE
AREA.
TONIGHT, ANY LINGERING CONVECTION SHOULD SUBSIDE SOON AFTER SUNSET,
THOUGH ADDITIONAL SHOWERS AND STORMS WILL BE ONGOING OVERNIGHT TO
THE WEST OF THE AREA. THIS ACTIVITY IS NOT EXPECTED TO MAKE IT INTO
THE AREA AS RIDGING ALOFT SHOULD HOLD FIRM. ANOTHER MOSTLY DRY AND
MILD NIGHT IS EXPECTED TONIGHT, WITH PATCHY FOG AGAIN BEING POSSIBLE
BEFORE SUNRISE THURSDAY MORNING.
THURSDAY AND THURSDAY NIGHT...
ANOTHER SEASONABLY HOT AND HUMID DAY IS EXPECTED ON THURSDAY WITH
ISOLATED TO WIDELY SCATTERED SHOWERS AND STORMS (20-30% COVERAGE)
EXPECTED TO DEVELOP IN THE AFTERNOON HOURS. ONCE AGAIN, MUCH OF
CENTRAL KY AND SOUTHERN IN WILL BE IN BETWEEN TWO FEATURES WHICH
WOULD SUPPORT GREATER COVERAGE OF STORMS: BETTER FORCING FROM A MID-
LEVEL SHORTWAVE ACROSS IL/IN AND A POOL OF GREATER LOW-LEVEL
MOISTURE ACROSS EASTERN KY. ADDITIONALLY, ANY LINGERING CONVECTIVE
DEBRIS CLOUDS FROM UPSTREAM CONVECTION COULD ALSO LIMIT
DESTABILIZATION THURSDAY AFTERNOON. RECENT GUIDANCE DEPICTS A
BROADER POOL OF 1000-2000 J/KG MLCAPE THURSDAY AFTERNOON, WHICH
SHOULD BE SUFFICIENT FOR SOME CONVECTIVE ACTIVITY. WHERE (IF) STORMS
DEVELOP, THERE WILL BE SOMEWHAT STRONGER FLOW ALOFT ALONG/NORTH OF
THE OHIO RIVER, RESULTING IN 15-20 KT OF DEEP-LAYER SHEAR. STILL,
THE INSTABILITY-SHEAR PARAMETER SPACE SUPPORTS TYPICAL SUMMERTIME
STORMS THURSDAY AFTERNOON AND EVENING.
MID-LEVEL SHORTWAVES/VORT LOBES WILL CONTINUE TO MOVE ACROSS THE MID-
MISSISSIPPI VALLEY THURSDAY NIGHT INTO FRIDAY MORNING, INITIATING
ADDITIONAL WAVES OF SHOWERS AND STORMS. THESE WAVES OF SHOWERS AND
STORMS MAY MAKE IT INTO OUR NORTHERN/WESTERN COUNTIES OVERNIGHT
THURSDAY INTO FRIDAY MORNING; HOWEVER, CONFIDENCE IN THIS SOLUTION
IS STILL FAIRLY LOW.
LONG TERM /FRIDAY THROUGH TUESDAY/
ISSUED AT 305 AM EDT WED AUG 5 2026
FRIDAY AND SATURDAY...
BY THE END OF THE WEEK, BAGGY MID- AND UPPER-LEVEL TROUGHING WILL BE
IN PLACE OVER MUCH OF THE MIDWEST, WITH RIDGING PLACED ON EITHER END
OF THE TROUGH ACROSS THE INTERMOUNTAIN WEST AND THE WESTERN NORTH
ATLANTIC. THIS WILL ALLOW A SFC COLD FRONT TO SINK TOWARD THE REGION
BY FRIDAY; HOWEVER, THE LACK OF AMPLIFICATION OF THE UPPER TROUGH
WILL LIKELY KEEP THE FRONT FROM MAKING ITS WAY THROUGH THE OHIO
VALLEY. NEVERTHELESS, AHEAD OF THIS BOUNDARY, ENSEMBLE MEAN PWATS
AROUND 1.8" (~75TH PERCENTILE OF CLIMATOLOGY) SHOULD KEEP A MOIST
AND UNSTABLE ENVIRONMENT IN PLACE ACROSS THE REGION. A MORE FOCUSED
CHANCE FOR SHOWERS AND STORMS IS FAVORED TO ARISE AS ONE OR TWO MID-
LEVEL SHORTWAVES/VORT LOBES ROUNDS THE BASE OF THE TROUGH FRIDAY
INTO SATURDAY. TIMING WILL BE IMPORTANT TO THE BETTER CHANCES FOR
RAIN, AS PASSAGE DURING PEAK HEATING WOULD MAXIMIZE SHOWER/STORM
CHANCES EITHER DAY. GIVEN SOMEWHAT BETTER FORCING, A STRONG STORM OR
TWO CAN'T BE COMPLETELY RULED OUT DURING THIS PERIOD, AND THERE IS A
MODEST SIGNAL IN NCAR AI SEVERE CONVECTION GUIDANCE FRIDAY INTO
SATURDAY. TEMPERATURES SHOULD TREND FAIRLY STEADY OVER THIS PERIOD,
WITH HIGHS IN THE UPPER 80S TO AROUND 90 AND LOWS IN THE UPPER 60S
AND LOW 70S.
SUNDAY THROUGH EARLY NEXT WEEK...
A BRIEF DECREASE IN PRECIPITATION CHANCES IS EXPECTED FOR THE SECOND
HALF OF THE WEEKEND AS THE UPPER RIDGE OVER THE WESTERN CONUS
BROADENS OUT. HEIGHT RISES AND SLIGHTLY LOWER PWATS ON SUNDAY SHOULD
SUPPRESS CONVECTIVE COVERAGE, WITH TEMPERATURES REMAINING SEASONABLY
HOT IN THE UPPER 80S AND LOW 90S.
AS WE HEAD INTO EARLY-TO-MID NEXT WEEK, A GRADUAL RETREAT IN THE
POSITIVE HEIGHT ANOMALIES IS EXPECTED AS PERSISTENT TROUGHING OVER
HUDSON BAY DIGS BACK TO THE SOUTHWEST. HOW QUICKLY THIS OCCURS IS
STILL UNCERTAIN, BUT IT WILL BRING BETTER SHOWER/STORM CHANCES AND A
SLIGHT FALL IN TEMPERATURES TO THE AREA WHEN IT DOES HAPPEN. AT THIS
TIME, THE UPPER RIDGE IS LIKELY TO CONTINUE TO DOMINATE ON MONDAY,
WITH IT POTENTIALLY BEING THE WARMEST DAY OF THE UPCOMING PERIOD
WITH WIDESPREAD LOW 90S FOR HIGHS. AS WE HEAD INTO TUESDAY AND THE
MIDDLE OF NEXT WEEK, THE PATTERN SHOULD BECOME MORE UNSETTLED, WITH
INCREASING CHANCES FOR (AT LEAST) AFTERNOON AND EVENING SHOWERS AND
STORMS.
AVIATION /06Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 129 AM EDT WED AUG 5 2026
LIGHT AND VARIABLE WINDS WILL CONTINUE EARLY THIS MORNING, WITH A
SCATTERED 5K FT STRATUS LAYER SPREADING FROM EAST TO WEST ACROSS THE
AREA. THE PREVALENCE OF THESE CLOUDS WILL PLAY A KEY ROLE IN THE
PATCHY FOG/MIST POTENTIAL AROUND SUNRISE, AS ALL SITES EXCEPT SDF
COULD SEE AT LEAST BRIEF MVFR/IFR VIS IF CLOUDS STAY AWAY.
CONFIDENCE IS A LITTLE LOWER THAN THE PREVIOUS FORECAST THAT WE'LL
COMPLETELY DECOUPLE, SO HAVE BACKED OFF THE FOG MENTION A BIT.
OTHERWISE, THERE IS HIGH CONFIDENCE IN VFR CONDITIONS ONCE THINGS
MIX OUT LATER THIS MORNING, WITH A 4-5K FT CU LAYER DEVELOPING WITH
DAYTIME HEATING. WINDS WILL REMAIN FAIRLY LIGHT AND VARIABLE THROUGH
THE DAY. A STRAY SHOWER OR STORM IS POSSIBLE EAST OF AN SDF-BWG
LINE THIS AFTERNOON; HOWEVER, CONFIDENCE IS LOW ENOUGH TO LEAVE OUT
OF THE LEX/RGA TAFS AT THIS TIME.
LMK WATCHES/WARNINGS/ADVISORIES
KY...NONE.
IN...NONE.
SHORT TERM...CSG
LONG TERM...CSG
AVIATION...CSG
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