223
FXUS63 KJKL 100759
AFDJKL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
359 AM EDT SUN AUG 10 2025
KEY MESSAGES
-MAINLY DRY CONDITIONS AND SEASONABLY HOT TEMPERATURES EXPECTED
TODAY.
-A SIGNIFICANT PATTERN CHANGE ARRIVES FOR THE NEW WORK WEEK,
BRINGING A MORE HUMID PATTERN WITH DAILY CHANCES FOR SCATTERED
AFTERNOON AND EVENING THUNDERSTORMS STARTING MONDAY.
-LOCALIZED TORRENTIAL DOWNPOURS AND STRONG, GUSTY WINDS ARE
POSSIBLE WITH THE THUNDERSTORMS THAT DEVELOP ON TUESDAY AND
WEDNESDAY.
SHORT TERM
(TODAY THROUGH MONDAY)
ISSUED AT 359 AM EDT SUN AUG 10 2025
SATELLITE IMAGERY SHOWS FOG DEVELOPING AND EXPANDING THROUGH THE
MAINSTEM RIVER VALLEYS AND LARGER TRIBUTARIES EARLY THIS MORNING
UNDER CLEAR SKIES. THERMOMETERS ARE AT SEASONABLE LEVELS, RANGING
IN THE MID AND UPPER 60S FOR ALL OF THE AREA, EXCEPT FOR THE
HIGHEST SUMMITS NEAR THE VIRGINIA-KENTUCKY BORDER. THE FAIR
WEATHER IS COURTESY OF A ~1024 HPA HIGH, EXTENDING FROM THE
CANADIAN MARITIMES SOUTHWESTWARD ALONG THE ATLANTIC SEABOARD TO
THE OUTER BANKS AND THEN WESTWARD INTO THE TENNESSEE VALLEY. THE
PARENT UPPER-LEVEL RIDGE EXTENDS FROM THE MID-MISSISSIPPI VALLEY
NORTHEASTWARD THROUGH THE ST. LAWRENCE VALLEY. A SUBTLE EAST-WEST
ORIENTED SURFACE TROUGH IS NOTED FROM SOUTHEAST MISSOURI EASTWARD
THROUGH THE BLUEGRASS TO NEAR CHARLESTON, WV. FURTHER UPSTREAM, A
SUBSTANTIAL 500HPA TROUGH SUPPORTS A COLD FRONT EXTENDING FROM LOW
PRESSURE OVER EASTERN MANITOBA SOUTHWARD INTO KANSAS AND THEN
SOUTHWESTWARD INTO NEW MEXICO.
THE HIGH PRESSURE IN OUR VICINITY, AS WELL AS WEAK HEIGHT RISES
ALOFT, WILL KEEP DEEP CONVECTION NEGLIGIBLE TODAY OVER THE VAST
MAJORITY OF EASTERN KENTUCKY -- JUST A DECENT CUMULUS FIELD AT
MOST LOCATIONS. HOWEVER, SOME GUIDANCE HINTS AT THE SUBTLE WEST-
TO-EAST ORIENTED SURFACE TROUGH LINGERING NEAR/NORTH OF MULDRAUGH
HILL TO ITS TRANSITIONAL INTERSECTION WITH THE POTTSVILLE
ESCARPMENT (IN THE ROCKCASTLE/JACKSON/ESTILL/MADISON COUNTY AREA).
IN THIS AREA, WHERE SOME OF THE HIGHEST ELEVATIONS OF THE
POTTSVILLE ESCARPMENT EXIST, MOST OF THE HREF CAMS SUGGEST ONE OR
MORE PIN-PRICK SHOWERS BLOSSOMING THIS AFTERNOON IN A WEAK
INSTABILITY, WEAK SHEAR ENVIRONMENT. SOME OF THE MODEL GUIDANCE
SUPPORTS AN ISOLATED SHOWER THREAT EXTENDING FURTHER SOUTH TO THE
VICINITY OF LAKE CUMBERLAND AND ALSO UP TOWARD THE RED RIVER
GORGE. THIS IS WHERE A SLIGHT CHANCE (15 TO 20 POP) OF SHOWERS HAS
BEEN ADDED TO THE FORECAST. SOME OF THE GUIDANCE ALSO HINTS AT
CONVECTIVE INITIATION OCCURRING OVER/ADJACENT TO BIG BLACK
MOUNTAIN BUT MENTIONABLE POPS WERE NOT INCLUDED IN THE FORECAST
FOR THAT AREA AT THIS TIME AS INSTABILITY WILL BE VERY MEAGER.
MID-LEVEL CAPPING AND DRY AIR WILL ALMOST CERTAINLY LIMIT CLOUD
DEPTH AND INHIBIT ANY THREAT OF LIGHTNING WITH CONVECTION THIS
AFTERNOON. AFTER ANY CONVECTION DISSIPATES THIS EVENING WITH THE
LOSS OF DIURNAL HEATING, THE UPPER-LEVEL RIDGING SLOWLY SHIFTS
OVERNIGHT, ALLOWING FOR MINUTE HEIGHT FALLS OVER THE COMMONWEALTH.
THE LATEST GUIDANCE SUGGESTS THAT HEIGHTS ALOFT MAY RISE AGAIN
SLIGHTLY ON MONDAY AS UPPER LEVEL RIDGING CONSOLIDATES SOUTH OF
BERMUDA AND RETROGRADES WESTWARD. INCREASINGLY SOUTHERLY TO
SOUTHWESTERLY LOW-LEVEL RETURN FLOW ON THE BACK SIDE OF THE HIGH
WILL BEGIN ADVECTING A HIGHER PWAT AIR MASS BACK ACROSS THE
EASTERN KENTUCKY COALFIELDS THROUGH THE DAY. THIS WILL CONTRIBUTE
TO RISING INSTABILITY LEVELS, BUT FORCING WILL BE LIMITED TO
DIFFERENTIAL HEATING AND PERHAPS WEAK 500HPA POSITIVE VORTICITY
CLOSER TO THE TENNESSEE BORDER AHEAD OF A WEAK VORTICITY MAXIMUM.
IN GENERAL, THE HIGHEST CHANCES FOR ANY SHOWER OR THUNDERSTORM
ACTIVITY APPEAR TO BE NEAR/SOUTH OF THE HAL ROGERS PKWY/KY-80
CORRIDOR, THOUGH SOME ISOLATED ACTIVITY COULD DEVELOP/SNEAK
FURTHER NORTH, ESPECIALLY OVER AND WEST OF THE POTTSVILLE
ESCARPMENT.
IN SENSIBLE TERMS, LOOK FOR A HOT AND MOSTLY DRY SUNDAY AFTER ANY
VALLEY FOG DISSIPATES BY MID-MORNING. HIGH TEMPERATURES ARE
FORECAST TO RANGE IN THE UPPER 80S TO LOWER 90S. THE ONLY
POTENTIAL FLY IN THE OINTMENT IS A POSSIBLE BRIEF SHOWER OR
SPRINKLE (GENERALLY ~20 PERCENT CHANCE OR LOWER). THIS NUISANCE
SHOWER ACTIVITY IS MOST FAVORED TO OCCUR OVER JACKSON AND ADJACENT
COUNTIES, THOUGH A BRIEF SHOWER OR SPRINKLE CANNOT BE ENTIRELY
RULED OUT FURTHER NORTH ALONG THE POTTSVILLE ESCARPMENT TO THE RED
RIVER GORGE AREA AND ALSO SOUTH TOWARD THE TENNESSEE BORDER.
ANOTHER FAIR MID-AUGUST NIGHT FOLLOWS SUNDAY NIGHT WITH FOG
FORMATION LIKELY AGAIN IN THE FAVORED RIVER VALLEY LOCALES. IT
WILL BE SEASONABLY MILD WITH LOWS IN THE MIDDLE TO UPPER 60S.
LOOKING AHEAD TO MONDAY, TEMPERATURES ARE FORECAST TO REACH
SIMILAR LEVELS, BUT RISING HUMIDITY LEVELS WILL MAKE IT FEEL
HOTTER, WITH MAXIMUM APPARENT TEMPERATURES REACHING THE MID 90S AT
MOST LOCATIONS. SCATTERED SHOWERS AND THUNDERSTORMS ARE ALSO
POSSIBLE, ESPECIALLY SOUTH OF THE HAL ROGERS PARKWAY/KY-80
CORRIDOR, THOUGH MORE ISOLATED ACTIVITY CANNOT BE RULED OUT
FURTHER NORTH, ESPECIALLY OVER AND WEST OF THE POTTSVILLE
ESCARPMENT.
LONG TERM
(MONDAY THROUGH SATURDAY)
ISSUED AT 458 PM EDT SAT AUG 9 2025
THE BEGINNING OF THE LONG TERM FORECAST PERIOD IS MARKED BY THE
BREAKDOWN OF THE ATMOSPHERIC RIDGING PATTERN THAT KEPT CONDITIONS
DRY ACROSS EASTERN KY. FROM MONDAY INTO TUESDAY, THE UPPER LEVEL
RIDGE PREVIOUSLY POSITIONED OVER THE APPALACHIANS WILL SHIFT EASTWARD
AS TROUGHING BEGINS TO DIG DEEPER INTO THE UPPER MIDWEST. IN THIS
SAME TIME FRAME, RIDGING BEGINS TO BUILD BACK OVER THE SOUTHEASTERN
AND SOUTH-CENTRAL CONUS. COLLECTIVELY, THESE FEATURES WILL PLACE
EASTERN KENTUCKY IN A PERSISTENT REGIME OF QUASI-ZONAL FLOW ALOFT
THROUGH THE NEXT WORK WEEK. AS SHORTWAVE FEATURES NAVIGATE THROUGH
THIS FLOW, AND ACTIVE WEATHER PATTERN WILL SET UP OVER THE FORECAST
AREA THROUGH THE END OF THE PERIOD.
ON MONDAY, ATMOSPHERIC FLOW IS EXPECTED TO GRADUALLY VEER TOWARDS
THE SOUTH AND THEN THE SOUTHWEST, LEADING TO INCREASINGLY EFFECTIVE
MOISTURE RETURN. ENSEMBLE DATA CONTINUES TO SUGGEST THAT THE HIGHEST
PWAT VALUES WILL REMAIN ACROSS SOUTHERN KENTUCKY ON THIS FIRST DAY
OF MOISTURE RETURN, AND SHOWER/THUNDERSTORM CHANCES ARE GENERALLY
CONTAINED TO THE KY80/HAL ROGERS PARKWAY CORRIDOR AS A RESULT. ANY
CONVECTIVE ACTIVITY THAT DEVELOPS ON MONDAY IS LIKELY TO BE TIED TO
THE DIURNAL HEATING CYCLE, AS THERE WILL BE LITTLE SYNOPTIC FORCING
PRESENT IN THE REGION EARLY NEXT WEEK. AFTERNOON HIGHS ARE FORECAST
TO WARM TO NEAR 90 DEGREES ACROSS THE ENTIRE FORECAST AREA ON
MONDAY, AND AS THE HUMIDITY INCREASES, MAXIMUM HEAT INDICES WILL
WARM INTO THE UPPER 90S. A FEW VALLEY AND URBAN LOCATIONS COULD
FLIRT WITH 100 DEGREE MAXAPTS ON MONDAY, BUT THE CONVECTION CHANCES
WILL LIMIT THE SPATIOTEMPORAL COVERAGE OF ANY HEAT-RELATED IMPACTS.
AFTER CONVECTION SUBSIDES WITH THE SUNSET, EXPECT OVERNIGHT RIDGE-
VALLEY TEMPERATURE SPLITS (RIDGE MINTS NEAR 70 AND VALLEY MINTS IN
THE UPPER 60S). THE SYNOPTICS AT PLAY SUPPORT NOCTURNAL VALLEY FOG
FORMATION, ESPECIALLY IN THE RIVER VALLEYS AND IN LOCATIONS WITH WET
GROUNDS.
PRECIPITATION CHANCES SPREAD ACROSS THE ENTIRETY OF EASTERN KENTUCKY
ON TUESDAY AND THEN INCREASE FURTHER HEADED INTO WEDNESDAY. THIS
INCREASE IN CONVECTIVE COVERAGE IS LARGELY DUE TO THE PERSISTENCE AND
AMPLIFICATION OF SOUTHWESTERLY-TO-WESTERLY FLOW THROUGHOUT THE
ATMOSPHERIC COLUMN. THE ORIENTATION OF THIS FLOW FAVORS PERSISTENT
GULF MOISTURE ADVECTION INTO THE REGION, AND LREF MEAN PWATS SURGE
TO NEAR 1.75 ACROSS THE FORECAST AREA BY TUESDAY AFTERNOON AND THEN
TO ABOVE 1.8 ON WEDNESDAY AFTERNOON. TUESDAY'S CONVECTIVE ACTIVITY
IS LIKELY TO REMAIN DIURNALLY-DRIVEN, ALTHOUGH GUIDANCE CONTINUES TO
SHOW A MORE WELL-DEFINED DISTURBANCE IN THE VICINITY OF THE FORECAST
AREA ON WEDNESDAY. SEVERE THUNDERSTORM PARAMETER SPACING REMAINS
UNIMPRESSIVE FOR THE DURATION OF THE FORECAST PERIOD, ALTHOUGH
INCREASING AMOUNTS OF SBCAPE AND THE AFOREMENTIONED PWAT VALUES
SUGGEST THAT ISOLATED WET DOWNBURSTS CANNOT BE ENTIRELY RULED OUT ON
TUESDAY AND WEDNESDAY. IT IS MORE LIKELY THAT THESE STORMS WILL BE
EFFICIENT RAINMAKERS, ESPECIALLY ONCE THE MORE VIGOROUS SHORTWAVE
DISTURBANCE ARRIVES ON WEDNESDAY. SOME OF THE AVAILABLE 12Z MODELED
FORECAST SOUNDINGS FOR WEDNESDAY AT KJKL SHOW PWAT VALUES
APPROACHING 2 INCHES, WITH LONG/SKINNY CAPE PROFILES, LOW LCLS, AND
A THICK WARM CLOUD LAYER PRESENT. IF MULTIPLE ROUNDS OF CONVECTION
ARE ABLE TO PASS OVER ANY GIVEN LOCATION IN AN ENVIRONMENT LIKE
THAT, LOCALIZED FLASH FLOODING WOULD BE POSSIBLE. WPC HAS INTRODUCED
A MARGINAL (LEVEL 1/4) EXCESSIVE RAINFALL OUTLOOK FOR THE ENTIRE
FORECAST AREA ON WEDNESDAY IN RESPONSE TO THIS SIGNAL, ALTHOUGH THE
EVOLUTION OF MESOSCALE FACTORS SUCH AS ANTECEDENT/UPSTREAM
CONVECTIVE ACTIVITY REMAIN UNCERTAIN AT THIS TEMPORAL RANGE. AT THE
CURRENT MOMENT, THERE IS NOT A SIGNAL FOR WIDESPREAD FLOODING IMPACT
IN ANY OF THE PROBABILISTIC RIVER FORECAST GUIDANCE, WHICH GIVES
CREDENCE TO THE IDEA THAT WEDNESDAY'S FLOOD RISK WILL BE CONFINED TO
ANY LOCALES THAT SEE MULTIPLE ROUNDS OF HEAVY RAIN OR A PARTICULARLY
PERSISTENT DOWNPOUR. INTERESTS ARE ENCOURAGED TO MONITOR FUTURE
FORECAST UPDATES AS HIGHER-RESOLUTION DATA BECOMES AVAILABLE AND THE
MESOSCALE DETAILS OF WEDNESDAY'S FORECAST BECOME MORE CLEAR.
THE INCREASING RAIN CHANCES AND CLOUD COVERAGE ON TUESDAY AND
WEDNESDAY SHOULD SUPPRESS ANY HEAT IMPACTS RELATED TO THE INCREASING
HUMIDITY. FORECAST HIGHS HAVE TRENDED A LITTLE BIT COOLER FOR THIS
MID-WEEK TIME FRAME, AND THE LATEST FORECAST GRIDS REFLECT HIGHS IN
THE MID TO UPPER 80S. IF AN AM ROUND OF CONVECTION COMES TO FRUITION
ON WEDNESDAY AND SKIES REMAIN CLOUDIER, THE NBM-SOURCED FORECAST
HIGHS COULD UNDER-PERFORM. CONFIDENCE WAS NOT HIGH ENOUGH TO DEVIATE
FROM THIS BASELINE DATA WITH THIS FORECAST PACKAGE ISSUANCE, BUT
THESE COOLER TEMPERATURES COULD FURTHER MITIGATE THE SEVERE WEATHER
POTENTIAL.
IN THE WAKE OF WEDNESDAY'S SHORTWAVE TROUGH, HIGH TEMPERATURES ARE
EXPECTED TO LINGER IN THE MID TO UPPER 80S ON THURSDAY. THE
COMMONWEALTH IS LIKELY TO REMAIN IN QUASI-ZONAL FLOW THROUGH THE END
OF THE NEXT WORK WEEK, ALTHOUGH A SHORTWAVE RIDGE SHOULD LEAD TO
SOME ATMOSPHERIC DRYING/WARMING LATE IN THE DAY ON THURSDAY AND INTO
FRIDAY. HIGHS ON FRIDAY CORRESPONDINGLY TICK BACK UP TOWARDS 90
DEGREES, BUT THE PATTERN REMAINS FAVORABLE FOR DIURNALLY-FORCED
CONVECTION. POPS REMAIN IN THE FORECAST THROUGH THE END OF THE
PERIOD, AND HEAT-RELATED IMPACTS ARE NOT EXPECTED. LIKEWISE, EXPECT
OVERNIGHT LOWS NEAR/ABOVE 70 ON RIDGETOPS AND IN THE UPPER 60S IN
THE VALLEYS. VALLEY FOG GRIDS HAVE BEEN ADDED TO THE BASELINE NBM
GRIDS EACH NIGHT THROUGH THE LONG TERM FORECAST PERIOD, ALTHOUGH IT
IS NOTED THAT ANY LEFTOVER CLOUD DECKS FROM TUESDAY AND WEDNESDAY'S
PRECIPITATION CHANCES COULD MITIGATE FOG FORMATION ON THOSE NIGHTS.
AVIATION
(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 145 AM EDT SUN AUG 10 2025
SURFACE AND UPPER LEVEL RIDGING WILL DOMINATE THROUGH THE PERIOD.
THIS WILL LEAD TO VFR AT TAF SITES. FOG IS DEVELOPING IN THE
MAINSTEM RIVER VALLEYS AND SHOULD PERSIST THERE THROUGH SUNRISE.
NON-TAF SITE VALLEY LOCATIONS COULD EXPERIENCE MVFR TO IFR OR IN
SOME CASES LOCALLY LOWER REDUCTIONS AT TIMES THROUGH 13Z.
OTHERWISE, SOME DIURNALLY-DRIVEN CUMULUS IN THE VFR RANGE SHOULD
DEVELOP ACROSS PORTIONS OF THE AREA AFTER 15Z; BUT, WITH THE AREA
MORE UNDER THE CENTER OF THE UPPER RIDGE, SHOWER COVERAGE WILL BE
EVEN MORE LIMITED THAT SATURDAY AND GENERALLY WEST OF THE TAF
SITES. WINDS WILL REMAIN LIGHT AND VARIABLE UNDER 5 KTS.
JKL WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...GEERTSON
LONG TERM...MARCUS
AVIATION...GEERTSON
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