992
FXUS63 KJKL 312011
AFDJKL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
411 PM EDT FRI JUL 31 2026
KEY MESSAGES
- THUNDERSTORMS ARE POSSIBLE AT TIMES FROM SATURDAY THROUGH
WEDNESDAY.
- HEAVY RAINFALL IS POSSIBLE ON SATURDAY AND SATURDAY NIGHT AND
COULD LEAD TO ISOLATED INSTANCES OF FLASH FLOODING.
SHORT TERM
(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 403 PM EDT FRI JUL 31 2026
AT 18Z A MID-LEVEL SCATTERED CU DECK WAS OBSERVED ACROSS PORTIONS OF
THE AREA, WITH HIGH LEVEL CIRRUS WORKING IN FROM THE WEST.
TEMPERATURES AROUND THE AREA LARGELY RANGE FROM THE UPPER 70S TO
MID 80S.
ANALYZING THE 500-MB HEIGHT CHARTS, SOME PROMINENT FEATURES ARE THE
TROUGHING OFF EAST CONUS, WITH A SKINNY RIDGE EXTENDING FROM THE
APPALACHIANS INTO THE OTTOWA VALLEY OF SOUTHERN QUEBEC. FARTHER
WEST, AN UPPER LEVEL LOW CAN BE SEN OVER THE UPPER MIDWEST AND UPPER
MISSISSIPPI VALLEY. A LARGE RIDGE REMAINS OVER WESTERN CONUS, WITH A
597-DM HIGH OVER THE 4-CORNERS REGION OF THE SOUTHWEST US. HEADING
FORWARD IN TIME THE UPPER LEVEL LOW OVER THE UPPER MIDWEST IS
EXPECTED TO PROGRESS SOUTHEAST INTO PORTIONS OF THE OHIO AND
TENNESSEE VALLEY.
THIS UPPER LEVEL LOW WILL BE RESPONSIBLE FOR INCREASING CLOUDS THIS
EVENING, AND ROUNDS OF RAIN AND THUNDERSTORMS THROUGH SATURDAY. PWAT
ACROSS THE AREA WILL START OUT AROUND 1-1.2 INCHES. ROUNDS OF
SHOWERS AND THUNDERSTORMS WILL INCREASE AFTER 8 AM, BUT WILL LIKELY
FEATURE A DRY SLOT, LEADING TO AREAS OF DESTABILIZATION HEADING INTO
THE AFTERNOON. AFTER A WARM FRONT MOVES THROUGH THE AREA SATURDAY
MORNING FROM SOUTHWEST TO NORTHEAST, HIGHER 2-2.2 INCH PWATS WILL
ADVECT INTO EASTERN KENTUCKY DURING THE AFTERNOON. THESE PWATS WILL
BE ABOVE THE 97TH PERCENTILE, EXCEEDING THE 99TH PERCENTILE AT
TIMES. AS THIS SURFACES LOW ATTEMPTS TO CLOSE OFF, THE MEAN SEA
LEVEL PRESSURE OF 1004 MB WOULD BE THE ALL TIME LOWEST PRESSURE
RECORDED IN THE AREA FOR THIS TIME OF YEAR (BELOW THE 1ST
PERCENTILE). MORE NOTABLY, LATEST MODEL RUNS ARE SHOWING MORE
AGREEMENT AROUND THE LOW CLOSING OFF. THIS COULD LEAD TO A SLOW
MOVING STORMS, OR SLOWER PROGRESSION OF THE OVERALL SYSTEM THROUGH
THE AREA. A LLJ AROUND 25-35 KTS WILL TRAVERSE THE AREA THE LATER
SATURDAY AFTERNOON. WITH 500-1200 J/KG OF MLCAPE ALONG AND WEST OF
THE I-75 CORRIDOR ALONG WITH 0-1 KM SRH AROUND 150 M2/S2, THE SPC HAS
PLACED AND AREA ENCOMPASSING THE CUMBERLAND PLATEAU, AND I-75 CORRIDOR
NORTHWARD ENCOMPASSING THE RED RIVER GORGE AREA, AND COVERING MUCH OF
THE BLUEGRASS AREA IN A SLIGHT RISK FOR SEVERE WEATHER. THE PRIMARY
HAZARD IN THESE AREA ARE STORMS THAT HAVE DAMAGING WIND GUSTS,
HOWEVER THERE'S ALSO A NON-ZERO CHANCE OF A BREIF TORNADO AS WELL.
TIMING FOR THE MOST SEVERE IS SOMEWHAT DEPENDENT ON WHAT HAPPENS IN
THE MORNING WITH THE FIRST ROUND. THE QUICKER STORMS CLEAR OUT IN
THE MORNING THE MORE TIME THERE IS FOR THE ATMOSPHERE TO DESTABILIZE
FOR ROUND 2, THAT SAID CURRENT THINKING IS DISCRETE CELLS COULD MOVE
THROUGH THE ABOVE HIGHLIGHTED AREAS BETWEEN 6 AND 10 PM.
WITH ABNORMALLY HIGH PWATS ABOVE 2.0 INCHES EXPECTED IN THE
AFTERNOON AND EARLY SATURDAY EVENING, ALONG WITH THE POTENTIAL FOR
THE LOW TO CLOSE OFF, BECOMING SLOWER, THE WPC ALSO HAS THE WESTERN
2/3RDS TO THE JACKSON CWA IN A SLIGHT RISK FOR EXCESSIVE RAINFALL,
WHICH COULD LEAD TO ISOLATED INSTANCES OF FLASH FLOODING.
IN SUMMARY, INCREASING CLOUDS THIS EVENING WITH MULTIPLE ROUNDS OF
SHOWERS AND THUNDERSTORMS SATURDAY. THE SECOND ROUND OF STORM COULD
BE SEVERE, GENERALLY THE CUMBERLAND PLATEAU, AND I-75 CORRIDOR
NORTHWARD ENCOMPASSING THE RED RIVER GORGE AREA, AND COVERING MUCH OF
THE BLUEGRASS AREA. THE BIGGEST SEVERE THREAT IS DAMAGING WIND GUSTS
THROUGH A BREIF TORNADO CANT BE RULED OUT. STORMS CAN PRODUCE HEAVY
RAINFALL THAT CAN ALSO LEAD TO ISOLATED INSTANCES OF FLASH FLOODING
ACROSS THE WESTERN 2/3RDS OF THE FORECAST AREA. TEMPERATES COOL
INTO THE UPPER 60S THIS EVENING BEFORE WARMING INTO THE LOW TO MID
80S TOMORROW. WITH CLOUDED SKIES SATURDAY NIGHT, TEMPERATURES WILL
TEND TO STAY ON THE WARMER SIDE RANGING FROM THE UPPER 60S TO NEAR
70 IN PLACES SATURDAY NIGHT.
LONG TERM
(SUNDAY THROUGH FRIDAY)
ISSUED AT 411 PM EDT FRI JUL 31 2026
THE LONG-TERM PERIOD DAWNS SUNDAY MORNING WITH A WEAK, CLOSED ~575
DAM LOW SPINNING OVER SOUTHWEST INDIANA WITHIN A POSITIVELY-
TILTED TROUGH THAT EXTENDS NORTHEASTWARD TOWARD JAMES BAY, WHERE A
BROADER 500 HPA TROUGH IS PIVOTING ACROSS EASTERN CANADA. THIS
UPPER-LEVEL LOW WILL LIE NEARLY VERTICALLY STACKED ATOP AN
OCCLUDING ~1004 MB SURFACE LOW. WHILE THAT DOES NOT SOUND ALL
THAT IMPRESSIVE, THE NAEFS AND ECMWF ENS SHOW THAT MSLP VALUES OF
THIS DEPTH FALL BELOW 1979-2009 CFSR CLIMATOLOGY, INDICATIVE OF
HOW RARE IT IS TO HAVE A DEVELOPED MID-LATITUDE CYCLONE PASSING
THROUGH THE OHIO VALLEY THIS TIME OF YEAR. THE SYSTEM'S COLD
FRONT WILL EXTEND FROM THE EASTERN SIDE OF THE LOW NEAR CINCINNATI,
SOUTHWARD ALONG THE I-75 CORRIDOR INTO TENNESSEE, AND THEN
SOUTHWARD INTO THE LOWER MISSISSIPPI VALLEY.
WHILE GUIDANCE STILL SHOWS THE NORTHERN STREAM 500 HPA TROUGH
PIVOTING ACROSS EASTERN CANADA AND ADJACENT PORTIONS OF THE
GREAT LAKES AND NORTHEAST LATER SUNDAY AND SUNDAY NIGHT AND
STEALING SOME OF THE ENERGY FROM THE SOUTHERN STREAM TROUGH/
CLOSING LOW, THE 31/12Z MODEL SUITE SEEMS TO BE LATCHING ONTO MORE
OF THE VORTICITY ENERGY REMAINING WITH THE CLOSED LOW AND
GYRATING OVER THE OHIO VALLEY AND CENTRAL APPALACHIANS ON MONDAY
AND TUESDAY. THAT SYSTEM ONLY SLOWLY DEPARTS LATER IN THE WEEK ON
WEDNESDAY AND THURSDAY AS BROAD UPPER-LEVEL TROUGHING DEVELOPS
OVER THE NORTH CENTRAL TO NORTHEAST CONUS, AND AN ASSOCIATED BELT
OF WESTERLIES ALOFT CAPTURES THE REMNANT LOW AND SWEEPS IT AWAY.
FLOW OVER THE OHIO VALLEY TRENDS QUASI-ZONAL BY LATE WEEK.
AT THE SURFACE, THE LOW PRESSURE SYSTEM OVER THE LOWER OHIO VALLEY
REMAINS NEARLY VERTICALLY STACKED AS IT DRIFTS TO OVER THE MID-
OHIO VALLEY ON MONDAY, WHERE IT WOBBLES AND LARGELY DISSIPATES
BEFORE ITS REMNANTS ARE PULLED AWAY TO THE NORTH BY MID-WEEK. AS A
RESULT, THE SYSTEM'S COLD FRONT WILL SLOWLY CROSS THE JKL CWA
DURING THE DAY ON SUNDAY. WITHIN THE WARM SECTOR, SOME OF THE
LONGEST-RANGE CAMS ARE HINTING AT THE POSSIBILITY OF ENOUGH SHEAR
AND INSTABILITY FOR AT LEAST WEAKLY ORGANIZED CONVECTION AHEAD OF
THE COLD FRONT AGAIN ON SUNDAY AFTERNOON, ESPECIALLY CLOSER TO VA
AND WV. WITH THE UPPER-LEVEL LOW LINGERING ALOFT, PWATS ARE NOW
LIKELY TO STAY ELEVATED THROUGH THE DAY ON SUNDAY, AS WELL AS
MONDAY AND TUESDAY (MORE SO THAN WHAT WAS EXPECTED IN RECENT
DAYS). THE RESULT WILL BE A LOT MORE CLOUD COVER AND DIURNALLY-
MODULATED CONVECTION WITH GREATEST RAINFALL COVERAGE DURING THE
AFTERNOON AND EVENING AND CONTINUED THOUGH LOWER RAIN CHANCES AT
NIGHT. THE COMBINATION OF A LINGERING NEARLY SATURATED DEEP WARM
CLOUD LAYER, SKINNY CAPE PROFILES, AND ELEVATED PWATS IN THE 1.75
TO 2.00 INCH RANGE, WARRANTED THE ADDITION OF MARGINAL RISK EROS
FOR BOTH MONDAY AND TUESDAY. THE THREAT FOR HEAVY RAINFALL
SUBSIDES LATER IN THE WEEK AS THE UPPER-LEVEL LOW DEPARTS AND
INCREASINGLY ZONAL FLOW ALLOWS DRIER AND WARMER AIR TO FILTER
EASTWARD FROM THE PLAINS MID-WEEK. WHILE A FEW POP-UP
THUNDERSTORMS WILL BE POSSIBLE FROM THURSDAY THROUGH SATURDAY,
ACTIVITY SHOULD REMAIN MORE ISOLATED TO PERHAPS SCATTERED AND BE
CONFINED LARGELY TO THE AFTERNOON AND EVENING HOURS.
IN SENSIBLE WEATHER TERMS, LOOK FOR A RELATIVE LULL IN THE RAINFALL
SUNDAY MORNING, GIVING WAY TO MORE WIDESPREAD SHOWER AND THUNDERSTORM
ACTIVITY DURING THE AFTERNOON. SOME OF THE CONVECTION COULD BE STRONG
WITH GUSTY WINDS AND TORRENTIAL DOWNPOURS. IT WILL BE HUMID AND MILD
WITH HIGHS MAINLY IN THE LOWER 80S. RAIN CHANCES WILL THEN FOLLOW A
DIURNAL CYCLE ON MONDAY AND TUESDAY, WITH COVERAGE GREATER DURING THE
AFTERNOON AND EVENING BUT STILL REMAINING POSSIBLE AT NIGHT. IT WILL
BE QUITE HUMID AND MUGGY WITH AFTERNOON HIGHS MAINLY IN THE LOWER 80S
AND NIGHTTIME LOWS IN THE MID TO UPPER 60S. THE PATTERN TURNS DRIER
FROM WEDNESDAY ONWARD WITH MORE SUNSHINE AND DAILY HIGH TEMPERATURES
WARMING INTO THE MID TO PERHAPS UPPER 80S, WHILE NIGHTTIME LOWS
RANGE FROM 65 TO 70F.
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 229 PM EDT FRI JUL 31 2026
A SCATTERED MID LEVEL CU FIELD WAS OBSERVED ACROSS NORTHERN TAF
SITES THIS AFTERNOON AS WELL AS HIGHER LEVEL CIRRUS WORKING IN
FROM THE WEST. VFR CONDITIONS LOOK TO CONTINUE THROUGH MUCH OF
THE TAF PERIOD, BUT INCREASING CLOUDS ARE EXPECTED WITH THE
APPROACHING LOW THIS EVENING. -SHRA WAS INTRODUCED TO ALL TAF
SITES ANYTIME AFTER 10-12Z SATURDAY MORNING, WITH THUNDERSTORM
PROBABILITIES GRADUALLY INCREASING FROM 13Z ONWARD. WINDS WILL BE
LIGHT AND VARIABLE THROUGH MUCH OF THE TAF PERIOD, BECOMING LIGHT
AND SOUTHERLY ANYTIME AFTER 12Z SATURDAY. ANY STORMS THAT DO PASS
OVER TAF LOCATIONS CAN DROP CONDITIONS FROM VFR INTO MVFR OR IFR
CONDITIONS.
JKL WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...GINNICK
LONG TERM...GEERTSON
AVIATION...GINNICK
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