509
FXUS63 KJKL 190315 AAA
AFDJKL
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE JACKSON KY
1115 PM EDT TUE AUG 18 2026
KEY MESSAGES
- MAINLY DRY AND COOLER WEATHER THROUGH WEDNESDAY, THOUGH LOCALLY
DENSE RIVER VALLEY FOG IS EXPECTED LATE TONIGHT.
- A COLD FRONT BRINGS SCATTERED TO WIDESPREAD THUNDERSTORMS
WEDNESDAY NIGHT AND THURSDAY, WITH A FEW STRONG WIND GUSTS AND
LOCALIZED HEAVY RAIN AND FLOODING POSSIBLE.
- NOTICEABLY COOLER AND LESS HUMID AIR ARRIVES THIS WEEKEND AND
CONTINUES INTO EARLY NEXT WEEK.
UPDATE
ISSUED AT 1115 PM EDT TUE AUG 18 2026
NO SIGNIFICANT CHANGES WERE MADE TO THE FORECAST WITH MAINLY JUST
THE INCLUSION OF THE LATEST OBS AND TRENDS FOR THE T/TD/SKY GRIDS.
STILL ANTICIPATED AREAS OF DENSE FOG DEVELOPING IN THE VALLEYS
LATER THIS NIGHT. THE FORECAST ADJUSTMENTS HAVE BEEN SENT TO THE
NDFD AND WEB SERVERS ALONG WITH A FRESHENING OF THE ZONES.
UPDATE ISSUED AT 740 PM EDT TUE AUG 18 2026
23Z SFC ANALYSIS SHOWS WEAK HIGH PRESSURE CURRENTLY IN CONTROL OF
THE WEATHER OVER EASTERN KENTUCKY. THIS IS WORKING TO SETTLE THE
WINDS AND KEEP SKIES MOSTLY CLEAR. CURRENTLY, TEMPERATURES ARE
RUNNING IN THE LOW TO MID 70S IN THE SHELTERED VALLEYS TO THE
UPPER 70S ON THE RIDGES. MEANWHILE, AMID LIGHT NORTH WINDS AT 5
MPH OR LESS, DEWPOINTS GENERALLY RANGE FROM THE LOWER 60S NORTH TO
NEAR 70 IN THE FAR SOUTH. HAVE UPDATED THE FORECAST MAINLY TO ADD
IN THE LATEST OBS AND TRENDS FOR THE T/TD/SKY GRIDS. THESE MINOR
ADJUSTMENTS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS ALONG WITH
A FRESHENING OF THE SAFS AND ZONES.
SHORT TERM
(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 425 PM EDT TUE AUG 18 2026
LATE THIS AFTERNOON, AN UPPER LEVEL LOW WAS CENTERED TO THE
SOUTHWEST OF HUDSON BAY WITH BROAD TROUGHING SOUTH INTO THE GREAT
LAKES TO MS VALLEY REGION WITH WESTERLY FLOW DOWNSTREAM ALOFT ACROSS
THE OH VALLEY TO MID ATLANTIC STATES. FURTHER SOUTHWEST, AN UPPER
LEVEL RIDGE WAS CENTERED IN THE SOUTHWEST CONUS AND THEN EXTENDED
NORTHWEST INTO OR. AT THE SURFACE, AN AREA OF HIGH PRESSURE WAS
CENTERED OVER THE LOWER OH VALLEY VICINITY WHILE A SFC LOW WAS IN
CANADA AND A FRONTAL ZONE EXTENDED INTO ONTARIO TO NORTHERN GREAT
LAKES TO SD TO MT.
TONIGHT AND WEDNESDAY, THE UPPER LOW IN CANADA WILL MEANDER ACROSS
THE SOUTHERN HUDSON BAY TO JAMES BAY REGION WITH UPPER TROUGHING
EXTENDING INTO THE GREAT LAKES TO LOWER OH VALLEY TO PORTIONS OF THE
MS VALLEY REGION. MEANWHILE, UPPER LEVEL RIDGING UPPER BUILDS INTO
THE NORTHWEST FROM THE DESERT SOUTHWEST/FOUR CORNERS. AT THE
SURFACE, HIGH PRESSURE WILL SLOWLY MOVE TO NEAR THE SW VA TO NE TN
AND SOUTHEASTERN KY AREA. ADDITIONAL SHORTWAVES IN NORTHWEST FLOW
MOVING AROUND THE WESTERN RIDGING WILL MOVE INTO THE CENTRAL CONUS
TO AND THE MID MS VALLEY TO LOWER OH VALLEY REGION BY LATE WEDNESDAY
AFTERNOON AND EVENING. FOR WEDNESDAY NIGHT, A SHORTWAVE TROUGH WILL
ENTER THE LOWER OH VALLEY FROM THE WEST WHILE A FRONTAL ZONE/SFC
TROUGH APPROACH. PW INITIALLY IN THE 25 TO 47 PERCENT RANGE OR 1 TO
1.3 INCHES THIS EVENING IS PROGGED TO DROP AS LOW AS THE 15TH TO
40TH PERCENTILE LATE THIS EVENING AND OVERNIGHT PER 12Z HREF. THIS
THEN REBOUNDS TO THE 45TH TO 50TH PERCENTILE NEAR THE VA BORDER TO
THE 85TH PERCENTILE, OR 1.15 TO 1.8 INCH RANGE THROUGH MID AFTERNOON
ON WEDNESDAY. MOISTURE IS TRANSPORTED FURTHER EAST AHEAD OF THE
SHORTWAVE TO END THE PERIOD INTO THE 70TH TO 85TH PERCENTILE (1.45
TO 1.85 INCH) RANGE NEAR SUNSET ON WEDNESDAY AND INCREASE A TAD MORE
BEFORE DAWN ON THURSDAY.
SFC HIGH PRESSURE BUILDING IN FOLLOWING RECENT RAINFALL AND DRY AIR
ALOFT WILL SET THE STAGE FOR FOG AT LEAST IN THE VALLEYS. SOME OF
THIS SHOULD BECOME DENSE AND THIS IS NOTED IN THE LATEST HWO. LOWS
MAINLY IN THE 60 TO 65 RANGE SHOULD BE QUITE REFRESHING FOLLOWING
THE HUMID WEATHER AS OF LATE. TEMPERATURES DO MODERATE BACK TO A
COUPLE OF DEGREES ABOVE NORMAL FOR WEDNESDAY UNDER MOSTLY SUNNY
SKIES. CONVECTION WILL BECOME MORE PROBABLE AS MOISTURE INCREASES
WEDNESDAY EVENING THROUGH WEDNESDAY NIGHT, WITH CHANCES SPREADING
FROM NORTHWEST TO SOUTHEAST. WITH THE INCREASING PW SOME LOCALLY
HEAVY AMOUNTS ARE NOT OF THE QUESTION IN THE NORTHWEST OR WEST LATE
WEDNESDAY NIGHT IF ANY HEAVY RAIN FALLS THEN COULD PRIME A FEW AREAS
FOR THE POSSIBILITY OF EXCESSIVE RAINFALL ON THURSDAY.
LONG TERM
(THURSDAY THROUGH TUESDAY)
ISSUED AT 330 PM EDT TUE AUG 18 2026
AT THE ONSET OF THE EXTENDED FORECAST PERIOD, LARGE-SCALE 500 MB
TROUGHING REMAINS ANCHORED ACROSS MUCH OF THE EASTERN CONUS. IN THE
PRE-DAWN HOURS THURSDAY, A NOCTURNAL 40-50 KT LOW-LEVEL JET (LLJ)
ORIENTED ACROSS WESTERN AND CENTRAL KENTUCKY WILL COINCIDE WITH A
SHORTWAVE PASSING THROUGH THE OHIO VALLEY. WHILE THE LLJ WEAKENS TO
30-40 KTS AS IT SHIFTS INTO EASTERN KENTUCKY, ROUNDS OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED THROUGH THURSDAY. THE FIRST ROUND WILL
MOVE THROUGH DURING THE MORNING HOURS, FAVORING AREAS ACROSS THE
CUMBERLAND, SOUTHERN LICKING, AND BIG SANDY RIVER BASINS NEAR THE
TN, VA, AND WV BORDERS. A BRIEF LULL IN ACTIVITY IS EXPECTED BEFORE
REDEVELOPMENT OCCURS EARLY THURSDAY AFTERNOON ALONG THE I-64
CORRIDOR, PROPAGATING SOUTH THROUGH THE REMAINDER OF THE DAY. MODELS
INDICATE DRIER AIR WORKING IN ALOFT BY LATE AFTERNOON, WHICH COULD
SUPPRESS RAIN CHANCES. HOWEVER, THE ENVIRONMENT WILL SUPPORT PWAT
VALUES NEAR 1.75 INCHES (80TH TO 85TH PERCENTILE OF CLIMATOLOGY).
GIVEN SATURATED SOILS FROM RECENT RAINFALL, ISOLATED INSTANCES OF
MINOR FLOODING REMAIN POSSIBLE THURSDAY THROUGH THURSDAY NIGHT,
SUPPORTING WPCS MARGINAL RISK (LEVEL 1 OF 4) FOR EXCESSIVE RAINFALL.
ADEQUATE STORM MOTION SHOULD KEEP ACTIVITY PROGRESSIVE, LIMITING
WIDESPREAD FLASH FLOODING POTENTIAL.
AS THE FRONTAL BOUNDARY ASSOCIATED WITH THURSDAYS CONVECTION LINGERS
NEAR THE AREA ON FRIDAY, SHOWER AND THUNDERSTORM CHANCES WILL
PERSIST, WITH THE HIGHEST PROBABILITIES DURING THE AFTERNOON ALONG
AND SOUTH OF THE HAL ROGERS PARKWAY / KY HIGHWAY 80 CORRIDOR. BEYOND
FRIDAY, MODELS AND ENSEMBLE GUIDANCE REMAIN IN BROAD AGREEMENT ON A
CONTINUED UPPER-LEVEL PATTERN FEATURING A RIDGE OVER THE WESTERN
CONUS AND TROUGHING ACROSS THE EAST, THOUGH AMPLITUDE DIFFERENCES
REMAIN. ANOTHER SHORTWAVE EMBEDDED WITHIN THE LONGWAVE TROUGH IS
PROJECTED TO DIG OUT OF THE UPPER MIDWEST INTO THE GREAT LAKES AND
OHIO VALLEY SATURDAY INTO SUNDAY. MULTIPLE 00Z AI-BASED GUIDANCE
SUITES FROM AUGUST 18TH SHOW CONDITIONAL SEVERE POTENTIAL ON
SATURDAY, PRIMARILY CENTERED OVER SW PENNSYLVANIA, WITH LOWER
PROBABILITIES (5-15 PERCENT) EXTENDING SOUTHWEST INTO EASTERN
KENTUCKY. AT PRESENT, POPS SUPPORT ISOLATED TO SCATTERED COVERAGE
ACROSS THE LICKING AND BIG SANDY BASINS ON SATURDAY. ISOLATED SHOWER
OR STORM ACTIVITY MAY LINGER ACROSS THE BIG SANDY EARLY SUNDAY
MORNING; OTHERWISE, DRY WEATHER IS EXPECTED TO RETURN THROUGH MONDAY
MORNING. BY MONDAY AFTERNOON, GUIDANCE DEPICTS ANOTHER UPPER LEVEL
LOW WHICH A FEW MODELS ATTEMPT TO CLOSE OFF DIGGING SOUTHEAST FROM
THE UPPER MIDWEST INTO THE NORTHERN GREAT LAKES. THIS FEATURE COULD
BRING ANOTHER ROUND OF SHOWER AND THUNDERSTORM CHANCES TO THE AREA
ON TUESDAY.
AVIATION
(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 815 PM EDT TUE AUG 18 2026
WEAK HIGH PRESSURE IS BUILDING INTO THE OHIO VALLEY THIS EVENING
AND USHERING IN DRIER AIR. MORE WIDESPREAD FOG IS PROBABLE
TONIGHT COMPARED TO LAST NIGHT AS THAT HIGH CRESTS OVER EASTERN
KENTUCKY. THIS FOG SHOULD BRING REDUCTIONS TO MVFR INITIALLY AS
EARLY AS 04Z IN SOME AREAS, WITH SOME REDUCTIONS TO IFR OR LOWER
IN MANY LOCATIONS BETWEEN 07Z AND 12Z, BEFORE LIFTING AND
DISSIPATING - ALLOWING CATEGORIES TO IMPROVE IN ALL AREAS BY 13Z.
LIGHT NORTHERLY WINDS WILL CONTINUE THROUGH THE NIGHT. WEST TO
NORTHWEST WINDS AT LESS THAN 10 KTS THEN RETURN BY MIDDAY
WEDNESDAY WITH THE POTENTIAL FOR A FEW CUMULUS, AS WELL, AFTER
ABOUT 15Z.
JKL WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...GREIF
SHORT TERM...JP
LONG TERM...GINNICK
AVIATION...JP/GREIF
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