444
FXUS63 KJKL 110818
AFDJKL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
418 AM EDT MON AUG 11 2025
KEY MESSAGES
-ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE FORECAST ON
MONDAY AS HUMIDITY RISES.
-SCATTERED SHOWERS AND THUNDERSTORMS ARE ANTICIPATED ON TUESDAY AND
FOR MUCH OF THE WEEK.
-LOCALLY HEAVY RAINFALL IS THE MAIN HAZARD THIS WEEK AND COULD
LEAD TO ISOLATED FLASH FLOODING, WITH THE GREATEST POTENTIAL ON
WEDNESDAY, THOUGH THE THREAT LINGERS INTO THURSDAY.
SHORT TERM
(TODAY THROUGH TUESDAY)
ISSUED AT 418 AM EDT MON AUG 11 2025
ANOTHER TRANQUIL EARLY MORNING IS UNDERWAY ACROSS EASTERN
KENTUCKY AS THE REGION REMAINS UNDER THE INFLUENCE OF AN ~1023 MB
SURFACE HIGH PRESSURE CENTERED JUST EAST OF THE DELMARVA
PENINSULA. SKIES ARE CLEAR AND WINDS ARE RELATIVELY LIGHT,
ALLOWING FOR FOG TO DEVELOP AND EXPAND THROUGH MANY OF THE
SHELTERED DEEP RIVER VALLEYS. TEMPERATURES ARE SEASONABLE, RANGING
IN THE MIDDLE TO UPPER 60S. LOOKING ALOFT, 500 HPA RIDGING
EXTENDS FROM THE TENNESSEE VALLEY NORTHEASTWARD ACROSS NEW
ENGLAND. A BROAD TROUGH IS FOUND WEST OF THE RIDGE WITH AN AXIS
EXTENDING FROM MANITOBA TO TEXAS. THIS TROUGH SUPPORTS A COLD
FRONT SPANNING FROM NEAR JAMES BAY SOUTHWESTWARD INTO THE TEXAS
PANHANDLE.
THE 500 HPA RIDGE ALOFT WILL BREAK DOWN TODAY/TONIGHT AND THE
ASSOCIATED SURFACE HIGH WILL DRIFT OFFSHORE AS THE AFOREMENTIONED
UPPER-LEVEL TROUGH SLOWLY PROPAGATES EASTWARD. THE TROUGH WILL BE
FILLING AS IT APPROACHES, BUT WILL STILL CONTRIBUTE TO GRADUAL
HEIGHT FALLS, PRIMARILY DURING THE DAY ON TUESDAY. UPPER-LEVEL
MODEL ANALYSIS DOES FAVOR AN UPPER-LEVEL HIGH CONSOLIDATING
BETWEEN BERMUDA AND THE BAHAMAS LATER TONIGHT AND TUESDAY BUT IT
WILL HAVE LIMITED IMPACTS ON OUR AREA IN THE SHORT-TERM. INSTEAD,
SOUTHERLY RETURN FLOW BETWEEN THE DEPARTING HIGH AND APPROACHING
SURFACE COLD FRONT WILL FUNNEL TROPICAL MOISTURE TOWARD THE OHIO
VALLEY BEGINNING TODAY. INITIALLY, THERE IS ENOUGH OF A DOWNSLOPE
SOUTHEASTERLY COMPONENT IN THE RETURN FLOW TO LIMIT PWAT RISES
TODAY TO AROUND 1.5 INCHES ALONG VIRGINIA-KENTUCKY BORDER AND 1.25
INCHES NORTH OF I-64. WITH THE RISING MOISTURE LEVELS, WE WILL
SEE GREATER DESTABILIZATION THIS AFTERNOON, ESPECIALLY IN THE
VICINITY OF THE VIRGINIA-KENTUCKY BORDER. DIFFERENTIAL SURFACE
HEATING, A SUBTLE PERTURBATION APPROACHING ALOFT, AND THIS
INCREASED MOISTURE/INSTABILITY ARE LIKELY TO BE ENOUGH FOR AT
LEAST SCATTERED CONVECTION TO FIRE OFF OVER THE FIRST TWO TIERS OF
COUNTIES CLOSEST TO VIRGINIA. FURTHER NORTH AND WEST, DEEP
CONVECTION IS STILL POSSIBLE UP TO ABOUT THE MOUNTAIN PARKWAY BUT
IS LIKELY TO BE MUCH MORE ISOLATED. RAP13 SOUNDINGS SUGGEST THAT
CAPE PROFILES MAY BE THICK ENOUGH FOR STRONGER UPDRAFTS TO
OVERCOME VERY WEAK LAPSE RATES (~5.0C/KM) IN THE 700 TO 500 MB
LAYER, SURPASS THE -20C LEVEL AND PRODUCE SPORADIC LIGHTNING,
THOUGH THE BEST CHANCES OF THIS ARE AGAIN OVER THOSE COUNTIES
CLOSE TO VIRGINIA. CONVECTION WILL DIMINISH WITH THE LOSS OF
DAYTIME HEATING THIS EVENING, WITH CLEARING SKIES SETTING THE
STAGE FOR FOG FORMATION IN THE FAVORED LOCALES. AS THE LOW-LEVEL
FLOW TURNS MORE SOUTHWESTERLY, THE MOISTURE ADVECTION WILL BECOME
UNOBSTRUCTED, ALLOWING PWATS TO SURGE TO 1.8+ INCHES ON TUESDAY.
THE DEEPER MOISTURE, SLIGHT STEEPENING OF MID-LEVEL LAPSE RATES,
AND MULTIPLE WEAK PERTURBATIONS EJECTING NORTHEAST FROM THE
APPROACHING TROUGH WILL PROMOTE RAIN CHANCES EXPANDING TO THE
ENTIRE FORECAST AREA.
IN SENSIBLE TERMS, LOOK FOR ANY VALLEY FOG THIS MORNING TO YIELD
TO MOSTLY SUNNY SKIES AREA-WIDE BY MID TO LATE MORNING. AN
EXTENSIVE CUMULUS FIELD SHOULD BUBBLE UP LATE MORNING AND
AFTERNOON WITH THE MOST ROBUST TOWERING CUMULUS MATURING INTO THE
TYPICAL POPUP SHOWERS AND THUNDERSTORMS. LOCATIONS BETWEEN THE HAL
ROGERS PARKWAY/KY-80 CORRIDOR AND THE VIRGINIA-KENTUCKY BORDER
HAVE THE HIGHEST RAIN CHANCES, 40-50 PERCENT, BUT THOSE CHANCES
TAPER OFF FURTHER NORTHWEST TO UNDER 15 PERCENT NORTH OF THE
MOUNTAIN PARKWAY. IT WILL BE HOT WITH HIGH TEMPERATURES IN THE
UPPER 80S TO LOWER 90S AND RISING HUMIDITY LEVELS WILL MAKE IT
FEEL MORE LIKE THE MIDDLE 90S. ANY LEFTOVER CONVECTION SHOULD FADE
THIS EVENING, LEAVING PARTLY CLOUDY SKIES OVERNIGHT. FOG IS A
GOOD BET IN THE FAVORED VALLEY LOCALES. IT WILL BE MILD WITH LOW
TEMPERATURES IN THE MID 60S TO NEAR 70. ON TUESDAY, MOSTLY SUNNY
SKIES FADE TO SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS.
ACTIVITY IS LIKELY TO BE MOST EXTENSIVE SOUTH OF THE MOUNTAIN
PARKWAY. IT WILL AGAIN BE HUMID, BUT NOT AS WARM, WITH HIGH
TEMPERATURES IN THE MID TO UPPER 80S EXPECTED.
LONG TERM
(TUESDAY THROUGH SUNDAY)
ISSUED AT 252 PM EDT SUN AUG 10 2025
A TROUGH, CURRENTLY APPROACHING THE AREA, IS EXPECTED TO BECOME THE
DOMINANT FEATURE FOR THE FIRST PART OF THE PERIOD. THE FORECAST AREA
WILL BE SITUATED BETWEEN THIS UPPER-LEVEL TROUGH, WHICH IS PROJECTED
TO BE OVER THE UPPER MIDWEST, AND A STRONG HIGH-PRESSURE SYSTEM TO
THE SOUTHEAST. ON TUESDAY, THE UPPER-LEVEL TROUGH WILL PIVOT THROUGH
THE GREAT LAKES BUT THE STRENGTH OF THE RIDGE TO THE SOUTHEAST WILL
PREVENT THE TROUGH FROM SHIFTING SOUTHWARD TOWARD THE AREA. HOWEVER,
THE INCREASED SOUTHERLY FLOW WILL STILL PROMOTE THE DEVELOPMENT OF
AFTERNOON SHOWERS AND THUNDERSTORMS.
THE TROUGH WILL CONTINUE TO MOVE THROUGH THE GREAT LAKES REGION. AT
THE SURFACE, A WEAK COLD FRONT WILL SAG SOUTHWARD INTO THE
COMMONWEALTH. THIS FRONTAL FORCING WILL INCREASE THE LIKELIHOOD OF
AFTERNOON SHOWERS AND THUNDERSTORMS ON BOTH WEDNESDAY AND THURSDAY.
FORECAST SOUNDINGS SUGGEST THAT THESE SHOWERS COULD BE EFFICIENT
RAIN PRODUCERS, A RISK REFLECTED IN THE WPCS MARGINAL RISK FOR
EXCESSIVE RAINFALL ON BOTH DAYS. THE GROUND IS CURRENTLY DRY, WHICH
WILL HELP TO MITIGATE IMMEDIATE FLOOD CONCERNS. HOWEVER, IF ANY
AREAS EXPERIENCE REPEATED SHOWERS AND STORMS, LOCALIZED HYDROLOGIC
ISSUES COULD ARISE.
MODEL DATA SUGGESTS THE COLD FRONT MAY STALL AND BECOME STATIONARY
OVER THE OHIO VALLEY. WITH A WEST-TO-EAST ORIENTED BAROCLINIC ZONE
POSITIONED NEAR THE AREA; AS A RESULT, CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE FROM FRIDAY INTO THE WEEKEND. UPPER-
LEVEL RIDGING IS THEN EXPECTED TO REBUILD OVER THE AREA TOWARD THE
END OF THE FORECAST PERIOD.
THE PERIOD WILL BE CHARACTERIZED BY MULTIPLE CHANCES FOR SHOWERS AND
THUNDERSTORMS. TEMPERATURES WILL START IN THE UPPER 80S TO LOW 90S,
WITH A SLIGHT COOL-DOWN EXPECTED MID-WEEK AS THE COLD FRONT
APPROACHES. TEMPERATURES WILL REBOUND BY FRIDAY. OVERNIGHT LOWS WILL
FOLLOW A SIMILAR TREND, AND RIVER VALLEY FOG IS EXPECTED TO FORM
EACH NIGHT.
AVIATION
(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 148 AM EDT MON AUG 11 2025
VFR WAS OBSERVED AT TAF ISSUANCE. FOG IS DEVELOPING IN THE
SHELTERED MAINSTEM RIVER VALLEYS BUT IS NOT FAVORED TO IMPACT THE
TAF SITES. ANY VALLEY FOG SHOULD DISSIPATE BY 13-14Z. MORE
CONVECTION IS EXPECTED DURING PEAK HEATING ON MONDAY, WITH THE
HIGHEST CHANCES GENERALLY OVER THE HIGHER TERRAIN ALONG AND
ADJACENT TO THE VIRGINIA-KENTUCKY BORDER. OUTSIDE OF ANY
CONVECTION, TERMINALS WILL REMAIN DRY WITH VFR CONDITIONS AND
LIGHT AND VARIABLE WINDS UNDER 5KTS.
JKL WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...GEERTSON
LONG TERM...VORST
AVIATION...GEERTSON
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page