456
FXUS63 KJKL 090738
AFDJKL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
338 AM EDT SAT AUG 9 2025
KEY MESSAGES
-THE WEEKEND LOOKS GREAT, WITH MAINLY DRY CONDITIONS AND WARM
TEMPERATURES EXPECTED FOR BOTH SATURDAY AND SUNDAY, MAKING IT
GREAT FOR OUTDOOR PLANS.
-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.
SHORT TERM
(TODAY THROUGH SUNDAY)
ISSUED AT 338 AM EDT SAT AUG 9 2025
A FEW HIGH CLOUDS ARE DRIFTING ACROSS EASTERN KENTUCKY EARLY THIS
MORNING AS FOG THICKENS AND EXPANDS THROUGH THE MAINSTEM RIVER
VALLEYS. TEMPERATURES ARE SEASONABLY MILD, RANGING IN THE MID TO
UPPER 60S. THE QUIET WEATHER IS COURTESY OF AN ELONGATED ~1026 MB
SURFACE HIGH PRESSURE CENTERED SOUTHEAST OF NOVA SCOTIA WITH A
PRONOUNCED SURFACE RIDGE EXTENDING SOUTHWEST ALONG THE SPINE OF
THE APPALACHIANS. ALOFT, A 595 DAM HIGH IS CENTERED OVER SOUTHWEST
NEW MEXICO WITH RIDGING EXTENDING NORTHEAST INTO THE OHIO VALLEY
AND THEN NORTHWARD TOWARD THE JAMES BAY. A WEAKNESS IN THE RIDGE
IS NOTED FROM THE LOWER MISSISSIPPI VALLEY TO THE MID-ATLANTIC
WITH STRONGER RIDGING EAST OF THE BAHAMAS. NORTHWEST OF THE RIDGE,
AN ~561 DAM LOW IS PASSING JUST NORTH OF THE US/CANADIAN BORDER
AND IS CENTERED OVER THE SASKATCHEWAN PRAIRIES. AN ASSOCIATED
OCCLUDING SURFACE LOW IS PASSING OVER SOUTHERN MANITOBA WHILE ITS
COLD FRONT EXTENDS DOWN INTO MINNESOTA AND THEN SOUTHWEST INTO
COLORADO AND WESTWARD THROUGH THE CENTRAL ROCKIES.
HEIGHTS OVER EASTERN KENTUCKY WILL REMAIN NEARLY STEADY TODAY AND
TONIGHT AS THE UPPER LEVEL RIDGE AXIS SHIFTS EASTWARD INTO NEW
ENGLAND. ON SUNDAY, HEIGHTS RISE SLIGHTLY OVER THE COMMONWEALTH AS
THE HIGH CENTER OVER THE DESERT SOUTHWEST DISSIPATES AND IS
REPLACED BY A LOOSELY DEFINED UPPER LEVEL HIGH CENTERED SOUTH OF
BERMUDA. THE UPPER LEVEL LOW TO OUR NORTHWEST OPENS INTO A BROADER
TROUGH WITH ITS ASSOCIATED ENERGY EJECTING TOWARD THE HUDSON BAY.
THE SYSTEMS ASSOCIATED COLD FRONT ONLY MAKES SLOW SOUTHEASTWARD
PROGRESS, DOZENS TO A FEW HUNDRED MILES, THROUGH THE SHORT-TERM
PERIOD. OVER EASTERN KENTUCKY, ABUNDANT MID-LEVEL DRY AIR AND WEAK
LAPSE RATES WILL LARGELY KEEP A LID ON THE THUNDERSTORM THREAT
FOR TODAY AND TOMORROW. WITH THAT BEING THE CASE, MODEL SOUNDINGS
STILL SUGGEST THAT TOWERING CUMULUS COULD REACH SUFFICIENT DEPTH,
GENERALLY SOUTHWEST OF US-421, FOR ISOLATED SPRINKLES OR PIN-PRICK
SHOWERS THIS AFTERNOON AND EVENING. FORCING IS MEAGER WITH SUBTLE
500MB POSITIVE VORTICITY ADVECTION IN THIS AREA. LITTLE IN THE
WAY OF CLOUD COVER TONIGHT WILL ONCE AGAIN FAVOR FOG FORMATION IN
THE TYPICAL RIVER VALLEY LOCALES. ON SUNDAY, SMALL HEIGHT RISES
WILL FURTHER STRENGTHEN AND LOWER THE CAP, PERHAPS SUFFICIENTLY
STRONG TO PRECLUDE ANY SHOWER/SPRINKLE ACTIVITY AT ALL.
IN MORE SENSIBLE TERMS, LOOK FOR ANY RIVER VALLEY FOG TO
LIFT/DISSIPATE BY 9 TO 10 AM WITH MOSTLY SUNNY SKIES THROUGH THE
REMAINDER OF THE DAY. A STRAY SHOWER OR SPRINKLE (UNDER 20 PERCENT
CHANCE) IS IN THE FORECAST FOR LOCATIONS NEAR/SOUTHWEST OF
US-421, BUT A VAST MAJORITY OF THE AREA WILL REMAIN RAIN-FREE. IT
WILL BE HOT WITH HIGH TEMPERATURES IN THE UPPER 80S TO NEAR 90F AT
MOST LOCATIONS. MOSTLY CLEAR SKIES FOLLOW FOR TONIGHT WITH SOME
FOG IN THE FAVORED VALLEY SPOTS. TEMPERATURES WILL BE VERY
COMFORTABLE, DIPPING BACK INTO THE MID 60S, EXCEPT LOW 60S IN THE
COOLEST HOLLOWS. ON SUNDAY, LOOK FOR MOSTLY SUNNY SKIES AND
TEMPERATURES REBOUNDING TO BETWEEN 87F AND 91F.
LONG TERM
(SUNDAY THROUGH FRIDAY)
ISSUED AT 502 PM EDT FRI AUG 8 2025
AFTER A SUNNY SUNDAY DOMINATED BY ATMOSPHERIC RIDGING, A PATTERN
SHIFT WILL FAVOR MORE ACTIVE WEATHER IN EASTERN KENTUCKY FOR MUCH OF
THE NEXT WORK WEEK. THE FORECAST GUIDANCE SUITE GENERALLY AGREES
UPON THE TIMING/POSITIONING OF THE SYNOPTIC-SCALE FEATURES
RESPONSIBLE FOR THIS PATTERN SHIFT, AND THIS LEADS TO GENERALLY HIGH
LEVELS OF CONFIDENCE IN THE BASELINE NBM FORECAST DATA USED TO
POPULATE THE LONG TERM GRIDS. THEREFORE, ONLY MINOR, CLIMATOLOGY-
BASED GRID EDITS WERE NEEDED WITH THIS FORECAST PACKAGE ISSUANCE.
WHEN THE PERIOD OPENS ON SUNDAY MORNING, MODELS COLLECTIVELY RESOLVE
A BROAD 500MB RIDGE STRETCHING UP FROM THE GULF COAST TOWARDS LAKE
ONTARIO. AT THE SAME TIME, UPPER LEVEL TROUGHING AND A RELATED
SURFACE COLD FRONT WILL EXTEND FROM SOUTH-CENTRAL CANADA DOWN INTO
THE UPPER MIDWEST. EASTERN KENTUCKY WILL BEGIN THE PERIOD POSITIONED
JUST TO THE RIGHT OF THE RIDGE'S AXIS; THIS FAVORS A SURFACE WEATHER
MAP REFLECTION OF NEARBY HIGH PRESSURE AND WEAK ANTICYCLONIC FLOW.
THE RESULTANT SENSIBLE WEATHER SHOULD BE MOSTLY SUNNY, WITH HIGHS IN
THE UPPER 80S TO LOWER 90S. SUBSIDENCE AND HEIGHT RISES SHOULD
PREVENT ANY DIURNALLY-DRIVEN CUMULUS CLOUDS FROM DEVELOPING INTO
MEANINGFUL SHOWERS/STORMS ON SUNDAY. OVERNIGHT, EXPECT RIDGE-VALLEY
TEMPERATURE SPLITS. VALLEY LOCATIONS ARE POISED TO COOL DOWN INTO
THE MID 60S, AND RIVER VALLEY FOG HAS BEEN ADDED TO THE FORECAST
GRIDS ACCORDINGLY. THE WARMER RIDGETOPS SHOULD REMAIN CLEARER AND IN
THE 68-70 RANGE. GIVEN ALL OF THE ABOVE, SUNDAY'S FORECAST LOOKS
SEASONABLY PLEASANT FOR ANY PLANNED OUTDOOR ACTIVITIES AND EVENTS.
ON MONDAY, THE AFOREMENTIONED RIDGE AXIS IS EXPECTED TO SHIFT
FURTHER TO THE EAST AND PLACE THE REGION ON THE WESTERN SIDE OF THE
RELATED SURFACE HIGH PRESSURE SYSTEM. IN RESPONSE TO THIS SHIFT,
ATMOSPHERIC FLOW IS FORECAST TO GRADUALLY VEER TOWARDS THE SOUTHWEST
EARLY NEXT WEEK AND FOSTER MOISTURE RETURN. AS THIS OCCURS, THE
MIDWESTERN COLD FRONT IS EXPECTED TO LOSE ITS UPPER ATMOSPHERIC
SUPPORT AND STALL OUT TO THE NORTH OF THE OHIO RIVER. WITH NO CLEAR
FRONTAL PASSAGE, HIGHS ARE FORECAST TO REMAIN IN THE UPPER 80S/LOWER
90S ON MONDAY AND TUESDAY. THESE WARM TEMPERATURES, COMBINED WITH
INCREASING AMOUNTS OF ATMOSPHERIC MOISTURE, WILL USHER DIURNALLY-
DRIVEN SCATTERED SHOWERS AND THUNDERSTORMS BACK INTO THE FORECAST ON
MONDAY AND TUESDAY AFTERNOONS.
RIDGING IS EXPECTED TO BUILD BACK OVER THE SOUTHEASTERN AND SOUTH-
CENTRAL CONUS BY MID-WEEK, PLACING THE GREATER OHIO RIVER VALLEY IN
A REGIME OF QUASI-ZONAL FLOW. A SERIES OF SHORTWAVE DISTURBANCES ARE
LIKELY TO RIDE THE RIDGE TOWARDS THE FORECAST AREA IN THE WEDNESDAY-
FRIDAY TIME FRAME, AND POPS REMAIN IN THE FORECAST THROUGH THE END
OF THE PERIOD AS A RESULT OF THIS ACTIVITY. THE LATEST
DETERMINISTIC RUNS OF BOTH THE GFS AND THE EURO SHOW A BETTER-
DEFINED SHORTWAVE TROUGH MOVING THROUGH THE COMMONWEALTH ON
WEDNESDAY, AND THIS MIRRORS THE TIMING OF THE HIGHEST POP GRIDS IN
THE NBM. IF THE GREATER CONVECTIVE COVERAGE ON WEDNESDAY COMES TO
FRUITION, FORECAST HIGHS COULD UNDER-PERFORM AND BE RELEGATED TO THE
LOW/MID-80S DUE TO THE RELATED INCREASE IN CLOUD COVER. IN A SIMILAR
MANNER, IF THESE CLOUDS LINGER OVERNIGHT INTO THURSDAY, THEY COULD
ALSO MITIGATE THE CLIMATOLOGICALLY-EXPECTED RIDGE-VALLEY TEMPERATURE
SPLITS AND LIMIT OVERNIGHT VALLEY FOG FORMATION. AS WEDNESDAY'S
FORECAST COMES WITHIN THE TEMPORAL RANGE OF HIGHER-RESOLUTION
MODELING, MESOSCALE TRENDS IN THE ABOVE VARIABLES WILL NEED TO BE
MONITORED CLOSELY. TRENDS IN MESOSCALE CONVECTIVE PARAMETERS WILL
ALSO NEED TO BE MONITORED. THE SYNOPTIC SIGNAL FOR ORGANIZED, STRONG-
TO-SEVERE CONVECTION IS UNREMARKABLE NEXT WEEK, WITH LREF JOINT
PROBABILITIES FOR FAVORABLE CAPE/CIN/SHEAR PARAMETERS GENERALLY LESS
THAN 20%. HOWEVER, INCREASING AMOUNTS OF SBCAPE AND INCREASING PWAT
VALUES (MEAN GRAND ENSEMBLE VALUES OF > 1.75 INCHES ON TUESDAY AND
WEDNESDAY) MEAN THAT ANY STORM THAT DOES DEVELOP NEXT WEEK COULD
PRODUCE LOCALLY HEAVY RAINFALL AND BRIEF BURSTS OF GUSTY WINDS.
IN SHORT, EXPECT ANOTHER WEEK OF TYPICAL DIURNAL SUMMERTIME
CONVECTION IN EASTERN KENTUCKY AND TYPICAL SUMMERTIME MAXTS IN THE
MID/UPPER 80S. THE INCREASE IN HUMIDITY ALONGSIDE THESE HIGHS WOULD
TYPICALLY POINT TOWARDS HEAT CONCERNS, BUT THE DAILY RAIN CHANCES
SHOULD PROVIDE LOCALIZED RELIEF AND REDUCE THE LIKELIHOOD/SPATIAL
COVERAGE OF HEAT INDICES ABOVE 100. THUS, THE MAIN IDEA OF THIS
PARTICULAR LONG TERM FORECAST PACKAGE IS THE SHIFT TOWARDS A MORE
ACTIVE PATTERN.
AVIATION
(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 141 AM EDT SAT AUG 9 2025
VALLEY FOG IS FORECAST THROUGH MID-MORNING SATURDAY, WITH
LOCALIZED IFR OR WORSE CONDITIONS. HOWEVER, TAF LOCATIONS ARE
LIKELY TO EVADE. OTHERWISE, VFR CONDITIONS ARE EXPECTED THROUGH
THE PERIOD.
JKL WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...GEERTSON
LONG TERM...MARCUS
AVIATION...GEERTSON/HAL
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page