633
FXUS63 KJKL 301939
AFDJKL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON KY
339 PM EDT THU JUL 30 2026
KEY MESSAGES
- DRIER WEATHER WITH MODESTLY LOWER HUMIDITY WILL PREVAIL THROUGH
THE END OF THE WORK WEEK.
- THUNDERSTORMS ARE POSSIBLE AT TIMES FROM SATURDAY THROUGH
WEDNESDAY.
- LOCALLY HEAVY RAINFALL IS POSSIBLE ON SATURDAY AND SATURDAY
NIGHT AND COULD LEAD TO ISOLATED INSTANCES OF FLASH FLOODING.
SHORT TERM
(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 339 PM EDT THU JUL 30 2026
AT 19Z, VISIBLE SATELLITE SHOWS MOSTLY SUNNY SKIES WITH A CU FIELD
STREAMING ACROSS THE AREA FROM THE NORTH, AS THEY ROTATE AROUND
NEARBY HIGH PRESSURE. ANALYZING THE 500-MB HEIGHT CHARTS, SOME
PROMINENT FEATURES ARE THE UPPER LEVEL LOW OVER NORTHERN NEW
ENGLAND, WITHIN A SUBSEQUENT TROUGH EXTENDING SOUTH ALONG THE
EASTERN US COASTLINE. WEAK RIDGING CAN BE SEEN FURTHER WEST OVER THE
UPPER MIDWEST, AND MISSISSIPPI VALLEY. AN AREA OF LOW PRESSURE OVER
THE NORTHERN PLAINS IS NORTH OF A SOUTHWESTERN HIGH OVER NEW MEXICO.
STEPPING THROUGH THIS EVENING AND FRIDAY, THE OVERALL PATTERN SHIFTS
EASTWARD, AS THE COASTAL TROUGH CONTINUES TO PROGRESS TOWARDS THE
ATLANTIC. HIGH PRESSURE CONTINUES TO BUILD INTO THE OHIO VALLEY AND
TENNESSEE VALLEY AS THE NORTHERN PLAINS LOW PRESSURE BEGINS TO DIG
INTO WESTERN PORTIONS OF THE OHIO VALLEY.
FOR SENSIBLE WEATHER, EXPECT MOSTLY CLEAR SKIES THIS EVENING, AS
TEMPERATURES COOL FROM THEIR CURRENT UPPER 70S TO LOWER 80S INTO THE
LOWER 60S ALONG RIDGE TOPS, AND UPPER 50S IN VALLEYS. PATCHY RIVER
VALLEY FOG IS EXPECTED TO DEVELOP OVERNIGHT, BEFORE MIXING OUT
BETWEEN 8 AND 9 AM FRIDAY MORNING.
WITH HIGH PRESSURE BRIEFLY BUILDING IN ON FRIDAY, MID TO UPPER 80S
ARE EXPECTED UNDER LIGHT EASTERLY WINDS. SKIES WILL BE A MIX OF SUN
AND CLOUDS, WITH NOTABLE INCREASING CLOUDS HEADING INTO THE EVENING
AND OVERNIGHT HOURS. THIS IS DUE TO THE APPROACHING SYSTEM.
TEMPERATURES WILL COOL INTO THE MID TO UPPER 60S. AS THE SURFACE LOW
DIGS INTO THE MID-MISSISSIPPI VALLEY OVERNIGHT, THE SYSTEMS WARM
FRONT AND EVENTUAL COLD FRONT WILL APPROACH PORTIONS OF KENTUCKY
TOWARDS SATURDAY MORNING. SOME ISOLATED TO SCATTERED SHOWERS AND
STORMS WILL BE POSSIBLE HEADING INTO SATURDAY MORNING, MAINLY ALONG
AND WEST OF THE CUMBERLAND PLATEAU.
LONG TERM
(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 435 AM EDT THU JUL 30 2026
THE MAIN CHANGE TO THE GRIDS FOR THE FIRST PART OF THE EXTENDED
FORECAST THIS MORNING WAS PRIMARILY TO INCLUDE MORE IN THE WAY OF
POP DETAILS AND TIMING PER THE LATEST CAMS GUIDANCE ON SATURDAY.
IT STILL LOOKS LIKE THIS NEXT SYSTEM IS ABLE TO TAKE ADVANTAGE OF
INCREASING MOISTURE POOLING AND A DIGGING MID LEVEL TROUGH
CROSSING INTO KENTUCKY THIS WEEKEND TO BRING AN INCREASING THREAT
FOR HEAVY RAIN - MAINLY ON SATURDAY AND SATURDAY NIGHT. THE SFC
PATTERN WILL FEATURE A DEEPENING AND COMPACT LOW PRESSURE SYSTEM
ROLLING INTO THE STATE ON SATURDAY AND SATURDAY NIGHT LIFTING AND
CONCENTRATING THE AVAILABLE MOISTURE - YIELDING A POTENTIAL FOR
HEAVY TO EXCESSIVE RAIN. EXPECT THE QUICK ARRIVAL OF CONVECTION
BY MIDDAY SATURDAY TO LIMIT THE INSTABILITY THAT CAN BUILD UP SO
THAT ONLY A SMALL THREAT FOR ORGANIZED OR SEVERE STORMS ARE
ANTICIPATED DESPITE SEMI-FAVORABLE WIND SHEAR WORKING OVER THE
CWA.
THE PREVIOUS LONG TERM DISCUSSION FOLLOWS:
THE LONG-TERM PERIOD OPENS FRIDAY MORNING WITH AN UPPER-LEVEL TROUGH
AXIS EXTENDING FROM ATLANTIC CANADA SOUTHWARD ALONG THE ATLANTIC
SEABOARD. MEANWHILE, AN ~588 DAM HIGH WILL BE IN PLACE OVER
ARIZONA AND NEW MEXICO WITH BROAD RIDGING EXTENDING TO THE NORTH
ACROSS THE CANADIAN PRAIRIES. LESS PROMINENT RIDGING EXTENDS EAST
AND NORTHEAST FROM THE HIGH TO ACROSS THE MID-MISSISSIPPI VALLEY,
OHIO VALLEY, AND BEYOND INTO SOUTHWEST QUEBEC. A SHARPENING AND
DIGGING UPPER-LEVEL SHORTWAVE TROUGH IS ALSO SLIDING ACROSS THE
UPPER MIDWEST THROUGH THE EASTERN SIDE OF THE RIDGE. AT THE
SURFACE, HIGH PRESSURE, CENTERED OVER WEST VIRGINIA, DOMINATES THE
THE CENTRAL APPALACHIANS AND INTO ADJACENT REGIONS. MEANWHILE,
LOW PRESSURE IS CONSOLIDATING FROM KANSAS TO IOWA AHEAD OF THE
SHORTWAVE TROUGH (AND WILL BECOME OUR MOST SIGNIFICANT WEATHER
MAKER OF THE FORECAST PERIOD).
THE SURFACE HIGH PRESSURE SYSTEM AND ASSOCIATED SHORTWAVE RIDGING
ALOFT WILL SHIFT EAST TO ALONG THE ATLANTIC SEABOARD BY THE END
OF THE DAY FRIDAY WHILE THE DEEPENING 500 HPA SHORTWAVE DIVES
SOUTHEAST AND THE ATTENDANT SURFACE LOW TRACKS ACROSS THE MID-
MISSISSIPPI VALLEY, MOVING DIRECTLY OVER THE COMMONWEALTH SATURDAY
NIGHT. SOME OF THE ENERGY WITHIN THIS TROUGH WILL BE CAPTURED BY
A BROADER 500 HPA TROUGH PIVOTING THROUGH EASTERN CANADA AND THE
GREAT LAKES. GUIDANCE SUGGESTS WHATEVER ENERGY REMAINS PINCHES OFF
INTO A CLOSED LOW THAT THEN RETROGRADES TOWARD THE LOWER MISSISSIPPI
VALLEY EARLY NEXT WEEK AND BECOMES ENTRAPPED UNDER THE EASTWARD-
BUILDING 500 HPA RIDGING. AS A RESULT, THE SURFACE LOW WILL
OCCLUDE, SINK SOUTHWARD, AND DECAY ON MONDAY. MEANWHILE, A COLD
FRONT ASSOCIATED WITH THE TROUGH PASSING THROUGH THE NORTHEAST
WILL BRUSH TO OUR NORTH AND EAST.
AS THE LOW PRESSURE SYSTEM APPROACHES, SOUTHERLY FLOW WILL SEND PWATS
RISING TO 1.75+ INCHES (AROUND 80TH PERCENTILE RELATIVE TO CLIMO) ON
SATURDAY, BUT THOSE HIGHER VALUES WILL BE SHORT-LIVED OVERALL AS
DRIER AIR SINKS BACK IN FROM THE NORTH BEHIND THE RETROGRADING LOW
AND TROUGH BRUSHING TO OUR NORTH. WPC HAS A MARGINAL TO SLIGHT
RISK FOR EXCESSIVE RAINFALL OVER THE JKL CWA ON SATURDAY AND
SATURDAY NIGHT TO ACCOUNT FOR THE POTENTIAL OF LOCALLY HEAVY
RAINFALL, WHICH IS THE MAIN CONCERN IN THE LONG-TERM PERIOD.
HOWEVER, SEVERAL DAYS OF ANTECEDENT DRYING AS WELL AS THE OVERALL
PROGRESSIVE NATURE OF THE SYSTEM SHOULD HELP MITIGATE HYDRO
CONCERNS. FORTUNATELY, THE INSTABILITY AND SHEAR PARAMETER SPACE
REMAINS WEAK AND THAT SHOULD PRECLUDE ANY NOTABLE SEVERE
CONVECTIVE WEATHER THREAT.
SENSIBLY, LOOK FOR INCREASING CLOUDS ON FRIDAY AND FRIDAY NIGHT WITH
HIGH TEMPERATURES IN THE LOWER TO MID 80S AND LOW TEMPERATURES IN
THE LOWER TO MIDDLE 60S. RAIN CHANCES RETURN ON SATURDAY AND PEAK
AT CATEGORICAL POPS SATURDAY NIGHT AND EARLY SUNDAY MORNING.
DAILY RAIN CHANCES FOLLOW FOR MONDAY THROUGH WEDNESDAY, BUT
CONVECTIVE COVERAGE SHOULD BE MORE SPARSE AND MODULATED BY THE
DIURNAL HEATING CYCLE. TEMPERATURES WILL CONTINUE TO RUN IN THE
LOWER TO MIDDLE 80S FOR HIGHS EACH AFTERNOON (EXCEPT UPPER 70S FOR
SOME LOCATIONS ON SUNDAY), WHILE NIGHTTIME LOWS DIP INTO THE 65
TO 70 DEGREE RANGE FOR MOST.
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 123 PM EDT THU JUL 30 2026
VFR CONDITIONS WILL PREVAIL THROUGH THE 18Z TAF PERIOD, WITH
MOSTLY CLEAR SKIES AND LIGHT AND VARIABLE WINDS. PATCHY VALLEY
FOG MAY DEVELOP THIS EVENING BUT SHOULDN'T EFFECT ANY TAF SITES,
AND WILL BE FAVORED AROUND OR NEAR RIVER VALLEY LOCATIONS. ONCE
THE VALLEY FOG MIXES OUT AROUND 13-14Z, EXPECT SIMILAR CONDITIONS
TO THOSE OF THURSDAY WITH LIGHT EASTERLY WINDS DEVELOPING FRIDAY
AFTERNOON.
JKL WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...GINNICK
LONG TERM...GEERTSON/GREIF
AVIATION...GINNICK
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