007  
FXUS63 KJKL 081207 AAA  
AFDJKL  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE JACKSON KY  
807 AM EDT MON SEP 8 2025  
   
KEY MESSAGES
 
 
 
- BELOW NORMAL TEMPERATURES AND DRY WEATHER WILL PERSIST THROUGH  
TUESDAY.  
 
- TEMPERATURES WILL GRADUALLY WARM TO NEAR NORMAL BY THURSDAY AND  
CONTINUE INTO NEXT WEEK WITH NO RAINFALL EXPECTED.  
 

 
   
UPDATE
 
 
ISSUED AT 805 AM EDT MON SEP 8 2025  
 
VALLEY FOG LINGERS ACROSS MUCH OF THE REGION, BUT HAS BEGUN TO  
LIFT. A FEW MID SLOPE AND RIDGETOP AREAS SUCH AS KBYL, KCPF, AND  
KPBZ ARE REPORTING DENSE FOG. AS WE MOVE THROUGH THE NEXT COUPLE  
OF HOURS THE FOG SHOULD LIFT AND DISSIPATE WITH IMPROVING  
VISIBILITIES IN ALL AREAS BY 9 AM TO 10 AM EDT. OTHERWISE, UNDER  
HIGH PRESSURE, TEMPERATURES WILL MODERATE A COUPLE OF DEGREES  
COMPARED TO SUNDAY, THOUGH STILL PEAK ABOUT 5 DEGREES BELOW NORMAL  
HIGHS FOR THIS DATE.  
 

 
   
SHORT TERM
 
(TODAY THROUGH TUESDAY)  
ISSUED AT 540 AM EDT MON SEP 8 2025  
 
THE PERIOD BEGINS WITH AN UPPER LEVEL LOW CENTERED IN THE  
SOUTHEAST HUDSON BAY/NORTHERN ONTARIO AREAS AND UPPER LEVEL  
TROUGHING SOUTH INTO THE GREAT LAKES AND EASTERN CONUS. THIS  
TROUGHING WAS IN BETWEEN RIDGING IN THE WESTERN ATLANTIC AND  
ANOTHER UPPER RIDGE EXTENDING FROM THE BAJA/PORTIONS OF THE  
PACIFIC INTO THE FOUR CORNERS AND PORTIONS OF THE ROCKIES. WEST  
OF THAT, AN UPPER LEVEL TROUGH IS NEARING THE PACIFIC COAST. AT  
THE SURFACE, A RIDGE OF HIGH PRESSURE EXTENDED FROM THE SOUTHERN  
GREAT LAKES TO MID ATLANTIC SATES AND INTO THE OH VALLEY REGION. A  
FEW MID LEVEL CLOUDS MOVE ACROSS THE REGION OVERNIGHT, BUT SKIES  
HAVE GENERALLY BEEN MOSTLY CLEAR. THIS HAS ALLOWED FOR VALLEY FOG  
TO FORM AND THIS HAS LIKELY BEEN DENSE IN SOME LOCATIONS PER  
REGION KY MESONET CAMERAS. VALLEY TEMPERATURES DROPPED INTO THE  
40S TO NEAR 50 WITH TEMPERATURES GENERALLY IN THE LOW 50S  
ELSEWHERE.  
 
A GENERAL AND GRADUAL INCREASE IN 500 MB HEIGHTS IS PROGGED ACROSS  
THE AREA TODAY AS THE AXIS OF UPPER LEVEL TROUGHING WORKS SLOWLY  
EAST AND NORTHEAST OF EASTERN KY. THIS TREND OF RISING HEIGHTS AT  
500 MB IS EXPECTED TO CONTINUE INTO TONIGHT AS WELL. THIS SHOULD  
OCCUR ALTHOUGH A BROAD UPPER TROUGH SHOULD PERSIST FROM CANADA  
INTO THE MS VALLEY AND PORTIONS OF THE EASTERN CONUS IN BETWEEN  
UPPER LEVEL RIDGING IN THE ATLANTIC AND UPPER LEVEL RIDGING FROM  
NORTHERN MEXICO NORTH INTO PARTS OF THE GREAT BASIN AND ROCKIES  
THAT BUILDS INTO THE PARTS OF THE SOUTHERN PLAINS TO CENTRAL  
PLAINS AND HIGH PLAINS. SFC HIGH PRESSURE REMAINS FROM THE MID  
ATLANTIC AND NORTHEAST INTO PARTS OF THE APPALACHIANS DURING THIS  
TIME DESPITE INVERTED TROUGHING EXTENDING INTO EASTERN KY THAT MAY  
TEND TO DRIFT WESTWARD. THIS INVERTED TROUGHING COULD BE A FOCUS  
FOR A BIT MORE CLOUD COVER AT TIMES. OTHERWISE, DIURNALLY DRIVEN  
CUMULUS SHOULD DEVELOP BOTH TODAY AND ON TUESDAY AFTER OVERNIGHT  
RIVER VALLEY FOG LIFTS AND DISSIPATES. TEMPERATURES WILL GRADUALLY  
MODERATE TODAY AND INTO TUESDAY, HOWEVER THEY SHOULD REMAIN BELOW  
NORMAL.  
   
LONG TERM
 
(TUESDAY NIGHT THROUGH SUNDAY)  
ISSUED AT 500 AM EDT MON SEP 8 2025  
 
THE PERIOD IS EXPECTED TO BEGIN WITH AN UPPER LEVEL RIDGE  
EXTENDING FROM MEXICO TO PORTIONS OF THE ROCKIES AND PLAINS WITH  
ANOTHER UPPER RIDGE IN THE WESTERN ATLANTIC CENTERED NORTHEAST OF  
BERMUDA. IN BETWEEN THESE TWO RIDGES, AN UPPER LEVEL TROUGH AXIS  
IS EXPECTED TO EXTEND SOUTH ACROSS THE GREAT LAKES TO THE MS  
VALLEY WHILE AN UPPER LEVEL LOW/TROUGH WILL CONTINUE TO WORK INTO  
THE WESTERN CONUS. ONE SHORTWAVE WORKING INTO OR THROUGH THE  
EASTERN CANADA TO MS VALLEY TROUGH SHOULD BE NEARING THE LOWER OH  
VALLEY AS THE PERIOD BEGINS WITH ANOTHER UPSTREAM OVER THE UPPER  
MS VALLEY WESTERN GREAT LAKES. AT THE SURFACE, A RIDGE OF HIGH  
PRESSURE IS EXPECTED TO BE ANCHORED FROM NEW ENGLAND TO THE  
SOUTHEASTERN CONUS AND ALSO INTO THE OH VALLEY.  
 
FROM TUESDAY NIGHT TO WEDNESDAY NIGHT, THE INITIAL SHORTWAVE  
TROUGH SHOULD MERGE WITH THE ONE TO THE NORTH THAT WORKS INTO THE  
EASTERN GREAT LAKES TO OH VALLEY WITH THE AXIS OF THIS TROUGH  
REACHING FROM QUEBEC TO THE LOWER OH VALLEY TO TN VALLEY BY LATE  
WEDNESDAY NIGHT. FURTHER EAST RIDGING REMAINS IN THE ATLANTIC  
WHILE UPPER LEVEL RIDGING BUILDS FURTHER INTO THE PLAINS/CENTRAL  
CONUS INCLUDING THE UPPER MS VALLEY. FURTHER WEST, THE UPPER LEVEL  
TROUGH/LOW WORKS SLOWLY ACROSS THE WESTERN CONUS. SFC HIGH  
PRESSURE REMAINS IN PLACE AT THE SURFACE, WITH THE PASSING  
SHORTWAVE OR SHORTWAVES MOISTURE STARVED AND ONLY LEADING TO A FEW  
CLOUDS MAINLY ON WEDNESDAY AFTERNOON AND EVENING. THE AIRMASS  
WILL CONTINUE TO MODERATE AND HIGHS WEDNESDAY SHOULD NEAR NORMALS.  
OTHERWISE, SUFFICIENT BREAKS IN THE CLOUDS AT NIGHT SHOULD FAVOR  
SMALL TO MODERATE RIDGE/VALLEY SPLITS AND VALLEY FOG IN THE  
TYPICALLY FAVORED LOCATIONS BOTH TUESDAY NIGHT AND WEDNESDAY  
NIGHT.  
 
THURSDAY NIGHT TO FRIDAY NIGHT, THE AXIS OF UPPER LEVEL TROUGHING  
WILL SHIFT EAST AND SOUTHEAST OF EASTERN KY THROUGH FRIDAY MORNING  
WITH UPPER LEVEL RIDGING CENTERED OVER THE SOUTHERN PLAINS AND  
EXTENDING ACROSS PARTS OF THE CENTRAL CONUS BUILDING INTO THE  
LOWER TO MIDDLE OH VALLEY AS WELL AS THE TN VALLEY. FURTHER WEST,  
THE UPPER LOW OVER THE WESTERN CONUS SHOULD MEANDER INTO THE  
GREAT BASIN VICINITY. MEANWHILE OVER CENTRAL CANADA AN UPPER LOW  
IS PROGGED TO MOVE FROM HUDSON BAY TO THE JAMES BAY AREA AND  
NORTHERN ONTARIO WITH AN ASSOCIATED SHORTWAVE TRIALING INTO THE  
NORTHERN GREAT LAKES BY LATE FRIDAY NIGHT. A RIDGE OF SFC HIGH  
PRESSURE SHOULD REMAIN IN PLACE ACROSS EASTERN KY DURING THIS TIME  
AS WELL. THE AIRMASS WILL WARM A BIT FURTHER WITH NEAR NORMAL  
HIGHS ANTICIPATED FOR FRIDAY. THURSDAY NIGHT AND FRIDAY NIGHT  
SHOULD FEATURE MORE OF THE SAME AS FAR AS SMALL TO MODERATE  
RIDGE/VALLEY TEMPERATURE SPLITS AND FOG DEVELOPMENT IN THE FAVORED  
VALLEY LOCATIONS.  
 
SATURDAY TO SUNDAY, RECENT GUIDANCE GENERALLY HAS AN UPPER LEVEL  
TROUGH AXIS NEARING A MARITIMES TO ST LAWRENCE VALLEY TO GREAT  
LAKES DURING THIS TIMEFRAME AND UPPER LEVEL RIDGING REMAINING  
FROM THE SOUTHERN PLAINS IN PORTIONS OF THE CENTRAL CONUS AND  
ANOTHER UPPER LEVEL TROUGH NEARING THE WEST COAST OF THE CONUS. A  
FEW SHORTWAVES MAY MOVE INTO PARTS OF THE OH VALLEY TO END THE  
PERIOD. THESE SYSTEMS AND ANY ASSOCIATED COLD FRONTS DROPPING  
ACROSS THE GREAT LAKES SHOULD BE RATHER MOISTURE STARVED WHILE SFC  
HIGH PRESSURE IS PROGGED TO REMAIN OVER THE SOUTHERN APPALACHIANS  
TO TN VALLEY REGIONS. GUIDANCE IS LARGELY RAIN FREE THROUGH THE  
END OF THE PERIOD, THOUGH SOME RECENT ECMWF RUNS HAVE PRECIPITATION  
REACHING NEAR THE OH RIVER OR SOUTH NEAR OR AFTER THE END OF THE  
PERIOD. 10 PERCENT POPS IN THE NORTH IS REASONABLE FOR NOW WITH  
SOME UNCERTAINTY IN THE TIMING AND EVOLUTION OF THE UPPER  
TROUGH/LOW. TEMPERATURES SHOULD REMAIN NEAR NORMAL FOR THIS TIME  
OF YEAR NEXT WEEKEND.  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)  
ISSUED AT 807 AM EDT MON SEP 8 2025  
 
OTHER THAN A FEW PATCHES OF MID LEVEL CLOUDS AT ISSUANCE TIME,  
SKIES WERE CLEAR ACROSS EASTERN KY WITH HIGH PRESSURE CENTERED  
OVER THE SOUTHERN GREAT LAKES DOMINATING THE WEATHER. VALLEY FOG  
DEVELOPED OVERNIGHT, BUT HAS NOT AFFECTED THE TAF SITES. SOME  
LOCATIONS CURRENTLY AFFECTED INCLUDE NON TAF SITE LOCATIONS KBYL,  
KCPF, AND KPBZ. WE CURRENTLY EXPECT ALL THE FOG WILL CLEAR OUT  
WITHIN 2 TO 3 HOURS AFTER SUNRISE, OR BY 9 TO 10 AM EDT, LEAVING  
VFR CONDITIONS BEHIND FOR ALL. WINDS WILL REMAIN LIGHT AND  
VARIABLE OVERNIGHT AND NORTHEAST TO EAST AT LESS THAN 10KT  
THEREAFTER, UNTIL BECOMING LIGHT AND VARIABLE TOWARD 00Z. NON TAF  
SITE LOCATIONS SHOULD EXPERIENCE REDUCTIONS TO MVFR OR LOWER AFTER  
ABOUT 04Z THROUGH THE END OF THE TAF PERIOD.  
 

 
   
JKL WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
UPDATE...JP  
SHORT TERM...JP  
LONG TERM...JP  
AVIATION...JP  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab KY Page Main Text Page