378  
FXUS63 KJKL 021558  
AFDJKL  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE JACKSON KY  
1158 AM EDT THU JUL 2 2020  
   
UPDATE
 
 
ISSUED AT 1158 AM EDT THU JUL 2 2020  
 
THE LAST OF THE MORNING LOW CLOUDS OVER THE THE CUMBERLAND BASIN HAVE  
FINALLY LIFTED AND BROKEN UP. FORECAST IS ON TRACK AND HAS ONLY  
BEEN UPDATED TO BLEND IN LATE MORNING OBS. |  
 
UPDATE ISSUED AT 915 AM EDT THU JUL 2 2020  
 
FOG AND LOW CLOUDS WERE VERY EXTENSIVE OVER THE SOUTHERN AND  
SOUTHEASTERN PORTIONS OF THE FORECAST AREA EARLY THIS MORNING, AND  
ARE TAKING SOME TIME TO DISSIPATE. HAVE UPDATED THE FORECAST TO  
TAKE THIS INTO ACCOUNT.  
 
UPDATE ISSUED AT 711 AM EDT THU JUL 2 2020  
 
IT'S A FOGGY MORNING ACROSS EASTERN KENTUCKY, ESPECIALLY IN THE  
DEEPER RIVER VALLEYS AND LOCATIONS SOUTH OF JKL. OBS SITES ARE  
CURRENTLY REPORTING THEIR LOWEST VIS, BUT FOG SEEMS TO BE LIFTING,  
AND ONLY A FEW OF OUR WEBCAMS ARE SHOWING CONTINUED DENSE FOG. AS  
SUCH, WILL KEEP WITH THE SPS FOR FOG AT THIS TIME, AS IT SHOULD  
CONTINUE TO LIFT AND IMPROVE OVER THE NEXT COUPLE OF HOURS.  
OTHERWISE, FORECAST SEEMS TO BE IN GOOD SHAPE. LOADED IN THE  
LATEST OBSERVATIONS FOR TEMPS, DEW POINTS, AND WINDS TO MAKE SURE  
THE NEAR TERM GRIDS WERE ON TRACK WITH THE CURRENT CONDITIONS.  
THIS ONLY RESULTED IN VERY MINOR CHANGES. TEMPERATURES SHOULD  
START WARMING FAIRLY QUICKLY OVER THE COMING HOURS.  
 

 
   
SHORT TERM
 
(TODAY THROUGH FRIDAY)  
ISSUED AT 411 AM EDT THU JUL 2 2020  
 
A DRY AIRMASS IS TRYING TO MOVE IN ALOFT, BUT MEANWHILE ABUNDANT  
LLVL MOISTURE REMAINS TRAPPED NEAR THE SURFACE. THIS HAS CREATED AN  
IDEAL SCENARIO FOR FOG DEVELOPMENT DURING THE OVERNIGHT AND EARLY  
MORNING HOURS. THE BEST FOG HAS SET UP IN THE RIVER VALLEY  
LOCATIONS, AS IS EVIDENT ON THE VISIBLE SATELLITE IMAGERY. HOWEVER,  
EVEN HIGHER ELEVATION OBSERVING SITES ARE REPORTING SOME FOG  
IMPACTS. AS A RESULT, WENT WITH GENERALLY AREAS OF FOG ACROSS THE  
ENTIRE CWA AND INCLUDED PATCHY DENSE FOG IN THE DEEPER RIVER  
VALLEYS. ALSO ISSUED AN SPS TO COVER THE FOG IMPACTS THROUGH THE  
MORNING COMMUTE.  
 
AFTER THE FOG DISSIPATES BETWEEN 8 AND 9AM, WE ARE LOOKING AT A  
PRETTY NICE DAY ACROSS EASTERN KENTUCKY. BOTH AN UPPER LEVEL AND A  
SURFACE HIGH PRESSURE SYSTEM WILL CONTINUE TO WORK INTO THE REGION  
FROM THE NNW, AND WILL THEN REMAIN IN CONTROL THROUGH THE REST OF  
THE SHORT TERM FORECAST. OUR LOCATION TO THE SE OF THE APPROACHING  
HIGH PRESSURE SYSTEM WILL KEEP WINDS ACROSS THE CWA GENERALLY NORTH  
TO NORTHEAST TODAY AND FRIDAY. HOWEVER, DESPITE THE FLOW, ABUNDANT  
SUNSHINE DURING THIS TIME OF THE YEAR WILL OUTWEIGH THE LIGHT  
NORTHERLY WIND FLOW. HIGHS TODAY AND FRIDAY WILL BE WARMER THAN THAT  
OF YESTERDAY, WITH UPPER 80S TO AROUND 90 DEGREES ON TAP.  
UNFORTUNATELY, EVEN THOUGH HIGH PRESSURE AND DRIER AIR IS MOVING  
INTO PLACE, WE WON'T LOSE ALL OF OUR LLVL MOISTURE IMMEDIATELY. SO  
CONDITIONS MAY REMAIN A BIT HUMID THROUGHOUT THE DAY, BUT SHOULD BE  
ON A DIMINISHING TREND.  
 
WITH MOSTLY CLEAR SKIES ALSO ON TAP FOR THE UPCOMING NIGHT, CAN'T  
RULE OUT SOME RIDGE/VALLEY SPLITS IN THE TEMPERATURES. THERE IS ALSO  
THE POTENTIAL FOR MORE FOG DEVELOPMENT. THOUGH HOPEFULLY THE  
CONTINUED INFLUX OF DRIER AIR WILL HELP TO SETTLE THE IMPACTS  
COMPARED TO THAT OF THE CURRENT FOG.  
   
LONG TERM
 
(FRIDAY NIGHT THROUGH WEDNESDAY)  
ISSUED AT 415 AM EDT THU JUL 2 2020  
 
THE MODELS CONTINUE TO BE IN GOOD AGREEMENT ALOFT ON THE MAIN  
ELEMENTS OF THE LONGWAVE PATTERN OVER THIS PART OF THE NATION DURING  
THE EXTENDED PORTION OF THE FORECAST. THEY ALL DEPICT GENERAL  
RIDGING IN PLACE OVER THE MID MISSISSIPPI VALLEY, COVERING MUCH OF  
THE TENNESSEE AND OHIO VALLEYS, AS WELL, WITH VARYING DEGREES OF  
WEAKNESS EMBEDDED WITHIN THE MOSTLY LIGHT MID LEVEL FLOW. THROUGHOUT  
THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK HEIGHTS OVER EASTERN  
KENTUCKY WILL BE MAINLY ABOVE 585 DECAMETERS AT 500MB. THE ECMWF  
TENDS TO BE A TAD STRONGER WITH THIS RIDGE THAN THE GFS BUT WITH NO  
WAVES OF SIGNIFICANCE ALOFT DURING THIS TIME THOSE DIFFERENCES ARE  
OF A MINOR CONCERN. GIVEN THIS BROAD AGREEMENT HAVE FAVORED THE  
BLENDED NBM STARTING POINT TO THE GRIDS WITH NO LARGE SCALE  
ADJUSTMENTS.  
 
SENSIBLE WEATHER WILL FEATURE A VERY TYPICAL SUMMER PATTERN WHERE  
TEMPERATURES WIND UP ON THE WARM SIDE OF NORMAL (IN THE UPPER 80S TO  
NEAR 90 FOR HIGHS AND MID 60S TO LOW 70S FOR LOWS) AND THE  
CONVECTION IS ALMOST ENTIRELY DRIVEN BY DIURNAL TRENDS. WHILE  
SATURDAY WILL BE SUNNY AND DRY - AND AS A CONSEQUENCE LIKELY OUR  
WARMEST DAY OF THE SET - MORE CLOUDS AND INCREASING LATE DAY  
CONVECTION CHANCES CAN BE EXPECTED FROM SUNDAY INTO THE MIDDLE OF  
THE NEW WORK WEEK. NIGHTS WILL BE RATHER MUGGY WITH A SMALL RIDGE TO  
VALLEY TEMPERATURE DIFFERENCE SETTING UP ALONG WITH SOME FOG IN THE  
RIVER VALLEYS. THE SHOWER AND STORM CHANCES WILL BE JUST A NOTCH  
ABOVE NORMAL THROUGH THE LATTER PART OF THE PERIOD WITH MOST PLACES  
PROBABLY ESCAPING RAIN ON ANY GIVEN DAY - SO STILL A RELIEF FROM THE  
HEAVY RAINS OF THE PAST FEW DAYS FOR MOST.  
 
MADE JUST SOME MINOR AND MAINLY POINT BASED ADJUSTMENTS TO THE  
TEMPERATURES IN THE EXTENDED FROM THE NBM EACH NIGHT - A BIT MORE SO  
ON FRIDAY AND SATURDAY NIGHT THAN THOSE LATER ONES. WITH THE POPS,  
ADJUSTED AND ENHANCED THE NBM'S APPROPRIATE DIURNALLY DRIVEN PATTERN  
THROUGH THE PERIOD.  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)  
ISSUED AT 722 AM EDT THU JUL 2 2020  
 
FOG WILL CONTINUE TO DIMINISH THROUGH THE 12Z HOUR, GIVING WAY TO  
MOSTLY SUNNY SKIES AND LIGHT WINDS FOR THE REMAINDER OF THE DAY. A  
FEW FAIR WEATHER VFR CU COULD DEVELOP DURING THE AFTERNOON, BUT  
SHOULD CAUSE NO IMPACT, AND WILL DISSIPATE QUICKLY HEADING INTO  
THE EVENING. WHILE FOG CANNOT BE RULED OUT FOR THE UPCOMING  
NIGHT, THE HOPE IS THAT THIS DRIER AIRMASS MOVING IN WILL HELP TO  
SUPPRESS THE EXTENT AND IMPACTS OF THE FOG. WENT WITH HIGH END  
MVFR IN THE TAFS AFTER 8Z, BUT WILL CONTINUE TO FINE TUNE THIS  
WITH THE UPCOMING TAF ISSUANCES.  
 

 
   
JKL WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
UPDATE...HAL  
SHORT TERM...JMW  
LONG TERM...GREIF  
AVIATION...JMW  
 
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