394  
FXUS63 KPAH 232345  
AFDPAH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PADUCAH KY  
645 PM CDT SAT SEP 23 2017  
   
UPDATE
 
 
ISSUED AT 645 PM CDT SAT SEP 23 2017  
 
UPDATED AVIATION DISCUSSION FOR 00Z TAFS.  
 

 
   
SHORT TERM
 
(TONIGHT THROUGH MONDAY NIGHT)  
ISSUED AT 210 PM CDT SAT SEP 23 2017  
 
HIGH PRESSURE WAS CENTERED OVER THE OHIO VALLEY EARLY THIS  
AFTERNOON, WITH A STRONG MID LEVEL RIDGE EXTENDING FROM THE GREAT  
LAKES TO TEXAS. AN UPPER LOW WAS OVER THE EASTERN GULF COAST, FL  
PANHANDLE REGION. AFTERNOON CU AGAIN MAINLY WEST OF THE WABASH AND  
KY LAKES AREA IN A REGION OF SLIGHTLY BETTER LOW LEVEL MOISTURE.  
 
PERSISTENCE MEANS ANOTHER MOSTLY CLEAR, CALM NIGHT WITH PATCHY FOG  
IN FAVORED AREAS OVERNIGHT. USED A MOS BLEND FOR OVERNIGHT LOWS.  
 
WITH RESPECT TO THE UPPER LOW TO OUR SOUTH. IT WILL MOVE WEST  
ACROSS THE GULF COAST REGION THROUGH SUNDAY EVENING. THE MODELS  
EXTEND VORTICITY NORTHWARD AND LOWER H5 HEIGHTS TO ABOUT 586 DM  
COINCIDENT WITH ADEQUATE LOW LEVEL MOISTURE ACROSS THE SOUTHERN  
1/2 OF THE AREA. WILL INCLUDE A SLIGHT CHANCE OF THUNDERSTORMS IN  
THIS AREA FOR THE AFTERNOON AND EARLY EVENING AS MID LEVEL LAPSE  
RATES PUSH 6 AND SFC/H8 COMPUTED LI'S ARE BELOW ZERO. THE NAM, GFS,  
EC AND CMC ALL SUGGEST THE CHANCE.  
 
FOR SUNDAY NIGHT THROUGH MONDAY NIGHT, WILL KEEP THE FORECAST DRY  
FOR NOW. CANNOT RULE OUT ISOLATED CONVECTION MONDAY. HOWEVER WILL  
HOLD FOR NOW GIVEN LESS FAVORABLE SUPPORT. TEMPERATURES WILL  
REMAIN ABOVE NORMAL SUNDAY THROUGH MONDAY NIGHT. STAYED CLOSE TO  
MOS GIVEN LITTLE AIRMASS CHANGE, PERSISTENCE.  
   
LONG TERM
 
(TUESDAY THROUGH SATURDAY)  
ISSUED AT 210 PM CDT SAT SEP 23 2017  
 
WITH HURRICANE MARIA IN THE ATLANTIC OFF THE EAST COAST AND A  
LONGWAVE TROUGH VERY SLOWLY PROGRESSING EASTWARD FROM THE WESTERN  
1/3 OF THE U.S. INTO THE UPPER MIDWEST AND THE CENTRAL PLAINS BY  
NEXT WEEKEND, THE OVERALL EXTENDED FORECAST PERIOD WILL REMAIN UNDER  
THE INFLUENCE OF BROAD HIGH PRESSURE.  
 
A VAST MAJORITY OF THE MEDIUM RANGE GUIDANCE SUPPORTS THIS DRY AND  
WARM SOLUTION. GIVEN THE SUBSIDENCE, THE DEPTH OF MOISTURE WILL BE  
LIMITED AND THE LIKELIHOOD OF HAZE AND SOME AIR QUALITY ISSUES  
(OZONE/PARTICULATE ALERTS IN URBANIZED AREAS) WILL LIKELY INCREASE.  
 
BELIEVE MAXIMUM TEMPERATURES MAY BE 1-2 DEGREES TOO LOW WITH THIS  
SCENARIO, BUT AM SOMEWHAT CONSTRAINED FROM A COLLABORATIVE  
STANDPOINT WITH THE REGIONALLY INITIALIZED MODEL GUIDANCE. FOR NOW,  
ATTEMPTED TO INCREASE TEMPERATURES SLIGHTLY IN SOME AREAS WITHOUT  
IMPACTING OVERALL BIG PICTURE.  
 
ALTHOUGH MAXIMUM TEMPERATURES WILL BE UP TO 10 DEGREES ABOVE NORMAL  
AND MINIMUM TEMPERATURES SOME 10 TO 15 DEGREES ABOVE NORMAL, HEAT  
INDEX CONCERNS WILL BE BELOW CRITICAL THRESHOLDS DURING THE EXTENDED  
TIME PERIODS.  
 

 
   
AVIATION
 
 
ISSUED AT 645 PM CDT SAT SEP 23 2017  
 
OTHER THAN SOME PATCHY FOG AGAIN LATE TONIGHT, VFR CONDITIONS ARE  
FORECAST THROUGH SUNDAY. AN ISOLATED STORM MAY POP UP IN THE HEAT OF  
THE AFTERNOON NEAR KCGI AND/OR KPAH, BUT CHANCES ARE TOO LOW TO  
INCLUDE A TAF MENTION. WINDS WILL BE LIGHT FROM THE EAST/SOUTHEAST.  
 

 
   
PAH WATCHES/WARNINGS/ADVISORIES
 
 
IL...NONE.  
MO...NONE.  
IN...NONE.  
KY...NONE.  

 
 

 
 
SHORT TERM...CN  
LONG TERM....KES  
AVIATION...RJP  
 
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