334  
FXUS63 KPAH 131120  
AFDPAH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PADUCAH KY  
520 AM CST WED DEC 13 2017  
   
UPDATE
 
 
ISSUED AT 520 AM CST WED DEC 13 2017  
 
AVIATION UPDATE.  
 

 
   
SHORT TERM
 
(TODAY THROUGH FRIDAY NIGHT)  
ISSUED AT 257 AM CST WED DEC 13 2017  
 
A WIND ADVISORY WILL BE IN EFFECT TODAY FOR MOST OF THE AREA,  
MINUS THE OZARK FOOTHILLS. STRONG LOW PRESSURE WILL BE NEAR KORD  
AROUND 18Z, WITH STRONG LOW LEVEL SOUTHWEST FLOW DEVELOPING AHEAD  
OF AN APPROACHING FRONT ASSOCIATED WITH THE LOW. SOUNDING DATA  
UTILIZING MOMENTUM TRANSFER SUGGESTS GUSTS TO 35 KTS OR SLIGHTLY  
HIGHER POSSIBLE OVER MOST OF THE AREA, GENERALLY FROM 16-22Z. THIS  
AXIS OF HIGHEST WINDS WILL BE MOVING EAST THROUGH THE DAY. SEE THE  
FIRE WEATHER SECTION FOR ADDITIONAL DETAILS REGARDING RH AND FIRE  
DANGER TODAY. TEMPERATURE WISE, WE USUALLY ARE NEVER WARM ENOUGH  
WITH FORECAST NUMBERS WHEN IT'S THIS DRY, WITH STRONG SW LOW TROP  
FLOW AND SUN. MAV WAS THE WARMEST GUIDANCE, AND WE WENT ANOTHER  
COUPLE OF DEGREES ABOVE THAT AREA WIDE. WE HAD A 34-41 DEGREE  
DIURNAL SWING JUST TWO DAYS AGO WITH SIMILAR CONDITIONS.  
OTHERWISE, SOME PASSING CLOUDS, TIMES OF SUN AS WELL.  
 
ROLLER COASTER RIDE WILL CONTINUE WITH RESPECT TO TEMPS. IN THE  
WAKE OF THE FRONT IT WILL COOL BACK DOWN TONIGHT AND THURSDAY.  
HIGHS THURSDAY WILL BE BACK IN THE UPPER 30S TO LOWER 40S. HOWEVER  
IT SHOULD NOT BE AS BREEZY. DRY WEATHER CONTINUES.  
 
FOR FRIDAY, A LONG WAVE POS TILT TROF WILL MOVE SOUTHEAST TOWARD  
THE AREA. HOWEVER, THIS SYSTEM TOO WILL BE MOISTURE STARVED. SO WE  
CONTINUE WITH A DRY FORECAST. ALL THE MODELS ARE IN SYNC KEEPING  
IT DRY. JUST VARIABLE CLOUD COVER.  
   
LONG TERM
 
(SATURDAY THROUGH TUESDAY)  
ISSUED AT 257 AM CST WED DEC 13 2017  
 
RELATIVELY GOOD AGREEMENT AMONG FORECAST MODELS LENDS HIGHER THAN  
AVERAGE CONFIDENCE TO THE LONG TERM PORTION OF THE FORECAST THROUGH  
THE WEEKEND. CONFIDENCE DECREASES SOMEWHAT HEADING INTO EARLY NEXT  
WEEK WITH GREATER MODEL VARIABILITY.  
 
A MODERATING TREND IS STILL EXPECTED OVER THE WEEKEND INTO EARLY  
NEXT WEEK AS A FLATTER UPPER LEVEL FLOW PATTERN TAKES SHAPE. IN THIS  
PATTERN, AN UPPER LOW OVER WESTERN MEXICO IS FORECAST TO TRANSITION  
TO AN OPEN WAVE AS IT PIVOTS NORTHEAST ACROSS THE SOUTHERN PLAINS  
INTO THE MISSISSIPPI VALLEY ON SUNDAY. THE END RESULT SHOULD BE AN  
INCREASED CHANCE FOR RAIN STARTING SATURDAY NIGHT AND CONTINUING  
INTO SUNDAY. FORECAST MODELS TAPER THE RAIN OFF FROM WEST TO EAST  
SUNDAY NIGHT. RIGHT NOW, MODEL FORECAST SOUNDINGS INDICATE A  
TEMPERATURE PROFILE SUPPORTIVE OF ALL LIQUID PRECIPITATION THROUGH  
THE PERIOD.  
 
BOTH THE ECMWF AND CMC BRING AN UPPER LEVEL TROUGH/DEFORMATION ZONE  
ACROSS THE AREA ON MONDAY WITH LITTLE FANFARE. HOWEVER, THE SLOWER  
00Z GFS DOESN'T BRING THE FEATURE THROUGH UNTIL TUESDAY AND DOES SO  
WITH SOME LIGHT PRECIPITATION LATE MONDAY NIGHT INTO TUESDAY  
MORNING. THE CONSENSUS OF AVAILABLE GUIDANCE FAVORS THE MORE  
PROGRESSIVE SCENARIO, SO WILL KEEP THE FORECAST DRY BEYOND SUNDAY  
NIGHT FOR NOW.  
 
WITH LESS AMPLIFICATION TO THE UPPER LEVEL FLOW PATTERN COMPARED TO  
RECENT DAYS, TEMPERATURES THROUGH THE PERIOD ARE FORECAST TO BE  
RELATIVELY MILD. CONSENSUS GUIDANCE PLACES HIGHS IN THE UPPER 40S TO  
LOWER 50S SATURDAY THROUGH TUESDAY, WITH LOWS GENERALLY IN THE  
30S.  
 

 
   
AVIATION
 
 
ISSUED AT 520 AM CST WED DEC 13 2017  
 
VFR CIG AND VSBYS CONDITIONS TODAY THROUGH TONIGHT. MAIN IMPACT  
WEATHER WILL BE WIND. SSW WINDS WILL INCREASE TO 15 TO 30 KTS WITH  
SOME GUSTS TO 35 KTS PEAKING FROM 16-22Z. THE WINDS WILL DIMINISH  
BY LATE AFTERNOON AND VEER TO THE WEST AND THEN NORTHWEST AS A  
FRONT MOVES SOUTHEAST ACROSS THE AREA. SUSTAINED WINDS WILL  
CONTINUE TO REACH 6 TO 12 KTS TOWARD SUNSET AND OVERNIGHT.  
 

 
   
FIRE WEATHER
 
 
ISSUED AT 257 AM CST WED DEC 13 2017  
 
THE COMBINATION OF DRY VEGETATION AND GUSTY SOUTHWEST WINDS WILL  
CREATE AN ELEVATED FIRE DANGER ACROSS MUCH OF THE FORECAST AREA  
TODAY. THE MAIN LIMITING FACTOR TO ISSUING A RED FLAG WARNING IS THE  
RELATIVE HUMIDITY, WHICH IS FORECAST TO REMAIN ABOVE 25 PERCENT  
ACROSS MOST OF THE AREA THIS AFTERNOON. THAT'S TAKING INTO ACCOUNT  
THE DRIEST MODEL GUIDANCE WE CAN FIND, INCLUDING THE HRRR, RAP13,  
AND GUIDANCE WEIGHTED IN FAVOR OF MODELS THAT RECENTLY VERIFIED THE  
BEST. THE MISSOURI OZARK FOOTHILLS APPEAR TO HAVE THE BEST CHANCE OF  
DROPPING SLIGHTLY BELOW 25 PERCENT FOR A FEW HOURS. AS A RESULT, WILL  
ADDRESS THE ELEVATED FIRE DANGER IN A SPS FOR NOW. WILL COORDINATE  
WITH FORESTRY OFFICIALS SHOULD RED FLAG CONDITIONS BECOME OF GREATER  
CONCERN LATER TODAY.  
 

 
   
PAH WATCHES/WARNINGS/ADVISORIES
 
 
IL...WIND ADVISORY FROM 10 AM THIS MORNING TO 4 PM CST THIS AFTERNOON  
FOR ILZ075>078-080>094.  
 
MO...WIND ADVISORY FROM 10 AM THIS MORNING TO 4 PM CST THIS AFTERNOON  
FOR MOZ087-110>112-114.  
 
IN...WIND ADVISORY FROM 10 AM THIS MORNING TO 4 PM CST THIS AFTERNOON  
FOR INZ081-082-085>088.  
 
KY...WIND ADVISORY FROM 10 AM THIS MORNING TO 4 PM CST THIS AFTERNOON  
FOR KYZ001>022.  
 

 
 

 
 
SHORT TERM...CN  
LONG TERM....RJP  
AVIATION.....CN  
FIRE WX......RJP/CN  
 
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