435  
FXUS63 KPAH 172227  
AFDPAH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PADUCAH KY  
527 PM CDT SUN JUN 17 2018  
   
UPDATE
 
 
ISSUED AT 524 PM CDT SUN JUN 17 2018  
 
UPDATED AVIATION DISCUSSION FOR 00Z TAF ISSUANCE.  
 

 
   
SHORT TERM
 
(TONIGHT THROUGH TUESDAY NIGHT)  
ISSUED AT 159 PM CDT SUN JUN 17 2018  
 
ISOLATED SHOWERS HAVE DEVELOPED WITH JUST A BIT OF THUNDER AS OF  
19Z. SATELLITE IMAGERY INDICATES THAT IT WILL BE MOST PREVALENT OVER  
THE SOUTHERN HALF OF THE AREA. THERE WILL BE SOME DECENT  
INSTABILITY, BUT NO SHEAR, SO A BRIEF STRONG UPDRAFT IS POSSIBLE  
WITH THE TYPICAL ISOLATED STRONG DOWNDRAFT POSSIBLE, BUT LIGHTNING  
AND BRIEF HEAVY DOWNPOURS WILL BE THE PRIMARY CONCERN LATE THIS  
AFTERNOON.  
 
HEAT INDICES OVER MOST OF THE AREA HAVE REACHED 100 WITH A FEW SITES  
TESTING 105. OUTFLOW WILL BE LIMITED, SO LOOK FOR HEAT INDICES OF  
100 TO 105 TO CONTINUE THROUGH THE REMAINDER OF THE AFTERNOON. IT  
APPEARS THAT MONDAY WILL BE SIMILAR TO TODAY WITH HEAT INDICES 100  
TO 105 AND POSSIBLY EVEN LESS CONVECTIVE ACTIVITY.  
 
THE UPPER RIDGE BREAKS DOWN A BIT FOR TUESDAY, SO TEMPERATURES WILL  
BE A FEW DEGREES COOLER. COVERAGE OF CONVECTION SHOULD INCREASE,  
ESPECIALLY IN THE NORTH, FARTHEST FROM THE SUPPRESSED RIDGE. THERE  
STILL WILL BE LITTLE SHEAR TO ORGANIZE CONVECTION, SO IT SHOULD BE  
RATHER QUICK UP AND DOWN AS HAS BEEN THE RULE LATELY.  
 
HEAT INDICES ON TUESDAY MAY REACH 100 IN A FEW LOCATIONS, BUT  
CONFIDENCE IS NOT GREAT GIVEN THE LIKELY INCREASE IN CLOUDS AND  
CONVECTION. ALTHOUGH THERE WILL BE LITTLE DIFFERENCE IN HEAT INDICES  
ACROSS THE AREA MONDAY AFTERNOON, WE WILL NOT MAKE ANY ADJUSTMENTS  
TO THE HEAT ADVISORY. EASTERN PORTIONS OF THE AREA JUST ARE NOT  
LIKELY TO REACH 4 DAYS OF 100+ READINGS TO SUPPORT THE ADVISORY  
THERE. THIS HAS BEEN COORDINATED WITH WFOS LMK AND IND. IF THE  
FORECAST TRENDS DRIER AND HOTTER FOR TUESDAY WE MAY EVENTUALLY NEED  
TO CONSIDER EXTENDING AND EXPANDING THE HEAT ADVISORY.  
   
LONG TERM
 
(WEDNESDAY THROUGH SUNDAY)  
ISSUED AT 159 PM CDT SUN JUN 17 2018  
 
DECENT AGREEMENT AMONG OPERATIONAL AND ENSEMBLE MODEL SOLUTIONS  
LENDS TO SOMEWHAT HIGHER THAN AVERAGE CONFIDENCE IN THE OVERALL  
SYNOPTIC PATTERN TO START THE LONG TERM, THOUGH TIMING AND PLACEMENT  
OF PEAK CONVECTIVE COVERAGE WILL LARGELY BE INFLUENCED BY LESS  
CERTAIN MESOSCALE FEATURES. OVERALL CONFIDENCE DECREASES TO AVERAGE  
BY THE WEEKEND WITH GREATER VARIABILITY NOTED IN MODEL SOLUTIONS.  
 
BY WEDNESDAY, THE UPPER LEVEL RIDGE CURRENTLY OVERHEAD IS FORECAST  
TO WEAKEN AND SHIFT INTO THE SOUTHEAST. THIS OCCURS AS ENERGY FROM  
AN UPPER LOW OVER THE WESTERN U.S. DRIFTS EAST INTO THE PLAINS. THE  
ACTION OF THIS ENERGY UPON THE VERY WARM AND HUMID AIR MASS IN PLACE  
SOUTH OF A WEAK STATIONARY FRONTAL BOUNDARY DRAPED JUST NORTH OF THE  
FORECAST AREA WILL HELP TO FOCUS GREATER SHOWER AND THUNDERSTORM  
COVERAGE THROUGH AT LEAST FRIDAY. EVEN THOUGH BETTER CHANCES SHOULD  
ALIGN WITH GREATER INSTABILITY EACH AFTERNOON AND EVENING, CHANCES  
REALLY CANNOT BE RULED OUT AT ANY TIME GIVEN THE PROXIMITY OF THE  
FRONTAL BOUNDARY AND TIMING OF INDIVIDUAL VORTICITY MAXIMA.  
 
BY NEXT WEEKEND, MODEL SOLUTIONS BEGIN TO DIVERGE--PARTICULARLY WITH  
RESPECT TO HOW QUICKLY THE UPPER LEVEL ENERGY SHIFTS EAST OF THE  
AREA. THE CMC IS THE FASTEST WITH A FRIDAY DEPARTURE, WHILE THE  
PREFERRED SLOWER ECMWF AND GFS TARGET SOMETIME SATURDAY. EVEN THOSE  
MODELS LINGER SMALL CHANCES INTO SUNDAY WITH THE PROSPECT OF MORE  
ENERGY APPROACHING FROM THE PLAINS. WILL KEEP AT LEAST SMALL CHANCES  
AROUND THROUGH THE WEEKEND, ESPECIALLY CONSIDERING THE AMOUNT OF  
HEAT AND HUMIDITY IN PLACE AND LACK OF ANY SUBSTANTIAL CAPPING ALOFT.  
 
THROUGH THE ENTIRE PERIOD, LIGHTNING AND LOCALLY HEAVY RAIN SHOULD  
BE THE MAIN THUNDERSTORM-RELATED CONCERNS. HOWEVER, A COUPLE OF  
STRONG/SEVERE STORMS CANNOT BE RULED OUT, ESPECIALLY BY THURSDAY AND  
FRIDAY AS BETTER FORCING ARRIVES. TEMPERATURES SHOULD REMAIN VERY  
WARM AND MUGGY WITH HIGHS FORECAST IN THE UPPER 80S TO NEAR 90 AND  
LOWS IN THE UPPER 60S TO LOWER 70S. OH YEAH, AND WHILE IT SEEMS LIKE  
SUMMER HAS ALREADY BEEN AROUND FOR WEEKS, IT OFFICIALLY KICKS OFF  
WITH THE SUMMER SOLSTICE AT 5:07 AM CDT THURSDAY JUNE 21.  
 

 
   
AVIATION
 
 
ISSUED AT 524 PM CDT SUN JUN 17 2018  
 
AFTER THE DIURNALLY DRIVEN CONVECTION DINISHES, SHORTLY AFTER  
SUNSET, IT SHOULD BE ANOTHER QUIET NIGHT WITH POTENTIAL FOR MVFR  
RESTRICTIVE FOG IN PATCHES TOWARD DAYBREAK. TMRW WILL SEE  
DIURNALLY DRIVEN CU IN THE LOW VFR RANGE DEVELOPING, WITH ISOLATED  
CONVECTION DURING THE HEAT OF THE AFTERNOON, ESP IN THE EAST.  
ADDED VICINITY MENTION FOR CB AT KOWB TO ACCOUNT.  
 

 
   
PAH WATCHES/WARNINGS/ADVISORIES
 
 
IL...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR ILZ075>078-080>094.  
 
MO...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR MOZ076-086-087-100-  
107>112-114.  
 
IN...NONE.  
KY...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR KYZ001>011.  
 

 
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab KY Page
The Nexlab IL Page
The Nexlab IN Page
The Nexlab MO Page Main Text Page