822  
FXUS61 KILN 201442  
AFDILN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE WILMINGTON OH  
1042 AM EDT SUN MAY 20 2018  
   
SYNOPSIS
 
 
A SURFACE BOUNDARY ENHANCED BY WEAK DISTURBANCES WILL BE THE  
FOCUS FOR SHOWER AND THUNDERSTORM DEVELOPMENT TODAY INTO  
TUESDAY. HIGH PRESSURE IS FORECAST TO PROVIDE DRIER CONDITIONS  
STARTING WEDNESDAY AND CONTINUING FOR THE REST OF THE WORK WEEK.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
14Z SURFACE ANALYSIS SHOWS THAT THE BOUNDARY HAS SAGGED INTO  
SOUTHEAST INDIANA AND ACROSS SOUTHERN OHIO. THE SHALLOW STABLE  
LAYER SHOULD MIX OUT THROUGH EARLY AFTERNOON WHICH WILL ALLOW  
THE EFFECTIVE BOUNDARY TO JUMP BACK NORTH CLOSER TO I-70.  
CONVERGENCE WILL BE WEAK ALONG THE BOUNDARY, BUT IT SHOULD  
SERVE AS A FOCUS FOR POOLING MOISTURE WHICH WILL ENHANCE  
INSTABILITY ALONG IT COMPARED TO THE REST OF THE REGION.  
 
HIGH RESOLUTION GUIDANCE HAS LOCKED ON TO A DISTURBANCE MOVING  
OUT OF DYING CONVECTION TO THE WEST AND THEN INITIATING STORMS  
IN EASTERN INDIANA NEAR THE BOUNDARY LATE THIS AFTERNOON AND  
THEN PROGRESSING EAST SOUTHEAST ACROSS THE FORECAST AREA INTO  
THE EVENING. THIS LOOKS LIKE A DAMAGING WIND THREAT WITH SOME  
MARGINALLY SEVERE HAIL NOT OUT OF THE QUESTION. HAVE ADJUSTED  
CORRIDOR OF HIGHER POPS NORTH BASED ON WHERE BOUNDARY IS  
EXPECTED BY TIME OF CONVECTIVE INITIATION.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/
 
 
STORMS THAT DEVELOP LATE THIS AFTERNOON WILL CONTINUE TO TRACK  
ACROSS THE FORECAST AREA INTO THE EVENING. LATER TONIGHT,  
ADDITIONAL SHORT WAVE ENERGY MAY TRIGGER MORE SHOWERS AND  
THUNDERSTORMS.  
 
FOR MONDAY, THUNDERSTORMS WILL BE POSSIBLE AGAIN IN THE  
PERSISTENTLY UNSTABLE AIRMASS POSITIONED ALONG THE SLOW MOVING  
BOUNDARY, AIDED BY ANOTHER ROUND OF SHORT WAVES EMBEDDED IN THE  
MEAN FLOW. HIGH TEMPERATURES REACHING AROUND 80 WILL ALLOW  
ENOUGH INSTABILITY FOR CONTINUED THUNDERSTORM DEVELOPMENT.  
 

 
   
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/
 
 
ACTIVE WEATHER PATTERN TO CONTINUE THROUGH EARLY NEXT WEEK WITH  
ILN/S FA ON THE PERIPHERY OF MID/UPPER LEVEL RIDGING.  
 
MID LEVEL SHORTWAVE TO INDUCE A SURFACE WAVE THAT TRACKS THROUGH THE  
AREA MONDAY NIGHT AND TUESDAY. THIS WILL ALLOW AN ASSOCIATED SURFACE  
FRONT TO DROP SOUTHEAST THROUGH THE OHIO VALLEY TUESDAY. THIS WILL  
OFFER A CONTINUED THREAT FOR SHOWERS AND THUNDERSTORMS. WARM  
TEMPERATURES TO CONTINUE WITH TUESDAYS HIGHS FROM THE UPPER 70S  
NORTHWEST TO THE LOWER 80S SOUTHEAST.  
 
NORTHWEST FLOW ALOFT TO DEVELOP WITH SURFACE HIGH PRESSURE BUILDING  
INTO THE GREAT LAKES. A LINGERING CHANCE FOR SHOWERS/THUNDERSTORMS  
WILL PERSISTING THE SOUTHEAST EARLY WEDNESDAY, OTHERWISE EXPECT DRY  
WEATHER. EXPECT HIGHS WEDNESDAY IN THE UPPER 70S TO LOWER 80S.  
 
THE SURFACE HIGH WILL BUILD SOUTHEAST WITH CONTINUED DRY WEATHER  
THURSDAY. ABOVE NORMAL TEMPERATURES WITH HIGHS FROM NEAR 80 NORTH TO  
THE LOWER/MIDDLE 80S SOUTH.  
 
SOUTHERLY LOW LEVEL FLOW DEVELOPS ON THE BACKSIDE OF RETREATING SFC  
HIGH PRESSURE FRIDAY WITH MID LEVEL RIDGING BUILDING INTO THE OHIO  
VALLEY. TEMPERATURES WILL WARM UP WITH HIGHS IN THE LOWER AND MIDDLE  
80S.  
 
MID LEVEL FLOW BACKS AHEAD OF A DEVELOPING TROF WITH MOISTURE  
INCREASING FRIDAY NIGHT. WILL MENTION CHANCE POPS FOR SHOWERS AND  
THUNDERSTORMS FRIDAY NIGHT WEST AND ACROSS THE ENTIRE AREA SATURDAY.  
WARM TEMPERATURES TO CONTINUE WITH HIGHS SATURDAY GENERALLY IN THE  
MIDDLE 80S.  
 

 
   
AVIATION /14Z SUNDAY THROUGH THURSDAY/
 
 
MVFR TO IFR CLOUDS ACROSS MUCH OF THE REGION WILL DIMINISH OVER  
THE NEXT FEW HOURS. SCATTERED CUMULUS WILL DEVELOP THIS  
AFTERNOON. THUNDERSTORMS MAY IMPACT THE AREA BETWEEN 21Z AND  
01Z WITH THE GREATEST POTENTIAL FROM KDAY TO KILN.  
 
ONCE CONVECTION PASSES, EXPECT VFR CONDITIONS DURING THE  
EVENING. SOME MVFR VISIBILITIES MAY DEVELOP LATE IN THE PERIOD  
IN MIST/FOG.  
 
OUTLOOK...THUNDERSTORMS POSSIBLE THROUGH TUESDAY.  
 

 
   
ILN WATCHES/WARNINGS/ADVISORIES
 
 
OH...NONE.  
KY...NONE.  
IN...NONE.  
 

 
 

 
SYNOPSIS...CONIGLIO  
NEAR TERM...  
SHORT TERM...CONIGLIO  
LONG TERM...AR  
AVIATION...  
 
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