511  
FXUS63 KIWX 241033  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
633 AM EDT SAT JUN 24 2017  
   
SYNOPSIS
 
 
ISSUED AT 359 AM EDT SAT JUN 24 2017  
 
COOLER, LESS HUMID, AND BREEZY CONDITIONS WILL BE IN STORE FOR THE  
WEEKEND. AN ISOLATED SHOWER IS POSSIBLE TODAY AND SUNDAY, BUT  
MOST OF THE PERIOD WILL REMAIN DRY. A SLIGHTLY BETTER CHANCE OF  
SHOWERS IS EXPECTED FOR MONDAY WHICH WILL BE FOLLOWED BY DRY  
CONDITIONS FOR TUESDAY AND MOST OF THE WEDNESDAY. HIGH  
TEMPERATURES TODAY WILL REACH INTO THE LOWER TO MID 70S WITH LOWS  
TONIGHT DROPPING INTO THE LOWER TO MID 50S. HIGH TEMPERATURES  
FOR SUNDAY WILL BE LIMITED TO THE UPPER 60S AND LOWER 70S.  
 

 
   
SHORT TERM
 
(TODAY AND TONIGHT)  
ISSUED AT 359 AM EDT SAT JUN 24 2017  
 
QUIETER WEATHER PATTERN IN STORE FOR THE WEEKEND WHICH WILL BE  
MARKED BY MUCH COOLER CONDITIONS, ALONG WITH AN OUTSIDE CHANCE OF  
A SHOWER.  
 
SECONDARY SFC TROUGH IS CURRENTLY TRACKING ACROSS THE FORECAST  
AREA EARLY THIS MORNING, WHICH WILL PROVIDE COOLER AND LESS HUMID  
CONDITIONS FOR TODAY WITH PERSISTENT LOW LEVEL COLD ADVECTION.  
WATER VAPOR IMAGERY EARLY THIS MORNING DEPICTS TWO MAIN SHORT  
WAVES OF INTEREST, ONE LEAD SHORT WAVE WORKING ACROSS NORTHERN  
IOWA EARLY THIS MORNING AND MORE PRONOUNCED UPPER LOW DROPPING  
ACROSS EASTERN NORTH DAKOTA. THIS LEAD SHORT WAVE SHOULD TRACK  
ACROSS THE THE AREA THIS AFTERNOON. MOISTURE AVAILABILITY WILL BE  
ON THE MEAGER SIDE WITH WELL MIXED LOW LEVELS LIMITING SURFACE-  
BASED INSTABILITY MAGNITUDE. GIVEN FAVORABLE TIMING OF THIS SHORT  
WAVE THIS AFTERNOON, CANNOT COMPLETELY RULE OUT A FEW ISOLATED  
SHOWERS OR SPRINKLES DEVELOPING MAINLY NORTHEAST INDIANA/SOUTH  
CENTRAL LOWER MICHIGAN/FAR NORTHWEST OHIO. MAY NEED TO INCLUDE  
SOME MENTION FOR THIS AFTERNOON BUT WINDOW OF ANY ISOLATED PRECIP  
POTENTIAL SHOULD BE LIMITED DUE TO RAPID PROGRESSION OF THIS WAVE  
EAST OF THE AREA LATE AFTERNOON. OTHERWISE, HIGHS TODAY SHOULD BE  
MAINLY IN THE LOW TO MID 70S WITH AFTERNOON WESTERLY GUSTS TO 20  
TO 25 MPH.  
 
THE STRONGER ND UPPER TROUGH WILL DIVE SOUTHEAST ACROSS GREAT LAKES  
TONIGHT POSSIBLY BRINGING A FEW SHOWERS TO LOWER MICHIGAN IN  
PROXIMITY TO ASSOCIATED MID/UPPER LEVEL COOL POCKET. MAINTENANCE OF  
MODEST LOW LEVEL HEIGHT GRADIENT TONIGHT SHOULD KEEP MINS IN THE  
LOWER TO MID 50S FOR MOST LOCATIONS.  
 

 
   
LONG TERM
 
(SUNDAY THROUGH FRIDAY)  
ISSUED AT 359 AM EDT SAT JUN 24 2017  
 
CONFIDENCE IN ISOLATED SHOWER DEVELOPMENT FOR SUNDAY BEGINNING TO  
WANE SOMEWHAT, WITH PRESENT INDICATIONS SUGGESTING LOCAL AREA  
COULD BE SITUATED BETWEEN NOTABLE SHORT WAVES FOR MOST OF THE DAY.  
THE ND VORT MAX WILL BE SHIFTING OFF TO THE EASTERN GREAT LAKES  
EARLY IN THE DAY, WITH NEXT UPSTREAM SHORT WAVE NOT EXPECTED TO  
BECOME MORE OF AN INFLUENCE UNTIL SUNDAY NIGHT/MONDAY. BOUNDARY  
LAYER MOISTURE ALSO BECOMES EVEN MORE IN QUESTION WITH DIURNAL  
MIXING SUNDAY AFTERNOON. NUDGED POPS SLIGHTLY DOWNWARD BUT  
MAINTAINED ISOLATED MENTION ACROSS THE NORTH SUNDAY AFTERNOON.  
MAINTAINED LOW TO MID RANGE CHANCE POPS FOR MONDAY AS MORE  
PRONOUNCED MID/UPPER LEVEL COOLING TAKES PLACE WITH WESTERN  
ONTARIO UPPER TROUGH DIGGING SOUTH. OTHERWISE, SUNDAY/MONDAY  
SHAPING UP TO BE THE COOLEST DAYS OF THE FORECAST PERIOD WITH  
HIGHS FROM THE UPPER 60S TO LOWER 70S.  
 
NEXT EASTERN PACIFIC TROUGH WILL BEGIN TO DAMPEN WESTERN CONUS UPPER  
RIDGING BY LATE MONDAY/TUESDAY AS THIS RIDGE SHIFTS ACROSS  
CENTRAL US. THIS WILL PROVIDE GRADUAL MODERATION IN TEMPERATURES  
FOR THE TUESDAY-THURSDAY PERIOD. THE NEXT CHANCES OF  
SHOWERS/STORMS SHOULD BE DELAYED MORE UNTIL THE LATE WEDNESDAY-  
FRIDAY TIMEFRAME WITH SOME INDICATION IN MEDIUM RANGE MODELS THAT  
EASTERN CONUS RIDGING MAY BE SOMEWHAT STUBBORN TO FULLY BREAKDOWN  
LIMITING MORE SIGNIFICANT MOISTURE TRANSPORT TO THE CORN BELT AND  
WESTERN GREAT LAKES REGION THROUGH WEDNESDAY NIGHT. MORE FAVORABLE  
MOISTURE TRANSPORT SHOULD SET UP FOR LATER THURSDAY INTO FRIDAY  
WITH INDICATIONS OF AN UNSETTLED PERIOD BY THE END OF NEXT WORK  
WEEK AS A SERIES OF PACIFIC WAVES INTERACT WITH LOW LEVEL  
BAROCLINIC ZONE SETTLING ACROSS THE REGION.  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)  
ISSUED AT 629 AM EDT SAT JUN 24 2017  
 
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WINDS WILL PICK UP  
LATE MORNING INTO THE AFTERNOON AS INCREASED MIXING OF SLIGHTLY  
STRONGER ABOVE GROUND WIND FIELDS OCCURS. CAN'T RULE OUT A STRAY  
SHOWER, BUT NOT ENOUGH CONFIDENCE OR COVERAGE POTENTIAL TO WARRANT  
MENTION IN TAFS.  
 

 
   
IWX WATCHES/WARNINGS/ADVISORIES
 
 
IN...BEACH HAZARDS STATEMENT THROUGH SUNDAY EVENING FOR INZ003.  
 
MI...BEACH HAZARDS STATEMENT THROUGH SUNDAY EVENING FOR MIZ077.  
 
OH...NONE.  
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT SUNDAY FOR LMZ043-046.  
 

 
 

 
 
SYNOPSIS...MARSILI  
SHORT TERM...MARSILI  
LONG TERM...MARSILI  
AVIATION...FISHER  
 
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