394  
FXUS63 KIWX 222325  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
725 PM EDT THU AUG 22 2019  
   
SYNOPSIS
 
 
ISSUED AT 723 PM EDT THU AUG 22 2019  
 
HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE GREAT LAKES REGION  
AND WILL BRING NEARLY PICTURE PERFECT WEATHER TO OUR AREA. EXPECT  
DRY CONDITIONS THROUGH THE WEEKEND WITH COMFORTABLE TEMPERATURES  
AND HUMIDITY LEVELS. CHANCES FOR RAIN RETURN LATE SUNDAY NIGHT.  
HIGH TEMPERATURES WILL BE IN THE 70S THROUGH SUNDAY AND LOWS WILL  
BE IN THE 50S. HAZARDOUS SWIMMING CONDITIONS ARE EXPECTED ON  
SOUTHERN LAKE MICHIGAN FRIDAY WITH HIGH WAVE ACTION AND DANGEROUS  
CURRENTS EXPECTED AT THE BEACHES.  
 

 
   
SHORT TERM
 
(THIS EVENING THROUGH FRIDAY)  
ISSUED AT 422 PM EDT THU AUG 22 2019  
 
FAIRLY QUIET WEATHER IN THE SHORT TERM, WITH MAINLY DRY CONDITIONS  
EXPECTED THROUGH FRIDAY. THE COLD FRONT RESPONSIBLE FOR RAIN SHOWERS  
SOUTH AND EAST OF US 24 TODAY WILL CONTINUE TO DRIFT SOUTHWARD  
TONIGHT, WITH SURFACE HIGH PRESSURE BUILDING IN OVER LAKE  
SUPERIOR. THE RESULTING NNE WINDS WILL FILTER DOWN ACROSS LAKE  
MICHIGAN LATE THIS AFTERNOON AND OVERNIGHT, BUILDING WAVES UP TO  
AROUND 3 TO 5 FEET.  
 
AS OF 4 PM, WAVES HAVE ALREADY CLIMBED TO 2 TO 3 FEET IN BERRIEN  
COUNTY, MI AND JUST OVER 4 FEET IN LAPORTE COUNTY, IN. HAVE  
ISSUED A SMALL CRAFT ADVISORY AND A BEACH HAZARDS STATEMENT FOR  
THE LAPORTE COUNTY WATERS/BEACHES. WAVES IN THIS AREA WILL  
APPROACH THE SHORE AT AT 30 TO 60 DEGREE ANGLE, WITH A PERIOD OF 5  
TO 6 SECONDS. DANGEROUS CURRENTS, PARTICULARLY LONGSHORE AND  
STRUCTURAL CURRENTS, ARE EXPECTED IN CONDITIONS LIKE THESE.  
FURTHER NORTH IN BERRIEN COUNTY, MI KEPT THE MODERATE SWIM RISK  
FOR NOW. EXPECTING WAVES TO BE SLIGHTLY LOWER (UP TO 4 FEET LATER  
TONIGHT) AND WAVE ANGLES OF APPROACH ARE 30 DEGREES OR LESS  
RELATIVE TO SHORE-WHICH MAKES STRONG OFFSHORE FLOWING CURRENTS  
LESS LIKELY. THAT BEING SAID, IF CONDITIONS WORSEN MAY NEED TO  
UPGRADE BERRIEN COUNTY TO A HIGH SWIM RISK AND ISSUE A BEACH  
HAZARDS STATEMENT. IT IS LIKELY WE EXTEND THE BEACH HAZARDS  
STATEMENT AND SMALL CRAFT ADVISORY THROUGH LATE FRIDAY EVENING, AS  
WAVES ONLY DROP TO AROUND 2 FEET LATE FRIDAY MORNING BEFORE  
CLIMBING BACK UP TO AROUND 3 TO 4 FEET IN THE AFTERNOON. WILL  
LEAVE THIS DECISION TO THE EVENING/MIDNIGHT SHIFTS WHEN CONFIDENCE  
MAY BE HIGHER.  
 
SURFACE HIGH PRESSURE/DRY AIR SHOULD KEEP THINGS DRY FRIDAY  
AFTERNOON, BUT SOME OF THE MODELS INDICATE WE COULD SEE A FEW POP UP  
SHOWERS/STORMS IN THE AFTERNOON ON FRIDAY (18Z-00Z-ISH)AS THE MAIN  
AXIS OF AN UPPER LEVEL TROUGH SWINGS THROUGH DURING PEAK HEATING.  
FOR NOW, LEFT THE FORECAST DRY GIVEN LOW CONFIDENCE. HIGHS WILL BE  
IN THE 70S.  
 

 
   
LONG TERM
 
(FRIDAY NIGHT THROUGH THURSDAY)  
ISSUED AT 422 PM EDT THU AUG 22 2019  
 
SURFACE HIGH PRESSURE PREVAILS THROUGH SUNDAY NIGHT, SO EXPECT CLEAR  
TO PARTLY CLOUDY SKIES AND DRY CONDITIONS. HIGH TEMPERATURES WILL  
RANGE FROM THE LOW 70S TO AROUND 80F. LOWS FRIDAY NIGHT INTO  
SATURDAY NIGHT WILL DROP INTO THE LOW TO MID 50S.  
 
THE NEXT CHANCES FOR PRECIPITATION START MONDAY, ESPECIALLY TOWARDS  
THE AFTERNOON HOURS. AN UPPER LEVEL LOW WILL TRAVERSE THE CANADIAN  
PRAIRIE MONDAY AND DRAG A TROUGH INTO THE GREAT LAKES BY TUESDAY.  
THE LOW BECOMES VERTICALLY STACKED SOUTHWEST OF HUDSON BAY TUESDAY  
AFTERNOON AND EVENING, THEN SETTLES OVER THE BAY THURSDAY INTO  
FRIDAY. THIS WILL BRING A TROUGH THROUGH MO/IA/IL/IN MONDAY INTO  
TUESDAY. AT THE SURFACE, THE GFS BRINGS A SURFACE LOW UP FROM MO  
INTO IL/IN BEFORE IT IS ABSORBED INTO THE STRONGER WAVE TO THE  
NORTH. THIS LIFTS A WARM FRONT ASSOCIATED WITH THIS LOW NORTHWARD  
THROUGH OUR CWA MONDAY, AND THEN THE TRAILING COLD FRONT WITH THE  
STRONGER SYSTEM TO THE NORTH THROUGH OUR FORECAST AREA TUESDAY INTO  
TUESDAY NIGHT. THERE ARE A FEW DISCREPANCIES BETWEEN MODELS WITH  
RESPECT TO THE PLACEMENT OF THE NORTHERN STREAM LOW AND THE STRENGTH  
OF THE LOW TO OUR SOUTHWEST. THE ECMWF IS WEAKER WITH THE UPPER  
LEVEL LOW TO OUR NORTH (HUDSON BAY AREA) AND THE STRENGTH OF THE  
TROUGH EXTENDING INTO MO/IA/IL/IN. AT THE SURFACE (TO OUR  
SOUTHWEST), THERE IS JUST A TROUGH. THE GFS TAKES THE NORTHERN UPPER  
LOW FURTHER NORTH AND THEN DEVELOPS A SEPARATE CLOSED LOW OVER  
WESTERN LAKE SUPERIOR TUESDAY MORNING, AND DIGS THE TROUGH FURTHER  
SOUTH AND EAST. THIS DEVELOPS THE SURFACE LOW TO OUR SOUTHWEST. SO  
WHAT DOES THIS ALL MEAN? THERE ARE SLIGHT DIFFERENCES IN TIMING OF  
THE INITIAL PRECIPITATION MONDAY (GFS STARTS SUNDAY NIGHT, ECMWF  
LATE MONDAY MORNING IN THE SOUTHWEST). THE COLD FRONT TIMING IS  
PRETTY CONSISTENT TUESDAY INTO TUESDAY NIGHT, BUT THE STRENGTH OF  
THE FRONT AND THE AMOUNT OF PRECIPITATION IS GREATER WITH THE GFS.  
ALL THIS IN MIND, I KEPT THE CONSENSUS POPS MON/TUESDAY, WITH A  
DIMINISHING TREND FROM WEST TO EAST THROUGH TUESDAY EVENING.  
 
PARTLY CLOUDY SKIES AND DRY CONDITIONS RETURN LATE TUESDAY NIGHT AND  
LINGER THROUGH WEDNESDAY WITH ANOTHER SURFACE HIGH BUILDING IN  
BEHIND THE FRONT. THURSDAY WE COULD SEE SOME CHANCES FOR RAIN  
DEPENDING ON STRENGTH OF THE BOTH THE NEXT WAVE ROTATING AROUND THE  
LOW IN HUDSON BAY, AND THE INCOMING HIGH PRESSURE OVER THE NORTHERN  
PLAINS. ECMWF HOLDS OFF UNTIL FRIDAY AFTERNOON TO BRING THE SURFACE  
COLD FRONT AND SUBSEQUENT PRECIPITATION CHANCES IN, BUT THE GFS  
BRINGS THE FRONT THROUGH ON THURSDAY MORNING. KEPT LOW CHANCE POPS  
IN FOR NOW. HIGHS MONDAY INTO THURSDAY WILL BE IN THE 70S AND LOW  
80S. LOWS WILL BE IN THE 50S AND 60S. WITH GUSTY WEST TO NORTHWEST  
WINDS BEHIND THE FRONT TUESDAY AFTERNOON INTO THURSDAY, A MODERATE  
SWIM RISK IS POSSIBLE FOR LAKE MICHIGAN BEACHES.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)  
ISSUED AT 721 PM EDT THU AUG 22 2019  
 
VFR THROUGH THE PERIOD AS HIGH PRESSURE MOVES INTO THE AREA. WINDS  
GENERALLY FROM NORTHEAST AROUND 5 KTS OR LESS TONIGHT AND 5 TO 9  
KNOTS ON FRIDAY.  
 

 
   
IWX WATCHES/WARNINGS/ADVISORIES
 
 
IN...BEACH HAZARDS STATEMENT THROUGH FRIDAY MORNING FOR INZ003.  
 
MI...NONE.  
OH...NONE.  
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT FRIDAY FOR LMZ046.  
 

 
 

 
 
SYNOPSIS...LASHLEY  
SHORT TERM...MCD  
LONG TERM...MCD  
AVIATION...LASHLEY  
 
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