867  
FXUS63 KIWX 221810  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
210 PM EDT MON JUL 22 2019  
   
SYNOPSIS
 
 
ISSUED AT 450 AM EDT MON JUL 22 2019  
 
EXPECT DECREASING CLOUD COVER TODAY INTO TONIGHT, WITH HIGHS IN THE  
70S AND OVERNIGHT LOWS IN THE 50S. ISOLATED RAIN SHOWERS ARE  
POSSIBLE THROUGH LATE MORNING. OTHERWISE, LIFE-THREATENING  
CONDITIONS ARE EXPECTED ON LAKE MICHIGAN. HIGH WAVE ACTION WILL  
CAUSE DANGEROUS CURRENTS, BEACH EROSION, AND LAKESHORE FLOODING. SEE  
THE LATEST STATEMENT FOR MORE INFORMATION. THERE IS A CHANCE FOR  
SHOWERS AND THUNDERSTORMS TUESDAY, BUT OTHERWISE IT WILL BE DRY  
THROUGH SATURDAY. HIGHS WILL BE IN THE UPPER 70S AND LOW 80S THROUGH  
THURSDAY, THEN WE'LL RISE BACK INTO THE MID TO UPPER 80S AND LOW 90S  
FRIDAY INTO SUNDAY.  
 

 
   
SHORT TERM
 
(THIS EVENING THROUGH TUESDAY)  
ISSUED AT 200 PM EDT MON JUL 22 2019  
 
LATEST SURFACE ANALYSIS SHOWS COLD FRONT ALONG OHIO RIVER VALLEY  
WITH HIGH PRESSURE CENTERED OVER THE DAKOTAS. SATELLITE/RADAR  
STILL INDICATING PLENTY OF POST-FRONTAL CLOUD COVER OVER MUCH OF  
THE AREA AND A FEW LINGERING SHOWERS ALONG SOUTHERN CWA BORDER.  
NOT MUCH CHANGE IN THE SHORT TERM AS SURFACE HIGH TO REMAIN  
DISPLACED TO THE WEST OF OUR AREA WHICH WILL MAINTAIN COOL DRY  
NORTHWEST FLOW. AMPLIFIED UPPER LEVEL PATTERN HAS RIDGE CENTERED  
OVER THE FOUR CORNERS WITH AXIS EXTENDING THROUGH THE SOUTHERN  
PROVINCES OF CANADA WHILE UPPER LOW JUST EAST OF HUDSON BAY WITH  
TROF AXIS EXTENDING THROUGH THE GREAT LAKES DOWN TO THE OH/TN  
VALLEY WHICH WILL MAINTAIN NW FLOW ALOFT AS WELL. LATEST VIS  
SATELLITE IMAGERY SHOWING CLEARING OVER FAR NW CWA AND EXPECTED TO  
SPREAD SOUTHEAST THROUGH THE REMAINDER OF THE CWA THIS EVENING AS  
UPPER TROF AXIS PIVOTS THROUGH THE AREA WITH AMPLE SUBSIDENCE AND  
DRYING BEHIND IT. DEWPOINTS WILL CONTINUE TO FALL REACHING THE  
LOWER 50S OVERNIGHT AND BRING LOW TEMPS TO A REFRESHING MID 50S.  
DRY AIRMASS AND LOW LEVEL THERMAL TROF SHIFTING EASTWARD SHOULD  
RESULT IN JUST SCATTERED DIURNAL CU ON TUESDAY. A WEAK DISTURBANCE  
DROPPING DOWN IN NW FLOW WILL BRING A NON-ZERO PRECIP CHANCE TO  
NE CWA TUESDAY AFTERNOON BUT ONLY AN ISOLATED SHOWER OR TWO AT  
BEST. VERY COMFORTABLE TEMPS FOR THIS TIME OF YEAR WITH HIGHS IN  
THE UPPER 70S TO NEAR 80F.  
 

 
   
LONG TERM
 
(TUESDAY NIGHT THROUGH MONDAY)  
ISSUED AT 200 PM EDT MON JUL 22 2019  
 
QUIET WEATHER PATTERN TO CONTINUE THROUGH MUCH OF THE LONG TERM  
PERIOD. UPPER TROF AXIS SHIFTS FURTHER EAST BUT NORTHWEST FLOW  
PATTERN MAINTAINS OVER THE REGION WITH UPPER RIDGE CENTERED OVER  
THE FOUR CORNERS. SURFACE HIGH PRESSURE BUILDS INTO THE REGION  
MAINTAINING SUNNY SKIES AND LOW HUMIDITIES THROUGH THURSDAY.  
NORTHERN EXTENT OF UPPER RIDGE WILL BREAK DOWN AS PACIFIC ENERGY  
COMES ONSHORE TUESDAY NIGHT. THIS DISTURBANCE WILL TRACK ACROSS  
SOUTHERN CANADA BEFORE DIPPING INTO THE NORTHERN GREAT LAKES  
REGION HEADING INTO THE WEEKEND. SURFACE HIGH PRESSURE WILL MOVE  
TOWARD THE EASTERN SEABOARD AS WELL RESULTING IN A DEVELOPING  
RETURN FLOW AHEAD OF THIS SYSTEM WHICH WILL BRING AN INCREASE IN  
HUMIDITY AND NUDGE HIGHS BACK INTO THE MID-UPPER 80S THIS WEEKEND.  
FORCING WILL BE DISPLACED WELL TO THE NORTH OF OUR AREA AND  
LACKING DEEP MOISTURE RETURN FROM THE GULF WILL HAVE WEEKEND  
STAYING MAINLY DRY WITH WEAK SIGNAL FROM ENSEMBLE MEAN AND ONLY A  
COUPLE INDIVIDUAL MEMBERS SHOWING MEASURABLE PRECIP IN NORTHERN  
CWA. PRECIP CHANCES NOT EXPECTED UNTIL BEGINNING OF NEXT WEEK WITH  
ARRIVAL OF SURFACE BOUNDARY.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)  
ISSUED AT 114 PM EDT MON JUL 22 2019  
 
SURFACE HIGH PRESSURE ACROSS THE NORTHERN PLAINS WILL BUILD INTO  
THE OHIO VALLEY DURING THE FCST PERIOD. AS DRIER AIR INFILTRATES  
THE REGION CLOUDS WILL PUSH EAST WITH ONLY HIGH CLOUDS DURING THE  
OVERNIGHT PERIOD INTO TUE MORNING. NORTHERLY WINDS WILL BE ABOUT  
10 TO 15 KTS THIS AFTN THEN SUBSIDING TO LESS THAN 5 TONIGHT. VFR  
CONDITIONS WILL PERSIST THROUGH THE FCST PERIOD.  
 

 
   
IWX WATCHES/WARNINGS/ADVISORIES
 
 
IN...BEACH HAZARDS STATEMENT THROUGH LATE TONIGHT FOR INZ003.  
 
LAKESHORE FLOOD ADVISORY UNTIL 5 AM CDT TUESDAY FOR INZ003.  
 
MI...BEACH HAZARDS STATEMENT THROUGH LATE TONIGHT FOR MIZ077.  
 
LAKESHORE FLOOD ADVISORY UNTIL 6 AM EDT TUESDAY FOR MIZ077.  
 
OH...NONE.  
LM...SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR LMZ043-046.  
 

 
 

 
 
SYNOPSIS...MCD  
SHORT TERM...JAL  
LONG TERM...JAL  
AVIATION...MF  
 
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