975  
FXUS63 KGRR 160019  
AFDGRR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAND RAPIDS MI  
819 PM EDT MON JUL 15 2019  
 
LATEST UPDATE...  
UPDATE/SYNOPSIS/AVIATION  
   
SYNOPSIS
 
 
ISSUED AT 820 PM EDT MON JUL 15 2019  
 
- PARTLY CLOUDY TONIGHT  
 
- REMNANTS OF BARRY COULD BRING HEAVY RAIN TO AREAS NEAR I-69  
TUESDAY INTO EARLY WEDNESDAY  
 
- HEAT RETURNS THURSDAY THROUGH SATURDAY, IT IS LIKELY THOSE 3  
DAYS WILL BE THE HOTTEST OF THE SUMMER SO FAR.  
 

 
   
UPDATE
 
 
ISSUED AT 820 PM EDT MON JUL 15 2019  
 
THE SHOWERS ASSOICATED WITH THE WARM FRONT HAVE PUSHED EAST OF  
THE AREA. IT WOULD NOT OUT OF THE QUESTION THEE STORMS OVER  
NORTHERN LAKE MICHIGAN COULD BRUSH THE AREA NORTH OF ROUTE 10  
EARLY TONIGHT BUT FOR THE MOST PART IT SHOULD STAY DRY.  
 
I AM VERY CONCERNED ABOUT THE REMNANTS OF T.D. BARRY MOVING INTO  
OUR CWA TUESDAY. WE HAVE A LARGE AREA OF PRECIPITABLE WATER VALUES  
OVER 2 INCHES COMING INTO THE I-94 AREA TOMORROW AND THE MODELS  
TEND TO UNDERPLAY THESE EVENTS. THE HREF PROBABILITY MATCH MEAN  
SHOWS FOR 24 HOUR RAINFALL HAS AREAS OVER 2 INCHES IN THE I-69  
AREA BY 8 AM TUESDAY. AREAS OF UP TO AN INCH ARE AS FAR NORTHWEST  
AS SOUTHERN KENT COUNTY. THIS WILL HAVE TO BE WATCHED FOR SURE.  
 
ANOTHER DISTURBING ASPECT TO THIS IS THE MODEL SOUNDING FOR OUR SE  
CWA TOMORROW AFTERNOON. THE RAP MODEL SHOWS NEARLY 2500 J/KG OF  
CAPE WITH THE EQUILIBRIUM LEVEL NEAR THE TROPOPAUSE (45,0000 FT).  
THERE IS NO CIN. ON TOP OF THAT THE LCL IS AROUND 1500 FT. GIVEN  
THE WATER IN THE AIR (OVER 2 INCHES / MORE THAN 2 STANDARD  
DEVIATIONS FROM CLIMO) AND ALL THAT CAPE, THESE COULD BE SOME  
VERY WET THUNDERSTORMS. IT SHOULD BE NOTED WE ARE IN THE MARGINAL  
RISK FOR EXCESSIVE RAIN TOMORROW, SOUTH OF A LINE FROM SOUTH HAVEN  
TO LANSING. THIS SOMETHING WE WILL HAVE TO WATCH CLOSELY.  
 

 
   
DISCUSSION
 
(THIS EVENING THROUGH NEXT MONDAY)  
ISSUED AT 318 PM EDT MON JUL 15 2019  
 
THE AXIS OF INSTABILITY WAS PIVOTING EASTWARD THROUGH THE CWA AT  
THIS TIME. THE STORMS CONTINUE TO ROLL EAST. IT APPEARS THERE WILL  
BE A BREAK IN THE ACTIVITY ONCE THEY CLEAR THE MT PLEASANT TO  
JACKSON REGION BY ABOUT 430 PM.  
 
THE TROPICAL MOISTURE LIFTING NORTHWARD THROUGH THE MS VALLEY WILL  
MOVE INTO SOUTHERN LOWER MI. IT DOES LOOK LIKE THE DEEP MOISTURE  
WILL RESULT IN NUMEROUS SHOWERS AND PERHAPS A FEW STORMS ON  
TUESDAY. THE GREATEST POTENTIAL WILL BE SOUTH OF A GRAND RAPIDS TO  
ALMA LINE. THERE IS AN INCREASED RISK THAT THE RAIN COULD BE  
HEAVY...WHICH WILL NEED TO BE MONITORED.  
 
IMPRESSIVE HEAT MOVES IN FOR THURSDAY INTO SATURDAY. THE AREA WILL  
BE IN THE BAROCLINIC ZONE SO SOME STORMS ARE EXPECTED AS WELL.  
NORTHERN PARTS OF THE CWA MAY SEE THERE TEMPERATURES IMPACTED BY  
THE CLOUDS/STORM SO WE ARE LESS CERTAIN OF THE DEGREE OF HEAT UP  
THERE. SOME OF THE STORMS COULD BE STRONG AND PULSE SEVERE IS  
POSSIBLE. A 300 MB JET WILL BE NOSING EASTWARD INTO THE NORTHERN  
GREAT LAKES REGION THURSDAY NIGHT INTO FRIDAY WHICH MAY INCREASE  
THE COVERAGE AND STRENGTH OF THE STORMS.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)  
ISSUED AT 820 PM EDT MON JUL 15 2019  
 
I EXPECT SOLID VFR CONDITIONS THROUGH THE NIGHT. HOWEVER AFTER  
NEARLY A WEEK WITH LITTLE IN THE WAY OF LOWER CIGS/VSBY THE  
REMNANTS OF T.D. BARRY WILL MOVE INTO OUR AREA TUESDAY. CURRENTLY  
THERE IS AN AREA OF MVFR/IFR CIGS OVER MO AND E IL ASSOICATED  
WITH THIS SYSTEM. IT WILL MOVE NORTHEAST INTO LOWER MICHIGAN BY  
MID MORNING AND SHOULD REMAIN IN PLACE INTO THE AFTERNOON. I AM  
NOT SURE AT THIS POINT HOW FAR NORTH THE RAIN SHIELD WILL GET.  
EVEN SO, I DO BELIEVE THE I-94 TAFS WILL BE SOLIDLY IN THE RAIN  
TOMORROW. THING IS THERE IS CONSIDERABLE INSTABILITY EVEN WITH  
ALL THE LOW CLOUDS AND PRECIPITATION. IT WOULD SEEM THUNDERSTORMS  
ARE POSSIBLE WITH THIS SYSTEM TOO. THE SPC SREF HAS A 30 PCT  
CHANCE OF THUNDERSTORM AT 21Z NEAR I-94 TUESDAY. SO I HAVE VCTS IN  
THE I-94 TAFS TOMORROW AFTERNOON. I HAVE CONDITIONS IMPROVING BY  
21Z BUT I AM NOT SURE THAT WILL REALLY BE TRUE. ONE WAY OR THE  
OTHER WE WILL HAVE TO MONITOR THIS CLOSELY.  
 

 
   
MARINE
 
 
ISSUED AT 318 PM EDT MON JUL 15 2019  
 
SOUTH TO SOUTHWEST WINDS COULD BE GUSTY UP AROUND LITTLE AND BIG  
SABLE POINTS THIS EVENING INTO TONIGHT. CLOSE CALL FOR A SMALL  
CRAFT ADVISORY. THE SOUTHWESTERLY FLOW GENERALLY PERSISTS INTO THE  
END OF THE WEEK...BUT LIKELY JUST UNDER CRITERIA. WAVES UP TO 2 TO  
4 FEET ARE FORECASTED.  
 

 
   
GRR WATCHES/WARNINGS/ADVISORIES
 
 
MI...NONE.  
LM...NONE.  

 
 

 
 
UPDATE...WDM  
SYNOPSIS...WDM  
DISCUSSION...MJS  
AVIATION...WDM  
MARINE...MJS  
 
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