896  
FXUS63 KGRR 071849  
AFDGRR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAND RAPIDS MI  
249 PM EDT TUE JUL 7 2020  
 
LATEST UPDATE...  
SYNOPSIS/DISCUSSION/MARINE  
   
SYNOPSIS
 
 
ISSUED AT 249 PM EDT TUE JUL 7 2020  
 
- SOME STORMS THIS AFTERNOON AND WEDNESDAY  
 
- BETTER CHANCE FOR STORMS LATE THURSDAY INTO FRIDAY  
 
- COOLER FOR THE WEEKEND, THEN HOT AGAIN BY MIDWEEK  
 

 
   
DISCUSSION
 
(THIS EVENING THROUGH NEXT TUESDAY)  
ISSUED AT 249 PM EDT TUE JUL 7 2020  
 
- CHANCE FOR STORMS THIS AFTERNOON AND WEDNESDAY -  
 
AS A WEAKER SHORTWAVE SKIRTS OVERTOP THE SUBTROPICAL RIDGE, A WEAKER  
SURFACE FRONT HAS INTERACTED WITH DIURNAL HEATING TO KICK UP A  
FEW SHOWERS AND STORMS THIS AFTERNOON. ANY SHOWERS OR STORMS THAT  
HAVE DEVELOPED ARE PRIMARILY EAST OF US-131 THANKS TO WESTERLY  
FLOW. THESE STORMS HAVE BEEN MORE OF THE PULSE-LIKE HIT-OR-MISS  
STORMS, WITH LOCALLY HEAVY RAIN RATES AND A FEW STRIKES OF  
LIGHTNING.  
 
UPPER RIDGING WILL PERSIST INTO WEDNESDAY, BUT ISOLATED SHOWERS AND  
STORMS WILL BE POSSIBLE AGAIN DUE TO LAKE BREEZE INFLUENCE DURING  
THE AFTERNOON AND EARLY EVENING EVENING.  
 
- BETTER CHANCE FOR STORMS LATE THURSDAY INTO FRIDAY -  
 
A TROUGH WILL ARRIVE THURSDAY LATER IN THE DAY AND INTO EARLY FRIDAY  
INCREASING CHANCES FOR SHOWERS AND STORMS. WITH DECENT HEIGHT FALLS  
AS THIS TROUGH MOVES IN, AND FAIRLY GOOD INFLUX OF MOISTURE, THIS  
MAY BE OUR BEST CHANCE FOR RAIN IN THE NEAR FUTURE. CONVECTION ALONG  
THE FRONT IS EXPECTED, AND THEN SOME CONTINUED DIURNALLY DRIVEN  
CONVECTION WILL BE POSSIBLE AS THE TROUGH SLOWLY PROGRESSES  
THROUGH THE REGION ON FRIDAY.  
 
- COOLER FOR THE WEEKEND, THEN HOT AGAIN BY MIDWEEK -  
 
WHILE UPPER HEIGHTS WILL PERSIST AND BUILD INTO THE REST OF THIS  
WEEK RESULTING IN TEMPERATURES IN THE 90S, SLIGHTLY COOLER WEATHER  
CAN BE EXPECTED FOR THE WEEKEND. FOLLOWING THE PASSAGE OF THE  
FRONT SATURDAY TEMPERATURES AND HUMIDITY WILL DROP AND PROVIDE  
SOME RELIEF FROM THE HEAT, BUT TEMPERATURES WILL STILL BE  
SLIGHTLY ABOVE NORMAL. HIGH TEMPERATURES LOOK TO BE LIMITED BACK  
INTO THE 80S FOR SATURDAY AND SUNDAY. HOTTER TEMPERATURES IN THE  
90S WILL RETURN BY MIDWEEK, HOWEVER, AS RIDGING BUILDS BACK INTO  
THE REGION.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)  
ISSUED AT 152 PM EDT TUE JUL 7 2020  
 
I EXPECT VFR CONDITIONS TO PREVAIL THROUGH THURSDAY. HOWEVER,  
THERE IS WEAK FRONT IN THE AREA THIS AFTERNOON AND SCATTED STORMS  
HAVE DEVELOPED NEAR AND EAST OF GRAND RAPIDS AS OF 1730Z. I EXPECT  
THE STORMS TO CONTINUE TO MOVE EAST AWAY FROM OUR AREA BY EVENING.  
MKG DOES NOT HAVE MUCH THREAT OF STORMS THIS AFTERNOON, AND FOR  
GRR AND AZO, THE THREAT SHOULD BE OVER BY 20Z IF NOT SOONER. BTL  
SHOULD HAVE THE STORMS EAST OF THEM BY 21Z. LAN AND JXN COULD HAVE  
STORMS INTO THE LATE AFTERNOON. AT LAN AND JXN I HAVE TEMPO GROUP  
FOR TSRA SINCE I BELIEVE THE COVERAGE OF THE STORMS SHOULD  
INCREASE OF TIME SO OUR I-69 TAF SITES HAVE THE GREATEST THREAT  
FOR THESE STORMS. THE STORMS MAY HAVE GUSTY WINDS ASSOCIATED WITH  
THEM.  
 
ONCE THE SUN SETS THE THREAT FOR STORMS WILL BE OVER. SKIES  
SHOULD FOR THE MOST PART CLEAR THIS EVENING. SOME VFR CIG CLOUDS  
MAY MOVE IN TOWARD MORNING FROM THE CONVECTION UPSTREAM (THE  
CONVECTION SHOULD HAVE DIED BUT I BELIEVE SOME TO THE CLOUDS WILL  
LINGER) THIS EVENING OVER WI/MN.  
 
IT WOULD NOT BE OUT OF THE QUESTION THAT OUR EASTERN TAF SITES  
WOULD SEE SCATTERED THUNDERSTORMS ON WEDNESDAY BUT THE THREAT IS  
NOT HIGH ENOUGH TO PUT IN THE TAFS AT THIS POINT.  
 

 
   
MARINE
 
 
ISSUED AT 249 PM EDT TUE JUL 7 2020  
 
WINDS REMAIN LIGHT THIS WEEK, THEREFORE WAVES WILL STAY LOW  
RESULTING IN LITTLE MARINE CONCERNS. THERE IS A CHANCE FOR SOME  
STORMS, MAINLY LATE THURSDAY INTO FRIDAY. LOCALLY HIGH WIND GUSTS  
WILL BE POSSIBLE, AS WELL AS HEAVY RAIN AND LIGHTNING.  
 

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

 
 

 
 
SYNOPSIS...THIELKE  
DISCUSSION...THIELKE  
AVIATION...WDM  
MARINE...THIELKE  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab MI Page
The Nexlab IN Page Main Text Page