025  
FXUS63 KGRR 192347  
AFDGRR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAND RAPIDS MI  
747 PM EDT TUE MAY 19 2026  
   
KEY MESSAGES
 
 
- BRIEF WINDOW FOR SHOWERS AND STORMS THIS AFTERNOON  
 
- DRY AND COOLER WEDNESDAY INTO THURSDAY, FROST POSSIBLE  
 
- SHOWERS AND STORMS RETURN FRIDAY INTO SATURDAY  
 

 
   
DISCUSSION
 
 
ISSUED AT 216 PM EDT TUE MAY 19 2026  
 
- BRIEF WINDOW FOR SHOWERS AND STORMS THIS AFTERNOON  
 
THUNDERSTORMS HAVE DEVELOPED EAST OF A KALAMAZOO TO LANSING LINE.  
IT IS IN THIS AREA WHERE SURFACE BASED CAPE IS HIGHEST (1500 TO  
2000 J/KG) WITH SHEAR VALUES AROUND 35 KNOTS. THIS IS ALSO IN THE  
AREA OF BETTER MOISTURE CONVERGENCE. DOWNDRAFT CAPE VALUES ARE  
ALSO AROUND 1000 J/KG. WITH THESE FACTORS STRONG TO SEVERE  
THUNDERSTORMS ARE POSSIBLE THROUGH 5PM WITH DAMAGING WINDS AS THE  
PRIMARY RISK AND SMALL HAIL AS THE SECONDARY. AS WE HEAD INTO THE  
EVENING OUR INSTABILITY AND SHEAR MOVE EAST WITH DRY CONDITIONS  
MOVING IN BEHIND THE COLD FRONT.  
 
- DRY AND COOLER WEDNESDAY INTO THURSDAY, FROST POSSIBLE  
 
HIGH PRESSURE BUILDS IN FOR WEDNESDAY AND THURSDAY WITH HIGHS IN THE  
MID 50S TO 60S. WITHIN THIS COOLER AIR MASS FROST IS POSSIBLE  
WEDNESDAY NIGHT INTO THURSDAY MORNING MAINLY FOR INLAND AND NORTHERN  
PORTIONS OF THE FORECAST AREA. THERE IS A 20 PERCENT CHANCE THAT  
AREAS ALONG AND NORTH OF US-10 FOR TEMPERATURES AT OR BELOW  
FREEZING. IF WINDS STAY IN THE 5 TO 15 MPH RANGE OVERNIGHT, FROST  
WOULD NOT BE A CONCERN.  
 
- SHOWERS AND STORMS RETURN FRIDAY INTO SATURDAY  
 
LOW LEVEL MOISTURE RETURNS AHEAD OF A SHORTWAVE TROUGH EXPECTED TO  
MOVE THROUGH FRIDAY AFTERNOON INTO SATURDAY MORNING. THIS WILL BRING  
ANOTHER ROUND OF SHOWERS AND STORMS TO THE AREA WITH DRIER  
CONDITIONS TRENDING FOR THE REST OF THE WEEKEND INTO NEXT WEEK.  
THERE IS DECENT AGREEMENT AS SEEN IN THE CLUSTER ANALYSIS WITH MOST  
MEMBERS KEEPING THE AREA DRY WITH TEMPERATURES WARMING UP AGAIN INTO  
NEXT WEEK.  
 

 
   
AVIATION /00Z TAFS THROUGH 00Z THURSDAY/
 
 
ISSUED AT 747 PM EDT TUE MAY 19 2026  
 
RAIN SHOWERS OR DRIZZLE IN THE VICINITY OF A COLD FRONT WILL BE  
PASSING THROUGH THIS EVENING. PATCHES OF MVFR CEILINGS/VISIBILITY  
ARE OCCURRING WITH BRIEF TEMPORARY IFR REPORTED AT A FEW  
LOCATIONS. MVFR CEILINGS WILL LIKELY PERSIST IN PATCHES ACROSS THE  
AREA TONIGHT, PERHAPS STAYING PREVAILING INTO WED MORNING. CLOUDS  
ARE FAVORED TO SCATTER OUT WITH BASES ABOVE 3,000 FEET WED  
AFTERNOON.  
 

 
   
MARINE
 
 
ISSUED AT 216 PM EDT TUE MAY 19 2026  
 
WINDS AND WAVES WILL GRADUALLY COME DOWN THIS EVENING WITH SOME  
ISOLATED SMALL CRAFT ADVISORY GUSTS THROUGH THE OVERNIGHT. IF WINDS  
TREND LOWER THE SMALL CRAFT ADVISORY COULD END EARLIER. A BRIEF  
PERIOD OF NORTHERLY SMALL CRAFT ADVISORY WINDS AND 4 FOOT WAVES IS  
POSSIBLE WEDNESDAY AFTERNOON. OTHERWISE, EASTERLY WINDS WILL KEEP  
WAVE HEIGHTS DOWN THROUGH THE REMAINDER OF THE WEEK.  
 

 
   
GRR WATCHES/WARNINGS/ADVISORIES
 
 
MI...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR LMZ844>849.  
 

 
 

 
 
DISCUSSION...RAH  
AVIATION...CAS  
MARINE...RAH  
 
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