366  
FXUS63 KGRR 200759  
AFDGRR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAND RAPIDS MI  
359 AM EDT WED MAY 20 2026  
   
KEY MESSAGES
 
 
- DRY WEATHER THROUGH THURSDAY NIGHT WITH FROST POSSIBLE TONIGHT  
 
- RAIN BACK IN THE FORECAST FRIDAY INTO THE WEEKEND  
 
- WARMER AND MAINLY DRY EARLY NEXT WEEK  
 

 
   
DISCUSSION
 
 
ISSUED AT 358 AM EDT WED MAY 20 2026  
 
- DRY WEATHER THROUGH THURSDAY NIGHT WITH FROST POSSIBLE TONIGHT  
 
SURFACE HIGH PRESSURE WILL BRING DRY WEATHER TODAY THROUGH  
THURSDAY NIGHT. CLOUDS WILL GRADUALLY ERODE TODAY WITH PARTLY  
CLOUDY SKIES EXPECTED TONIGHT. WE MAY NEED A FROST ADVISORY  
TONIGHT ACROSS CENTRAL LOWER MICHIGAN, BUT AFTER COORDINATION WITH  
OTHER OFFICES DECIDED TO HOLD OFF ON THE ADVISORY/WARNING DECISION  
UNTIL LATER TODAY AS THERE MAY BE A GOOD AMOUNT OF HIGH CLOUDS  
AROUND YET WHICH WOULD AFFECT LOW TEMPERATURES. IN ADDITION, THERE  
IS A FAIR AMOUNT OF WIND IN THE LOWEST 2,000 FEET. A PARTLY  
CLOUDY DAY IS EXPECTED ON THURSDAY WITH MID AND HIGH CLOUDS  
STREAMING IN FROM THE WEST. IT WILL BE COOLER THAN NORMAL TODAY  
AND THURSDAY WITH HIGHS IN THE 50S AND 60S TODAY WARMING TO THE  
60S ON THURSDAY. NORMAL HIGHS ARE AROUND 70.  
 
- RAIN BACK IN THE FORECAST FRIDAY INTO THE WEEKEND  
 
RAIN RETURNS TO THE FORECAST ON FRIDAY AND ESPECIALLY FOR FRIDAY  
NIGHT AND SATURDAY. A SHORTWAVE TROUGH ALOFT LIFTS FROM THE  
SOUTHERN PLAINS STATES INTO THE GREAT LAKES FOR FRIDAY NIGHT AND  
SATURDAY WITH AN UPPER TROUGH THEN SWINGING THROUGH ON SUNDAY. A  
HEALTHY SURGE OF MOISTURE COMES IN ON A LOW LEVEL JET FRIDAY NIGHT  
AND SATURDAY WHICH IS WHEN WE SHOULD HAVE THE HIGHEST  
CONCENTRATION OF SHOWERS AND THUNDERSTORMS. THIS TIME FRAME WILL  
ESSENTIALLY BE AFFECTED BY A WARM FRONT OF SORTS WITH A COLD FRONT  
MOVING THROUGH ON SUNDAY. BOTTOM LINE IS THE WEATHER WILL BE A BIT  
UNSETTLED DURING THIS TIME.  
 
- WARMER AND MAINLY DRY EARLY NEXT WEEK  
 
WARMER AND DRIER WEATHER IS EXPECTED EARLY NEXT WEEK WITH ZONAL  
FLOW ALOFT TRENDING TOWARDS RIDGING. AT THE SURFACE, RIDGING WILL  
BE IN PLACE. HIGH TEMPERATURES WILL BE WARMING INTO THE 70S TO  
NEAR 80 DEGREES.  
 

 
   
AVIATION /06Z TAFS THROUGH 06Z THURSDAY/
 
 
ISSUED AT 159 AM EDT WED MAY 20 2026  
 
A COLD FRONT HAS PROGRESSED THROUGH ALL OF THE TAF SITES AS WE  
APPROACH 06Z WITH WEST TO NORTHWEST WINDS NOW PREVAILING. MAIN  
POST FRONTAL CONCERN IS THE EXTENT OF MVFR CEILINGS THAT MAY  
DEVELOP THE REMAINDER OF THE NIGHT. AT THIS POINT, JXN IS THE ONLY  
TAF SITE WITH A MVFR CEILING. WE DO THINK THAT THERE WILL BE SOME  
EXPANSION OF THE MVFR CEILINGS EARLY THIS MORNING ESPECIALLY SOUTH  
AND EAST OF GRR. THESE LOWER CEILINGS MAY PERSIST THROUGH THE  
MORNING HOURS. THIS AFTERNOON AND EVENING VFR WEATHER IS EXPECTED.  
NORTHWEST WINDS AT 5-15 KNOTS WILL VEER TO THE NORTH AND  
NORTHEAST THIS AFTERNOON AND THIS EVENING.  
 

 
   
MARINE
 
 
ISSUED AT 358 AM EDT WED MAY 20 2026  
 
OUR TYPICAL ADVANCING HIGH SCENARIO PRESENTS ITSELF TODAY ON THE  
FIRST DAY OF THE SURF ZONE FORECAST SEASON. A HIGH BUILDING INTO  
THE GREAT LAKES FROM THE NORTHWEST WINDS INCREASE NORTHERLY WINDS  
DOWN THE SHORELINE THROUGH AN ENHANCED PRESSURE GRADIENT ALONG THE  
LAKESHORE. THE COMBINATION OF THE HIGH BUILDING IN AND THERMAL  
AFFECTS (TROUGHING DEVELOPING OVER THE LOWER PENINSULA) DUE TO A  
THINNING OF THE LOW CLOUDS PRODUCES STRONGER WINDS DOWN THE  
SHORELINE. THE WINDS CAN BE SEEN IN THE HRRR GUIDANCE. WHILE WE  
ARE NOT EXPECTING MANY SWIMMERS TODAY (BUOY WATER TEMPS ARE IN THE  
LOWER 50S) WE WILL STILL ISSUE A BEACH HAZARD STATEMENT AS THE  
SEASON HAS BEGUN. A CORRESPONDING SMALL CRAFT ADVISORY WILL BE IN  
EFFECT AS WELL, BOTH RUNNING FROM 100PM INTO TONIGHT. WINDS GO  
OFFSHORE LATE TONIGHT AND INTO THURSDAY WHICH WILL LEAD TO  
IMPROVING CONDITIONS.  
 

 
   
GRR WATCHES/WARNINGS/ADVISORIES
 
 
MI...BEACH HAZARDS STATEMENT FROM 1 PM EDT THIS AFTERNOON THROUGH  
LATE TONIGHT FOR MIZ056-064-071.  
MARINE...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 2 AM EDT  
THURSDAY FOR LMZ844>846.  
 

 
 

 
 
DISCUSSION...DUKE  
AVIATION...DUKE  
MARINE...DUKE  
 
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