542  
FXUS63 KGRR 052320  
AFDGRR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAND RAPIDS MI  
720 PM EDT THU JUN 5 2025  
   
KEY MESSAGES
 
 
- NEAR NORMAL TEMPERATURES WITH SOME LATE WEEKEND RAIN CHANCES  
 
- WARMING UP LATER NEXT WEEK  
 

 
   
DISCUSSION
 
 
ISSUED AT 336 PM EDT THU JUN 5 2025  
 
- NEAR NORMAL TEMPERATURES WITH SOME LATE WEEKEND RAIN CHANCES  
 
TEMPERATURES NEAR NORMAL WITH HIGHS IN THE MID 70S AND LOWS IN THE  
MID 50S (COOLER NEAR LAKE MICHIGAN) SHOULD PERSIST UNTIL MID NEXT  
WEEK. HIGH PRESSURE WILL GENERALLY BE IN PLACE OVER THE REGION  
THROUGH SATURDAY. ON FRIDAY, LINGERING MOISTURE / HIGHER HUMIDITY  
OVER SOUTHERN MICHIGAN, AND PROXIMITY TO THE STATIONARY FRONT AND  
WEAK LOW DRAPED ACROSS INDIANA/OHIO, MAY ALLOW A FEW LIGHT RAIN  
SHOWERS TO DEVELOP NEAR I-94.  
 
THERE ARE A COUPLE CHANCES FOR SHOWERS AND POSSIBLY A THUNDERSTORM  
BETWEEN SATURDAY NIGHT AND SUNDAY NIGHT. A WEAK SHORTWAVE TROUGH AND  
ASSOCIATED SURFACE LOW MOVING THROUGH THE SOUTHERN GREAT LAKES  
SATURDAY NIGHT TO SUNDAY MORNING MAY TOUCH OFF SHOWERS DEPENDING ON  
ITS EXACT TRACK, WITH CHANCES FOR PRECIP ABOUT 30 PERCENT IN  
SOUTHERN MICHIGAN. ON ITS HEELS IS A LARGER AND ROBUST UPPER-LEVEL  
LOW DIVING IN FROM SOUTH-CENTRAL CANADA WITH A LEADING COLD FRONT  
ARRIVING LATER SUNDAY. PRECIPITATION CHANCES ARE GREATER THAN 60  
PERCENT NEAR I-96 AND TO THE NORTH. CAPE PROGGED AROUND 500 J/KG IS  
WORTH A MENTION OF A CHANCE OF A THUNDERSTORM SUNDAY EVENING. THERE  
WILL BE SOME WIND SHEAR PRESENT ALSO, SUPPORTING A THREAT OF SOME  
GUSTIER WINDS.  
 
- WARMING UP LATER NEXT WEEK  
 
ENSEMBLES ARE BROADLY IN AGREEMENT OF A WARMING TREND NEXT WEEK  
WEDNESDAY INTO FRIDAY WITH SOUTHWESTERLY LOW-LEVEL FLOW FROM THE  
SOUTH-CENTRAL PLAINS TOWARD THE GREAT LAKES. TEMPERATURES ARE  
LOOKING TO CLIMB INTO THE 80S POSSIBLY WEDNESDAY AND LIKELY THURSDAY-  
FRIDAY. WITH MANY ENSEMBLE MEMBERS SHOWING INCREASING PWAT, SURFACE  
DEW POINTS, AND CAPE LATE IN THE WEEK GOING INTO THE WEEKEND, BOTH  
HEAT/HUMIDITY AND CHANCES FOR THUNDERSTORMS WILL BECOME MORE OF THE  
STORY.  
 

 
   
AVIATION /00Z TAFS THROUGH 00Z SATURDAY/
 
 
ISSUED AT 720 PM EDT THU JUN 5 2025  
 
VFR CONDITIONS ARE ONGOING AT ALL TERMINALS AS EARLIER STRATUS AND  
SMOKE HAVE MIXED OUT. MKG, GRR, AND LAN ARE FORECAST TO REMAIN VFR  
THROUGH THE TAF WINDOW. MODEL SOUNDINGS SUGGEST MVFR CIGS/FOG  
DEVELOP AFTER 6-8Z AT AZO, BTL, AND JXN WHERE LOW-LEVEL MOISTURE  
IS BETTER. A PERIOD OF IFR CIGS IS FAVORED AT JXN NEAR DAYBREAK  
AS DEWPOINTS/CROSSOVER TEMPS ARE NOTABLY HIGHER DUE TO STRATUS  
PERSISTING WELL INTO THE AFTERNOON TODAY. CONDITIONS WILL SLOWLY  
IMPROVE AFTER DAYBREAK WITH THESE THREE SITES FORECAST TO REACH  
VFR IN THE EARLY AFTERNOON FRIDAY. OTHERWISE EXPECT NORTHEAST  
WINDS AOB 10 KNOTS, WITH THE EXCEPTION OF MKG WHERE A LAKE BREEZE  
FRIDAY AFTERNOON WILL RESULT IN NORTHWEST WINDS.  
 

 
   
MARINE
 
 
ISSUED AT 336 PM EDT THU JUN 5 2025  
 
WEAK GRADIENT FLOW FROM A HIGH PRESSURE SYSTEM WILL KEEP CONDITIONS  
BELOW HAZARDOUS LEVELS THROUGH THE REST OF THE WEEK ON LAKE  
MICHIGAN. WINDS AND WAVES INCREASE SUNDAY/MONDAY AS A LOW PRESSURE  
SYSTEM MOVES OVER THE GREAT LAKES. PERIODS OF REDUCED VISIBILITY ARE  
POSSIBLE AT TIMES THROUGH FRIDAY MORNING DUE TO WILDFIRE SMOKE ON  
THE WATER.  
 

 
   
GRR WATCHES/WARNINGS/ADVISORIES
 
 
MI...AIR QUALITY ALERT UNTIL NOON EDT FRIDAY FOR MIZ037>040-043>046-  
050>052-056>059-064>067-071>074.  
MARINE...NONE.  
 

 
 

 
 
DISCUSSION...CAS  
AVIATION...THOMAS  
MARINE...THOMAS  
 
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