122  
FXUS63 KGRR 292312  
AFDGRR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAND RAPIDS MI  
712 PM EDT FRI AUG 29 2025  
   
KEY MESSAGES
 
 
- SUNNY THROUGH EARLY NEXT WEEK AND WARMING  
 
- COOL AND WET MID NEXT WEEK  
 

 
   
DISCUSSION
 
 
ISSUED AT 210 PM EDT FRI AUG 29 2025  
 
- SUNNY THROUGH EARLY NEXT WEEK AND WARMING  
 
THE ARRIVAL OF SURFACE HIGH PRESSURE AND A VERY DRY MOISTURE PROFILE  
ALOFT WILL KEEP SKIES MOSTLY CLOUD FREE THIS WEEKEND. TONIGHT WILL  
FEATURE VERY FAVORABLE RADIATIONAL COOLING CONDITIONS AS WINDS CALM  
AND SKIES REMAIN CLEAR. EXPECT THAT SIMILAR TO LAST NIGHT,  
TEMPERATURES ACROSS OUR TYPICAL COLD SPOTS WILL FALL NOTABLY LOWER  
THAN GUIDANCE. WILL GO WITH A FROST ADVISORY ACROSS CLARE AND  
OSCEOLA COUNTIES AS ITS LIKELY THAT TEMPERATURES WILL AT LEAST GET  
DOWN INTO THE MID 30S, PARTICULARLY IN THE NORMAL COLD SPOTS.  
HIGHS WILL BE IN THE MID 70S SATURDAY AND UPPER 70S SUNDAY AS THE  
TROUGH PULLS AWAY.  
 
A BRIEF PERIOD OF RIDGING THEN ARRIVES EARLY NEXT WEEK AS 850 MB  
TEMPS CLIMB INTO THE LOW TO MID TEENS. THIS WILL TRANSLATE TO HIGHS  
AROUND 80 FOR MONDAY AND TUESDAY. A CONTINUED DRY AIRMASS AND HIGH  
PRESSURE WILL KEEP SUNSHINE PLENTIFUL.  
 
- COOL AND WET MID NEXT WEEK  
 
CONDITIONS CHANGE INTO WEDNESDAY AND THURSDAY AS LARGE SCALE  
TROUGHING RETURNS TO THE REGION. THIS WILL BE AN ANOMALOUS TROUGH  
FOR THIS TIME OF YEAR WITH 500 MB HEIGHTS APPROACHING 4 STANDARD  
DEVIATIONS BELOW NORMAL. THIS WILL BRING COOL CONDITIONS BACK TO  
WEST MICHIGAN. THIS TROUGH WILL ALSO DRIVE A LOW PRESSURE SYSTEM AND  
ASSOCIATED COLD FRONT THROUGH THE REGION WEDNESDAY BRINGING SHOWERS,  
AND POSSIBLY SOME THUNDER WEDNESDAY AFTERNOON. 850 MB TEMPS FALL  
BACK INTO THE SINGLE DIGITS BEHIND THIS FRONT BRINGING LAKE EFFECT  
RAIN SHOWERS BACK INTO THE FORECAST THURSDAY INTO FRIDAY.  
 

 
   
AVIATION /00Z TAFS THROUGH 00Z SATURDAY/
 
 
ISSUED AT 712 PM EDT FRI AUG 29 2025  
 
VFR IS LIKELY THROUGH SATURDAY WITH LIGHT AND VARIABLE WINDS. ONE  
EXCEPTION MAY BE SHALLOW OR PATCHY FOG TONIGHT BETWEEN 08 AND 12  
Z. MODELS HAVE BEEN HINTING AT THE POSSIBILITY, THOUGH CONFIDENCE  
IS NOT PARTICULARLY HIGH. SCATTERED CUMULUS CLOUDS ABOVE 3,000  
FEET ARE AGAIN EXPECTED DURING THE LATE MORNING AND AFTERNOON.  
 

 
   
MARINE
 
 
ISSUED AT 210 PM EDT FRI AUG 29 2025  
 
LIGHT WINDS AND LOW WAVES EXPECTED THROUGH THE HOLIDAY WEEKEND, WITH  
WIND DIRECTION CHANGES MOSTLY GOVERNED BY A DAYTIME LAKE BREEZE AND  
NIGHTTIME LAND BREEZE. WATER TEMPERATURES ARE IN THE MID 50S TO MID  
60S AFTER UPWELLING CREATED BY RECENT NORTH-NORTHEAST WINDS.  
 

 
   
GRR WATCHES/WARNINGS/ADVISORIES
 
 
MI...FROST ADVISORY FROM 2 AM TO 8 AM EDT SATURDAY FOR MIZ039-040.  
MARINE...NONE.  
 

 
 

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