530  
FXUS63 KGRR 051833  
AFDGRR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAND RAPIDS MI  
232 PM EDT MON OCT 5 2026  
   
KEY MESSAGES  
 
- SOME FROST ACROSS INTERIOR PORTIONS OF CENTRAL LOWER TONIGHT  
 
- SMALL CHANCES OF RAIN NORTH EARLY TUESDAY AND TUESDAY NIGHT  
 
- MOSTLY DRY AND INCREASINGLY WARMER WEDNESDAY AND BEYOND  
 
 
   
DISCUSSION  
 
ISSUED AT 232 PM EDT MON OCT 5 2026  
 
- SOME FROST ACROSS INTERIOR PORTIONS OF CENTRAL LOWER TONIGHT  
 
WE HAVE ONE MORE NIGHT IN THIS SERIES OF COOL NIGHTS WHERE FROST IS  
LIKELY, MAINLY FOR THE FAR NE PORTION OF THE AREA. THIS IS THE AREA  
WHERE WINDS WILL REMAIN LIGHTER CLOSER TO THE SFC RIDGE, AND A LACK  
OF CLOUD COVER WILL BE LATE TONIGHT. THIS DOES NOT LOOK TO BE A  
MAJOR EVENT AS TEMPS HAVE WARMED UP A LITTLE AS COMPARED TO LAST  
NIGHT.  
 
- SMALL CHANCES OF RAIN NORTH EARLY TUESDAY AND TUESDAY NIGHT  
 
THE NORTHERN COUNTIES THAT DO NOT LOOK TO HAVE THE FROST POTENTIAL  
WILL SEE A BIT MORE CLOUD COVER OVERNIGHT, AND WINDS ALOFT  
INCREASING AS MENTIONED ABOVE. THESE FACTORS WILL BE THE RESULT OF A  
WARM FRONT THAT WILL BE APPROACHING THAT PART OF THE AREA LATE  
TONIGHT AND FIRST THING TUESDAY MORNING. THESE ARE LIKELY TO BE  
SPRINKLES MORE THAN ANYTHING ELSE AS THE AIR BELOW ABOUT 7-8K FT  
WILL BE RATHER DRY.  
 
AFTER A DRY DAY ON TUESDAY, THERE WILL BE ANOTHER SMALL CHANCE OF  
RAIN SHOWERS ACROSS THE NORTHERN THIRD OF THE FORECAST AREA. THIS IS  
THE RESULT OF THE COLD FRONT MOVING THROUGH AND THE ASSOCIATED UPPER  
WAVE BARELY GRAZING THE AREA. THE UPPER JET CORE STAYS JUST NORTH OF  
THE AREA, AND THEREFORE THE BEST FORCING AND INSTABILITY WILL STAY  
NORTH.  
 
- MOSTLY DRY AND INCREASINGLY WARMER WEDNESDAY AND BEYOND  
 
THE UPPER WAVE ON WEDNESDAY MOVES BY, BUT THE LOWER HEIGHTS REMAIN  
ENTRENCHED ACROSS LOWER MICHIGAN AND THE REGION FOR ONE MORE DAY,  
BEFORE THE LONG WAVE TROUGH EXITS THE REGION. THIS WILL BRING COOLER  
TEMPERATURES FOR THE AREA AFTER A BRIEF WARM UP TUESDAY AND  
WEDNESDAY.  
 
UPPER HEIGHTS WILL BE RISING THEN BEGINNING THURSDAY NIGHT AND WILL  
CONTINUE INTO EARLY NEXT WEEK AS A LONG WAVE UPPER RIDGE SLOWLY  
BUILDS OUR WAY. THE BUILDING HEIGHTS, AND INCREASING RETURN FLOW  
FROM THE SSW BRINGING A WARM FRONT THROUGH FRIDAY NIGHT WILL GIVE  
THE TEMPERATURES A NICE BUMP FOR NEXT WEEKEND.  
 
THE AFOREMENTIONED WARM FRONT COMING THROUGH FRIDAY NIGHT COULD  
BRING A SMALL CHANCE OF BRIEF LIGHT RAIN. CHANCES ARE THAT MOISTURE  
WILL BE LACKING IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE. 850 MB  
TEMPERATURES WILL BE WARMING INTO THE UPPER TEENS C, POTENTIALLY  
ALLOWING SOME AREAS TO APPROACH 80 F THIS WEEKEND.  
 
THERE IS SOME UNCERTAINTY NEXT MONDAY, REGARDING AN UPPER TROUGH  
THAT MAY TRY TO COME NORTH OUT OF THE WESTERN GULF. RIGHT NOW THE  
NBM BLEND IS KEEPING THE FORECAST DRY. THIS COULD CHANGE DEPENDING  
ON HOW THE LONG WAVE TROUGH STARTS TO MOVE EAST AND LIFTS IT OUT.  
 
 
   
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/  
 
ISSUED AT 117 PM EDT MON OCT 5 2026  
 
CLEAR SKIES ARE EXPECTED THROUGH THE PERIOD. NORTHWEST WIND WILL  
DIMINISH THIS AFTERNOON AND BECOME LIGHT AND VARIABLE TONIGHT.  
 
 
   
MARINE  
 
ISSUED AT 232 PM EDT MON OCT 5 2026  
 
WE WILL BE ISSUING A GALE WARNING FOR THE NORTHERN TWO MARINE ZONES  
(NORTH OF WHITEHALL) FOR TOMORROW AND TOMORROW EVENING. WE WILL BE  
ISSUING A SMALL CRAFT ADVISORY FOR THE NORTHERN TWO ZONES AHEAD OF  
THE GALES FOR TONIGHT AND TUESDAY MORNING, AND WHITEHALL TO SOUTH  
HAVEN FOR TUESDAY INTO WEDNESDAY.  
 
STRONGER SSW WINDS AHEAD OF A FRONTAL SYSTEM WILL ARRIVE OVER THE  
NEARSHORE WATERS LATE TONIGHT, AND LAST INTO TUESDAY. THE WINDS WILL  
CHANGE TO BECOME FROM THE WNW BEHIND THE SYSTEM ON WEDNESDAY. IT  
LOOKS TO TAKE UNTIL WEDNESDAY AFTERNOON FOR WINDS AND WAVES TO COME  
DOWN BELOW CRITERIA.  
 
 
   
GRR WATCHES/WARNINGS/ADVISORIES  
 
MI...NONE.  
MARINE...SMALL CRAFT ADVISORY FROM 8 AM TUESDAY TO 4 PM EDT WEDNESDAY FOR  
LMZ845>847.  
SMALL CRAFT ADVISORY FROM 5 AM TO 2 PM EDT TUESDAY FOR LMZ848-  
849.  
GALE WARNING FROM 2 PM TO 11 PM EDT TUESDAY FOR LMZ848-849.  
 
 
 
 
 
DISCUSSION...NJJ  
AVIATION...04  
MARINE...NJJ  
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