959  
FNUS73 KGRR 281342  
FWSGRR  
 
SPOT FORECAST FOR SER 439S...USFS  
NATIONAL WEATHER SERVICE GRAND RAPIDS MI  
942 AM EDT MON SEP 28 2026  
 
FORECAST IS BASED ON IGNITION TIME OF 1200 EDT ON SEPTEMBER 28.  
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER  
SERVICE.  
 
PLEASE CONTACT OUR OFFICE AT (616) 949-5150, IF YOU HAVE QUESTIONS  
OR CONCERNS WITH THIS FORECAST.  
   
DISCUSSION  
 
HIGH PRESSURE WILL BRING FAIR AND DRY WEATHER TODAY AND TUESDAY  
WITH LIGHT WINDS. RELATIVE HUMIDITY WILL DROP TO AROUND 50 PERCENT  
THIS AFTERNOON.  
   
REST OF TODAY  
 
SKY/WEATHER.........SUNNY (0-10 PERCENT).  
TEMPERATURE.........67 AT IGNITION...MAX 74.  
RH..................63 PERCENT AT IGNITION...MIN 51 PERCENT.  
WIND (20 FT)........WINDS NORTHEAST AT 3 MPH AT  
IGNITION...OTHERWISE LIGHT WINDS BECOMING  
NORTHWEST 5 TO 6 MPH LATE IN THE AFTERNOON.  
MIXING HEIGHT.......2600 FT AGL AT IGNITION...OTHERWISE 4500 FT  
AGL.  
MIXING WINDS........NORTH 7 TO 9 MPH.  
SMOKE DISPERSAL.....180 /FAIR/ AT IGNITION. MAX...360 /GOOD/.  
 
TIME (EDT) NOON 2 PM 4 PM 6 PM 8 PM 10 PM  
SKY (%).........4 2 5 4 10 20  
WEATHER COV.....  
WEATHER TYPE....NONE NONE NONE NONE NONE NONE  
TSTM COV........  
TEMP............67 72 74 71 62 58  
RH..............63 53 51 57 78 90  
20 FT WIND......NE 3 N 3 NW 5 NW 6 NW 5 N 2  
20 FT WIND GUST.9 10 13 15 13 7  
MIX HGT (FT)....2600 4300 4300 2000 400 400  
MIXING WIND.....NE 7 N 7 N 8 N 12 NW 8 N 8  
SMOKE DISPRSL...180 300 350 230 30 30  
   
TONIGHT  
 
SKY/WEATHER.........MOSTLY CLEAR (20-30 PERCENT) THEN BECOMING  
MOSTLY CLOUDY (45-55 PERCENT) THEN BECOMING  
PARTLY CLOUDY (45-55 PERCENT).  
TEMPERATURE.........MIN 48.  
RH..................MAX 100 PERCENT.  
WIND (20 FT)........NORTHWEST WINDS 5 TO 6 MPH BECOMING LIGHT.  
MIXING HEIGHT.......400 FT AGL.  
MIXING WINDS........NORTH 7 TO 12 MPH SHIFTING TO THE EAST AROUND 5  
MPH AFTER 3 AM.  
SMOKE DISPERSAL.....230 (FAIR) EARLY IN THE EVENING DECREASING TO  
20 (POOR) LATE IN THE NIGHT.  
   
TUESDAY  
 
SKY/WEATHER.........PARTLY SUNNY (50-60 PERCENT) THEN BECOMING  
MOSTLY SUNNY (30-40 PERCENT).  
TEMPERATURE.........MAX 73.  
RH..................MIN 57 PERCENT.  
WIND (20 FT)........LIGHT WINDS BECOMING SOUTHWEST 5 TO 7 MPH IN  
THE AFTERNOON.  
MIXING HEIGHT.......3600 FT AGL.  
MIXING WINDS........SOUTHEAST 3 TO 6 MPH SHIFTING TO THE SOUTHWEST  
6 TO 13 MPH IN THE LATE MORNING AND AFTERNOON.  
SMOKE DISPERSAL.....10 (POOR) EARLY IN THE MORNING INCREASING TO  
420 (GOOD) IN THE AFTERNOON.  
 
 
FORECASTER...OSTUNO  
REQUESTED BY...KORY BORGMAN  
TYPE OF REQUEST...PRESCRIBED  
.TAG 2622654.0/GRR  
.DELDT 09/28/26  
.FORMATTERVERSION 2.0.0  
.EMAIL KORY.BORGMAN@USDA.GOV  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab MI Page
The Nexlab IN Page
Main Text Page