555  
FNUS73 KGRR 211304  
FWSGRR  
 
SPOT FORECAST FOR 437 UNIT 1...FOREST SERVICE  
NATIONAL WEATHER SERVICE GRAND RAPIDS MI  
904 AM EDT WED JUN 21 2017  
 
FORECAST IS BASED ON IGNITION TIME OF 1100 EDT ON JUNE 21.  
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
 
THE FOG WILL LIFT VERY SOON IF IT HAS NOT ALREADY.  
OTHERWISE HIGH PRESSURE WILL BRING A DRY AND SUNNY DAY WITH  
RELATIVELY LIGHT WINDS. SHOWERS AND STORMS MOVE IN TONIGHT, WITH  
SCATTERED STORMS CONTINUING THURSDAY AND THURSDAY NIGHT.  
   
TODAY
 
 
SKY/WEATHER.........SUNNY (15-25 PERCENT). AREAS OF FOG EARLY IN  
THE MORNING.  
TEMPERATURE.........69 AT IGNITION...MAX 76.  
RH..................57 PERCENT AT IGNITION...MIN 38 PERCENT.  
WIND (20 FT)........WINDS WEST AT 6 MPH AT IGNITION...OTHERWISE  
LIGHT WINDS BECOMING SOUTHWEST 5 TO 10 MPH.  
MIXING HEIGHT.......3600 FT AGL AT IGNITION...OTHERWISE 6500-7000  
FT AGL DECREASING TO 4100-4600 FT AGL LATE IN  
THE DAY.  
MIXING WINDS........SOUTHWEST 1 TO 8 MPH.  
SMOKE DISPERSAL.....100 /POOR/ AT IGNITION. MAX...600 /EXCELLENT/.  
HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED  
FIRE GROWTH AT IGNITION...MAX 5.  
 
TIME (EDT) 11 AM 1 PM 3 PM 5 PM 7 PM 9 PM  
SKY (%).........5 23 30 27 31 37  
WEATHER COV.....  
WEATHER TYPE....NONE NONE NONE NONE NONE NONE  
TSTM COV........  
TEMP............69 74 76 75 73 69  
RH..............57 46 42 43 48 55  
20 FT WIND......W 5 W 6 W 7 W 7 SW 6 S 5  
20 FT WIND GUST. 10 15 15 10  
MIX HGT (FT)....3600 6000 7000 5900 3000 800  
HAINES INDEX....4 4 4 5 5 5  
SMOKE DISPERSAL 100 400 600 500 200 0  
   
TONIGHT
 
 
SKY/WEATHER.........PARTLY CLOUDY (45-55 PERCENT) THEN BECOMING  
CLOUDY (85-95 PERCENT). ISOLATED SHOWERS AND  
THUNDERSTORMS THROUGH ABOUT 2 AM. WIDESPREAD  
SHOWERS AND THUNDERSTORMS OVERNIGHT, THEN  
SCATTERED SHOWERS AND THUNDERSTORMS TOWARD  
DAYBREAK.  
TEMPERATURE.........MIN 61.  
RH..................MAX 90 PERCENT.  
WIND (20 FT)........SOUTHWEST WINDS 5 TO 9 MPH SHIFTING TO THE  
SOUTHEAST 5 TO 10 MPH. GUSTY AND ERRATIC WINDS  
EXPECTED NEAR THUNDERSTORMS AFTER MIDNIGHT.  
MIXING HEIGHT.......1100-1600 FT AGL.  
MIXING WINDS........SOUTHEAST 2 TO 9 MPH INCREASING TO 12 TO 13 MPH  
TOWARD DAYBREAK.  
SMOKE DISPERSAL.....0-100 (POOR).  
HAINES INDEX........2 TO 5 OR VERY LOW POTENTIAL FOR LARGE PLUME  
DOMINATED FIRE GROWTH TO OR MODERATE POTENTIAL  
FOR LARGE PLUME DOMINATED FIRE GROWTH.  
   
THURSDAY
 
 
SKY/WEATHER.........MOSTLY CLOUDY (75-85 PERCENT). SCATTERED  
SHOWERS AND THUNDERSTORMS.  
TEMPERATURE.........MAX 81.  
RH..................MIN 63 PERCENT.  
WIND (20 FT)........SOUTHWEST WINDS 7 TO 12 MPH. GUSTS UP TO 25 MPH  
IN THE AFTERNOON. GUSTY AND ERRATIC WINDS  
EXPECTED NEAR THUNDERSTORMS.  
MIXING HEIGHT.......2900-3400 FT AGL.  
MIXING WINDS........SOUTHWEST 14 TO 23 MPH INCREASING TO 22 TO 30  
MPH IN THE AFTERNOON.  
SMOKE DISPERSAL.....100-1000 (POOR TO EXCELLENT).  
HAINES INDEX........3 TO 4 OR VERY LOW POTENTIAL FOR LARGE PLUME  
DOMINATED FIRE GROWTH TO OR LOW POTENTIAL FOR  
LARGE PLUME DOMINATED FIRE GROWTH.  
 

 
FORECASTER...MEADE  
REQUESTED BY...BEN WAGNER  
TYPE OF REQUEST...PRESCRIBED  
.TAG 1711372.0/GRR  
.EMAIL BENWAGNER@FS.FED.US  
 
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