868  
FNUS75 KRIW 161156  
FWSRIW  
 
SPOT FORECAST FOR GROUSE MOUNTAIN RX...USFS  
NATIONAL WEATHER SERVICE RIVERTON WY  
556 AM MDT THU OCT 16 2025  
 
FORECAST IS BASED ON IGNITION TIME OF 0600 MDT ON OCTOBER 16.  
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER  
SERVICE  
   
DISCUSSION  
 
WETTER AND COOLER CONDITIONS WILL BE SEEN TODAY AS A LOW PRESSURE  
SYSTEM MOVES ACROSS WYOMING. THIS WILL BRING SNOW SHOWERS THROUGH  
THE DAY, MOST PERSISTENT IN THE AFTERNOON. A LITTLE LIGHTNING  
CANNOT BE RULED OUT AS WELL. A BREEZY NORTHWEST WIND WILL DEVELOP  
AFTER 1200. PRECIPITATION WILL BEGIN TO WANE AFTER SUNSET, COMING  
TO AN END BY MIDNIGHT. TOTAL SNOW ACCUMULATION OF 2 TO 4 INCHES  
IS EXPECTED WITH AMOUNTS INCREASING AT HIGHER ELEVATIONS. FRIDAY  
WILL BE SLIGHTLY WARMER AND DRY AS CLOUDS CLEAR BY LATE MORNING.  
   
..THUNDERSTORMS IMPLY STRONG GUSTY AND ERRATIC WINDS  
 
   
TODAY  
 
SKY/WEATHER.........CLOUDY (85-95 PERCENT). SNOW SHOWERS THROUGH  
THE DAY WITH A SLIGHT CHANCE OF A THUNDERSTORM.  
CWR.................55 PERCENT INCREASING TO 80 PERCENT IN THE  
AFTERNOON.  
CHANCE OF PCPN......90 PERCENT.  
CHANCE OF THUNDER...15 PERCENT.  
MAX TEMPERATURE.....AROUND 34.  
MIN HUMIDITY........90 PERCENT.  
WIND (20 FT)........NORTHWEST 6 TO 10 MPH WITH GUSTS TO 15 MPH.  
RIDGETOP WIND.......NORTHWEST 10 TO 15 MPH.  
MIXING HEIGHT.......INCREASING TO 2000 FT AGL BY 1300.  
TRANSPORT WINDS.....NORTHWEST 9 TO 16 MPH.  
SMOKE DISPERSAL.....POOR.  
 
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........75 75 90 85 90 90 90 95 100 95 95 95  
WEATHER COV.....SCT SCT NUM DEF DEF DEF NUM DEF DEF DEF NUM DEF  
WEATHER TYPE....SW SW SW SW SW SW SW SW SW SW SW SW  
TSTM COV........ ISO ISO ISO ISO ISO ISO  
CWR.............60 60 60 60 60 60 80 80 80 80 80 80  
CHC OF PCPN (%).50 50 70 80 80 80 70 90 90 80 70 80  
CHC OF THDR (%).10 10 10 10 10 10 10 10 10 20 20 20  
TEMP............31 30 31 31 32 33 33 34 33 34 33 32  
RH..............97 97 99 99 97 96 95 94 94 93 94 93  
20 FT WIND DIR..N NW N N NW NW NW NW NW NW NW NW  
20 FT WIND SPD..4 4 5 5 6 6 8 8 9 9 9 9  
20 FT WIND GUST.6 6 6 6 7 10 12 12 13 13 13 13  
RIDGE WIND DIR..N NW N N NW NW NW NW NW NW NW NW  
RIDGE WIND SPD..10 10 10 10 10 15 15 15 15 15 15 15  
MIX HGT (KFT)...0.5 0.5 0.5 0.5 1.0 1.5 1.5 2.0 2.0 2.0 2.0 1.5  
TRANSP WIND DIR.N N N N N N N NW NW NW NW NW  
TRANSP WIND SPD.9 9 10 10 12 13 15 15 16 16 16 16  
SDSPL KT-FT/10004 3 4 6 9 14 22 23 30 29 27 23  
   
TONIGHT  
 
SKY/WEATHER.........CLOUDY (90-100 PERCENT). SNOW SHOWERS MOSTLY  
COMING TO AN END AROUND MIDNIGHT.  
CWR.................30 PERCENT DECREASING TO 1 PERCENT OVERNIGHT.  
CHANCE OF PCPN......70 PERCENT.  
CHANCE OF THUNDER...5 PERCENT.  
MIN TEMPERATURE.....AROUND 24.  
MAX HUMIDITY........97 PERCENT.  
WIND (20 FT)........NORTHWEST WINDS 7 TO 8 MPH UNTIL 2400, THEN  
LIGHT.  
RIDGETOP WIND.......NORTHWEST 10 TO 15 MPH.  
MIXING HEIGHT.......DECREASING TO 500 FT AGL BY 0300.  
TRANSPORT WINDS.....NORTHWEST 10 TO 15 MPH.  
SMOKE DISPERSAL.....POOR.  
 
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM  
SKY (%).........95 100 95 95 95 85 85 90 90 90 85 85  
WEATHER COV.....NUM NUM SCT ISO ISO ISO SCT ISO  
WEATHER TYPE....SW SW SW SW SW SW SW SW  
TSTM COV........  
CWR.............30 30 30 30 30 30 0 0 0 0 0 0  
CHC OF PCPN (%).70 60 50 20 20 20 15 10 10 10 10 10  
CHC OF THDR (%).10 10 10 0 0 0 0 0 0 0 0 0  
TEMP............32 30 30 29 29 29 29 28 28 28 27 27  
RH..............97 98 98 97 97 96 96 97 97 96 95 92  
20 FT WIND DIR..NW NW NW NW NW NW NW NW NW NW NW NW  
20 FT WIND SPD..8 8 8 7 7 7 6 6 6 6 6 5  
20 FT WIND GUST.12 12 12 10 10 10 10 7 7 7 7 8  
RIDGE WIND DIR..NW NW NW NW NW NW NW NW NW NW NW NW  
RIDGE WIND SPD..15 15 15 15 15 15 15 10 10 10 10 10  
MIX HGT (KFT)...1.5 1.0 1.0 1.0 1.0 1.0 1.5 1.5 1.5 0.5 0.5 0.5  
TRANSP WIND DIR.NW NW NW NW NW NW NW W W W W W  
TRANSP WIND SPD.15 15 15 14 14 14 13 12 13 12 12 10  
SDSPL KT-FT/100017 15 15 14 14 14 14 13 15 7 7 10  
   
FRIDAY  
 
SKY/WEATHER.........MOSTLY CLOUDY (75-85 PERCENT) THEN BECOMING  
MOSTLY SUNNY (35-45 PERCENT).  
CWR.................0 PERCENT.  
CHANCE OF PCPN......10 PERCENT.  
CHANCE OF THUNDER...1 PERCENT.  
MAX TEMPERATURE.....AROUND 37.  
MIN HUMIDITY........74 PERCENT.  
WIND (20 FT)........WEST AROUND 5 MPH.  
RIDGETOP WIND.......WEST 10 TO 15 MPH.  
MIXING HEIGHT.......INCREASING TO 3000 FT AGL BY 1500.  
TRANSPORT WINDS.....WEST 10 TO 17 MPH.  
SMOKE DISPERSAL.....POOR TO FAIR.  
 
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........90 80 70 70 45 45 45 40 35 35 30 30  
WEATHER COV.....  
WEATHER TYPE....  
TSTM COV........  
CWR.............0 0 0 0 0 0 0 0 0 0 0 0  
CHC OF PCPN (%).10 10 10 10 10 10 0 0 0 0 0 0  
CHC OF THDR (%).0 0 0 0 0 0 0 0 0 0 0 0  
TEMP............26 25 25 26 29 31 33 35 36 37 36 35  
RH..............88 94 94 94 83 79 78 75 73 72 72 72  
20 FT WIND DIR..W NW W W W W W W W W W W  
20 FT WIND SPD..5 4 4 4 4 5 5 6 6 6 6 6  
20 FT WIND GUST.10 10 10 10 10 11 12 13 14 14 14 14  
RIDGE WIND DIR..W NW W W W W W W W W W W  
RIDGE WIND SPD..10 10 10 10 10 10 10 10 10 15 15 15  
MIX HGT (KFT)...1.0 0.5 0.5 0.5 1.0 1.5 2.0 2.5 2.5 3.0 2.5 2.0  
TRANSP WIND DIR.W W W W W W W W W W W W  
TRANSP WIND SPD.10 9 9 9 9 10 12 14 15 17 16 15  
SDSPL KT-FT/100010 2 2 4 9 14 19 27 34 44 33 24  
   
FORECAST DAYS 3 THROUGH 5  
   
SATURDAY  
 
PARTLY CLOUDY. CHANCE OF SNOW SHOWERS IN THE MORNING. LOWS IN THE  
MID 20S. HIGHS IN THE MID 30S. WEST WINDS 4 TO 8 MPH.   
SUNDAY  
 
MOSTLY CLEAR. SLIGHT CHANCE OF SHOWERS AND SNOW SHOWERS IN THE  
AFTERNOON. LOWS IN THE LOWER 20S. HIGHS IN THE MID 40S. SOUTHWEST  
WINDS 6 TO 10 MPH WITH GUSTS TO 15 MPH.   
MONDAY  
 
COLDER. SNOW SHOWERS LIKELY. LOWS IN THE MID 20S. HIGHS IN THE  
UPPER 20S. WEST WINDS 6 TO 10 MPH.  
 
 
FORECASTER...MYERS  
REQUESTED BY...PAUL HOOD  
TYPE OF REQUEST...PRESCRIBED  
.TAG 2523564.2/RIW  
.DELDT 10/16/25  
.FORMATTERVERSION 2.0.0  
.EMAIL PAUL_HOOD@NPS.GOV,PATRICK.TENNEY@USDA.GOV,ELI.BERMAN@USDA.GOV,ERIC.HAWES@USDA.GOV  
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