446
FNUS75 KRIW 101858
FWSRIW
SPOT FORECAST FOR IRON MOUNTAIN RX...BLM
NATIONAL WEATHER SERVICE RIVERTON WY
1158 AM MST WED DEC 10 2025
FORECAST IS BASED ON IGNITION TIME OF 1200 MST ON DECEMBER 11.
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER
SERVICE
..HIGH WIND WARNING IN EFFECT UNTIL 5 AM MST THURSDAY
DISCUSSION
AT IGNITION TIME/12PM THURSDAY, WINDS ARE FORECAST TO BE OUT OF THE
WEST-NORTHWEST WITH GUSTS BETWEEN 25MPH AND 35MPH. AN OCCASION GUST
OF 40 MPH CANNOT BE RULED OUT (25% CHANCE). GUSTY WINDS ARE EXPECTED
TO BE ONGOING THROUGH MUCH OF THE AFTERNOON AND BEGIN TO DECREASE
AFTER 1900L. WINDS FROM 1900L THURSDAY THROUGH FRIDAY WILL BE FROM
THE WEST-NORTHWEST AND GENERALLY AROUND 10 MPH WITH GUSTS OF 15 MPH
POSSIBLE. EXPECT INTERMITTENT CLOUDS THROUGH THE AFTERNOON ON
THURSDAY. FAIR TO POOR MIXING HEIGHTS AND SMOKE DISPERSAL. LESS THAN
5% CHANCE OF PRECIPITATION.
..THUNDERSTORMS IMPLY STRONG GUSTY AND ERRATIC WINDS
THURSDAY
SKY/WEATHER.........SUNNY (20-30 PERCENT).
CHANCE OF PCPN......0 PERCENT.
MIN HUMIDITY........36 PERCENT.
WIND (20 FT)........NORTHWEST WINDS 11 TO 16 MPH WITH GUSTS TO
AROUND 26 MPH.
MIXING HEIGHT.......2500 FT AGL UNTIL 1700, THEN 500 FT AGL.
TRANSPORT WINDS.....NORTHWEST 23 TO 28 MPH UNTIL 1700, THEN AROUND
18 MPH.
SMOKE DISPERSAL.....FAIR UNTIL 1600, THEN POOR.
TIME (MST) 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........15 15 15 20 25 30
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CHC OF PCPN (%).0 0 0 0 0 0
RH..............40 38 36 39 42 45
20 FT WIND DIR..W W W NW NW NW
20 FT WIND SPD..14 15 16 16 14 11
20 FT WIND GUST.22 24 26 26 21 18
MIX HGT (KFT)...2.0 2.5 2.5 2.0 1.0 0.5
TRANSP WIND DIR.NW NW NW NW NW NW
TRANSP WIND SPD.25 28 26 26 23 18
SDSPL KT-FT/100049 60 57 42 19 9
THURSDAY NIGHT
SKY/WEATHER.........PARTLY CLOUDY (35-45 PERCENT).
CHANCE OF PCPN......0 PERCENT.
MAX HUMIDITY........63 PERCENT.
WIND (20 FT)........NORTHWEST WINDS 8 TO 10 MPH WITH GUSTS TO
AROUND 16 MPH.
MIXING HEIGHT.......500 FT AGL.
TRANSPORT WINDS.....NORTHWEST 15 TO 18 MPH.
SMOKE DISPERSAL.....POOR.
TIME (MST) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
SKY (%).........35 30 30 30 30 30 35 40 45 45 40 40
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CHC OF PCPN (%).0 0 0 0 0 0 0 0 0 0 0 0
RH..............48 48 48 45 46 49 51 54 56 58 59 60
20 FT WIND DIR..NW NW W W W W W W W NW NW NW
20 FT WIND SPD..10 10 10 9 9 8 8 8 8 8 8 8
20 FT WIND GUST.16 16 14 14 13 12 11 10 10 10 11 11
MIX HGT (KFT)...0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
TRANSP WIND DIR.NW NW W W NW NW NW NW NW NW NW NW
TRANSP WIND SPD.18 17 17 16 16 15 15 15 15 15 15 15
SDSPL KT-FT/10009 6 5 4 4 4 4 4 4 4 4 4
FRIDAY
SKY/WEATHER.........MOSTLY SUNNY (35-45 PERCENT).
CHANCE OF PCPN......0 PERCENT.
MIN HUMIDITY........46 PERCENT.
WIND (20 FT)........WEST WINDS 7 TO 8 MPH UNTIL 1700, THEN LIGHT.
GUSTS UP TO 16 MPH.
MIXING HEIGHT.......500 FT AGL UNTIL 0700, THEN 1500 FT AGL AFTER
0900.
TRANSPORT WINDS.....NORTHWEST 13 TO 15 MPH.
SMOKE DISPERSAL.....POOR.
TIME (MST) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........35 35 30 30 30 30 30 30 30 35 40 45
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CHC OF PCPN (%).0 0 0 0 0 0 0 0 0 0 0 0
RH..............62 64 64 61 57 53 49 47 46 49 53 57
20 FT WIND DIR..NW W W W W W W W W W W W
20 FT WIND SPD..8 7 7 7 8 8 8 8 8 7 7 6
20 FT WIND GUST.11 10 10 10 10 11 12 13 13 12 11 10
MIX HGT (KFT)...0.5 0.1 0.1 0.5 0.5 1.0 1.0 1.5 1.5 1.0 0.5 0.5
TRANSP WIND DIR.NW NW NW NW W W W W W NW NW NW
TRANSP WIND SPD.15 14 14 14 15 15 15 15 15 14 14 13
SDSPL KT-FT/10003 3 3 6 9 13 16 19 22 15 9 3
FORECAST DAYS 3 THROUGH 5
SATURDAY
PARTLY CLOUDY. LOWS IN THE LOWER 30S. HIGHS IN THE MID 40S. WEST
WINDS AROUND 8 MPH AND GUSTS AROUND 13 MPH.
SUNDAY
PARTLY CLOUDY. LOWS IN THE UPPER 20S. HIGHS IN THE MID 40S. SOUTH
WINDS AROUND 7 MPH AND GUSTS AROUND 12 MPH.
MONDAY
PARTLY CLOUDY. LOWS IN THE UPPER 20S. HIGHS IN THE MID 40S. LIGHT
SOUTHERLY WINDS AROUND 6 MPH.
FORECASTER...GERHARDT
REQUESTED BY...RACHELE OMAN
TYPE OF REQUEST...PRESCRIBED
.TAG 2527206.0/RIW
.DELDT 12/10/25
.FORMATTERVERSION 2.0.0
.EMAIL CSTURDEVANT@BLM.GOV,ROMAN@BLM.GOV
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