043
FNUS75 KRIW 161523
FWSRIW
SPOT FORECAST FOR IRON MOUNTAIN PILE RX...BLM
NATIONAL WEATHER SERVICE RIVERTON WY
823 AM MST TUE DEC 16 2025
FORECAST IS BASED ON IGNITION TIME OF 1200 MST ON DECEMBER 17.
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER
SERVICE
DISCUSSION
WINDS WEDNESDAY START FROM THE SOUTH, BUT WILL BE SOUTHWEST BY
MIDDAY AS AN APPROACHING WEATHER SYSTEM MOVES IN. WINDS WILL BE WEST
BY EARLY AFTERNOON, WITH SPEEDS QUICKLY INCREASING TO BE 25 TO 35
MPH, WITH GUSTS 40 TO 55 MPH. THESE STRONG WEST WINDS WINDS WILL BE
STRONGEST FOR THE FIRST HALF OF THE AFTERNOON, BUT GUSTS 40 TO 45
MPH CONTINUE INTO THE EVENING AS WINDS SHIFT TO BE SLIGHTLY WEST-
NORTHWEST. GUSTS UNDER 40 MPH OCCUR AFTER 0100L, WITH GUSTS 20 TO 30
MPH INTO THURSDAY MORNING. THESE STRONG WINDS WILL BRING GOOD TO
EXCELLENT SMOKE DISPERSAL, BEST EARLY AFTERNOON WITH THE STRONGEST
WINDS.
FOR PRECIPITATION CHANCES, THE BEST CHANCES (ABOUT 60 PERCENT) OCCUR
WEDNESDAY 1100L THROUGH ABOUT 1700L. PRECIPITATION WILL LIKELY BE IN
THE FORM OF RAIN OR RAIN/SNOW MIX, WITH PERHAPS ALL SNOW IF IT DOES
PRECIPITATE LATE IN THE DAY. TOTAL LIQUID EQUIVALENT ACCUMULATIONS
WOULD MOST LIKELY (70%) BE AROUND 0.05 INCHES, WITH THE HIGHER END
POSSIBILITY AROUND 0.1 INCHES.
LOOKING AHEAD, THURSDAY WINDS WILL BE GUSTING AROUND 20 MPH, WITH
POOR SMOKE DISPERSAL ALL DAY. WINDS WILL GENERALLY BE FROM THE
SOUTHWEST, WITH NO PRECIPITATION EXPECTED.
..THUNDERSTORMS IMPLY STRONG GUSTY AND ERRATIC WINDS
WEDNESDAY
SKY/WEATHER.........PARTLY SUNNY (60-70 PERCENT). RAIN OR RAIN/SNOW
MIX SHOWERS LIKELY IN THE AFTERNOON.
CWR.................22 PERCENT DECREASING TO 0 PERCENT LATE IN THE
AFTERNOON.
CHANCE OF PCPN......60 PERCENT.
MAX TEMPERATURE.....AROUND 45.
MIN HUMIDITY........44-48 PERCENT.
WIND (20 FT)........BREEZY. SOUTHWEST WINDS TURNING WEST 25 TO 35 MPH
WITH GUSTS 40 TO 55 MPH.
RIDGETOP WIND.......SOUTH AROUND 25 MPH UNTIL 1300, THEN WEST 35 TO
40 MPH.
MIXING HEIGHT.......4000 FT AGL.
TRANSPORT WINDS.....WEST 25 TO 30 MPH UNTIL 1300, THEN NORTHWEST
35 TO 45 MPH.
SMOKE DISPERSAL.....GOOD UNTIL 1300, THEN VERY GOOD TO EXCELLENT UNTIL 1600,
THEN GOOD UNTIL 1800, THEN BECOMING POOR.
TIME (MST) 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........55 50 50 55 65 75
WEATHER COV.....LKY LKY LKY LKY LKY
WEATHER TYPE....RW RW RS RS RS
TSTM COV........
CWR.............20 20 20 20 20 0
CHC OF PCPN (%).60 60 60 60 60 10
TEMP............43 43 44 41 39 36
RH..............51 49 47 56 64 73
20 FT WIND DIR..S W W W W W
20 FT WIND SPD..16 23 28 29 27 23
20 FT WIND GUST.24 35 42 42 39 35
RIDGE WIND DIR..S W W W W W
RIDGE WIND SPD..25 35 40 40 40 35
MIX HGT (KFT)...2.5 3.5 4.0 3.5 3.0 2.5
TRANSP WIND DIR.W W W W NW NW
TRANSP WIND SPD.28 38 47 43 39 35
SDSPL KT-FT/100064 114 173 134 102 72
WEDNESDAY NIGHT
SKY/WEATHER.........MOSTLY CLOUDY (40-65 PERCENT).
CWR.................0 PERCENT.
CHANCE OF PCPN......10 PERCENT.
MIN TEMPERATURE.....AROUND 25.
MAX HUMIDITY........AROUND 45 PERCENT.
WIND (20 FT)........WEST WINDS 25 TO 30 MPH WITH GUSTS AROUND 40 MPH
UNTIL 0100, THEN WEST TO NORTHWEST 20 TO 25 MPH
WITH GUSTS AROUND 30 MPH.
RIDGETOP WIND.......WEST 30 TO 35 MPH UNTIL 0300, THEN NORTHWEST
AROUND 25 MPH.
MIXING HEIGHT.......500 FT AGL.
TRANSPORT WINDS.....NORTHWEST 25 TO 35 MPH UNTIL 0400, THEN 20 TO
25 MPH.
SMOKE DISPERSAL.....GOOD UNTIL 1900 DECREASING TO FAIR UNTIL AROUND
2400, THEN POOR.
TIME (MST) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
SKY (%).........65 55 45 40 30 25 30 35 45 45 45 45
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 0 0 0 0 0 0 0
TEMP............34 33 32 31 30 29 29 28 28 27 26 26
RH..............69 61 53 49 47 45 43 41 40 39 38 38
20 FT WIND DIR..W W W W W W W W W W NW NW
20 FT WIND SPD..23 24 24 24 23 22 21 20 19 17 17 15
20 FT WIND GUST.34 35 35 35 34 32 30 29 26 25 24 22
RIDGE WIND DIR..W W W W W W W W W W NW NW
RIDGE WIND SPD..35 35 35 35 35 30 30 30 30 25 25 25
MIX HGT (KFT)...2.0 1.5 1.5 1.5 2.0 2.0 1.5 1.0 0.5 0.5 0.5 0.5
TRANSP WIND DIR.NW NW NW NW NW NW NW NW NW NW NW NW
TRANSP WIND SPD.35 35 35 35 33 32 31 30 29 26 25 23
SDSPL KT-FT/100060 49 38 47 55 62 45 30 16 13 11 8
THURSDAY
SKY/WEATHER.........PARTLY SUNNY (65-75 PERCENT).
CWR.................0 PERCENT.
CHANCE OF PCPN......10 PERCENT.
MAX TEMPERATURE.....AROUND 38.
MIN HUMIDITY........35-38 PERCENT.
WIND (20 FT)........WEST WINDS AROUND 15 MPH WITH GUSTS AROUND 20 MPH
UNTIL 1000, THEN SOUTHWEST 10 TO 12 MPH WITH GUSTS
AROUND 20 MPH.
RIDGETOP WIND.......WEST 15 TO 20 MPH UNTIL 1100, THEN SOUTHWEST.
MIXING HEIGHT.......2000 FT AGL UNTIL 1100, THEN 2500 FT AGL UNTIL
1700, THEN 500 FT AGL.
TRANSPORT WINDS.....WEST 15 TO 25 MPH UNTIL 1100. SOUTH AROUND 15
MPH AFTER 1700.
SMOKE DISPERSAL.....POOR.
TIME (MST) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........50 60 65 70 80 85 80 75 70 70 75 80
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
CHC OF PCPN (%).0 0 0 0 0 10 10 10 10 10 10 0
TEMP............25 25 25 27 30 33 35 36 37 37 36 35
RH..............39 41 42 40 37 35 35 35 38 43 49 54
20 FT WIND DIR..W W W W SW SW SW SW SW SW S S
20 FT WIND SPD..13 11 10 10 10 10 10 10 10 9 8 8
20 FT WIND GUST.19 17 14 14 14 16 16 16 14 14 13 13
RIDGE WIND DIR..W W W W SW SW SW SW SW SW S S
RIDGE WIND SPD..20 20 15 15 15 15 15 15 15 15 15 15
MIX HGT (KFT)...0.5 0.5 0.5 1.0 2.0 2.5 2.5 2.0 2.0 1.5 1.0 0.5
TRANSP WIND DIR.NW NW W W W W W SW SW SW S S
TRANSP WIND SPD.21 18 17 17 17 17 17 17 17 16 15 15
SDSPL KT-FT/10008 7 6 17 27 37 35 33 32 21 13 5
FORECAST DAYS 3 THROUGH 5
FRIDAY
WARMER. PARTLY CLOUDY. LOWS IN THE LOWER 30S. HIGHS AROUND 50.
SOUTHWEST WINDS AROUND 15 MPH WITH GUSTS AROUND 25 MPH.
SATURDAY
MOSTLY CLOUDY. SLIGHT CHANCE OF RAIN AND SNOW SHOWERS. LOWS IN
THE LOWER 30S. HIGHS IN THE MID 40S. WEST WINDS AROUND 15 MPH
WITH GUSTS 20 TO 25 MPH.
SUNDAY
MOSTLY CLOUDY. SLIGHT CHANCE OF SHOWERS AND SNOW SHOWERS. LOWS IN
THE LOWER 30S. HIGHS IN THE LOWER 40S. SOUTH WINDS AROUND 10 MPH.
FORECASTER...WITTMANN
REQUESTED BY...CHRIS STURDEVANT
TYPE OF REQUEST...PRESCRIBED
.TAG 2527726.0/RIW
.DELDT 12/16/25
.FORMATTERVERSION 2.0.0
.EMAIL ROMAN@BLM.GOV,CSTURDEVANT@BLM.GOV
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