885
FNUS75 KRIW 160033
FWSRIW
SPOT FORECAST FOR TELEPHONE...USFS
NATIONAL WEATHER SERVICE RIVERTON WY
633 PM MDT TUE SEP 15 2026
FORECAST IS BASED ON FORECAST START TIME OF 0600 MDT ON SEPTEMBER 16.
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER
SERVICE
DISCUSSION
CLOUD COVER WILL SLOWLY INCREASE DURING THE DAY WITH A WEATHER
SYSTEM PASSING TO THE SOUTH. A FEW SHOWERS ARE POSSIBLE LATE THE
AFTERNOON, BUT WILL BE VERY ISOLATED AND BRIEF. SOUTHWEST WINDS
WILL REMAIN LIGHT THROUGH THE DAY, WITH ANY GUSTS HOLDING BELOW 10
MPH.
THE WEATHER SYSTEM SHIFTS NORTHWARD ON THURSDAY, BRINGING A BETTER
CHANCE FOR SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON.
CURRENT ACCUMULATION FORECAST AROUND THE FIRE STANDS BETWEEN 0.10
AND 0.20 INCHES OF RAINFALL THROUGH THURSDAY EVENING. WINDS WILL
REMAIN LIGHT FROM THE SOUTH THROUGH THE DAY, GENERALLY AROUND 5
MPH. HUMIDITY AGAIN REMAINS ELEVATED, STAYING ABOVE 40 PERCENT
THROUGH THE AFTERNOON.
..THUNDERSTORMS IMPLY STRONG GUSTY AND ERRATIC WINDS
WEDNESDAY
SKY/WEATHER.........MOSTLY SUNNY (30-40 PERCENT).
CWR.................0 PERCENT.
CHANCE OF PCPN......10 PERCENT.
CHANCE OF THUNDER...10 PERCENT.
MAX TEMPERATURE.....AROUND 69.
MIN HUMIDITY........33 PERCENT.
WIND (20 FT)........LIGHT WINDS UNTIL 1400, THEN SOUTHWEST 7 TO 8
MPH UNTIL 1700, THEN LIGHT. GUSTY AND ERRATIC
WINDS EXPECTED NEAR THUNDERSTORMS LATE IN THE
AFTERNOON.
RIDGETOP WIND.......NORTH AROUND 10 MPH UNTIL 1000, THEN SOUTHWEST.
MIXING HEIGHT.......1000 FT AGL UNTIL 1000. 8000 FT AGL AFTER 1200.
TRANSPORT WINDS.....WEST 9 TO 18 MPH UNTIL 1700, THEN SOUTH.
SMOKE DISPERSAL.....POOR UNTIL 1000, THEN VERY GOOD.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........20 20 10 10 10 10 15 40 50 50 55 45
WEATHER COV..... SCH
WEATHER TYPE.... RW
TSTM COV........ SCH
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
CHC OF PCPN (%).0 0 0 0 0 0 0 0 10 10 10 10
CHC OF THDR (%).0 0 0 0 0 0 0 0 10 10 10 10
TEMP............39 37 40 52 61 64 67 69 68 68 68 68
RH..............62 70 67 54 44 40 35 33 34 33 34 34
20 FT WIND DIR..N N N NW W W SW SW SW SW S SW
20 FT WIND SPD..3 3 3 4 3 4 6 6 7 8 7 6
20 FT WIND GUST.4 4 4 6 4 6 7 10 10 12 10 10
RIDGE WIND DIR..N N N NW W W SW SW SW SW S SW
RIDGE WIND SPD..10 10 10 10 10 10 10 15 15 15 15 15
MIX HGT (KFT)...0.5 0.5 0.5 1.0 2.5 4.5 6.5 7.5 8.0 8.0 7.5 6.5
TRANSP WIND DIR.W W NW W W W SW SW W SW SW S
TRANSP WIND SPD.9 9 9 9 12 14 18 17 17 16 14 13
SDSPL KT-FT/10005 5 4 8 25 54 106 112 121 114 89 72
WEDNESDAY NIGHT
SKY/WEATHER.........MOSTLY CLOUDY (65-75 PERCENT).
CWR.................0 PERCENT.
CHANCE OF PCPN......10 PERCENT.
CHANCE OF THUNDER...8 PERCENT.
MIN TEMPERATURE.....AROUND 39.
MAX HUMIDITY........96 PERCENT.
WIND (20 FT)........LIGHT WINDS.
RIDGETOP WIND.......SOUTH 10 TO 15 MPH UNTIL 2000, THEN SOUTHEAST
UNTIL 0300, THEN LIGHT.
MIXING HEIGHT.......5500 FT AGL UNTIL 1900, THEN 500 FT AGL.
TRANSPORT WINDS.....SOUTHEAST 8 TO 13 MPH UNTIL 0500, THEN EAST
AROUND 7 MPH.
SMOKE DISPERSAL.....GOOD UNTIL 1900. POOR AFTER 2000.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
SKY (%).........60 55 60 60 60 55 65 75 80 75 75 70
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 0 0 0 0 0 0 0 0 0
CHC OF THDR (%).10 0 0 0 0 0 0 0 0 0 0 0
TEMP............66 63 58 54 50 48 47 45 44 43 41 40
RH..............37 40 47 52 57 62 65 73 76 79 84 87
20 FT WIND DIR..S SE SE E SE SE SE SE SE SE E NE
20 FT WIND SPD..6 5 4 5 5 6 6 5 3 2 1 1
20 FT WIND GUST.10 6 6 6 6 7 10 6 4
RIDGE WIND DIR..S SE SE E SE SE SE SE SE SE E NE
RIDGE WIND SPD..15 10 10 10 10 10 15 10 10 5 5 5
MIX HGT (KFT)...5.5 2.0 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
TRANSP WIND DIR.S S SE SE SE SE SE SE SE SE SE E
TRANSP WIND SPD.13 10 9 10 10 12 13 10 8 8 8 7
SDSPL KT-FT/100060 19 5 5 5 6 6 5 4 4 4 3
THURSDAY
SKY/WEATHER.........PARTLY SUNNY (65-75 PERCENT). RAIN SHOWERS
LIKELY AND CHANCE OF THUNDERSTORMS IN THE
AFTERNOON.
CWR.................0 PERCENT INCREASING TO 63 PERCENT IN THE
AFTERNOON.
CHANCE OF PCPN......70 PERCENT.
CHANCE OF THUNDER...31 PERCENT.
MAX TEMPERATURE.....AROUND 67.
MIN HUMIDITY........47 PERCENT.
WIND (20 FT)........LIGHT WINDS. GUSTY AND ERRATIC WINDS EXPECTED
NEAR THUNDERSTORMS IN THE AFTERNOON.
RIDGETOP WIND.......LIGHT WINDS UNTIL 1100, THEN SOUTHWEST 10 TO 15
MPH.
MIXING HEIGHT.......2000 FT AGL UNTIL 1200, THEN 2500 FT AGL UNTIL
1300, THEN 6000 FT AGL UNTIL 1500, THEN 3500 FT
AGL.
TRANSPORT WINDS.....EAST 7 TO 8 MPH UNTIL 0900, THEN LIGHT UNTIL
1000, THEN SOUTHWEST 8 TO 13 MPH.
SMOKE DISPERSAL.....POOR UNTIL 1100. POOR EARLY IN THE MORNING
INCREASING TO GOOD IN THE AFTERNOON AFTER 1300.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
SKY (%).........65 65 65 60 60 60 60 65 70 75 70 65
WEATHER COV..... LKY LKY LKY LKY LKY LKY
WEATHER TYPE.... RW RW RW RW RW RW
TSTM COV........ CHC CHC CHC CHC CHC CHC
CWR.............0 0 0 0 0 0 60 60 60 60 60 60
CHC OF PCPN (%).0 0 0 0 0 0 70 70 70 70 70 70
CHC OF THDR (%).0 0 0 10 10 10 30 30 30 30 30 30
TEMP............40 39 43 50 55 60 65 67 67 67 67 67
RH..............89 96 89 75 64 55 50 47 47 47 47 49
20 FT WIND DIR..N N N W W SW S SW SW SW SW SW
20 FT WIND SPD..1 1 1 1 2 4 5 6 6 6 6 6
20 FT WIND GUST. 6 6 7 10 10 10 7
RIDGE WIND DIR..N N N W W SW S SW SW SW SW SW
RIDGE WIND SPD..5 5 5 5 5 10 10 10 15 15 15 10
MIX HGT (KFT)...0.5 0.5 0.5 1.0 1.0 2.0 2.5 6.0 5.0 3.5 3.0 3.0
TRANSP WIND DIR.E E E N W W SW SW SW SW W W
TRANSP WIND SPD.7 8 8 6 8 9 10 12 13 13 13 12
SDSPL KT-FT/10003 4 4 4 8 18 24 62 54 40 35 28
FORECAST DAYS 3 THROUGH 5
FRIDAY
PARTLY CLOUDY. SHOWERS LIKELY AND CHANCE OF THUNDERSTORMS. LOWS
IN THE LOWER 40S. HIGHS IN THE UPPER 60S. LIGHT WINDS.
SATURDAY
PARTLY CLOUDY. CHANCE OF SHOWERS AND THUNDERSTORMS. LOWS IN THE
MID 30S. HIGHS IN THE LOWER 60S. NORTHWEST WINDS AROUND 7 MPH.
SUNDAY
PARTLY CLOUDY. LOWS IN THE LOWER 30S. HIGHS IN THE MID 60S. LIGHT
WINDS.
FORECASTER...STRAUB
REQUESTED BY...BRANDON BONES
TYPE OF REQUEST...WILDFIRE
.TAG 2621796.0/RIW
.DELDT 09/14/26
.FORMATTERVERSION 2.0.0
.EMAIL BRANBON.BONENBERGER@USDA.GOV
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