Spot Forecast
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
166
FNUS75 KRIW 130216
FWSRIW
Spot Forecast for Telephone...USFS
National Weather Service Riverton WY
816 PM MDT Sat Sep 12 2026
Forecast is based on forecast start time of 2100 MDT on September 12.
If conditions become unrepresentative, contact the National Weather
Service
.DISCUSSION...
Winds tonight switch back from the southeast around 2400, but
will remain below 5 mph through the night. Excellent humidity
recovery expected, reaching near 80 percent.
On Sunday, winds start light and variable, before turning from the
southwest around 1100. Winds will be slightly lower than Saturday,
with gusts 20 to 25 mph through the afternoon. Humidity falls to
the 25 to 30 percent range after 1300 and continues into the
evening.
Monday will see drier conditions return, with humidity down near
20 percent. Winds will be gusty again, with frequent westerly
gusts around 30 mph through the afternoon.
.REST OF TONIGHT...
Sky/weather.........Mostly cloudy (55-65 percent) then becoming
partly cloudy (25-35 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...3 percent.
Min temperature.....Around 39.
Max humidity........79 percent.
Wind (20 ft)........Light winds.
Ridgetop wind.......Northeast around 10 mph until 0200, then east
until 0300, then light.
Mixing height.......500 ft AGL.
Transport winds.....West 8 to 9 mph until 0200, then southeast
around 8 mph.
Smoke dispersal.....Poor.
TIME (MDT) 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........65 55 30 25 30 30 35 25 20
Weather cov.....
Weather type....
Tstm cov........
CWR.............0 0 0 0 0 0 0 0 0
Chc of pcpn (%).0 0 0 0 0 0 0 0 10
Chc of thdr (%).0 0 0 0 0 0 0 0 0
Temp............58 55 53 52 51 49 47 46 44
RH..............33 37 41 44 46 52 56 60 65
20 FT wind dir..N N N NE E E E E E
20 FT wind spd..4 3 3 3 3 3 2 2 2
20 FT wind gust.5 4 4 4 4 4
Ridge wind dir..N N N NE E E E E E
Ridge wind spd..10 10 10 10 10 10 5 5 5
Mix hgt (kft)...0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
Transp wind dir.W W W W SW SE SE SE E
Transp wind spd.9 8 8 8 8 8 8 8 8
SDspl kt-ft/10005 4 4 4 4 4 4 4 4
.SUNDAY...
Sky/weather.........Sunny (10-20 percent).
CWR.................0 percent.
Chance of pcpn......10 percent.
Chance of thunder...9 percent.
Max temperature.....Around 73.
Min humidity........26 percent.
Wind (20 ft)........Light winds until 1100, then southwest 7 to 16
mph with gusts to around 21 mph.
Ridgetop wind.......Light winds until 0900, then south 10 to 15 mph
until 1200, then southwest 20 to 25 mph.
Mixing height.......1000 ft AGL until 1000. 8500 ft AGL after 1400.
Transport winds.....East around 8 mph until 0800, then south 8 to 9
mph until 1000, then southwest 13 to 18 mph
until 1200, then 24 to 30 mph.
Smoke dispersal.....Poor until 1000, then Excellent.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........15 20 10 10 5 5 5 10 15 20 15 15
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 0 0 0 10 10 0 0
Chc of thdr (%).0 0 0 0 0 0 0 0 10 10 0 0
Temp............42 40 42 52 60 64 68 70 71 73 71 71
RH..............73 79 74 59 46 40 34 31 29 27 26 27
20 FT wind dir..E E E SE S SW SW SW SW SW SW SW
20 FT wind spd..2 1 2 3 5 7 11 13 14 15 15 16
20 FT wind gust. 4 6 10 14 18 19 20 20 21
Ridge wind dir..E E E SE S SW SW SW SW SW SW SW
Ridge wind spd..5 5 5 10 10 15 20 20 20 25 25 25
Mix hgt (kft)...0.5 0.5 0.5 1.0 2.5 4.0 5.5 7.0 8.0 8.0 8.5 8.0
Transp wind dir.E E SE S SW SW SW SW SW SW SW SW
Transp wind spd.8 8 8 9 13 18 24 28 30 29 30 29
SDspl kt-ft/10004 4 4 9 29 62 115 173 213 205 226 202
.SUNDAY NIGHT...
Sky/weather.........Mostly clear (15-25 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Min temperature.....Around 33.
Max humidity........69 percent.
Wind (20 ft)........Southwest winds 8 to 13 mph with gusts to
around 18 mph until 2100, then light until
2200, then west 7 to 12 mph with gusts to
around 17 mph.
Ridgetop wind.......West 15 to 20 mph.
Mixing height.......7000 ft AGL until 1900. 500 ft AGL after 2000.
Transport winds.....West 15 to 24 mph until 2100, then 13 to 20
mph.
Smoke dispersal.....Very good until 1900. Poor after 2000.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........15 15 10 10 15 15 20 25 25 15 20 20
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 0 0 0 0 0 0 0
Chc of thdr (%).0 0 0 0 0 0 0 0 0 0 0 0
Temp............70 66 60 55 51 49 47 45 43 42 40 37
RH..............29 32 37 45 52 56 60 65 69 67 67 67
20 FT wind dir..SW SW SW W W W W NW NW W W W
20 FT wind spd..13 10 8 6 7 7 8 9 9 11 12 11
20 FT wind gust.18 14 12 10 10 10 12 13 13 16 17 16
Ridge wind dir..SW SW SW W W W W NW NW W W W
Ridge wind spd..20 15 15 15 15 15 15 15 15 20 20 20
Mix hgt (kft)...7.0 3.5 1.0 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 1.0
Transp wind dir.SW SW W W W W W W W W W W
Transp wind spd.24 17 15 13 14 14 15 16 16 18 20 18
SDspl kt-ft/1000144 50 10 7 7 7 7 8 9 11 12 13
.MONDAY...
Sky/weather.........Sunny (5-15 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Max temperature.....Around 60.
Min humidity........22 percent.
Wind (20 ft)........West winds 11 to 17 mph. Gusts up to 29 mph
increasing to 31 mph in the afternoon.
Ridgetop wind.......West 20 to 25 mph.
Mixing height.......500 ft AGL until 0800. 6000 ft AGL after 1100.
Transport winds.....West 18 to 26 mph until 1300, then 23 to 28
mph.
Smoke dispersal.....Poor until 0800, then Very good.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........10 10 10 5 5 5 5 5 5 5 5 5
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 0 0 0 0 0 0 0
Chc of thdr (%).0 0 0 0 0 0 0 0 0 0 0 0
Temp............36 33 36 43 47 52 56 58 59 60 60 60
RH..............64 63 54 42 35 31 27 23 23 23 22 23
20 FT wind dir..W W W W W W W W W W W W
20 FT wind spd..11 12 13 14 16 17 17 17 17 16 15 15
20 FT wind gust.16 17 18 19 22 23 25 25 23 22 20 20
Ridge wind dir..W W W W W W W W W W W W
Ridge wind spd..20 20 20 20 25 25 25 25 25 25 25 25
Mix hgt (kft)...0.5 0.5 2.5 3.0 4.0 5.0 4.5 6.0 6.0 5.5 5.5 5.5
Transp wind dir.W W W W W W W W W W W W
Transp wind spd.18 20 21 22 24 25 26 28 25 24 23 23
SDspl kt-ft/100010 11 42 60 86 105 109 143 127 117 110 108
.FORECAST DAYS 3 THROUGH 5...
.TUESDAY...
Mostly clear. Lows around 30. Highs in the mid 60s. Light winds.
.WEDNESDAY...
Mostly clear. Lows in the mid 30s. Highs in the mid 60s. Light
winds.
.THURSDAY...
Partly cloudy. Chance of showers and slight chance of
thunderstorms. Lows in the mid 30s. Highs in the mid 60s. Light
winds.
$$
Forecaster...Straub
Requested by...Bones
Type of request...WILDFIRE
.TAG 2621751.0/RIW
.DELDT 09/12/26
.FormatterVersion 2.0.0
.EMAIL brandon.bonenberger@usda.gov