Spot Forecast
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
503
FNUS75 KRIW 112358
FWSRIW
Spot Forecast for Telephone...USFS
National Weather Service Riverton WY
558 PM MDT Fri Sep 11 2026
Forecast is based on forecast start time of 1800 MDT on September 11.
If conditions become unrepresentative, contact the National Weather
Service
.DISCUSSION...
Winds will continue from the west through around 2000, before
switching back from the east overnight, generally in the 5 to 10
mph range. Excellent humidity recovery expected overnight,
reaching above 90 percent. No precipitation is expected overnight.
Saturday will see a return of gusty west winds during the
afternoon. Wind gusts of 20 to 25 mph will be common, with some
gusts of 30 mph possible after 1100. Humidity levels will be
slightly higher than Friday, only falling to around 25 percent
after 1300. Skies remain mostly clear, with no precipitation
expected.
Light southeast winds will return after 2000 Saturday night,
holding around 5 mph. Winds again increase on Sunday, turning more
from the southwest, but again gusting 20 to 25 mph in the
afternoon.
...Thunderstorms imply strong gusty and erratic winds...
.TONIGHT...
Sky/weather.........Partly cloudy (35-45 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Min temperature.....Around 34.
Max humidity........96 percent.
Wind (20 ft)........West winds 10 to 14 mph with gusts to around 22
mph until 2000, then light until 0100, then
east around 7 mph until 0200, then light.
Ridgetop wind.......West 20 to 25 mph until 2000, then northwest 10
to 15 mph until 2400, then northeast until
0100, then southeast until 0300, then light.
Mixing height.......7000 ft AGL until 1900. 500 ft AGL after 2000.
Transport winds.....West 21 to 28 mph until 2000, then 9 to 16 mph
until 2400, then south 8 to 9 mph.
Smoke dispersal.....Excellent until 1900. Poor after 2000.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........25 50 45 35 30 30 50 60 45 35 25 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............65 63 59 55 52 51 49 45 44 43 42 37
RH..............23 25 29 34 41 46 50 60 68 76 79 89
20 FT wind dir..W W W N NE E SE E SE E SE S
20 FT wind spd..14 10 4 3 4 5 4 7 5 3 2 2
20 FT wind gust.22 20 18 16 13 10 10 10 8 7 6 5
Ridge wind dir..W W W NW NW N NE SE S SE S SW
Ridge wind spd..25 20 15 15 15 10 10 10 10 5 5 5
Mix hgt (kft)...7.0 4.0 1.0 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 W W S S SE SE SE S
Transp wind spd.28 21 16 14 13 9 9 9 9 8 8 8
SDspl kt-ft/1000171 76 11 7 6 5 4 5 5 4 4 4
.SATURDAY...
Sky/weather.........Mostly sunny (35-45 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Max temperature.....Around 71.
Min humidity........24 percent.
Wind (20 ft)........Light winds until 1100, then west 7 to 16 mph
with gusts 20 to 25 mph.
Ridgetop wind.......Light winds until 1000, then southwest 10 to 15
mph until 1200, then west 20 to 25 mph.
Mixing height.......1500 ft AGL until 1000. 9000 ft AGL after 1400.
Transport winds.....West 7 to 13 mph until 1100. 25 to 30 mph after
1400.
Smoke dispersal.....Poor until 1100, then excellent.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........20 30 20 15 20 25 25 35 35 40 45 65
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............35 34 38 48 58 63 66 69 69 71 70 71
RH..............96 96 85 59 43 38 33 28 27 24 24 24
20 FT wind dir..SW W N NW W SW SW W W W W W
20 FT wind spd..1 1 2 2 4 7 11 15 15 16 15 14
20 FT wind gust. 6 10 16 20 20 22 20 19
Ridge wind dir..SW W N NW W SW SW W W W W W
Ridge wind spd..5 5 5 5 10 15 20 25 25 25 25 20
Mix hgt (kft)...0.5 0.5 0.5 1.5 2.5 5.0 7.0 8.5 9.0 9.0 8.5 8.0
Transp wind dir.SW W W W W W W W W W W W
Transp wind spd.7 7 8 9 13 20 24 26 30 30 29 25
SDspl kt-ft/10003 3 4 12 27 85 147 191 228 234 217 181
.SATURDAY NIGHT...
Sky/weather.........Mostly cloudy (60-70 percent) then becoming
partly cloudy (30-40 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...3 percent.
Min temperature.....Around 39.
Max humidity........87 percent.
Wind (20 ft)........West winds around 12 mph with gusts to around
17 mph until 1900, then light.
Ridgetop wind.......West 15 to 20 mph until 2000, then around 10
mph until 2300, then north until 2400, then
southeast until 0200, then light.
Mixing height.......7500 ft AGL until 1900. 500 ft AGL after 2000.
Transport winds.....West 14 to 23 mph until 2000, then 8 to 9 mph
until 0100, then southeast around 8 mph.
Smoke dispersal.....Excellent until 1900. Poor after 2000.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........65 60 60 70 65 65 55 45 50 40 15 15
Weather cov..... SCH SCH
Weather type.... RW RW
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............69 67 61 56 53 50 49 47 45 45 43 42
RH..............25 29 35 42 47 54 57 63 69 73 78 81
20 FT wind dir..W W W W W N SE SE SE E NE NE
20 FT wind spd..12 6 4 3 3 3 3 3 2 2 2 2
20 FT wind gust.17 10 6 4 4 4 4 4
Ridge wind dir..W W W W W N SE SE SE E NE NE
Ridge wind spd..20 15 10 10 10 10 10 10 5 5 5 5
Mix hgt (kft)...7.5 3.0 1.0 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 W W W SE SE SE SE SE
Transp wind spd.23 14 9 8 8 8 8 8 8 8 8 8
SDspl kt-ft/1000151 38 7 4 4 4 4 4 4 4 4 4
.SUNDAY...
Sky/weather.........Sunny (20-30 percent).
CWR.................0 percent.
Chance of pcpn......10 percent.
Chance of thunder...5 percent.
Max temperature.....Around 70.
Min humidity........26 percent.
Wind (20 ft)........Light winds until 1100, then southwest 8 to 15
mph with gusts to around 20 mph.
Ridgetop wind.......Light winds until 0800, then south around 10
mph until 1100, then southwest 15 to 20 mph
until 1500, then around 25 mph.
Mixing height.......1500 ft AGL until 1000, then 2500 ft AGL until
1100, then 5500 ft AGL until 1300, then 11000
ft AGL until 1500, then 7500 ft AGL.
Transport winds.....East around 8 mph until 0900, then southwest 10
to 18 mph until 1200, then 21 to 29 mph.
Smoke dispersal.....Poor until 1100, then excellent.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........20 15 15 15 15 15 20 25 30 35 35 30
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 10 10 10 10 10 10
Chc of thdr (%).0 0 0 0 0 0 10 10 10 10 10 10
Temp............41 39 43 51 56 61 66 68 69 69 70 69
RH..............84 87 79 66 55 46 38 34 31 30 27 26
20 FT wind dir..NE NE SE S S SW SW SW SW SW SW W
20 FT wind spd..2 2 3 4 6 8 11 13 14 15 15 15
20 FT wind gust. 4 6 7 12 16 18 19 20 20 20
Ridge wind dir..NE NE SE S S SW SW SW SW SW SW W
Ridge wind spd..5 5 10 10 10 15 20 20 20 25 25 25
Mix hgt (kft)...0.5 0.5 0.5 1.5 2.5 5.0 5.5 11 9.5 7.5 7.5 7.5
Transp wind dir.E E SE S SW SW SW SW SW SW SW SW
Transp wind spd.8 8 8 10 12 18 21 29 29 28 28 26
SDspl kt-ft/10004 4 3 13 24 81 103 278 234 183 183 176
.FORECAST DAYS 3 THROUGH 5...
.MONDAY...
Cooler. Mostly clear. Lows in the lower 30s. Highs around 60.
West winds around 13 mph.
.TUESDAY...
Mostly clear. Lows in the upper 20s. Highs in the mid 60s. Light
winds.
.WEDNESDAY...
Mostly clear. Lows in the lower 30s. Highs in the mid 60s. Light
winds.
$$
Forecaster...Straub
Requested by...Bonenberger
Type of request...WILDFIRE
.TAG 2621689.0/RIW
.DELDT 09/11/26
.FormatterVersion 2.0.0
.EMAIL brandon.bonenberger@usda.gov