Spot Forecast
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
398
FNUS75 KRIW 142251
FWSRIW
Spot Forecast for Telephone...USFS
National Weather Service Riverton WY
Issued by National Weather Service Cheyenne WY
451 PM MDT Mon Sep 14 2026
Forecast is based on forecast start time of 0600 MDT on September 15.
If conditions become unrepresentative, contact the National Weather
Service
.DISCUSSION...
West winds will decrease this evening, with light and variable winds after 2400.
Tuesday will see much lighter winds, which will remain from the southeast gusting around
15 mph. After humidity recovery above 80 percent tonight, drier air returns during the
afternoon, with humidity falling to 25 percent.
Another weak front moves into the region during the day Wednesday. Winds will start the day
light from the southeast, before increasing to around 20 mph around 1600, with gusts continuing
well into the overnight hours Wednesday night. The front will limit keep humidity elevated,
staying above 35 percent. Cloud cover will increase during the afternoon, with a low chance
for a shower after 1600.
.TUESDAY...
Sky/weather.........Sunny (20-30 percent) then becoming mostly
sunny (40-50 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Max temperature.....Around 65.
Min humidity........25 percent.
Wind (20 ft)........Light winds until 1300, then south 7 to 9 mph
with gusts to around 18 mph.
Ridgetop wind.......Light winds until 1100, then southwest 10 to 15
mph.
Mixing height.......2000 ft AGL until 1100. 5500 ft AGL after 1400.
Transport winds.....Southeast around 7 mph until 0900, then
southwest 7 to 16 mph until 1500, then 15 to 17
mph.
Smoke dispersal.....Poor until 1000. Very good after 1300.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........10 15 15 25 30 35 40 55 60 60 55 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 0 0 0 0 0 0
Chc of thdr (%).0 0 0 0 0 0 0 0 0 0 0 0
Temp............30 28 30 38 48 52 56 60 61 63 64 65
RH..............75 77 73 58 44 38 33 29 28 25 24 24
20 FT wind dir..E NE NE E S S S S S S S S
20 FT wind spd..1 1 1 1 2 4 6 7 8 9 9 8
20 FT wind gust.4 2 4 5 7 10 12 14 17 18 18 18
Ridge wind dir..E N NE S SW SW SW SW SW SW SW SW
Ridge wind spd..5 5 5 5 5 10 10 15 15 15 15 15
Mix hgt (kft)...0.5 0.5 0.5 1.5 2.0 2.5 3.0 4.0 5.0 5.5 5.5 5.0
Transp wind dir.SE SE E S SW SW SW SW SW SW SW SW
Transp wind spd.7 7 7 7 8 9 12 15 16 17 16 15
SDspl kt-ft/10003 4 6 9 16 29 44 101 138 126 148 107
.TUESDAY NIGHT...
Sky/weather.........Mostly clear (20-30 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...4 percent.
Min temperature.....Around 35.
Max humidity........70 percent.
Wind (20 ft)........South winds around 7 mph with gusts to around
17 mph until 1900, then light.
Ridgetop wind.......South 10 to 15 mph until 2200, then east until
2400, then northwest.
Mixing height.......4000 ft AGL until 1900, then 500 ft AGL.
Transport winds.....South 8 to 13 mph until 2100, then light until
0100, then northwest 7 to 9 mph.
Smoke dispersal.....Good until 1900. Poor after 2100.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........35 40 15 10 15 15 10 15 15 20 15 10
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............63 61 57 51 48 45 43 41 40 40 38 37
RH..............26 29 36 42 45 51 55 60 64 61 67 69
20 FT wind dir..S S S E NE N N N N N N N
20 FT wind spd..7 5 3 3 3 3 3 3 3 3 3 3
20 FT wind gust.17 11 8 7 6 6 7 7 7 7 6 6
Ridge wind dir..SW S S SE E NE N N NW NW NW NW
Ridge wind spd..15 10 10 10 10 10 10 10 10 10 10 10
Mix hgt (kft)...4.0 2.0 1.0 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
Transp wind dir.SW S S SE SE SW W NW NW NW NW NW
Transp wind spd.13 9 8 5 6 6 6 7 8 8 8 9
SDspl kt-ft/100074 31 14 4 4 4 4 4 4 4 4 4
.WEDNESDAY...
Sky/weather.........Mostly sunny (35-45 percent).
CWR.................0 percent.
Chance of pcpn......10 percent.
Chance of thunder...13 percent.
Max temperature.....Around 69.
Min humidity........32 percent.
Wind (20 ft)........Light winds until 1300, then southwest 7 to 9
mph with gusts to around 18 mph. Gusty and
erratic winds expected near thunderstorms in
the afternoon.
Ridgetop wind.......Northwest around 10 mph until 1100, then
southwest.
Mixing height.......1000 ft AGL until 1000, then 2500 ft AGL until
1100, then 5000 ft AGL until 1200, then 8500 ft
AGL until 1700, then 6000 ft AGL.
Transport winds.....West 8 to 16 mph until 1200, then southwest 14
to 21 mph.
Smoke dispersal.....Poor until 1000. Good early in the morning
increasing to very good in the afternoon after
1200.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........10 15 20 20 20 20 20 30 40 45 55 65
Weather cov..... SCH SCH SCH SCH SCH SCH
Weather type.... RW RW RW RW RW RW
Tstm cov........ SCH SCH SCH SCH SCH SCH
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............37 36 42 48 54 60 66 67 67 68 67 67
RH..............71 74 66 57 50 42 35 34 33 32 33 35
20 FT wind dir..NW N NW W W W SW SW SW SW SW S
20 FT wind spd..3 3 3 4 5 6 6 7 8 9 9 8
20 FT wind gust.6 6 7 8 10 11 13 14 17 18 18 17
Ridge wind dir..N NW NW W W SW SW SW SW S S S
Ridge wind spd..10 10 10 10 10 10 15 15 15 15 15 15
Mix hgt (kft)...0.5 0.5 0.5 1.0 2.5 5.0 7.0 8.0 8.5 8.0 7.0 6.0
Transp wind dir.NW NW NW W W W W W W SW SW S
Transp wind spd.9 9 8 9 13 16 20 21 21 18 15 14
SDspl kt-ft/10004 5 6 7 30 59 102 106 109 113 90 63
.FORECAST DAYS 3 THROUGH 5...
.THURSDAY...
Mostly cloudy. Showers likely and slight chance of thunderstorms.
Lows in the upper 30s. Highs in the upper 60s. Light winds.
.FRIDAY...
Mostly cloudy. Chance of showers and slight chance of
thunderstorms. Lows around 40. Highs in the mid 60s. Light winds.
.SATURDAY...
Partly cloudy. Chance of showers and slight chance of
thunderstorms. Lows in the lower 30s. Highs in the lower 60s.
Northwest winds around 7 mph.
$$
Forecaster...Straub
Requested by...Brandon Bones
Type of request...WILDFIRE
.TAG 2621796.1/RIW
.DELDT 09/14/26
.FormatterVersion 2.0.0
.EMAIL timothy.sherwin@blm.gov,brandon.bonenberger@usda.gov