Spot Forecast
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
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FNUS75 KRIW 151126
FWSRIW
Spot Forecast for Grouse Mountain RX...USFS
National Weather Service Riverton WY
526 AM MDT Wed Oct 15 2025
Forecast is based on ignition time of 0600 MDT on October 15.
If conditions become unrepresentative, contact the National Weather
Service
.DISCUSSION...
A weather system will move northward toward Wyoming and bring periods
of showers over the next 36 hours. Coverage of showers will increase
through the day as a cold front approaches the burn site. Cooler air
will move in later this afternoon and likely turn rain to snow between
1500 and 1800 with snow showers continuing tonight and into Thursday.
Isolated thunderstorms will be possible through the day, with the best
chance between 1300 and 1700 this afternoon. A gusty southwest breeze
will develop this afternoon with gusts near of over 20 mph possible.
Mixing and smoke dispersal should become good after 1100. Drier weather
should return by Friday.
...Thunderstorms imply strong gusty and erratic winds...
.TODAY...
Sky/weather.........Mostly cloudy (65-75 percent). Chance of rain
showers in the morning and a slight chance of
thunderstorms, then rain showers likely and
slight chance of thunderstorms in the afternoon.
Snow showers likely late in the afternoon.
CWR.................25 percent increasing to 60 percent in the
afternoon.
Chance of pcpn......70 percent.
Chance of thunder...24 percent.
Max temperature.....Around 41.
Min humidity........79 percent.
Wind (20 ft)........South winds 8 to 13 mph with gusts to around 19
mph. Gusty and erratic winds expected near
thunderstorms in the afternoon.
Ridgetop wind.......South 15 to 20 mph.
Mixing height.......1000 ft AGL until 1000, then 3500 ft AGL until
1200, then 5000 ft AGL until 1600, then 2000 ft
AGL.
Transport winds.....South 20 to 28 mph until 1500, then southwest
15 to 18 mph.
Smoke dispersal.....Poor until 1000, becoming good after 1100, then
poor after 1600.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........70 65 60 50 55 60 70 70 70 70 75 80
Weather cov.....CHC CHC CHC CHC CHC CHC LKY LKY LKY LKY LKY LKY
Weather type....RW RW RW RW RW RW RW RW RW RW RS RS
Tstm cov........ SCH SCH SCH SCH SCH SCH SCH SCH SCH SCH SCH
CWR.............10 10 19 10 10 10 60 60 60 60 60 60
Chc of pcpn (%).40 40 40 40 50 50 60 60 60 60 60 70
Chc of thdr (%).10 20 20 20 20 20 20 20 20 20 20 20
Temp............36 36 35 35 38 40 41 40 41 40 38 37
RH..............100 96 98 100 93 84 81 84 79 82 86 87
20 FT wind dir..S S S S S S S S SE SE S S
20 FT wind spd..13 13 12 12 12 11 11 11 11 11 9 8
20 FT wind gust.19 18 18 18 18 17 17 17 17 17 14 13
Ridge wind dir..S S S S S S S S SE SE S S
Ridge wind spd..20 20 20 20 20 20 20 20 20 20 15 15
Mix hgt (kft)...0.5 0.5 0.5 1.0 2.5 3.5 4.5 5.0 5.0 3.5 2.0 1.0
Transp wind dir.SE SE SE SE S S S S S S S SW
Transp wind spd.21 21 20 20 21 24 26 28 25 18 16 15
SDspl kt-ft/10006 6 6 17 42 72 99 118 109 58 28 16
.TONIGHT...
Sky/weather.........Cloudy (85-95 percent). Slight chance of
thunderstorms in the evening. Snow showers
likely.
CWR.................65 percent.
Chance of pcpn......80 percent.
Chance of thunder...16 percent.
Min temperature.....Around 29.
Max humidity........96 percent.
Wind (20 ft)........Southwest winds around 7 mph until 2000, then
light. Gusty and erratic winds expected near
thunderstorms in the evening.
Ridgetop wind.......Southwest 10 to 15 mph until 2100, then light
until 0500.
Mixing height.......500 ft AGL.
Transport winds.....Southwest 7 to 14 mph until 2200, then light
until 2400, then northwest 7 to 9 mph.
Smoke dispersal.....Poor.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........85 90 90 90 90 90 90 90 95 95 95 95
Weather cov.....LKY LKY LKY LKY LKY LKY LKY LKY LKY DEF DEF DEF
Weather type....SW SW SW SW SW SW SW SW SW SW SW SW
Tstm cov........SCH SCH SCH SCH SCH SCH
CWR.............70 70 70 70 70 70 60 60 60 60 60 60
Chc of pcpn (%).70 70 70 60 60 60 60 60 60 80 80 80
Chc of thdr (%).20 20 20 10 10 10 10 10 10 10 10 10
Temp............35 35 33 33 32 32 32 31 31 31 31 31
RH..............93 92 94 92 93 94 92 94 93 92 92 90
20 FT wind dir..SW SW W NW NW NW W W W W W W
20 FT wind spd..7 7 5 2 1 1 2 2 2 2 2 3
20 FT wind gust.11 11 7
Ridge wind dir..SW SW W NW NW NW W W W W W W
Ridge wind spd..15 15 10 5 5 5 5 5 5 5 5 10
Mix hgt (kft)...1.0 0.5 1.0 0.5 0.5 0.5 0.5 1.0 0.5 1.0 1.0 0.5
Transp wind dir.SW S W SW W NW NW NW NW NW NW NW
Transp wind spd.14 14 10 7 6 6 7 7 7 7 8 9
SDspl kt-ft/100010 8 7 3 3 2 3 7 2 5 6 4
.THURSDAY...
Sky/weather.........Cloudy (90-100 percent). Snow showers through
the day.
CWR.................93 percent.
Chance of pcpn......90 percent.
Chance of thunder...13 percent.
Max temperature.....Around 33.
Min humidity........90 percent.
Wind (20 ft)........Light winds.
Ridgetop wind.......West around 10 mph.
Mixing height.......2000 ft AGL.
Transport winds.....West 9 to 16 mph.
Smoke dispersal.....Poor.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........95 95 95 95 95 95 95 95 95 95 95 90
Weather cov.....DEF DEF DEF DEF DEF DEF DEF DEF DEF DEF DEF DEF
Weather type....SW SW SW SW SW SW SW SW SW SW SW SW
Tstm cov........
CWR.............90 90 90 90 90 90 90 90 90 90 90 90
Chc of pcpn (%).90 90 90 90 90 90 90 90 90 90 90 90
Chc of thdr (%).10 10 10 10 10 10 10 10 10 10 10 10
Temp............31 29 29 29 32 33 32 32 32 32 32 31
RH..............90 93 96 94 91 91 92 93 93 93 92 92
20 FT wind dir..W W W NW NW W W W W W W W
20 FT wind spd..3 4 5 5 5 5 5 5 6 6 6 5
20 FT wind gust. 6 7 7 7 7 7 7 8 8 8 7
Ridge wind dir..W W W NW NW W W W W W W W
Ridge wind spd..10 10 10 10 10 10 10 10 10 10 10 10
Mix hgt (kft)...0.5 1.0 1.0 1.0 1.5 1.5 2.0 1.5 1.5 1.5 1.5 1.5
Transp wind dir.W W W W W W W W W W W NW
Transp wind spd.9 9 10 12 10 13 14 15 15 16 16 15
SDspl kt-ft/10005 7 7 10 14 19 22 22 21 22 20 17
.FORECAST DAYS 3 THROUGH 5...
.FRIDAY...
Mostly cloudy. Lows in the mid 20s. Highs in the mid 30s.
Light winds.
.SATURDAY...
Partly cloudy. Chance of snow showers. Lows in the lower 20s.
Highs in the upper 30s. Light winds.
.SUNDAY...
Mostly clear. Slight chance of showers and snow showers. Lows in
the mid 20s. Highs in the mid 40s. Light winds.
$$
Forecaster...Hattings
Requested by...Paul Hood
Type of request...PRESCRIBED
.TAG 2523564.1/RIW
.DELDT 10/15/25
.FormatterVersion 2.0.0
.EMAIL eric.hawes@usda.gov,patrick.tenney@usda.gov,paul_hood@nps.gov,Eli.Berman@usda.gov