Spot Forecast
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
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404
FNUS75 KRIW 181005
FWSRIW
Spot Forecast for Cone Cabin...Yellowstone NP
National Weather Service Riverton WY
405 AM MDT Mon Aug 18 2025
Forecast is based on forecast start time of 0600 MDT on August 18.
If conditions become unrepresentative, contact the National Weather
Service
.DISCUSSION...
Mainly clear skies and light winds this Monday morning before
becoming partly cloudy with southwest winds around 15 to 20 mph
after noon and towards sunset. Warming trend starts this afternoon
giving way minimum relative humidity values down to around 20
percent. Minimal storm chances (<10%) that should remain to the
east over the Absarokas. A stray outflow wind up to 30 to 40 mph
is possible from these but likelihood low at this point in time.
Otherwise, smoke dispersal poor this morning before becoming good
in the afternoon with the increased winds.
Warming trend continues Tuesday and Wednesday with dry conditions
expected. Next chance for isolated thunderstorms comes Thursday
afternoon and evening becoming more widespread Friday and this
upcoming weekend.
...Thunderstorms imply strong gusty and erratic winds...
.TODAY...
Sky/weather.........Sunny (20-30 percent).
CWR.................0 percent.
Chance of pcpn......10 percent.
Chance of thunder...6 percent.
Max temperature.....Around 75.
Min humidity........20 percent.
Wind (20 ft)........Light winds until 1000, then southwest 8 to 12
mph with gusts to around 17 mph.
Ridgetop wind.......Southwest 10 to 15 mph until 1200, then 15 to
20 mph.
Mixing height.......1500 ft AGL until 1000, then 3000 ft AGL until
1100, then 6000 ft AGL until 1200, then 9000 ft
AGL until 1300, then 12500 ft AGL until 1700,
then 10000 ft AGL.
Transport winds.....South 10 to 16 mph until 1100, then southwest
18 to 22 mph.
Smoke dispersal.....Poor until 1000, then fair until 1100, then
very good until 1200, then excellent.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........15 15 10 10 10 10 10 15 20 25 30 35
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 10 0
Chc of thdr (%).0 0 0 0 0 0 0 0 10 10 10 0
Temp............42 43 49 57 65 68 71 73 73 75 75 72
RH..............79 79 71 57 43 37 30 28 24 20 20 22
20 FT wind dir..S S SW SW SW SW SW SW SW SW SW SW
20 FT wind spd..5 5 4 6 8 10 12 12 12 11 11 9
20 FT wind gust.6 6 6 10 12 14 17 17 17 16 16 13
Ridge wind dir..S S SW SW SW SW SW SW SW SW SW SW
Ridge wind spd..10 10 10 15 15 15 20 20 20 20 20 15
Mix hgt (kft)...1.0 1.0 1.0 1.5 3.0 6.0 9.0 11 12 13 12 10
Transp wind dir.S S S S SW SW SW SW SW SW SW SW
Transp wind spd.10 10 10 13 16 21 21 22 22 21 20 18
SDspl kt-ft/10008 8 8 18 42 110 163 209 230 225 205 162
.TONIGHT...
Sky/weather.........Mostly clear (20-30 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Min temperature.....Around 44.
Max humidity........51 percent.
Wind (20 ft)........Southwest winds around 8 mph until 1900, then
light.
Ridgetop wind.......Southwest 10 to 15 mph until 2200, then light.
Mixing height.......10000 ft AGL until 1900. 1000 ft AGL after
2000.
Transport winds.....Southwest 8 to 17 mph until 2300, then south 7
to 8 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 (%).........35 30 20 25 25 20 15 15 15 15 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............72 70 63 58 56 54 51 50 49 46 46 45
RH..............22 25 30 37 38 40 41 43 44 47 49 51
20 FT wind dir..SW SW SW SW S S SE SE SE SE SE SE
20 FT wind spd..8 6 5 3 2 2 2 2 2 2 2 2
20 FT wind gust.12 10 6 4
Ridge wind dir..SW SW SW SW S S SE SE SE SE SE SE
Ridge wind spd..15 15 10 10 5 5 5 5 5 5 5 5
Mix hgt (kft)...10 6.5 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0
Transp wind dir.W W W SW SW S S S S S S S
Transp wind spd.17 14 10 8 8 7 8 8 8 8 8 7
SDspl kt-ft/1000148 78 8 6 6 5 6 6 6 6 6 5
.TUESDAY...
Sky/weather.........Sunny (10-20 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Max temperature.....Around 79.
Min humidity........11 percent.
Wind (20 ft)........Light winds until 1200, then southwest 7 to 8
mph with gusts to around 14 mph.
Ridgetop wind.......Light winds until 1000, then southwest 10 to 15
mph.
Mixing height.......1500 ft AGL until 1000. 10000 ft AGL after
1300.
Transport winds.....Southwest 7 to 15 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 (%).........15 20 5 5 5 5 5 10 10 15 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 0 0 0 0
Chc of thdr (%).0 0 0 0 0 0 0 0 0 0 0 0
Temp............44 45 51 58 66 69 73 74 76 78 78 77
RH..............50 51 45 38 30 23 18 14 13 12 11 11
20 FT wind dir..SE SE S S S SW SW SW SW SW SW SW
20 FT wind spd..2 2 2 2 4 6 7 8 8 8 8 7
20 FT wind gust.6 6 6 6 7 10 13 14 14 14 14 14
Ridge wind dir..SE SE S S S SW SW SW SW SW SW SW
Ridge wind spd..5 5 5 5 10 10 15 15 15 15 15 15
Mix hgt (kft)...1.0 0.5 0.5 1.5 4.0 6.0 7.5 8.5 9.0 10 10 9.5
Transp wind dir.S S S S S SW SW SW SW SW SW SW
Transp wind spd.7 7 7 8 13 14 14 15 15 15 15 14
SDspl kt-ft/10005 4 4 11 42 70 93 110 120 129 127 115
.FORECAST DAYS 3 THROUGH 5...
.WEDNESDAY...
Partly cloudy. Lows in the upper 40s. Highs in the upper 70s.
Light winds.
.THURSDAY...
Partly cloudy. Lows in the mid 40s. Highs in the mid 70s. Light
winds.
.FRIDAY...
Mostly clear. Lows in the lower 40s. Highs in the mid 70s. Light
winds.
$$
Forecaster...Lowe
Requested by...Laura Dooley
Type of request...WILDFIRE
.TAG 2520110.0/RIW
.DELDT 08/18/25
.FormatterVersion 2.0.0
.EMAIL laura_dooley@nps.gov,jessica_page@nps.gov