379
FNUS75 KRIW 221025
FWSRIW

Spot Forecast for Cone Cabin...Yellowstone National Park
National Weather Service Riverton WY
425 AM MDT Fri Aug 22 2025

Forecast is based on forecast start time of 0500 MDT on August 22.
If conditions become unrepresentative, contact the National Weather
Service

.DISCUSSION...

...Thunderstorms imply strong gusty and erratic winds...

Light winds will continue through 1000 before shifting from the
northwest. Most general gusts today should remain below 15 mph.
Isolated showers and thunderstorms are possible this afternoon
between 1400 and 1800, but most should remain to the east. Any
storms could still produce gusty winds briefly reaching 40 mph.
Humidity levels fall to 20 to 25 percent through the afternoon.

Saturday conditions will be similar, with light morning winds
shifting from the northwest for the afternoon. Thunderstorm
chances will be lower, with a reduced threat for gusty winds.

.REST OF TONIGHT...

Sky/weather.........Mostly clear (20-30 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Min temperature.....Around 42.
Max humidity........82 percent.
Wind (20 ft)........Light winds.
Ridgetop wind.......East around 10 mph.
Mixing height.......1000 ft AGL.
Transport winds.....Southeast around 9 mph.
Smoke dispersal.....Poor.

TIME (MDT)      5AM
Sky (%).........25
Weather cov.....
Weather type....
Tstm cov........
CWR.............0
Chc of pcpn (%).0
Chc of thdr (%).0
Temp............44
RH..............76
20 FT wind dir..SE
20 FT wind spd..3
20 FT wind gust.6
Ridge wind dir..E
Ridge wind spd..10
Mix hgt (kft)...1.0
Transp wind dir.SE
Transp wind spd.9
SDspl kt-ft/10007

.TODAY...

Sky/weather.........Sunny (20-30 percent). Isolated showers and
                    thunderstorms late in the afternoon.
CWR.................0 percent.
Chance of pcpn......20 percent.
Chance of thunder...17 percent.
Max temperature.....Around 75.
Min humidity........22 percent.
Wind (20 ft)........Light winds until 1400, then southwest 7 to 10
                    mph. Gusty and erratic winds expected near
                    thunderstorms late in the afternoon.
Ridgetop wind.......Northeast around 10 mph until 1200, then
                    southwest until 1700, then northwest.
Mixing height.......1500 ft AGL until 1000, then 10500 ft AGL.
Transport winds.....Southeast around 9 mph until 0800, then
                    northwest until 1200, then west.
Smoke dispersal.....Poor until 1000. Very good after 1400.

TIME (MDT)      6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........15  25  10  5   5   5   5   25  30  25  45  45
Weather cov.....                                        ISO ISO
Weather type....                                        RW  RW
Tstm cov........                                        ISO ISO
CWR.............0   0   0   0   0   0   0   0   0   0   0   0
Chc of pcpn (%).0   0   0   0   0   0   0   10  10  10  10  20
Chc of thdr (%).0   0   0   0   0   0   0   10  10  10  10  20
Temp............43  42  48  56  63  67  70  72  73  74  73  71
RH..............79  79  72  59  45  37  32  28  24  22  22  26
20 FT wind dir..E   NE  NE  NE  NE  NE  SW  SW  SW  SW  W   NW
20 FT wind spd..4   4   5   5   5   5   6   6   7   8   8   8
20 FT wind gust.6   6   6   7   6   6   7   10  10  12  12  12
Ridge wind dir..E   NE  NE  NE  NE  NE  SW  SW  SW  SW  W   NW
Ridge wind spd..10  10  10  10  10  10  10  15  15  15  15  15
Mix hgt (kft)...1.0 1.0 1.0 1.5 3.0 5.5 7.5 9.0 10  11  11  8.0
Transp wind dir.SE  E   E   NE  NW  W   W   W   W   W   W   W
Transp wind spd.9   9   10  10  10  10  12  13  14  15  15  15
SDspl kt-ft/10007   7   8   12  27  49  77  98  118 136 133 106

.TONIGHT...

Sky/weather.........Mostly clear (20-30 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...3 percent.
Min temperature.....Around 40.
Max humidity........88 percent.
Wind (20 ft)........Northeast winds around 8 mph until 1900, then
                    east 7 to 10 mph until 0100, then light.
Ridgetop wind.......Northeast around 15 mph until 1900, then east.
Mixing height.......6000 ft AGL until 1900, then 1000 ft AGL.
Transport winds.....East 12 to 17 mph.
Smoke dispersal.....Good until 1900. Poor after 2000.

TIME (MDT)      6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........35  20  15  15  15  15  15  25  20  20  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............69  65  60  54  52  49  47  45  44  43  42  41
RH..............31  39  48  64  66  68  75  75  80  84  85  85
20 FT wind dir..NE  E   E   E   E   E   E   E   E   E   E   E
20 FT wind spd..8   10  9   8   8   7   7   6   6   6   6   6
20 FT wind gust.12  14  13  12  12  10  10  10  10  10  7   7
Ridge wind dir..NE  E   E   E   E   E   E   E   E   E   E   E
Ridge wind spd..15  15  15  15  15  15  15  15  15  15  10  10
Mix hgt (kft)...6.0 2.5 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0
Transp wind dir.E   E   E   E   E   E   E   E   SE  E   SE  SE
Transp wind spd.15  17  16  15  15  14  14  13  13  13  12  12
SDspl kt-ft/100077  37  12  11  11  10  10  9   9   9   8   8

.SATURDAY...

Sky/weather.........Sunny (15-25 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...4 percent.
Max temperature.....Around 76.
Min humidity........19 percent.
Wind (20 ft)........Light winds until 1200, then west 7 to 9 mph
                    until 1700, then northwest around 7 mph.
Ridgetop wind.......Southeast around 10 mph until 1000, then west
                    until 1600, then northwest.
Mixing height.......1500 ft AGL until 1000. 10000 ft AGL after
                    1400.
Transport winds.....Southeast 9 to 12 mph until 1000, then west 12
                    to 16 mph until 1400, then 14 to 16 mph.
Smoke dispersal.....Poor until 1000. Very good after 1200.

TIME (MDT)      6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........20  30  10  5   5   5   5   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   0   0   0   0
Chc of thdr (%).0   0   0   0   0   0   0   0   0   0   0   0
Temp............40  41  48  56  62  67  70  74  74  75  75  74
RH..............88  85  74  62  49  40  32  24  21  21  20  19
20 FT wind dir..SE  E   E   S   SW  SW  W   W   W   W   W   NW
20 FT wind spd..6   6   4   4   6   6   7   8   8   8   9   7
20 FT wind gust.7   7   6   6   7   10  10  12  12  12  13  11
Ridge wind dir..SE  E   E   S   SW  SW  W   W   W   W   W   NW
Ridge wind spd..10  10  10  10  10  15  15  15  15  15  15  15
Mix hgt (kft)...1.0 0.5 1.0 1.5 2.5 5.0 7.0 8.0 9.0 10  9.5 9.0
Transp wind dir.SE  SE  SE  S   SW  W   W   W   W   W   W   NW
Transp wind spd.12  12  9   9   12  13  16  15  15  15  16  14
SDspl kt-ft/10008   7   6   13  26  54  100 106 119 132 133 107

.FORECAST DAYS 3 THROUGH 5...
.SUNDAY...
Partly cloudy. Areas of smoke in the evening. Slight chance of
showers and thunderstorms. Lows around 40. Highs in the lower
70s. Light winds.
.MONDAY...
Mostly cloudy. Chance of showers and slight chance of
thunderstorms. Lows in the lower 40s. Highs around 70. Light
winds.
.TUESDAY...
Mostly cloudy. Chance of showers and thunderstorms. Lows in the
lower 40s. Highs in the upper 60s. Light winds.

$$
Forecaster...Straub
Requested by...E Folts
Type of request...WILDFIRE
.TAG 2520175.3/RIW
.DELDT 08/22/25
.FormatterVersion 2.0.0
.EMAIL laura_dooley@nps.gov,ed_folts@partner.nps.gov