Spot Forecast
Issued by NWS Riverton, WY

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299
FNUS75 KRIW 282109
FWSRIW

Spot Forecast for Willow Creek Fire...BLM
National Weather Service Riverton WY
309 PM MDT Thu Aug 28 2025

Forecast is based on forecast start time of 0600 MDT on August 29.
If conditions become unrepresentative, contact the National Weather
Service

.DISCUSSION...

Drier conditions are expected across the area today with a very
isolated shower or thunderstorm possible as chances remain around
10%. Moisture will start to diminish over the region but min RH is
expected to remain above critical values. Forecasted percentages
range from 30 to 45% for much of the area. Winds increase in the
afternoon from the northwest at around 10 mph with periodic gusts
near 20 mph. An brief isolated gust near 30 mph cannot be ruled out
with any nearby showers or thunderstorms. Skies are forecast to
gradually clear out through the morning leading to partly to mostly
clear skies. Precipitation chances diminish for Saturday with at
best a very isolated shower or thunderstorm possible with chances
around 5 to 10%. Dry and warmer conditions look likely to redevelop
across the area for Sunday into the first half of next week.
Fortunately at this time any concerns for elevated fire weather
conditions remains low as winds look light and min RH stays above
critical values.

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

.FRIDAY...

Sky/weather.........Sunny (10-20 percent).
CWR.................0 percent.
Chance of pcpn......10 percent.
Chance of thunder...6 percent.
Max temperature.....62-69.
Min humidity........35 percent.
Wind (20 ft)........Light winds until 1200, then north 7 to 9 mph
                    with gusts to around 14 mph.
Ridgetop wind.......Light winds until 1000, then northwest 10 to 15
                    mph.
Mixing height.......7000 ft AGL after 1300.
Transport winds.....West around 7 mph until 0700, then north until
                    0800, then northwest 7 to 15 mph.
Smoke dispersal.....Poor until 1000. Good early in the morning
                    increasing to very good in the afternoon after
                    1400.

TIME (MDT)      6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........15  10  10  5   10  10  10  15  15  15  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   10
Chc of thdr (%).0   0   0   0   0   0   0   0   0   0   0   10
Temp............47  49  52  54  57  60  62  64  65  66  65  64
RH..............76  72  68  64  57  50  43  40  37  34  36  37
20 FT wind dir..SE  E   E   N   NW  NW  N   NW  NW  N   N   N
20 FT wind spd..3   3   2   3   5   6   7   7   8   8   8   9
20 FT wind gust.4   5       5   7   10  11  11  12  13  13  14
Ridge wind dir..SE  E   E   N   NW  NW  N   NW  NW  N   N   N
Ridge wind spd..5   5   5   5   10  10  15  15  15  15  15  15
Mix hgt (kft)...0.1 0.1 0.1 0.5 2.0 4.0 5.5 6.5 6.5 7.0 7.0 6.5
Transp wind dir.W   N   N   NW  NW  NW  NW  NW  NW  NW  NW  N
Transp wind spd.7   7   6   7   9   12  13  13  14  14  15  15
SDspl kt-ft/100012  12  8   13  33  66  84  95  101 114 111 109

.FRIDAY NIGHT...

Sky/weather.........Mostly clear (15-25 percent).
CWR.................0 percent.
Chance of pcpn......10 percent.
Chance of thunder...7 percent.
Min temperature.....Around 47.
Max humidity........58-69 percent.
Wind (20 ft)........North winds 7 to 9 mph with gusts to around 17
                    mph until 2100, then light.
Ridgetop wind.......North 10 to 15 mph until 0100, then northeast
                    until 0300, then light.
Mixing height.......6000 ft AGL until 1900.
Transport winds.....North 7 to 15 mph.
Smoke dispersal.....Very good early in the evening decreasing to
                    good late in the night until 1900. Poor after
                    2000.

TIME (MDT)      6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........25  25  25  25  30  25  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 (%).10  10  10  10  10  10  0   0   0   0   0   0
Chc of thdr (%).10  10  10  10  10  10  0   0   0   0   0   0
Temp............63  61  57  55  53  52  52  51  51  50  49  48
RH..............39  43  49  51  54  57  59  61  62  62  63  63
20 FT wind dir..N   N   N   N   N   NE  NE  NE  NE  E   E   E
20 FT wind spd..9   8   7   6   6   6   5   5   4   4   4   4
20 FT wind gust.17  14  12  11  10  7   6   6   6   6   6   6
Ridge wind dir..N   N   N   N   N   NE  NE  NE  NE  E   E   E
Ridge wind spd..15  15  15  10  10  10  10  10  10  5   5   5
Mix hgt (kft)...6.0 1.5 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1
Transp wind dir.N   N   N   N   N   N   N   N   N   N   N   NW
Transp wind spd.15  14  13  12  10  9   8   8   8   7   7   7
SDspl kt-ft/1000102 44  14  15  13  12  10  10  10  10  10  10

.SATURDAY...

Sky/weather.........Sunny (5-15 percent).
CWR.................0 percent.
Chance of pcpn......10 percent.
Chance of thunder...6 percent.
Max temperature.....65-73.
Min humidity........30-36 percent.
Wind (20 ft)........Light winds until 1200, then northwest 7 to 9
                    mph with gusts to around 17 mph.
Ridgetop wind.......Light winds until 1000, then northwest 10 to 15
                    mph.
Mixing height.......8500 ft AGL after 1200.
Transport winds.....Northwest 7 to 15 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  5   5   5   5   5   5   10  10  10  10  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   10  10  10  10  10  10
Chc of thdr (%).0   0   0   0   0   0   10  10  10  10  10  10
Temp............48  50  52  55  58  61  64  66  66  66  67  66
RH..............62  60  58  54  48  43  38  35  33  33  31  31
20 FT wind dir..E   NE  N   N   N   NW  NW  NW  NW  NW  NW  NW
20 FT wind spd..4   4   4   4   5   6   7   8   8   8   9   9
20 FT wind gust.6   6   6   6   7   10  12  14  14  16  17  17
Ridge wind dir..E   NE  N   N   N   NW  NW  NW  NW  NW  NW  NW
Ridge wind spd..5   5   5   5   10  10  10  15  15  15  15  15
Mix hgt (kft)...0.1 0.1 0.1 0.5 2.5 4.5 7.0 7.5 8.0 8.5 8.0 7.0
Transp wind dir.NW  W   NW  NW  NW  NW  NW  NW  NW  NW  NW  NW
Transp wind spd.7   7   7   7   8   10  13  14  14  14  15  15
SDspl kt-ft/100010  12  13  15  32  61  98  113 130 136 128 119

.FORECAST DAYS 3 THROUGH 5...
.SUNDAY...
Clear. Lows in the upper 40s. Highs in the lower 70s. Light
winds.
.LABOR DAY...
Mostly clear. Lows around 50. Highs in the mid 70s. Light winds.
.TUESDAY...
Mostly clear. Lows in the lower 50s. Highs in the mid 70s. Light
winds.

$$
Forecaster...Dziewaltowski
Requested by...Dionysius Nicolas - Plans Section
Type of request...WILDFIRE
.TAG 2520679.3/RIW
.DELDT 08/28/25
.FormatterVersion 2.0.0
.EMAIL dionysius-caesar_nicolas@firenet.gov,dnicolas@blm.gov