530
FNUS75 KRIW 272158
FWSRIW

Spot Forecast for Willow Creek Fire...BLM
National Weather Service Riverton WY
358 PM MDT Wed Aug 27 2025

Forecast is based on forecast start time of 0600 MDT on August 28.
If conditions become unrepresentative, contact the National Weather
Service

.DISCUSSION...The recent storm system will linger through
Thursday, with the fire site at the southern edge of the Thursday
showers and thunderstorms. Thu morning will start with a slight
chance of showers and fog early in the morning, with the best
chance of isolated thunderstorms from 1000-1400, then less of a
chance later in the afternoon. Winds should increase from the
west-northwest after 1200 Thu with gusts 15-20 mph. Showers remain
possible Thu evening, then should diminish after midnight. North-
northwest flow returns Friday with drier conditions, though a very
small chance of showers and thunderstorms. Gusty northwest winds
of 15 mph will return Friday afternoon. Saturday will then be
drier with northwest flow.

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

.THURSDAY...

Sky/weather.........Partly to mostly cloudy (60-80 percent), becoming
                    partly cloudy to mostly sunny (20-40 percent) in
                    the afternoon. Scattered rain showers in the morning
                    with very isolated thunderstorms. Isolated showers
                    and thunderstorms in the early afternoon. Patchy
                    fog also possible early in the morning.
CWR.................15-25 percent.
Chance of pcpn......40 percent in the morning, then 20-30 percent in
                    the afternoon.
Chance of thunder...30-40 percent from 0900-1500.
Max temperature.....62-68.
Min humidity........50-60 percent.
Wind (20 ft)........Light south-southwest winds until 1100, then
                    west-northwest 8 to 10 mph with gusts to
                    around 15-18 mph. Strongest winds should be
                    from 1600-1800. Gusty and erratic winds
                    expected near thunderstorms in the late
                    morning.
Ridgetop wind.......South around 10 mph until 1000, then west
                    12-16 mph.
Mixing height.......Less than 1000 ft AGL through 0900, increasing to
                    around 4000 ft AGL around 1200, then 5500 ft AGL
                    after 1500.
Transport winds.....Southwest around 10 mph until 1100, then west 15
                    to 12 mph.
Smoke dispersal.....Poor until 1000. Good early in the morning
                    increasing to very good in the afternoon after
                    1500.

TIME (MDT)      6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........70  65  60  60  60  65  65  65  65  65  60  50
Weather cov.....SCT SCT SCT SCT SCT SCT SCT SCT SCT SCT SCT SCT
Weather type....RW  RW  RW  RW  RW  RW  RW  RW  RW  RW  RW  RW
Tstm cov........            ISO ISO ISO SCT SCT SCT SCT SCT SCT
CWR.............10  10  10  10  10  10  20  20  20  20  20  20
Chc of pcpn (%).40  40  40  40  40  40  40  40  40  40  40  30
Chc of thdr (%).10  10  10  10  10  10  30  30  30  30  30  30
Temp............49  48  50  53  56  58  61  64  65  65  65  65
RH..............88  89  88  83  78  74  69  64  61  59  58  59
20 FT wind dir..S   S   SW  SW  SW  W   W   W   W   W   NW  NW
20 FT wind spd..4   4   5   5   6   7   8   9   9   9   9   9
20 FT wind gust.6   6   6   7   10  11  12  13  14  14  14  14
Ridge wind dir..S   S   SW  SW  SW  W   W   W   W   W   NW  NW
Ridge wind spd..10  10  10  10  10  10  15  15  15  15  15  15
Mix hgt (kft)...0.1 0.1 0.1 1.0 2.0 3.0 4.0 4.5 4.5 5.5 4.5 5.0
Transp wind dir.SW  SW  SW  W   W   W   W   W   W   W   W   W
Transp wind spd.8   8   9   9   10  13  15  16  17  17  17  16
SDspl kt-ft/100012  12  13  20  36  56  69  93  98  115 106 101

.THURSDAY NIGHT...

Sky/weather.........Partly cloudy (30-50 percent). Slight chance of
                    showers and thunderstorms early in the evening
                    until midnight.
CWR.................0-5 percent.
Chance of pcpn......10-15 percent.
Chance of thunder...15 percent.
Min temperature.....Around 48.
Max humidity........75-85 percent.
Wind (20 ft)........Northwest winds 8 to 10 mph with gusts 12 to 15
                    mph until 2100, then light from the north.
                    Gusty and erratic winds expected near
                    thunderstorms early in the evening.
Ridgetop wind.......Northwest 10 to 15 mph until 2100, then north
                    8 to 10 mph through the night.
Mixing height.......4500 ft AGL until 2000, then less than 1000
                    ft AGL through the night.
Transport winds.....Northwest 10 to 15 mph until 2100, then north
                    8 to 10 mph.
Smoke dispersal.....Good until 1900, becoming poor after 2000.

TIME (MDT)      6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........40  35  35  35  35  35  25  25  25  25  20  20
Weather cov.....SCH SCH SCH SCH SCH SCH
Weather type....RW  RW  RW  RW  RW  RW
Tstm cov........SCH SCH SCH
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............64  61  57  55  54  53  52  51  51  50  49  48
RH..............59  62  67  70  72  73  73  74  75  75  76  75
20 FT wind dir..NW  NW  NW  NW  NW  NE  E   E   E   E   E   E
20 FT wind spd..9   7   6   5   5   5   5   4   4   4   4   4
20 FT wind gust.13  11  8   7   6   6   6   6   6       6   6
Ridge wind dir..NW  NW  NW  NW  NW  NE  E   E   E   E   E   E
Ridge wind spd..15  15  10  10  10  10  10  10  10  10  10  10
Mix hgt (kft)...4.5 2.0 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1
Transp wind dir.W   W   NW  NW  W   W   W   W   W   W   NW  NW
Transp wind spd.16  13  10  9   8   8   8   8   8   8   8   8
SDspl kt-ft/100096  51  13  12  12  12  12  12  12  12  12  12

.FRIDAY...

Sky/weather.........Mostly sunny (20-30 percent). Very slight
                    chance of showers and thunderstorms in
                    the afternoon.
CWR.................0-5 percent.
Chance of pcpn......10 percent in the afternoon.
Chance of thunder...10 percent in the afternoon.
Max temperature.....63-68.
Min humidity........35-45 percent.
Wind (20 ft)........Light north winds until 1300, then northwest
                    8 to 10 mph with gusts to around 15 mph. Gusty
                    and erratic winds expected near thunderstorms
                    in the afternoon.
Ridgetop wind.......North around 8 mph until 1000, then northwest
                    10 to 12 mph with gusts 15 to 18 mph.
Mixing height.......Less than 1000 ft AGL until 1000, 4500 ft AGL
                    around 1200, then 7500 ft AGL after 1500.
Transport winds.....North 8 to 10 mph in the morning, becoming
                    northwest 10 to 15 mph in the afternoon.
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 (%).........25  25  25  25  25  25  40  40  40  40  40  40
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 (%).5   5   5   5   5   5   10  10  10  10  10  10
Chc of thdr (%).0   0   0   0   0   0   10  10  10  10  10  10
Temp............48  49  52  55  58  62  64  66  66  66  66  65
RH..............73  69  65  60  55  50  47  44  43  42  42  44
20 FT wind dir..E   NE  W   W   W   NW  NW  NW  NW  NW  NW  NW
20 FT wind spd..5   5   4   4   5   6   6   7   8   8   9   9
20 FT wind gust.6   6   6   6   6   8   10  11  12  13  14  14
Ridge wind dir..E   NE  W   W   W   NW  NW  NW  NW  NW  NW  NW
Ridge wind spd..10  10  10  10  10  10  10  15  15  15  15  15
Mix hgt (kft)...0.1 0.1 0.5 0.5 2.5 4.5 6.5 6.5 7.0 7.5 6.5 5.5
Transp wind dir.N   NW  NW  NW  NW  NW  NW  NW  NW  NW  NW  NW
Transp wind spd.8   8   8   8   8   10  12  13  13  14  14  15
SDspl kt-ft/100012  14  17  19  32  53  85  96  109 120 113 103

.FORECAST DAYS 3 THROUGH 5...
.SATURDAY...
Partly cloudy. Lows in the upper 40s. Highs in the upper 60s.
Light winds.
.SUNDAY...
Mostly 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.

$$
Forecaster...McDonald
Requested by...Dionysius Nicolas - Plans Section
Type of request...WILDFIRE
.TAG 2520679.2/RIW
.DELDT 08/27/25
.FormatterVersion 2.0.0
.EMAIL dnicolas@blm.gov,dionysius-caesar_nicolas@firenet.gov