479
FNUS75 KRIW 210148
FWSRIW

Spot Forecast for Spring Creek...BLM
National Weather Service Riverton WY
748 PM MDT Wed Aug 20 2025

Forecast is based on forecast start time of 2000 MDT on August 20.
If conditions become unrepresentative, contact the National Weather
Service

.DISCUSSION...
An axis of moisture in the mid-levels of the atmosphere will stream
east-northeast across the fire overnight. There will be embedded
light showers, mostly dry, within this axis. After a period of dry
weather and more sun around midday, the chance for showers and
thunderstorms increases after 1500L Thursday as daytime heating
aids development. Coverage should peak early Thursday evening
before moving east. A cold front passed early Wednesday evening
leading to gusty northwest wind. This front will usher in cooler
temperatures for Thursday. Also, overnight humidity recovery will
be much improved by Thursday night.

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

.REST OF TONIGHT...

Sky/weather.........Mostly cloudy (60-70 percent) with isolated,
                    showers, mostly dry.
CWR.................0 percent.
Chance of pcpn......10 percent.
Chance of thunder...5 percent.
Min temperature.....64 to 67.
Max humidity........39 to 42 percent.
Wind (20 ft)........Northwest 11 to 16 mph with occasional gusts
                    to 22 mph until 2100L, then becoming east to
                    northeast 7 to 11 mph around 2300L.
Ridgetop wind.......Northwest 15 to 20 mph with gusts near 30 mph
                    until 2100L, then becoming northeast 13 to
                    18 mph.
Mixing height.......9000 ft AGL until 2000L, then decreasing to
                    less than 1500 ft AGL by 2200L.
Transport winds.....Northwest 15 to 20 mph until 2100L, then
                    becoming northeast 10 to 15 mph.
Smoke dispersal.....Very Good until 2000L, then becoming Poor
                    by 2200L.

TIME (MDT)      8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........50  55  60  70  75  65  60  50  55  55
Weather cov.....ISO ISO ISO ISO ISO ISO ISO ISO ISO ISO
Weather type....RW  RW  RW  RW  RW  RW  RW  RW  RW  RW
Tstm cov........
CWR.............0   0   0   0   0   0   0   0   0   0
Chc of pcpn (%).10  10  10  10  10  10  10  10  10  10
Chc of thdr (%).5   5   5   5   5   5   5   5   5   5
Temp............84  80  78  77  75  74  73  72  71  69
RH..............18  20  22  24  25  26  28  29  31  34
20 FT wind dir..NE  E   E   E   E   E   E   E   E   E
20 FT wind spd..8   9   9   8   8   7   6   6   6   5
20 FT wind gust.13  13  13  12  11  10  10  8   7   6
Ridge wind dir..NE  E   E   NE  E   E   E   E   E   E
Ridge wind spd..15  20  15  15  15  15  15  15  10  10
Mix hgt (kft)...1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0
Transp wind dir.N   NE  NE  NE  NE  N   N   NW  N   NE
Transp wind spd.16  18  16  15  15  14  14  13  12  10
SDspl kt-ft/100017  19  17  15  15  14  14  13  12  10

.THURSDAY...

Sky/weather.........Partly sunny (40-50 percent) with a
                    few mostly dry early morning showers.
                    Then, a slight chance of showers and
                    thunderstorms after 1500L.
CWR.................0 percent.
Chance of pcpn......10 percent until 0800L, then dry. Increasing
                    to 30 percent after 1500L.
Chance of thunder...Near zero until 1200L, then increasing
                    to 20 percent after 1500L.
Max temperature.....83 to 86.
Min humidity........25 to 28 percent.
Wind (20 ft)........East wind 6 to 9 mph until 0900L, then becoming
                    west-southwest 6 to 9 mph by 1100L. Gusty and
                    erratic winds 30 to 40 mph expected near
                    thunderstorms late in the afternoon.
Ridgetop wind.......East around 10 mph until 0900L, then becoming
                    southwest by 1100L.
Mixing height.......Less than 1500 ft AGL until 0900L, then
                    gradually rising to around 8000 ft AGL
                    by 1500L.
Transport winds.....East around 10 mph until 0900L, then becoming
                    southwest 10 to 15 mph by 1200L.
Smoke dispersal.....Poor until 0900L, then becoming Good by 1400L.

TIME (MDT)      6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........55  50  40  35  35  30  30  35  45  45  50  50
Weather cov.....ISO ISO                             SCH SCH SCH
Weather type....RW  RW                              RW  RW  RW
Tstm cov........                                    ISO ISO ISO
CWR.............0   0   0   0   0   0   0   0   0   0   0   0
Chc of pcpn (%).10  10  0   0   0   0   0   5   10  20  30  30
Chc of thdr (%).0   0   0   0   0   0   0   5   10  10  15  20
Temp............68  68  70  69  72  76  78  82  83  84  85  83
RH..............36  39  38  39  40  36  34  33  30  27  27  29
20 FT wind dir..E   SE  S   SW  SW  SW  SW  SW  SW  SW  S   SE
20 FT wind spd..5   5   6   6   6   6   6   6   6   6   6   7
20 FT wind gust.6   6       7   7   7   7   8   10  10  10  11
Ridge wind dir..E   E   S   S   SW  SW  SW  SW  SW  SW  S   E
Ridge wind spd..10  10  10  15  15  15  10  10  10  15  15  15
Mix hgt (kft)...1.0 1.0 1.5 2.0 2.5 3.5 4.0 5.5 6.5 8.0 8.0 6.5
Transp wind dir.NW  E   SW  SW  SW  SW  SW  SW  SW  W   W   S
Transp wind spd.10  10  10  13  13  13  12  12  12  13  13  14
SDspl kt-ft/100010  10  13  24  30  39  42  55  65  88  88  81

.THURSDAY NIGHT...

Sky/weather.........Mostly cloudy (60-70 percent) with a chance
                    of showers until 0300L. A chance of
                    thunderstorms until 2000L, then isolated
                    thunderstorms until 0100L.
CWR.................5 percent.
Chance of pcpn......30 to 40 percent until 0100L, then
                    decreasing to near zero after 0300L.
Chance of thunder...30 percent until 2000L, then gradually
                    decreasing to zero by 0300L.
Min temperature.....59 to 61.
Max humidity........65 to 68 percent.
Wind (20 ft)........East-southeast winds 7 to 12 mph, decreasing
                    to 6 to 9 mph after 0500L. Gusty and erratic
                    winds 30 to 40 mph expected until 2100L.
Ridgetop wind.......East 15 mph.
Mixing height.......Around 7000 ft AGL until 1900L, then
                    gradually decreasing to less than 1500 ft AGL
                    by 2200L.
Transport winds.....East around 15 mph until 0200L, then
                    decreasing to around 10 mph.
Smoke dispersal.....Good until 1900L, then Poor by 2200L.

TIME (MDT)      6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........50  55  65  70  70  70  65  65  65  60  50  40
Weather cov.....CHC CHC CHC CHC CHC CHC CHC CHC CHC
Weather type....RW  RW  RW  RW  RW  RW  RW  RW  RW
Tstm cov........CHC CHC CHC SCH SCH SCH SCH SCH SCH
CWR.............0   0   0   0   0   0   0   0   0   0   0   0
Chc of pcpn (%).40  40  40  40  30  30  30  20  10  5   5   5
Chc of thdr (%).30  30  20  20  20  20  10  10  5   0   0   0
Temp............81  79  74  71  70  69  68  66  65  64  63  61
RH..............33  36  41  46  50  52  53  55  57  59  61  64
20 FT wind dir..E   E   E   E   E   E   E   E   E   E   E   E
20 FT wind spd..8   9   11  12  12  12  11  10  9   8   7   6
20 FT wind gust.13  14  16  17  17  16  14  14  14  11  11  10
Ridge wind dir..E   E   E   E   E   E   E   E   E   E   E   E
Ridge wind spd..15  15  20  20  20  20  20  20  20  15  15  15
Mix hgt (kft)...4.5 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.SE  E   E   E   E   E   E   E   E   E   E   E
Transp wind spd.15  15  18  21  22  21  20  20  18  15  13  13
SDspl kt-ft/100060  34  19  21  23  21  20  20  19  15  13  13

.FORECAST DAYS 3 THROUGH 5...
.FRIDAY...
Becoming mostly sunny early, then gradually increasing clouds
and a slight chance of showers and thunderstorms after 1500L.
Highs around 80. Lows in the upper 50s. Typical diurnal
upslope/downslope wind pattern.
.SATURDAY...
Partly cloudy with isolated afternoon and evening showers and
thunderstorms. Highs in the upper 70s. Lows in the upper 50s.
Southeast wind 5 to 10 mph.
.SUNDAY...
Partly cloudy with isolated afternoon and evening showers and
thunderstorms. Highs in the upper 70s. Lows in the upper 50s.
Southeast wind 5 to 10 mph.
.MONDAY...
Mostly cloudy with isolated morning showers. A chance of
showers and thunderstorms in the afternoon and evening. Highs
in the mid 70s. Lows in the mid 50s. East wind 5 to 10 mph.

$$
Forecaster...CNJ
Requested by...Travis Pardue
Type of request...WILDFIRE
.TAG 2519957.6/RIW
.DELDT 08/20/25
.FormatterVersion 2.0.0
.EMAIL travis_pardue@firenet.gov