Spot Forecast
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
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FNUS75 KRIW 200155
FWSRIW
Spot Forecast for Spring Creek...BLM
National Weather Service Riverton WY
755 PM MDT Tue Aug 19 2025
Forecast is based on forecast start time of 2000 MDT on August 19.
If conditions become unrepresentative, contact the National Weather
Service
.DISCUSSION...
Poor humidity recovery occurs overnight with another hot day to
follow on Wednesday. Relative humidity again drops to around
10 percent Wednesday afternoon. There appears to be enough
mid-level moisture in the atmosphere to produce a few late day
showers and thunderstorms over the Absaroka Mountains. These move
to the east-northeast during the late afternoon and evening. The
moisture axis may keep these to the north of the Spring Creek Fire,
or potentially track closer to the fire. Any close by showers and
thunderstorms will have the potential to produce 40 to 50 mph
outflow wind. The period that bears watching is 1600L to 2100L
Wednesday. A weak frontal boundary Wednesday night will cool
temperatures Thursday and raise the relative humidity.
...Thunderstorms imply strong gusty and erratic winds...
.REST OF TONIGHT...
Sky/weather.........Mostly clear (5-15 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Min temperature.....68 to 71.
Max humidity........33 to 36 percent.
Wind (20 ft)........West-southwest 8 to 13 mph until 2000L, then
becoming east-southeast 8 to 14 mph by 2100L.
Occasional gusts 18 to 23 mph until 0400L.
Ridgetop wind.......West-southwest 10 to 15 mph until 2000L.
Becoming east-southeast 15 to 20 mph until
0100L, then decreasing to 10 to 15 mph by
0400L.
Mixing height.......Gradually decreasing to less than 1500 ft AGL
by 2200L.
Transport winds.....South-southwest around 15 mph until 2000L,
then becoming east-southeast around 15 mph.
Smoke dispersal.....Decreasing to Poor by 2200L.
TIME (MDT) 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........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
Chc of pcpn (%).0 0 0 0 0 0 0 0 0 0
Chc of thdr (%).0 0 0 0 0 0 0 0 0 0
Temp............83 79 78 77 76 75 75 73 73 72
RH..............15 15 19 22 25 34 34 36 36 37
20 FT wind dir..SE E E SE SE SE SE SE SE SE
20 FT wind spd..9 12 14 15 16 14 12 11 9 8
20 FT wind gust.13 17 19 22 23 20 18 17 14 12
Ridge wind dir..SE E E SE SE SE SE SE SE SE
Ridge wind spd..15 20 20 20 25 20 20 20 15 15
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.S E SE SE SE SE SE SE SE SE
Transp wind spd.17 20 21 22 23 22 20 18 16 15
SDspl kt-ft/100017 21 22 23 24 23 20 19 17 15
.WEDNESDAY...
Sky/weather.........Mostly sunny (10-20 percent) early before
clouds increase in the afternoon. Becoming
partly cloudy (40-50 percent) with isolated
showers and thunderstorms (mostly dry)
after 1600L.
CWR.................0 percent.
Chance of pcpn......0 percent in the morning, then 15 percent
after 1600L.
Chance of thunder...0 percent until 1600L, then 5 percent.
Max temperature.....91 to 94.
Min humidity........10 to 13 percent.
Wind (20 ft)........East-southeast wind 6 to 9 mph until 0900L,
then becoming west-southwest 8 to 13 mph by
1200L. Occasional afternoon gusts to 18 mph.
Wind may switch to the northwest behind
shower/thunderstorm outflow after 1600L.
There is the potential for erratic wind
gusts 40 to 50 mph from any showers or storms.
Ridgetop wind.......East-southeast 10 to 15 mph until 0900L, then
becoming southwest by 1200L.
Mixing height.......Less than 1500 ft AGL until 0900L, then
gradually increasing to 12000 ft AGL by 1500L.
Transport winds.....East-southeast around 10 mph until 0900L, then
becoming southwest 10 to 15 mph by 1300L.
Smoke dispersal.....Poor until 0900L, then gradually increasing
to Very Good by 1300L.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........10 10 10 10 20 25 25 25 30 30 40 40
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 0 0 0 10 15
Chc of thdr (%).0 0 0 0 0 0 0 0 0 0 5 5
Temp............71 72 77 80 82 85 88 90 92 93 93 92
RH..............36 34 29 26 24 19 15 14 13 11 10 11
20 FT wind dir..E SE S S SW SW SW W W W W NW
20 FT wind spd..6 6 5 5 6 6 7 7 8 8 8 8
20 FT wind gust.10 8 7 7 7 10 10 11 12 13 13 13
Ridge wind dir..E SE S S SW SW SW W W W W NW
Ridge wind spd..15 10 10 10 10 15 15 15 15 15 15 15
Mix hgt (kft)...1.0 1.0 1.5 2.5 4.0 6.0 9.0 11 13 14 15 14
Transp wind dir.S S S SW SW W W W W W W W
Transp wind spd.13 12 10 10 12 13 14 15 15 15 15 15
SDspl kt-ft/100013 12 13 23 38 67 106 141 168 180 187 178
.WEDNESDAY NIGHT...
Sky/weather.........Partly cloudy (35-45 percent). Isolated
showers and thunderstorms (mostly dry)
until 2100L.
CWR.................0 percent.
Chance of pcpn......15 percent until 2100L, then decreasing to 0.
Chance of thunder...5 percent until 2000L, then decreasing to 0.
Min temperature.....64 to 67.
Max humidity........40 to 43 percent.
Wind (20 ft)........Northwest wind 8 to 13 mph until 2000L, then
becoming easterly 7 to 10 mph by 2300L.
There is the potential for erratic wind
gusts 40 to 50 mph from any showers and storms.
Ridgetop wind.......Northwest 10 to 15 mph until 2000L, then
becoming easterly by 2300L.
Mixing height.......11000 ft AGL until 1900L, then decreasing to
less than 1500 ft AGL by 2200L.
Transport winds.....West around 15 mph until 1900L, then becoming
north to northeast 10 to 15 mph by 2200L.
Smoke dispersal.....Very Good until 1900L, then Poor after 2200L.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........40 40 45 50 30 35 40 40 45 45 45 45
Weather cov.....ISO ISO ISO
Weather type....RW RW RW
Tstm cov........ISO ISO
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
Chc of pcpn (%).15 15 10 5 0 0 0 0 0 0 0 0
Chc of thdr (%).5 5 0 0 0 0 0 0 0 0 0 0
Temp............91 88 83 79 77 76 75 74 73 71 69 67
RH..............12 14 16 19 21 23 25 27 28 30 32 36
20 FT wind dir..NW NW NE NE NE E E E NE NE E S
20 FT wind spd..8 8 8 9 8 8 7 7 6 6 6 5
20 FT wind gust.12 13 13 13 13 12 11 11 10 10 8 7
Ridge wind dir..NW NW NE NE NE E E E NE NE E S
Ridge wind spd..15 15 15 15 15 15 15 15 15 10 10 10
Mix hgt (kft)...12 2.5 1.5 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0
Transp wind dir.W N N NE E E NE NE NE NE N N
Transp wind spd.15 15 15 16 15 15 14 14 13 12 12 10
SDspl kt-ft/1000153 34 17 17 15 15 14 14 13 12 12 11
.FORECAST DAYS 2 THROUGH 5...
.THURSDAY...
Partly cloudy and cooler. A slight chance of late day showers
and thunderstorms. Highs 81 to 86. Lows in the lower 60s.
Northwest wind around 10 mph.
.FRIDAY...
Partly cloudy with a chance of showers and thunderstorms, mainly
during the afternoon and early evening. Highs in the upper 70s.
Lows in the lower 60s. East wind 5 to 10 mph.
.SATURDAY...
Partly cloudy with a chance of showers and thunderstorms,
mainly during the afternoon and early evening. Highs in the
upper 70s. Lows in the upper 50s. East wind 5 to 10 mph.
.SUNDAY...
Partly cloudy with a slight chance of afternoon showers and
thunderstorms. Highs in the upper 70s. Lows in the upper 50s.
Typical upslope/downslope diurnal wind pattern.
$$
Forecaster...CNJ
Requested by...Travis Pardue
Type of request...WILDFIRE
.TAG 2519957.5/RIW
.DELDT 08/19/25
.FormatterVersion 2.0.0
.EMAIL travis_pardue@firenet.gov