Spot Forecast
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
350
FNUS75 KRIW 012100
FWSRIW
Spot Forecast for Hams Fork Rx Unit 6/8...USFS
National Weather Service Riverton WY
300 PM MDT Mon Jun 1 2026
Forecast is based on ignition time of 0900 MDT on June 02.
If conditions become unrepresentative, contact the National Weather
Service
.DISCUSSION...
Light southwest winds around 5 to 10 mph are forecast from ignition
time with poor ventilation and mixing heights. Mixing heights and
ventilation rates quickly increase after 1100L as winds become more
westerly and increase to around 10 to 15 mph. Westerly wind gusts of
20 to 25 mph are expected to occur between 1300L and 1800L and this
is when instability will be greatest. High temperatures are forecast
to be in the low 60s with mostly sunny skies. Minimum relative
humidity values are forecast to be between 21 and 25 percent with
humidity improving after 1800L Tuesday. The westerly afternoon winds
weaken around 1900L and become more northerly before becoming
northeasterly and light Tuesday night. Around 5 degrees warmer on
Wednesday with similar wind.
...Thunderstorms imply strong gusty and erratic winds...
.TUESDAY...
Sky/weather.........Sunny (5-15 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Max temperature.....Around 63.
Min humidity........26 percent.
Wind (20 ft)........Light winds until 1200, then west 7 to 9 mph
with gusts to around 20 mph.
Ridgetop wind.......West 10 to 15 mph.
Mixing height.......3500 ft AGL until 1100. 9000 ft AGL after 1300.
Transport winds.....West 8 to 16 mph until 1200, then 20 to 24 mph.
Smoke dispersal.....Poor to fair until1100, then increasing to very
good to excellent in the afternoon until 1700.
TIME (MDT) 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........20 10 5 5 0 10 10 15 10
Weather cov.....
Weather type....
Tstm cov........
CWR.............0 0 0 0 0 0 0 0 0
Chc of pcpn (%).0 0 0 0 0 0 0 0 0
Chc of thdr (%).0 0 0 0 0 0 0 0 0
Temp............47 54 58 60 61 61 62 61 61
RH..............38 33 29 27 27 26 26 27 26
20 FT wind dir..SW SW W W W W W W W
20 FT wind spd..3 5 6 7 8 9 9 9 9
20 FT wind gust.10 12 14 16 18 18 19 20 20
Ridge wind dir..SW SW W W W W W W W
Ridge wind spd..10 10 15 15 15 15 15 15 15
Mix hgt (kft)...2.0 3.5 5.0 6.0 7.5 8.5 9.0 8.5 7.5
Transp wind dir.SW W W W W W W W W
Transp wind spd.8 14 16 20 22 22 24 23 21
SDspl kt-ft/100015 45 67 105 141 162 192 171 137
.TUESDAY NIGHT...
Sky/weather.........Mostly clear (20-30 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Min temperature.....Around 38.
Max humidity........43 percent.
Wind (20 ft)........West winds 7 to 9 mph with gusts to around 20
mph until 2000, then light.
Ridgetop wind.......Northwest 10 to 15 mph until 2200, then
northeast until 0100, then light.
Mixing height.......7000 ft AGL until 1900. 500 ft AGL after 2000.
Transport winds.....West 15 to 20 mph until 2000, then gradually
becoming easterly around 7 mph until 0300
Wednesday then southeast 7 to 8 mph.
Smoke dispersal.....Very good until 1900. Poor after 2000.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........10 10 30 35 25 20 10 10 10 10 15 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............60 57 54 49 47 45 44 43 43 42 41 41
RH..............27 28 34 39 41 43 43 42 42 41 41 40
20 FT wind dir..W W W N N NE NE E E E E E
20 FT wind spd..9 7 5 4 4 4 3 2 2 2 2 2
20 FT wind gust.20 18 12 10 10 10 8 7 6 6 6 6
Ridge wind dir..W W W N N NE NE E E E E E
Ridge wind spd..15 15 10 10 10 10 10 5 5 5 5 5
Mix hgt (kft)...7.0 5.0 1.0 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
Transp wind dir.W W W NW N N N E SE S SE SE
Transp wind spd.20 15 10 9 9 9 8 7 7 7 8 8
SDspl kt-ft/1000121 65 7 4 4 4 3 3 3 3 4 4
.WEDNESDAY...
Sky/weather.........Sunny (15-25 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Max temperature.....Around 67.
Min humidity........22 percent.
Wind (20 ft)........Light winds until 1100, then west 7 to 9 mph
with gusts to around 20 mph.
Ridgetop wind.......Light winds until 0800, then southwest 10 to 15
mph until 1400, then west.
Mixing height.......1500 ft AGL until 0900. 9500 ft AGL after 1200.
Transport winds.....South 7 to 8 mph until 0900, then west 10 to 16
mph until 1200, then 17 to 21 mph.
Smoke dispersal.....Poor until 0900 and increasing to excellent in
the afternoon after 1200.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........10 20 15 5 10 20 25 25 25 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............39 43 47 51 56 61 64 66 66 66 66 65
RH..............40 39 36 32 28 25 22 21 21 22 22 23
20 FT wind dir..E SE S SW SW W W W W W W W
20 FT wind spd..2 2 3 5 6 7 8 9 9 9 9 8
20 FT wind gust.6 7 10 11 13 16 18 18 19 19 20 19
Ridge wind dir..E SE S SW SW W W W W W W W
Ridge wind spd..5 5 10 10 15 15 15 15 15 15 15 15
Mix hgt (kft)...0.5 0.5 1.5 3.0 4.5 6.0 8.0 8.5 9.0 9.5 8.5 8.0
Transp wind dir.S S SW W W W W W W W W W
Transp wind spd.7 7 8 10 13 16 20 20 21 21 18 17
SDspl kt-ft/10003 4 12 26 50 87 133 142 159 168 139 121
.FORECAST DAYS 3 THROUGH 5...
.WEDNESDAY NIGHT...
Partly cloudy. Lows in the mid 40s. Light east winds around 5
mph.
.THURSDAY...
Partly cloudy. Lows in the mid 40s. Highs in the mid 60s. West
winds around 12 mph with gusts of 20 to 30 mph.
.FRIDAY...
Mostly clear. Lows around 40. Highs in the upper 60s. West winds
around 10 mph with gusts up to 20 mph.
.SATURDAY...
Mostly clear. Lows in the mid 40s. Highs in the lower 70s.
Southwest winds around 13 mph with gusts of 20 to 30 mph.
$$
Forecaster...Gerhardt
Requested by...Michael McEwen
Type of request...PRESCRIBED
.TAG 2614723.0/RIW
.DELDT 06/01/26
.FormatterVersion 2.0.0
.EMAIL michael.mcewen@usda.gov