Spot Forecast
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
165
FNUS75 KRIW 091218
FWSRIW
Spot Forecast for Hams Fork RX Unit 8/6...USFS
National Weather Service Riverton WY
618 AM MDT Tue Jun 9 2026
Forecast is based on ignition time of 0800 MDT on June 09.
If conditions become unrepresentative, contact the National Weather
Service
.DISCUSSION...
Increasing shower activity this morning with better chances after
1200L for the afternoon hours. This will be the chance for
thunderstorm activity as a cold front approaches from the west.
West winds around 10 mph this morning becoming stronger after
1200L pushing 15 to 20 mph through sunset around 2100L. As a
result, smoke dispersal will be poor until 1200L becoming good
during the stronger wind period until later tonight. Shower
activity becomes more limited after 2100L as well, dissipating
and pushing east by midnight tonight. Cooler temperatures about 10
degrees less than Monday afternoon, resulting in minimum humidity
values dropping to around the 40 percent mark. Mainly dry and
similar winds/humidity for Wednesday.
...Thunderstorms imply strong gusty and erratic winds...
.TODAY...
Sky/weather.........Mostly cloudy (80-90 percent). Chance of rain
showers in the morning, then rain showers and
chance of thunderstorms in the afternoon.
CWR.................0 percent increasing to 65 percent in the
afternoon.
Chance of pcpn......80 percent.
Chance of thunder...38 percent.
Max temperature.....Around 52.
Min humidity........45 percent.
Wind (20 ft)........Light winds until 0900, then west 8 to 11 mph
with gusts to around 16 mph. Gusty and erratic
winds expected near thunderstorms in the
afternoon.
Ridgetop wind.......West around 10 mph until 0700, then northeast
until 0900, then west 15 to 20 mph.
Mixing height.......500 ft AGL until 0900, then 4000 ft AGL.
Transport winds.....Northwest around 12 mph until 0800, then
southwest 15 to 24 mph until 1400, then west 22
to 25 mph.
Smoke dispersal.....Poor until 0900. Good there after.
TIME (MDT) 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........85 90 90 90 90 85 75 75 75 75
Weather cov.....SCH CHC CHC CHC LKY LKY DEF DEF DEF LKY
Weather type....RW RW RW RW RW RW RW RW RW RW
Tstm cov........ CHC CHC CHC CHC CHC CHC
CWR.............0 0 0 0 70 70 70 70 70 70
Chc of pcpn (%).10 20 30 40 70 70 80 80 70 70
Chc of thdr (%).0 10 10 10 40 40 40 40 40 40
Temp............48 50 50 48 46 46 47 47 48 50
RH..............56 52 52 58 68 73 65 74 65 61
20 FT wind dir..W W W W SW SW SW W W W
20 FT wind spd..6 8 8 9 10 11 10 10 10 9
20 FT wind gust.10 12 12 13 14 16 14 14 14 13
Ridge wind dir..W W W W SW SW SW W W W
Ridge wind spd..15 15 15 15 15 20 15 15 15 15
Mix hgt (kft)...2.5 3.0 3.0 3.0 3.0 3.5 4.0 4.0 4.0 4.0
Transp wind dir.W SW SW SW SW SW SW W W W
Transp wind spd.15 18 20 21 22 24 25 24 23 22
SDspl kt-ft/100036 52 49 51 52 70 90 83 76 77
.TONIGHT...
Sky/weather.........Mostly cloudy (55-65 percent) then becoming
partly cloudy (45-55 percent) then becoming
mostly cloudy (50-60 percent) then becoming
partly cloudy (25-35 percent). Chance of rain
showers early in the evening. Slight chance of
thunderstorms early in the evening.
CWR.................0 percent.
Chance of pcpn......30 percent.
Chance of thunder...23 percent.
Min temperature.....Around 39.
Max humidity........76 percent.
Wind (20 ft)........West winds 7 to 9 mph until 2100, then light.
Gusty and erratic winds expected near
thunderstorms early in the evening.
Ridgetop wind.......West 10 to 15 mph.
Mixing height.......1500 ft AGL until 2100, then 500 ft AGL.
Transport winds.....West 9 to 18 mph.
Smoke dispersal.....Fair until 2100. Poor there after.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........60 50 55 50 35 40 25 10 10 15 15 15
Weather cov.....CHC CHC SCH SCH
Weather type....RW RW RW RW
Tstm cov........SCH SCH SCH SCH
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
Chc of pcpn (%).30 30 10 10 0 0 0 0 0 0 0 0
Chc of thdr (%).20 20 20 10 0 0 0 0 0 0 0 0
Temp............48 45 47 46 44 44 43 42 42 41 40 39
RH..............63 76 69 72 73 68 67 69 66 64 67 67
20 FT wind dir..W W W W W W W W SW SW SW SW
20 FT wind spd..9 7 7 6 5 4 4 4 4 4 4 3
20 FT wind gust.13 10 10 7 6 6 6 6 6 6 6 4
Ridge wind dir..W W W W W W W W SW SW SW SW
Ridge wind spd..15 15 15 10 10 10 10 10 10 10 10 10
Mix hgt (kft)...2.5 2.5 1.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
Transp wind dir.W W W W W W W W W W W W
Transp wind spd.18 16 14 12 10 9 10 10 9 9 9 9
SDspl kt-ft/100043 35 17 7 5 5 5 5 4 5 4 5
.WEDNESDAY...
Sky/weather.........Mostly sunny (30-40 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Max temperature.....Around 53.
Min humidity........35 percent.
Wind (20 ft)........Light winds until 0800, then west 9 to 17 mph
with gusts to around 23 mph.
Ridgetop wind.......Southwest 10 to 15 mph until 0900, then west 20
to 25 mph.
Mixing height.......1000 ft AGL until 0800. 8000 ft AGL after 1400.
Transport winds.....West 10 to 13 mph until 0800. 33 to 39 mph
after 1200.
Smoke dispersal.....Poor until 0800. Excellent after 1500.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........15 20 20 15 15 15 25 35 15 50 50 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 40 43 45 47 48 50 51 51 53 51 51
RH..............67 64 62 55 51 47 42 41 37 35 36 36
20 FT wind dir..SW SW W W W W W W W W W W
20 FT wind spd..4 6 9 12 13 14 15 16 17 17 16 17
20 FT wind gust.6 7 13 17 18 19 20 22 23 23 22 23
Ridge wind dir..SW SW W W W W W W W W W W
Ridge wind spd..10 10 15 20 20 20 25 25 25 25 25 25
Mix hgt (kft)...0.5 1.0 3.5 4.5 5.5 6.0 6.5 7.0 7.5 8.0 8.0 7.5
Transp wind dir.W W W W W W W W W W W W
Transp wind spd.10 13 20 22 25 29 33 36 37 39 38 36
SDspl kt-ft/10005 9 56 87 118 154 195 213 238 277 257 236
.FORECAST DAYS 3 THROUGH 5...
.THURSDAY...
Clear. Lows in the lower 30s. Highs in the lower 60s. Northwest
winds around 7 mph.
.FRIDAY...
Clear. Lows in the upper 30s. Highs in the upper 60s. Light
winds.
.SATURDAY...
Clear. Lows in the lower 40s. Highs around 70. Light winds.
$$
Forecaster...Lowe
Requested by...Greg Gamertsfelder
Type of request...PRESCRIBED
.TAG 2615181.0/RIW
.DELDT 06/09/26
.FormatterVersion 2.0.0
.EMAIL Greg.gamertsfelder@usda.gov