Spot Forecast
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
729
FNUS75 KRIW 010150
FWSRIW
Spot Forecast for Bull Fire...USFS
National Weather Service Riverton WY
750 PM MDT Tue Sep 30 2025
Forecast is based on forecast start time of 2000 MDT on September 30.
If conditions become unrepresentative, contact the National Weather
Service
.DISCUSSION...
A few rain showers may be possible overnight between 0200 and 0600,
but generally staying mostly cloudy otherwise. Temperatures will
drop to the mid 30s overnight. If heavier showers occur, there is
a 30% chance that precipitation could change over to snow for a
brief time. Thunderstorms are not likely, but there is an
outside chance (around 10% likelihood) of an isolated lightning
strike or rumble of thunder with the showers overnight. Winds will
generally remain light (less than 10 mph) downslope/downvalley
overnight, with gusty winds from the west-southwest 15 to 25 mph
possible with the showers.
Wednesday, temperatures warm into the low 50s, similar to Tuesday.
With RHs only dropping to around 60 to 65% during the day. Winds
will increase from the west southwest Wednesday afternoon 10 to
15 mph with gusts near 20 to 25 mph possible. Chances for isolated
showers and thunderstorms will continue through much of the afternoon.
Shower and thunderstorm chances significantly decrease after 1700
Wednesday. Winds return to light downslope/downvalley flows after
sunset Wednesday night. Thursday will be warmer and drier, but breezy.
...Thunderstorms imply strong gusty and erratic winds...
.REST OF TONIGHT...
Sky/weather.........Mostly cloudy (60-70 percent). Scattered rain
showers and isolated thunderstorms possible,
with most likely chances after 0200.
CWR.................3 percent.
Chance of pcpn......40 percent.
Chance of thunder...19 percent.
Min temperature.....Around 36.
Max humidity........96 percent.
Wind (20 ft)........Light downslope/downvalley winds. Gusty
and erratic winds possible near thunderstorms.
Ridgetop wind.......Southwest 10 to 15 mph.
Mixing height.......500 ft AGL until 2400, then dropping to near
ground level.
Transport winds.....Southwest 10 to 13 mph.
Smoke dispersal.....Poor.
TIME (MDT) 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........70 60 55 60 60 65 70 60 55 60
Weather cov.....SCT SCT ISO ISO ISO SCT SCT SCT SCT SCT
Weather type....RW RW RW RW RW RW RW RW RW RW
Tstm cov........ISO ISO ISO ISO ISO ISO ISO ISO ISO ISO
CWR.............0 0 0 0 0 0 0 0 0 0
Chc of pcpn (%).30 30 20 20 20 30 40 40 40 30
Chc of thdr (%).20 10 10 10 10 10 10 10 10 10
Temp............42 39 39 38 37 37 37 36 36 36
RH..............89 91 92 94 95 94 96 95 95 95
20 FT wind dir..SW SW SW SW SW SW SW SW SW SW
20 FT wind spd..6 6 6 6 6 6 5 5 5 5
20 FT wind gust.10 11 11 11 10 10 10 8 8 8
Ridge wind dir..SW SW SW SW SW SW SW SW SW SW
Ridge wind spd..15 15 15 15 10 10 10 10 10 10
Mix hgt (kft)...0.5 0.5 0.5 0.5 0.1 0.1 0.1 0.1 0.1 0.1
Transp wind dir.W SW SW W W SW SW SW SW SW
Transp wind spd.13 13 13 13 12 12 10 10 10 10
SDspl kt-ft/10003 3 6 6 2 2 2 2 2 2
.WEDNESDAY...
Sky/weather.........Mostly sunny (45-55 percent). Slight chance of
showers and thunderstorms through much of the day.
CWR.................1 percent.
Chance of pcpn......20 percent.
Chance of thunder...18 percent.
Max temperature.....Around 50.
Min humidity........63 percent.
Wind (20 ft)........Light winds until 1200, then southwest 7 to 8
mph with gusts to around 13 mph until 1700,
then light. Gusty and erratic winds possible
near thunderstorms.
Ridgetop wind.......Southwest 10 to 15 mph.
Mixing height.......500 ft AGL until 0800, increasing through 1100
to 4000 ft AGL, then 4500 ft AGL after 1400.
Transport winds.....Southwest 9 to 16 mph.
Smoke dispersal.....Poor until 1000. Fair early in the morning
increasing to good in the afternoon after 1300.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........65 65 60 60 60 60 55 55 55 50 45 35
Weather cov.....SCH SCH SCH SCH SCH SCH SCH SCH SCH SCH SCH
Weather type....RW RW RW RW RW RW RW RW RW RW RW
Tstm cov........SCH SCH SCH SCH SCH SCH SCH SCH SCH SCH SCH
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
Chc of pcpn (%).20 20 20 10 20 20 20 20 20 20 10 10
Chc of thdr (%).10 10 10 10 10 10 20 20 20 10 10 10
Temp............37 37 38 38 41 44 47 47 48 49 49 50
RH..............96 95 94 93 85 77 68 68 68 67 66 64
20 FT wind dir..SW SW S SW SW SW SW SW SW SW SW SW
20 FT wind spd..5 4 4 5 5 6 7 8 8 8 8 6
20 FT wind gust.6 6 6 6 7 10 11 13 12 13 12 10
Ridge wind dir..SW SW S SW SW SW SW SW SW SW SW SW
Ridge wind spd..10 10 10 10 10 15 15 15 15 15 15 15
Mix hgt (kft)...0.5 0.5 0.1 0.5 1.5 2.5 3.5 4.0 4.5 4.5 4.5 4.0
Transp wind dir.SW SW SW SW SW SW SW SW W W SW W
Transp wind spd.10 9 9 10 10 13 14 15 16 15 15 14
SDspl kt-ft/10003 3 2 3 12 26 39 50 61 59 56 49
.WEDNESDAY NIGHT...
Sky/weather.........Mostly clear (15-25 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Min temperature.....Around 40.
Max humidity........71 percent.
Wind (20 ft)........Light downslope/downvalley winds.
Ridgetop wind.......South around 10 mph until 0200, then 10 to 15
mph.
Mixing height.......3000 ft AGL until 1900, then dropping to near
ground level.
Transport winds.....Southwest 9 to 12 mph until 2300, then south 10
to 13 mph.
Smoke dispersal.....Poor.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........30 15 15 20 15 10 5 10 10 10 15 15
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............50 48 47 44 43 42 41 41 41 41 40 40
RH..............63 66 69 74 73 73 74 73 70 68 66 65
20 FT wind dir..SW SW SW S S S S S S S S SE
20 FT wind spd..6 5 4 4 4 5 6 6 6 6 6 6
20 FT wind gust.11 10 8 7 7 8 10 10 10 10 10 10
Ridge wind dir..SW SW SW S S S S S S S S SE
Ridge wind spd..10 10 10 10 10 10 10 10 10 10 15 15
Mix hgt (kft)...3.0 0.5 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1
Transp wind dir.W SW SW S S S S S S S S S
Transp wind spd.12 10 9 9 9 10 12 12 12 12 13 13
SDspl kt-ft/100032 5 2 2 2 2 2 2 2 2 2 1
.THURSDAY...
Sky/weather.........Sunny (15-25 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...4 percent.
Max temperature.....Around 57.
Min humidity........40 percent.
Wind (20 ft)........Southeast winds around 7 mph until 0800, then
light until 1100, then southwest 7 to 9 mph.
Gusts up to 18 mph.
Ridgetop wind.......South around 15 mph until 1400, then southwest.
Mixing height.......7000 ft AGL after 1200.
Transport winds.....Southwest 13 to 20 mph.
Smoke dispersal.....Poor until 1000. Good early in the morning
increasing to very good in the afternoon after
1300.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........20 15 15 10 10 10 10 15 15 20 20 25
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............40 41 42 43 47 50 54 56 56 57 56 55
RH..............63 62 61 59 55 49 45 43 41 41 41 41
20 FT wind dir..SE SE SE SE S S SW SW SW SW SW W
20 FT wind spd..7 7 6 6 6 7 8 9 9 9 8 7
20 FT wind gust.10 10 11 11 12 13 14 14 14 14 14 13
Ridge wind dir..SE SE SE SE S S SW SW SW SW SW W
Ridge wind spd..15 15 15 15 15 15 15 15 15 15 15 15
Mix hgt (kft)...0.1 0.1 0.5 0.5 2.5 4.0 6.0 6.5 7.0 7.0 6.0 5.5
Transp wind dir.S S S S S SW SW SW SW SW SW SW
Transp wind spd.14 14 13 13 14 17 20 20 18 18 17 16
SDspl kt-ft/10001 3 4 6 28 62 101 108 108 115 93 74
.FORECAST DAYS 3 THROUGH 5...
.FRIDAY...
Mostly cloudy. Chance of showers and slight chance of
thunderstorms. Lows in the lower 40s. Highs in the mid 50s. South
winds around 7 mph.
.SATURDAY...
Colder. Showers likely and chance of thunderstorms. Lows in the
upper 30s. Highs in the lower 40s. Light winds.
.SUNDAY...
Mostly cloudy with chance of showers, snow showers and slight
chance of thunderstorms. A few inches of snowfall are possible.
Lows around 30. Highs in the upper 30s. Light winds.
$$
Forecaster...Hensley
Requested by...Matt Ziegler
Type of request...WILDFIRE
.TAG 2522667.3/RIW
.DELDT 09/30/25
.FormatterVersion 2.0.0
.EMAIL wytdc@firenet.gov