Spot Forecast
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
000
FNUS75 KRIW 161018
FWSRIW
Spot Forecast for South Cache...Yellowstone National Park Fire Dispatch
National Weather Service Riverton WY
418 AM MDT Sat Aug 16 2025
Forecast is based on forecast start time of 0500 MDT on August 16.
If conditions become unrepresentative, contact the National Weather
Service
.DISCUSSION...
Increasing clouds this morning becoming mostly cloudy for the
remainder of the day. Southwest winds will remain light through
about 10AM less than 10 mph before increasing to 15 to 20 mph
thereafter into the afternoon before becoming more southerly through
the early evening. These will diminish to less than 10 mph once
again towards sunset after 8-9PM remaining southerly overnight into
Sunday morning. Storm chances increase after 10-11AM peaking between
12-6PM before pushing to the east after 8PM. Frequent lightning and
gusty outflow winds expected over 40 mph with any storm nearby.
Temperatures this afternoon into the upper 60s, and thus, relative
humidity values above the 30 percent mark. Improving skies overnight
to partly cloudy after midnight into Sunday morning. Similar
conditions Sunday as Saturday, with a warming trend and dry
conditions expected for Monday and into much of next week.
...Thunderstorms imply strong gusty and erratic winds...
.TODAY...
Sky/weather.........Mostly cloudy (65-75 percent). Isolated rain
showers late in the morning. Scattered showers
and thunderstorms in the afternoon.
CWR.................0 percent increasing to 39 percent in the
afternoon.
Chance of pcpn......50 percent.
Chance of thunder...36 percent.
Max temperature.....Around 68.
Min humidity........30 percent.
Wind (20 ft)........Light winds until 1700, then south around 8
mph. Gusty and erratic winds expected near
thunderstorms in the afternoon.
Ridgetop wind.......Southwest 10 to 15 mph.
Mixing height.......2000 ft AGL after 0900 until 1100, then 5000 ft
AGL until 1200, then 7000 ft AGL until 1300,
then 9000 ft AGL until 1400, then 7000 ft AGL
until 1600, then 5000 ft AGL.
Transport winds.....Southwest 9 to 16 mph until 1700, then south
around 15 mph.
Smoke dispersal.....Poor until 1100, then good early in the morning
increasing to very good in the afternoon until
1600, then fair.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........55 60 60 65 70 70 75 75 80 85 80 80
Weather cov..... ISO ISO SCT SCT SCT SCT SCT SCT
Weather type.... RW RW RW RW RW RW RW RW
Tstm cov........ SCT SCT SCT SCT SCT SCT
CWR.............0 0 0 0 0 0 40 40 40 40 40 40
Chc of pcpn (%).10 10 10 10 20 20 30 40 40 50 40 30
Chc of thdr (%).0 0 0 10 10 10 30 30 30 40 40 30
Temp............48 47 50 56 62 66 67 68 65 64 63 63
RH..............63 65 61 49 39 34 32 31 35 35 38 36
20 FT wind dir..S S S S S S S S S S S S
20 FT wind spd..5 5 5 5 6 6 6 6 6 6 6 8
20 FT wind gust.6 6 6 7 10 12 13 12 10 7 10 12
Ridge wind dir..SW SW SW SW SW SW SW SW S S S S
Ridge wind spd..10 10 10 10 15 15 15 15 15 10 15 15
Mix hgt (kft)...0.1 0.1 0.1 1.0 2.0 5.0 7.0 9.0 7.0 6.0 5.0 3.5
Transp wind dir.SW SW SW SW SW W W W W SW SW S
Transp wind spd.9 10 10 12 13 15 16 15 15 14 14 15
SDspl kt-ft/10001 1 1 8 25 67 100 114 92 71 58 45
.TONIGHT...
Sky/weather.........Mostly cloudy (65-75 percent) then becoming
partly cloudy (35-45 percent). Scattered rain
showers early in the evening. Isolated
thunderstorms early in the evening. Isolated
rain showers early in the evening.
CWR.................3 percent.
Chance of pcpn......30 percent.
Chance of thunder...20 percent.
Min temperature.....Around 46.
Max humidity........64 percent.
Wind (20 ft)........South winds 7 to 9 mph until 2100, then light.
Gusty and erratic winds expected near
thunderstorms early in the evening.
Ridgetop wind.......South 10 to 15 mph.
Mixing height.......4500 ft AGL until 1900.
Transport winds.....Southwest 9 to 17 mph.
Smoke dispersal.....Good until 1900. Poor after 2000.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........75 70 65 60 50 40 35 30 30 30 30 25
Weather cov.....SCT SCT ISO ISO
Weather type....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 (%).30 30 20 20 0 10 0 0 0 0 0 0
Chc of thdr (%).20 20 20 10 0 10 0 0 0 0 0 0
Temp............60 58 54 52 52 50 49 48 48 47 47 47
RH..............38 45 51 52 59 61 58 61 61 60 60 60
20 FT wind dir..S S S SE SE S S S S S S S
20 FT wind spd..9 8 7 6 5 5 5 5 5 4 4 4
20 FT wind gust.13 12 10 7 6 6 6 6 6 6 6 6
Ridge wind dir..S S S SE SE S S S S S S S
Ridge wind spd..15 15 15 10 10 10 10 10 10 10 10 10
Mix hgt (kft)...4.5 2.0 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1
Transp wind dir.SW SW W SW SW SW S S S S SW SW
Transp wind spd.16 17 14 12 10 10 10 10 10 9 9 9
SDspl kt-ft/100061 29 2 1 1 0 0 0 0 1 1 0
.SUNDAY...
Sky/weather.........Mostly sunny (35-45 percent) then becoming
mostly cloudy (65-75 percent). Rain showers
likely and chance of thunderstorms in the
afternoon.
CWR.................0 percent increasing to 12 percent in the
afternoon.
Chance of pcpn......60 percent.
Chance of thunder...36 percent.
Max temperature.....Around 69.
Min humidity........27 percent.
Wind (20 ft)........Light winds until 1100, then southwest 8 to 11
mph with gusts to around 19 mph. Gusty and
erratic winds expected near thunderstorms in
the afternoon.
Ridgetop wind.......Southwest 10 to 15 mph until 1300, then 15 to
20 mph.
Mixing height.......1500 ft AGL after 0800 until 1000, then 3500 ft
AGL until 1100, then 5500 ft AGL until 1200,
then 8000 ft AGL until 1700, then 5000 ft AGL.
Transport winds.....Southwest 9 to 18 mph until 1200, then 17 to 21
mph.
Smoke dispersal.....Poor until 1000, then fair until 1100, then
good until 1200, then good early in the morning
increasing to very good in the afternoon until
1700, then good.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........35 40 25 15 15 25 35 50 60 70 70 70
Weather cov..... LKY LKY LKY LKY LKY LKY
Weather type.... RW RW RW RW RW RW
Tstm cov........ CHC CHC CHC CHC CHC CHC
CWR.............0 0 0 0 0 0 10 10 10 10 10 10
Chc of pcpn (%).10 10 10 10 10 10 60 60 60 60 60 60
Chc of thdr (%).0 0 0 10 10 10 40 40 40 30 30 30
Temp............46 47 50 55 60 63 66 67 67 67 66 64
RH..............64 64 56 48 42 35 29 27 27 29 32 35
20 FT wind dir..S S S SW SW SW SW SW SW SW SW SW
20 FT wind spd..4 5 5 5 6 8 10 11 10 10 10 9
20 FT wind gust.7 8 10 10 13 16 18 19 19 18 18 17
Ridge wind dir..S S S SW SW SW SW SW SW SW SW SW
Ridge wind spd..10 10 10 10 15 15 15 20 15 15 15 15
Mix hgt (kft)...0.1 0.1 0.5 1.5 3.5 5.5 7.5 8.0 8.0 8.0 6.5 5.0
Transp wind dir.SW S S SW SW SW SW SW SW SW SW SW
Transp wind spd.9 10 10 12 15 18 21 20 20 18 17 17
SDspl kt-ft/10001 0 3 15 45 89 138 132 135 129 98 76
.FORECAST DAYS 3 THROUGH 5...
.MONDAY...
Partly cloudy. Slight chance of showers and thunderstorms. Lows
in the mid 40s. Highs around 70. Light winds.
.TUESDAY...
Mostly clear. Lows in the mid 40s. Highs in the mid 70s. Light
winds.
.WEDNESDAY...
Mostly clear. Lows in the upper 40s. Highs in the mid 70s. South
winds around 7 mph.
$$
Forecaster...Lowe
Requested by...E Folts
Type of request...WILDFIRE
.TAG 2520012.0/RIW
.DELDT 08/16/25
.FormatterVersion 2.0.0
.EMAIL ebf124@gmail.com,laura_dooley@nps.gov