Spot Forecast
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
840
FNUS75 KRIW 191245
FWSRIW
Spot Forecast for SVF Unit 1...USFS-BTF
National Weather Service Riverton WY
645 AM MDT Thu Mar 19 2026
Forecast is based on ignition time of 0900 MDT on March 19.
If conditions become unrepresentative, contact the National Weather
Service
.DISCUSSION...
Warm and dry weather will continue today with a mainly clear sky
and only a few passing mid and high level clouds. Wind should be
similar to yesterday with largely light and diurnal wind until
around 1200 then a west wind developing with gusts to around 15
mpg until around 1800. Humidity will be similar to yesterday,
dropping to around 20 percent in the afternoon. Mixing and smoke
dispersal will be poor until inversions break around noon and then
becoming fair and possibly good after 1300. Higher mixing heights
on Friday may bring better smoke dispersal in the afternoon.
...Thunderstorms imply strong gusty and erratic winds...
.REST OF TODAY...
Sky/weather.........Sunny (0-10 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 1200, then west 7 to 8 mph
with gusts to around 13 mph.
Ridgetop wind.......South 10 to 15 mph until 1400, then west.
Mixing height.......2500 ft AGL until 1300, then 4000 ft AGL.
Transport winds.....Southwest 9 to 13 mph until 1300, then west 14
to 16 mph.
Smoke dispersal.....Poor until 1200, then fair to possibly good.
TIME (MDT) 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........0 0 0 0 0 0 0 0 0
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 52 58 61 65 67 67 67 67
RH..............60 45 40 35 30 25 24 25 28
20 FT wind dir..S S S SW SW W W W W
20 FT wind spd..4 4 4 5 6 7 7 8 8
20 FT wind gust.6 6 6 7 10 11 11 13 13
Ridge wind dir..S S S SW SW W W W W
Ridge wind spd..10 10 10 10 15 15 15 15 15
Mix hgt (kft)...1.0 1.5 2.0 2.5 3.5 4.0 4.0 4.0 3.5
Transp wind dir.S S SW SW W W W W W
Transp wind spd.9 9 9 13 14 16 16 16 15
SDspl kt-ft/10009 10 15 30 43 59 59 55 42
.TONIGHT...
Sky/weather.........Clear (0-10 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Min temperature.....Around 40.
Max humidity........61 percent.
Wind (20 ft)........West winds around 7 mph until 1900, then light.
Ridgetop wind.......Southwest 10 to 15 mph until 2100, then light
until 2300, then southeast around 10 mph.
Mixing height.......1000 ft AGL.
Transport winds.....West 8 to 14 mph until 0100, then south.
Smoke dispersal.....Poor.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........0 5 5 5 10 10 10 10 10 10 10 10
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............64 60 55 52 49 48 45 44 44 43 43 41
RH..............34 40 49 52 55 55 58 55 55 58 59 61
20 FT wind dir..W SW SW S S S SE SE SE SE SE SE
20 FT wind spd..7 6 4 2 2 3 4 4 4 4 4 4
20 FT wind gust.11 8 6 6 6 6 6 6 6
Ridge wind dir..W SW SW S S S SE SE SE SE SE SE
Ridge wind spd..15 10 10 5 5 10 10 10 10 10 10 10
Mix hgt (kft)...2.5 1.5 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0
Transp wind dir.W W W W SW SW SW SW S S S S
Transp wind spd.14 12 9 8 8 8 9 9 9 9 9 9
SDspl kt-ft/100027 13 9 8 8 8 9 9 9 9 9 9
.FRIDAY...
Sky/weather.........Sunny (5-15 percent).
CWR.................0 percent.
Chance of pcpn......0 percent.
Chance of thunder...0 percent.
Max temperature.....Around 68.
Min humidity........25 percent.
Wind (20 ft)........Light winds until 1500, then west around 7 mph.
Ridgetop wind.......South around 10 mph until 1200, then southwest.
Mixing height.......2500 ft AGL until 1200, then 5500 ft AGL.
Transport winds.....Southwest 8 to 17 mph.
Smoke dispersal.....Poor until 1100, becoming good after 1400.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........15 10 10 5 5 5 5 10 10 10 10 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............40 41 42 46 51 57 61 64 66 67 68 68
RH..............61 59 57 54 50 45 39 33 28 25 25 26
20 FT wind dir..SE S S S S SW SW SW W W W W
20 FT wind spd..4 4 3 3 4 4 4 6 6 7 7 7
20 FT wind gust.6 6 6 6 6 8 10 11 11 11
Ridge wind dir..SE S S S S SW SW SW W W W W
Ridge wind spd..10 10 10 10 10 10 10 10 15 15 15 15
Mix hgt (kft)...1.0 1.0 1.0 1.0 1.5 2.5 3.5 4.0 5.0 5.5 4.5 3.5
Transp wind dir.S S S S S SW SW SW SW SW SW SW
Transp wind spd.9 9 8 8 9 10 13 14 16 17 16 15
SDspl kt-ft/10009 9 8 7 12 22 38 50 68 84 65 49
.FORECAST DAYS 3 THROUGH 5...
.SATURDAY...
Mostly clear. Lows in the lower 40s. Highs in the mid 60s. Light
winds.
.SUNDAY...
Cooler. Partly cloudy. Lows in the mid 30s. Highs in the mid 50s.
Light winds.
.MONDAY...
Partly cloudy. Lows in the mid 30s. Highs in the upper 50s. Light
winds.
$$
Forecaster...Hattings
Requested by...Michael McEwen
Type of request...PRESCRIBED
.TAG 2605908.1/RIW
.DELDT 03/19/26
.FormatterVersion 2.0.0
.EMAIL michael.mcewen@usda.gov