Spot Forecast
Issued by NWS Riverton, WY
Issued by NWS Riverton, WY
622
FNUS75 KRIW 171006
FWSRIW
Spot Forecast for Fourmile...BLM-WY-HDD
National Weather Service Riverton WY
406 AM MDT Sat Aug 17 2024
Forecast is based on forecast start time of 0700 MDT on August 17.
If conditions become unrepresentative, contact the National Weather
Service
.DISCUSSION...
Dry to start the day. Winds will be out of the southwest, increasing
to 10 to 15 mph during the afternoon, with gusts around 20 mph. Models
are showing a cluster of storms moving into southwest Wyoming later this
afternoon. Chances increase after 1400L, with peak chances (about 60%)
occurring between 1500L and 1800L. Strong wind around 40 mph is the main
hazard with any storms. Storms will be coming from the southwest, so
wind direction is favored from that direction initially, but would likely
become more erratic as the storms pass through.
Looking ahead, Sunday looks similar, with a southwest wind direction and
around 20 mph afternoon gusts. Scattered showers and thunderstorms are
possible (30%) during the afternoon.
...Thunderstorms imply strong gusty and erratic winds...
...Haines index is high level haines both day and night...
.TODAY...
Sky/weather.........Sunny (20-30 percent) then becoming mostly
cloudy (80-90 percent) after 1400. Isolated
showers and thunderstorms in the afternoon.
CWR.................0 percent increasing to 15 percent in the
afternoon.
Chance of pcpn......60 percent.
LAL.................1 until 1500, then 3.
Max temperature.....Around 84.
Min humidity........Around 20 percent.
Wind (20 ft)........Light winds favoring a southwest direction
until 1100. Then, winds southwest around 13 mph
with gusts to around 20 mph in the afternoon.
Likely southwest wind with gusts around 40 mph
after 1600 with showers and thunderstorms. Gusty
and erratic winds expected near thunderstorms
in the afternoon.
Ridgetop wind.......Southwest around 10 mph until 1000, then southwest
around 20 mph until after 12000, then around 30 mph
after 1600 with thunderstorms.
Haines Index........6 decreasing to 4 in the afternoon.
TIME (MDT) 7 AM 9 AM 11 AM 1 PM 3 PM 5 PM
Sky (%).........10 5 5 30 80 90
Weather cov..... ISOLTD SCTTRD
Weather type....NONE NONE NONE NONE RNSHWR RNSHWR
Tstm cov........ ISOLTD SCTTRD
CWR.............0 0 0 20 20 20
Chc of pcpn (%).0 0 0 0 30 50
LAL.............1 1 1 1 3 3
Temp............48 58 72 81 80 70
RH..............68 47 33 22 28 52
20 ft wind......SW 3 S 2 SW 9 SW 11 SW 11 SW 13
20 ft wind gust.4 13 16 16 18
Ridgetop wind...SW 10 S 5 SW 15 SW 20 SW 20 SW 20
Haines index....6 6 6 4 4 4
.TONIGHT...
Sky/weather.........Mostly cloudy (70-80 percent) becoming
partly cloudy (30-40 percent) after 2300.
Isolated showers and thunderstorms early
in the evening.
CWR.................1 percent.
Chance of pcpn......25 percent.
LAL.................2 until 2100, then 1.
Min temperature.....Around 50.
Max humidity........Over 90 percent.
Wind (20 ft)........Southwest to southeast winds around 10 mph with
gusts to around 18 mph until 2100, then light favoring
a west to southwest direction. Gusty and erratic winds
expected near thunderstorms early in the evening.
Ridgetop wind.......South 15 to 20 mph until 2000. West around 10
mph after 2400.
Haines Index........2 to 3.
TIME (MDT) 6 PM 8 PM 10 PM MIDNGT 2 AM 4 AM
Sky (%).........90 75 60 45 35 30
Weather cov.....ISOLTD ISOLTD
Weather type....RNSHWR RNSHWR NONE NONE NONE NONE
Tstm cov........ISOLTD ISOLTD
CWR.............0 0 0 0 0 0
Chc of pcpn (%).30 20 10 10 10 10
LAL.............2 2 1 1 1 1
Temp............70 65 59 55 53 51
RH..............53 63 77 89 91 97
20 ft wind......SW 11 SE 9 S 4 SW 4 W 3 SW 3
20 ft wind gust.16 13 6 6 4 4
Ridgetop wind...SW 20 SE 15 S 10 SW 10 W 10 SW 10
Haines index....2 2 2 3 3 3
.SUNDAY...
Sky/weather.........Mostly sunny (30-40 percent). Scattered showers
and thunderstorms in the afternoon.
CWR.................10 percent.
Chance of pcpn......30 percent.
LAL.................1 until 1200, then 3.
Max temperature.....Around 80.
Min humidity........Around 34 percent.
Wind (20 ft)........Light winds until 1300, then southwest 9 to 14
mph with gusts to around 20 mph. Gusty and
erratic winds expected near thunderstorms in
the afternoon.
Ridgetop wind.......Northwest to north around 10 mph until 1100,
then west 10 to 15 mph until 1500, then southwest
15 to 20 mph until 2000.
Haines Index........3.
TIME (MDT) 6 AM 8 AM 10 AM NOON 2 PM 4 PM
Sky (%).........35 35 15 5 25 50
Weather cov..... SCTTRD SCTTRD SCTTRD
Weather type....NONE NONE NONE RNSHWR RNSHWR RNSHWR
Tstm cov........ SCTTRD SCTTRD SCTTRD
CWR.............0 0 0 10 10 10
Chc of pcpn (%).0 0 0 30 30 30
LAL.............1 1 1 3 3 3
Temp............49 53 61 71 75 77
RH..............98 94 77 56 46 42
20 ft wind......NW 3 N 3 NW 2 SW 4 W 6 W 9
20 ft wind gust.4 4 6 10 13
Ridgetop wind...NW 10 N 10 NW 5 SW 10 W 15 W 15
Haines index....3 3 3 3 3 3
.FORECAST DAYS 3 THROUGH 5...
.MONDAY...
Partly cloudy. Chance of showers and thunderstorms. Lows in the
lower 50s. Highs in the lower 80s. Southwest winds around 10 mph.
.TUESDAY...
Mostly clear. Lows in the upper 40s. Highs in the mid 80s. Southwest
winds around 10 mph.
.WEDNESDAY...
Partly cloudy. Lows around 50. Highs in the lower 80s. Southwest
winds around 15 mph.
$$
Forecaster...Wittmann
Requested by...Clarke Whitehead
Type of request...WILDFIRE
.TAG 2420426.0/RIW
.DELDT 08/17/24
.FormatterVersion 2.0.0
.EMAIL cwhitehead@blm.gov