Suppression Forecast
Issued by NWS Riverton, WY

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FNUS75 KRIW 241023
FWSRIW

Spot Forecast for SZ Fire Readiness Review...USFS SHF
National Weather Service Riverton WY
423 AM MDT Wed May 24 2017

Forecast is based on ignition time of 0800 MDT on May 24.
If conditions become unrepresentative...contact the National Weather
Service.

.DISCUSSION...

...Very Windy Today Ahead of a Dry Cold Front this Evening...

A dry cold front is expected to sweep across the fire site between
9 PM and midnight. Ahead of this dry cold front, strong westerly
winds will develop this afternoon with sustained wind around 30
mph and gusts 45 to 60 mph. This is mainly dry cold front, but
there is a remote shot of a brief shower and even isolated
thunderstorm late this afternoon and evening. Winds will decrease
especially after midnight Wednesday night. Much lighter winds and
cooler conditions will occur Thursday with a chance of showers and
perhaps a thunderstorm mainly in the afternoon. A better chance of
rain and snow showers will occur on Friday. Snow levels Thursday
and Friday look to oscillate between 7500 and 8500 feet.

...Thunderstorms imply strong gusty and erratic winds...
...Haines index is high level haines both day and night...

FORECASTER...Murrell

.TODAY...

Sky/weather.........Mostly sunny (10-20 percent) then becoming
                    partly cloudy (40 percent) with a very isolated
                    shower or thunderstorm possible in the late afternoon.
Max temperature.....64-68.
Min humidity........Around 20 percent.
20-foot winds.......Upslope/upvalley 5-10 mph by 9 AM, then west 10-20
                    mph with gusts to 30 mph by noon, then quickly
                    increasing from west southwest at 25-35 mph with gusts
                    around 55 mph by around 2 pm. Gustier and erratic
                    winds expected near any thunderstorms.
Ridge top winds.....West around 15 mph becoming west southwest
                    30-40 mph in the afternoon. Gusts to 60-65 mph.
LAL.................1 until 3 PM...then 2.
Chc of wetting rain.near zero.
Haines Index........3 or very low potential for large plume
                    dominated fire growth.
Mixing height.......6500 ft AGL in the afternoon.
Transport winds.....West 30 to 50 mph.
Smoke dispersal.....Excellent in the afternoon.

.TONIGHT...

Sky/weather.........Partly cloudy (40-50 percent). A very isolated
                    shower or thunderstorm possible in the evening.
Min temperature.....30-35.
Max humidity........75 percent.
20-foot winds.......West 20-30 mph, becoming northwest around 15 mph
                    between 9 pm and midnight. Northwest decreasing
                    to 5-10 mph after 3 AM. Gusty and erratic winds
                    expected near any thunderstorms.
Ridge top winds.....West southwest around 30 mph becoming northwest
                    15-20 between 9 PM and midnight.
LAL.................2 until midnight, then 1.
Chc of wetting rain.near zero.
Haines Index........2 or very low potential for large plume
                    dominated fire growth.
Mixing height.......800 ft AGL after midnight.
Transport winds.....West southwest around 30 mph becoming northwest
                    15-20 between 9 PM and midnight.
Smoke dispersal.....Decreasing to poor between 9 PM and midnight.

.THURSDAY...

Sky/weather.........Partly cloudy (40-50 percent) then becoming
                    mostly cloudy (60-70 percent). Isolated showers
                    and thunderstorms in the afternoon.
Max temperature.....50.
Min humidity........30 percent.
20-foot winds.......Upslope/upvalley 4-8 mph by 9 AM...becoming west to
                    southwest 5-10 mph in the afternoon. Gusty and erratic
                    winds expected near any thunderstorms in the afternoon.
Ridge top winds.....West northwest around 10 mph...becoming southwest
                    around 10 mph in the afternoon.
LAL.................No Tstms until Noon, then 1-8 strikes.
Chc of wetting rain.5 percent.
Haines Index........3 or very low potential for large plume
                    dominated fire growth.
Mixing height.......5500-6500 ft AGL in the afternoon.
Transport winds.....West southwest 10-15 mph.
Smoke dispersal.....Good.

.FORECAST DAYS 3 THROUGH 5...

.THURSDAY NIGHT...
Mostly cloudy. Isolated showers and thunderstorms in the evening,
then scattered snow showers after midnight. Lows in the upper
20s. Winds generally less than 10 mph.

.FRIDAY...
Cloudy with rain and snow showers likely. An isolated thunderstorm
is possible. Highs in the lower 40s. Winds generally less than 10
mph.

.SATURDAY...
Partly cloudy with slight chance of showers and thunderstorms.
Lows around 30. Highs in the lower 50s. Winds generally less than
10 mph.

.SUNDAY...
Partly cloudy with slight chance of showers and thunderstorms.
Lows in the lower 30s. Highs in the upper 50s. Winds generally
less than 10 mph.

$$
Forecaster...Murrell
Requested by...Jesse Harrand
Type of request...PRESCRIBED
.TAG 1709965.0/RIW
.EMAIL jharrand@fs.fed.us



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