FNUS75 KRIW 171850 FWSRIW SPOT FORECAST FOR FONTENELLE...USFS BTF NATIONAL WEATHER SERVICE RIVERTON WY 1250 PM MDT FRI AUG 17 2012 FORECAST IS BASED ON REQUEST TIME OF 1150 MDT ON AUGUST 17. IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER SERVICE. .DISCUSSION...NORTHWEST FLOW WILL CONTINUE TODAY AHEAD OF A WEAK UPPER LEVEL DISTURBANCE. IT WILL BE BREEZY AT TIMES WHEN THE WINDS ALOFT MIX DOWN TO THE SURFACE THIS AFTERNOON. OTHERWISE...A RIDGE OF HIGH PRESSURE BUILDS OVER WESTERN WYOMING ON SATURDAY AND SUNDAY. TODAYS HIGH TEMPERATURES WILL BE WARMER THAN YESTERDAY. MINIMUM RELATIVE HUMIDITIES SHOULD RANGE FROM 15 TO 25 PERCENT THROUGH THE WEEKEND. THERE WILL BE A CHANCE OF THUNDERSTORMS ON SUNDAY AS AN UPPER LEVEL DISTURBANCE APPROACHES...HOWEVER THERE SHOULD BE ADEQUATE MOISTURE TO SUPPORT WET THUNDERSTORMS. GIVEN THE DRYNESS OF THE FUELS...THIS SITUATION WILL BE WATCHED CLOSELY BUT IT DOES NOT APPEAR TO BE HIGH IMPACT AT THIS TIME DUE TO THE LIMITED INSTABILITY AND ADEQUATE MOISTURE AT ALL LEVELS EXPECTED WITH THIS FEATURE. ...THUNDERSTORMS IMPLY STRONG GUSTY AND ERRATIC WINDS... ...HAINES INDEX IS HIGH LEVEL HAINES BOTH DAY AND NIGHT... FORECASTER...LIPSON .REST OF TODAY... SKY/WEATHER.........MOSTLY SUNNY (20-30 PERCENT). AREAS OF SMOKE. MAX TEMPERATURE.....84 AT 8200 FEET AND 76 AT 9700 FEET. MIN HUMIDITY........15 PERCENT AT 8200 FEET AND 18 PERCENT AT 9700 FEET. 20 FOOT WINDS.......WEST SOUTHWEST 10 TO 20 MPH WITH GUSTS TO 25 MPH. AFTER 1500 WINDS WILL FLUCTUATE BETWEEN WEST AND NORTH AT 5 TO 15 MPH WITH GUSTS TO 25 MPH. RIDGE TOP WINDS.....NORTHWEST AROUND 15 MPH TO 20 MPH. LAL.................1. CHC OF WETTING RAIN.ZERO PERCENT. HAINES INDEX........5 OR MODERATE POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......8200-9200 FT AGL. TRANSPORT WINDS.....NORTHWEST 16 TO 25 MPH. SMOKE DISPERSAL.....VERY GOOD (148900 KNOT-FT). .TONIGHT... SKY/WEATHER.........MOSTLY CLEAR (15-25 PERCENT). AREAS OF SMOKE. MIN TEMPERATURE.....42-47 EXCEPT 37 AT 8200 FEET. MAX HUMIDITY........58-68 PERCENT EXCEPT 68 TO 75 PERCENT AT 8200 FEET. 20 FOOT WINDS.......NORTH WINDS BY 2100 AT 8 TO 12 MPH AND GUSTY IN THE EVENING BECOMING DOWNSLOPE/DOWNVALLEY 4-7 MPH BY 0300. RIDGE TOP WINDS.....NORTHWEST AROUND 15 MPH BECOMING SOUTH AROUND 5 MPH EARLY IN THE MORNING. LAL.................1. CHC OF WETTING RAIN.ZERO PERCENT. HAINES INDEX........5 OR MODERATE POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......6300-7300 FT AGL DECREASING TO 900-1900 FT AGL AFTER MIDNIGHT. TRANSPORT WINDS.....NORTHWEST 17 TO 24 MPH BECOMING NORTH 8 TO 10 MPH AFTER MIDNIGHT. SMOKE DISPERSAL.....VERY GOOD (120600 KNOT-FT) DECREASING TO POOR (14800 KNOT-FT) AFTER MIDNIGHT. .SATURDAY... SKY/WEATHER.........MOSTLY SUNNY (15-25 PERCENT). AREAS OF SMOKE. MAX TEMPERATURE.....81 AT 8200 FEET AND 73 AT 9700 FEET. MIN HUMIDITY........15 PERCENT AT 8200 FEET AND 19 PERCENT AT 9700 FEET. 20 FOOT WINDS.......UPSLOPE/UPVALLEY 5-9 MPH. RIDGE TOP WINDS.....SOUTHWEST AROUND 5 MPH IN THE MORNING BECOMING LIGHT AND VARIABLE. LAL.................1. CHC OF WETTING RAIN.ZERO PERCENT. HAINES INDEX........5 OR MODERATE POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......2700-3700 FT AGL INCREASING TO 8800-9800 FT AGL IN THE AFTERNOON. TRANSPORT WINDS.....WEST 6 TO 9 MPH. SMOKE DISPERSAL.....POOR (17400 KNOT-FT) INCREASING TO GOOD (74800 KNOT-FT) IN THE AFTERNOON. .FORECAST DAYS 3 THROUGH 5... .SATURDAY NIGHT...MOSTLY CLEAR. AREAS OF SMOKE. LOWS IN THE LOWER 40S. WINDS GENERALLY LESS THAN 10 MPH. .SUNDAY...PARTLY CLOUDY WITH ISOLATED SHOWERS AND THUNDERSTORMS. LOWS IN THE MID 40S. HIGHS IN THE LOWER 70S. WINDS GENERALLY LESS THAN 10 MPH. .MONDAY...MOSTLY CLEAR. LOWS IN THE LOWER 40S. HIGHS IN THE LOWER 70S. WINDS GENERALLY LESS THAN 10 MPH. .TUESDAY...PARTLY CLOUDY. SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS. LOWS IN THE MID 40S. HIGHS IN THE MID 70S. WINDS GENERALLY LESS THAN 10 MPH. $$ FORECASTER...LIPSON REQUESTED BY...USFS REASON FOR REQUEST...WILDFIRE .TAG 20120817.FONTE.01/RIW