FNUS75 KRIW 211610 FWSRIW SPOT FORECAST FOR PORCUPINE...USFS BTF NATIONAL WEATHER SERVICE RIVERTON WY 1010 AM MDT FRI AUG 21 2009 FORECAST IS BASED ON REQUEST TIME OF 0937 MDT ON AUGUST 21. IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER SERVICE. .DISCUSSION... STRONG HIGH PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER OVER WEST-CENTRAL WYOMING THROUGH SATURDAY. VERY WARM TEMPERATURES ALONG WITH POOR OVERNIGHT RELATIVE HUMIDITY RECOVERIES ARE EXPECTED TODAY AND SATURDAY. AS HIGH LEVEL MONSOON MOISTURE BEGINS TO INCREASE OVER SOUTHWEST AND WEST-CENTRAL WYOMING SATURDAY AFTERNOON...A SLIGHT CHANCE FOR AN ISOLATED HIGH BASED STORM OVER THE HIGHER PEAKS IS POSSIBLE BUT BY NO MEANS LIKELY. A STRONG PACIFIC COLD FRONT WILL MOVE IN FROM THE WEST SUNDAY MORNING. A GOOD CHANCE FOR SHOWERS AND THUNDERSTORMS ALONG WITH MUCH COOLER TEMPERATURES ARE ANTICIPATED FOR SUNDAY AFTERNOON. ...THUNDERSTORMS IMPLY STRONG GUSTY AND ERRATIC WINDS... ...HAINES INDEX IS HIGH LEVEL HAINES BOTH DAY AND NIGHT... FORECASTER...CHURCH .TODAY... SKY/WEATHER.........SUNNY (0-10 PERCENT). MAX TEMPERATURE.....75-78. MIN HUMIDITY........15-18 PERCENT. 20 FOOT WINDS.......UPSLOPE/UPVALLEY 4-7. RIDGE TOP WINDS.....EAST 5-10 MPH SHIFTING TO THE WEST IN THE AFTERNOON. LAL.................1. CHC OF WETTING RAIN.ZERO PERCENT. HAINES INDEX........5 OR MODERATE POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......4800 FT AGL INCREASING TO 8300 FT AGL IN THE AFTERNOON. TRANSPORT WINDS.....SOUTHEAST 5 TO 10 MPH SHIFTING TO THE SOUTHWEST 9 TO 12 MPH IN THE AFTERNOON. SMOKE DISPERSAL.....FAIR TO GOOD (53500-74300 KNOT-FT). .TONIGHT... SKY/WEATHER.........MOSTLY CLEAR (10-20 PERCENT). MIN TEMPERATURE.....51-55. MAX HUMIDITY........32-38 PERCENT. 20 FOOT WINDS.......DOWNSLOPE/DOWNVALLEY 4-7 MPH. RIDGE TOP WINDS.....WEST AROUND 10 MPH SHIFTING TO THE NORTH LATE IN THE EVENING. LAL.................1. CHC OF WETTING RAIN.ZERO PERCENT. HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......4600 FT AGL DECREASING TO 1000 FT AGL AFTER MIDNIGHT. TRANSPORT WINDS.....WEST 10 TO 12 MPH SHIFTING TO THE EAST AFTER MIDNIGHT...THEN SHIFTING TO THE NORTH AROUND 8 MPH EARLY IN THE MORNING. SMOKE DISPERSAL.....POOR TO FAIR (3900-43800 KNOT-FT). .SATURDAY... SKY/WEATHER.........MOSTLY SUNNY (10-20 PERCENT) THEN BECOMING PARTLY CLOUDY (35-45 PERCENT). SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN THE AFTERNOON. MAX TEMPERATURE.....79-83. MIN HUMIDITY........13-17 PERCENT. 20 FOOT WINDS.......UPSLOPE/UPVALLEY 4-7 MPH. GUSTY AND ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS IN THE AFTERNOON. RIDGE TOP WINDS.....EAST AROUND 5 MPH SHIFTING TO THE SOUTHWEST AROUND 15 MPH LATE IN THE AFTERNOON. LAL.................1 UNTIL 1200...THEN 2. CHC OF WETTING RAIN.LESS THAN 5 PERCENT. HAINES INDEX........6 OR HIGH POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......6900 FT AGL INCREASING TO 12800 FT AGL IN THE AFTERNOON. TRANSPORT WINDS.....EAST AROUND 5 MPH SHIFTING TO THE SOUTHWEST AROUND 10 MPH LATE IN THE AFTERNOON. SMOKE DISPERSAL.....VERY GOOD (104400 KNOT-FT). .FORECAST DAYS 3 THROUGH 5... .SATURDAY NIGHT...PARTLY CLOUDY. SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN THE EVENING. LOWS IN THE LOWER 50S. WINDS GENERALLY LESS THAN 10 MPH. .SUNDAY...COOLER. PARTLY CLOUDY. CHANCE OF SHOWERS AND THUNDERSTORMS. LOWS IN THE MID 40S. HIGHS IN THE MID 60S. WINDS WEST 10 TO 20 MPH. .MONDAY...PARTLY CLOUDY WITH CHANCE OF SHOWERS AND THUNDERSTORMS. LOWS IN THE MID 40S. HIGHS IN THE LOWER 60S. WINDS GENERALLY LESS THAN 10 MPH. .TUESDAY...PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS. LOWS IN THE MID 40S. HIGHS IN THE MID 60S. WINDS GENERALLY LESS THAN 10 MPH. $$ FORECASTER...CHURCH REQUESTED BY...BILL MOE REASON FOR REQUEST...WILDFIRE .TAG 20090821.PORCU.01/RIW