FNUS75 KRIW 121553 FWSRIW SPOT FORECAST FOR LOWER GROS VENTRE...USFS BTF NATIONAL WEATHER SERVICE RIVERTON WY 953 AM MDT SAT SEP 12 2009 FORECAST IS BASED ON IGNITION TIME OF 0900 MDT ON SEPTEMBER 12. IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER SERVICE. .DISCUSSION...AN UPPER LOW WILL CONTINUE TO RETROGRADE FROM OVER SOUTH DAKOTA INTO CENTRAL WYOMING TODAY. NORTH WINDS WILL RESULT TODAY. A FEW MORE CLOUDS WILL BE AROUND TODAY. THE UPPER LOW WILL LIFT NORTH TONIGHT AND SUNDAY WITH THE FLOW BACKING TO THE SOUTHWEST...WITH SOME GUSTY WINDS POSSIBLE. SOME SUBTROPICAL MOISTURE WILL MOVE IN WITH CLOUD COVER ON THE INCREASE FOR SUNDAY AS WELL AS THE CHANCE OF SHOWERS AND POSSIBLY THUNDERSTORMS. ANOTHER UPPER LOW WILL SPIN-UP OVER THE GREAT BASIN MAKING CONDITIONS MORE FAVORABLE FOR SHOWERS AND THUNDERSTORMS TO DEVELOP MONDAY AND TUESDAY. ...THUNDERSTORMS IMPLY STRONG GUSTY AND ERRATIC WINDS... ...HAINES INDEX IS HIGH LEVEL HAINES BOTH DAY AND NIGHT... FORECASTER...LIPSON .TODAY... SKY/WEATHER.........SUNNY (5-15 PERCENT) THEN CLOUDS MOVING IN FROM THE EAST AND BECOMING PARTLY CLOUDY (35-45 PERCENT) DURING THE AFTERNOON. MAX TEMPERATURE.....72 AT 7000 FEET AND 60 AT 9200 FEET. MIN HUMIDITY........17 PERCENT AT 7000 FEET AND 26 PERCENT AT 9200 FEET. 20 FOOT WINDS.......BELOW 8000 FEET UPSLOPE/UPVALLEY 5-9 MPH. WINDS BECOMING NORTH 10 TO 15 MPH ALONG THE WEST FORK BY 1700. ABOVE 8000 FEET...EAST WINDS 10 TO 20 MPH BECOMING NORTH 8 TO 11 MPH BY 1200. RIDGE TOP WINDS.....NORTHEAST 10 TO 15 MPH. LAL.................1. CHC OF WETTING RAIN.ZERO PERCENT. HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......1100 FT AGL INCREASING TO 5600 FT AGL IN THE AFTERNOON. TRANSPORT WINDS.....NORTHEAST 13 TO 15 MPH. SMOKE DISPERSAL.....POOR (13200 KNOT-FT) INCREASING TO GOOD (66700 KNOT-FT) IN THE AFTERNOON. .TONIGHT... SKY/WEATHER.........MOSTLY CLEAR (10-20 PERCENT). MIN TEMPERATURE.....37-39. MAX HUMIDITY........70 PERCENT AT 7000 FEET AND 64 PERCENT AT 9200 FEET. 20 FOOT WINDS.......EAST WINDS AROUND 8 MPH INCRAESING TO 10 TO 20 MPH BY 2100. THESE WINDS WILL CHANNEL DOWN THE HORSETAIL CREEK AT 10 TO 20 MPH. MORE SHELTERED AREAS INCLUDING THE WEST FORK WILL SEE DOWNSLOPE/DOWNVALLEY WINDS OF 5 TO 9 MPH. AFTER 0300 DOWNSLOPE/DOWNVALLEY 4-7 MPH. TO 15 MPH. RIDGE TOP WINDS.....EAST AROUND 15 MPH. LAL.................1. CHC OF WETTING RAIN.ZERO PERCENT. HAINES INDEX........3 OR VERY LOW POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......4200 FT AGL DECREASING TO 400 FT AGL AFTER MIDNIGHT. TRANSPORT WINDS.....EAST 15 TO 17 MPH. SMOKE DISPERSAL.....POOR TO FAIR (4900-52900 KNOT-FT). .SUNDAY... SKY/WEATHER.........PARTLY CLOUDY (45-55 PERCENT) THEN BECOMING MOSTLY CLOUDY (60-70 PERCENT). MAX TEMPERATURE.....71 AT 7000 FEET AND 59 AT 9200 FEET. MIN HUMIDITY........26 PERCENT AT 7000 FEET AND 37 PERCENT AT 9200 FEET. 20 FOOT WINDS.......BELOW AT 8000 FEET UPSLOPE/UPVALLEY 5-9 MPH BECOMING SOUTHWEST 10 TO 13 MPH BY 1200 WITH SOME GUSTS TO 20 MPH ALONG THE HORSETAIL CREEK BY 1200. ABOVE 8000 FEET EAST WINDS 5 TO 10 MPH UNTIL 0700. THEN WINDS BECOMING SOUTH 6 TO 12 MPH WITH GUSTS TO 15 MPH ALONG THE WEST FORK. AT 1200 WINDS WILL SHIFT TO SOUTHWEST 12 TO 19 MPH WITH SOME GUSTS TO 22 MPH THROUGH THE UPPER SADDLE AS IT THE WIND CHANNELS FROM THE WEST THERE. RIDGE TOP WINDS.....SOUTH 10 TO 15 MPH SHIFTING TO THE SOUTHWEST AROUND 20 MPH LATE IN THE AFTERNOON. LAL.................1. CHC OF WETTING RAIN.ZERO PERCENT. HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......1200 FT AGL INCREASING TO 7700 FT AGL IN THE AFTERNOON. TRANSPORT WINDS.....SOUTHWEST 14 TO 23 MPH. SMOKE DISPERSAL.....POOR (11200 KNOT-FT) INCREASING TO VERY GOOD (134900 KNOT-FT) IN THE AFTERNOON. .FORECAST DAYS 3 THROUGH 5... .SUNDAY NIGHT...PARTLY CLOUDY. SLIGHT CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS IN THE EVENING...THEN SLIGHT CHANCE OF SHOWERS AFTER MIDNIGHT. LOWS IN THE LOWER 40S. SOUTHWEST WINDS AROUND 10 MPH. .MONDAY...PARTLY CLOUDY. SLIGHT CHANCE OF SHOWERS AND ISOLATED 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 ISOLATED THUNDERSTORMS. LOWS IN THE MID 40S. HIGHS IN THE LOWER 60S. WINDS GENERALLY LESS THAN 10 MPH. .WEDNESDAY...PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS. LOWS IN THE MID 40S. HIGHS IN THE LOWER 60S. WINDS GENERALLY LESS THAN 10 MPH. $$ FORECASTER...LIPSON REQUESTED BY...MCFARLAND REASON FOR REQUEST...PRESCRIBED .TAG 20090912.LOWER.01/RIW