FNUS75 KRIW 101142 FWSRIW SPOT FORECAST FOR SNAKE FIRE...NPS YNP NATIONAL WEATHER SERVICE RIVERTON WY 542 AM MDT SAT AUG 10 2013 FORECAST IS BASED ON REQUEST TIME OF 2149 MDT ON AUGUST 09. IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER SERVICE. .DISCUSSION...DRIER AIR WILL PUSH UP ACROSS EASTERN IDAHO TODAY WITH THE FIRE AREA REMAINING JUST ON THE WESTERN FRINGE OF THE MOIST AND UNSTABLE AIRMASS TODAY. MID-LEVEL CLOUDS DRIFTING ACROSS THE AREA THIS MORNING WILL BLOSSOM INTO SCATTERED AFTERNOON THUNDERSTORMS THIS AFTERNOON. THIS ACTIVITY WILL BE MOSTLY NORTH AND EAST OF THE FIRE AREA AFTER SUNSET. DRIER AIR WILL GRADUALLY WORK ITS WAY INTO THE FIRE AREA SUNDAY AND MONDAY WITH THUNDERSTORM ACTIVITY TRENDING MORE ISOLATED...TEMPERATURES TRENDING WARMER...AND RELATIVE HUMIDITY LOWER. ...THUNDERSTORMS IMPLY STRONG GUSTY AND ERRATIC WINDS... ...HAINES INDEX IS HIGH LEVEL HAINES BOTH DAY AND NIGHT... FORECASTER...MEUNIER .TODAY... SKY/WEATHER.........MOSTLY CLOUDY (70-80) PERCENT. SOME CLEARING AROUND NOON THEN INCREASING CLOUDS WITH SCATTERED SHOWERS AND THUNDERSTORMS IN THE MID TO LATE AFTERNOON. MAX TEMPERATURE.....NEAR 75 AT 7500 FEET...67-70 AT 9000 FEET. MIN HUMIDITY........23-26 PERCENT. 20 FOOT WINDS.......SOUTH 4 TO 8 MPH...BECOMING WEST SOUTHWEST IN THE EARLY AFTERNOON. WIND FIELD BECOMING INCREASINGLY ERRATIC AND GUSTY BETWEEN 1400 AND 1600 WITH THUNDERSTORMS IN THE VICINITY. RIDGE TOP WINDS.....SOUTHWEST 10 TO 15 MPH. LAL.................1 UNTIL 1200...THEN 2 UNTIL 1400...THEN 4. CHC OF WETTING RAIN.15 PERCENT. HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......1000-2000 FT AGL UNTIL 0900...INCREASING TO 9800-10800 FT AGL IN THE AFTERNOON. TRANSPORT WINDS.....SOUTHWEST 13 TO 17 MPH. SMOKE DISPERSAL.....POOR UNTIL 0900...INCREASING TO VERY GOOD IN THE AFTERNOON. .TONIGHT... SKY/WEATHER.........MOSTLY CLOUDY WITH ISOLATED SHOWERS AND THUNDERSTORMS UNTIL AROUND SUNSET...THEN PARTLY CLOUDY (25-35 PERCENT). MIN TEMPERATURE.....41-44. MAX HUMIDITY........65-70 PERCENT. 20 FOOT WINDS.......GUSTY AND ERRATIC WINDS FROM THUNDERSTORM OUTFLOWS... PRIMARILY FROM THE NORTH AND EAST...LIKELY TO PREVAIL UNTIL AROUND SUNSET...THEN BECOMING DOWNSLOPE/DOWNVALLEY OR SOUTH 4-7 MPH. RIDGE TOP WINDS.....SOUTH AROUND 10 MPH...BECOMING SOUTHWEST AFTER MIDNIGHT. LAL.................2 UNTIL 2100...THEN 1. CHC OF WETTING RAIN.7 PERCENT. HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......6300-7300 FT AGL DECREASING TO 600-1600 FT AGL AFTER MIDNIGHT. TRANSPORT WINDS.....SOUTHWEST 10 TO 15 MPH. SMOKE DISPERSAL.....VERY GOOD UNTIL SUNSET...DECREASING TO POOR AFTER MIDNIGHT. .SUNDAY... SKY/WEATHER.........MOSTLY SUNNY (15-25 PERCENT) THEN BECOMING PARTLY CLOUDY (30-40 PERCENT). ISOLATED AFTERNOON THUNDERSTORMS. MAX TEMPERATURE.....76-79 AT 7500. 69-72 AT 9000 FEET. MIN HUMIDITY........18-21 PERCENT. 20 FOOT WINDS.......SOUTH 4-8 MPH...BECOMING WEST SOUTHWEST 5-10 MPH IN THE AFTERNOON. GUSTY AND ERRATIC WINDS NEAR ANY THUNDERSTORMS IN THE AFTERNOON. RIDGE TOP WINDS.....WEST SOUTHWEST AROUND 10 MPH. LAL.................1 UNTIL 1300...THEN 2. CHC OF WETTING RAIN.LESS THAN 5 PERCENT. HAINES INDEX........5 OR MODERATE POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......1000-2000 FT AGL UNTIL 0900...INCREASING TO 10500-11500 FT AGL IN THE AFTERNOON. TRANSPORT WINDS.....SOUTHWEST 10 TO 15 MPH. SMOKE DISPERSAL.....POOR UNTIL 0900...INCREASING TO VERY GOOD IN THE AFTERNOON. .FORECAST DAYS 3 THROUGH 5... .SUNDAY NIGHT...MOSTLY CLEAR. LOWS IN THE MID 40S. WINDS GENERALLY LESS THAN 10 MPH. .MONDAY...MOSTLY CLEAR. LOWS IN THE UPPER 40S. HIGHS IN THE UPPER 70S. WINDS GENERALLY LESS THAN 10 MPH. .TUESDAY...MOSTLY CLEAR. LOWS IN THE MID 40S. HIGHS IN THE MID 70S. WINDS GENERALLY LESS THAN 10 MPH. .WEDNESDAY...MOSTLY CLEAR. LOWS IN THE MID 40S. HIGHS IN THE MID 70S. WINDS GENERALLY LESS THAN 10 MPH. $$ FORECASTER...MEUNIER REQUESTED BY...BILL MAYER REASON FOR REQUEST...WILDFIRE .TAG 20130809.SNAKE.01/RIW