FNUS75 KRIW 132154 FWSRIW SPOT FORECAST FOR NEW BOOT...BRIDGER TETON NATIONAL FOREST NATIONAL WEATHER SERVICE RIVERTON WY 354 PM MDT SUN SEP 13 2009 FORECAST IS BASED ON REQUEST TIME OF 1517 MDT ON SEPTEMBER 13. IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER SERVICE. .DISCUSSION...A FEW SHOWERS AND PERHAPS A STRAY THUNDERSTORM WILL OCCUR OVER THE AREA LATE THIS AFTERNOON AND TONIGHT AS A LOW PRESSURE CENTER RETREATS NORTH INTO MONTANA AND A PACIFIC TROUGH NOW APPROACHING THE PACIFIC COAST BEGINS TO SEND MOISTURE NORTHEAST TOWARD THE AREA. AS THE PACIFIC TROUGH TRANSITIONS INTO A CLOSED OFF LOW PRESSURE CENTER...CUT OFF FROM THE JET STREAM OFF TO THE NORTHWEST...THERE WILL BE AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS AS MOISTURE CONTINUES TO FEED INTO THE AREA DURING WHICH TIME THE LOW PRESSURE CENTER SLOWS DOWN ITS FORWARD PROGRESS IN THE GREAT BASIN. SCATTERED SHOWERS AND LATE DAY THUNDERSTORMS ARE EXPECTED MONDAY. ON TUESDAY NUMEROUS SHOWERS AND THUNDERSTORMS WILL OCCUR. TUESDAY WILL FEATURE THE COOLEST AND HIGHEST RELATIVE HUMIDITY DURING THE FORECAST PERIOD. ON WEDNESDAY... AS THE LOW TAKES A RIGHT TURN INTO THE FOUR CORNERS AREA OF THE COUNTRY AND WEAKENS...THE SHOWER ACTIVITY WILL DIMINISH TO SCATTERED SHOWER AND THUNDERSTORM ACTIVITY. ...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 CLOUDY (60-70 PERCENT). AN AREA OF SCATTERED SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM WILL ARRIVE BY 1615. MAX TEMPERATURE.....AROUND 66. MIN HUMIDITY........35 PERCENT BEFORE INCREASING THROUGH THE REST OF THE AFTERNOON. 20 FOOT WINDS.......SOUTH WINDS AROUND 15 MPH WITH GUSTS TO AROUND 25 MPH. SOUTH WINDS OF 25 TO 35 MPH ARE POSSIBLE WHEN THESE SHOWERS MOVE THROUGH LATE THIS AFTERNOON. RIDGE TOP WINDS.....SOUTHWEST AROUND 25 TO 30 MPH. LAL.................2. CHC OF WETTING RAIN.LESS THAN 5 PERCENT. HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......6500 FT AGL. TRANSPORT WINDS.....SOUTHWEST AROUND 28 MPH. SMOKE DISPERSAL.....VERY GOOD (140000 KNOT-FT). .TONIGHT... SKY/WEATHER.........MOSTLY CLOUDY (65-75 PERCENT). SCATTERED RAIN SHOWERS AND ISOLATED THUNDERSTORMS IN THE EVENING...THEN ISOLATED RAIN SHOWERS AFTER MIDNIGHT. MIN TEMPERATURE.....46-49. MAX HUMIDITY........68-71 PERCENT. 20 FOOT WINDS.......SOUTH WINDS 8 TO 17 MPH WITH GUSTS TO AROUND 25 MPH UNTIL MIDNIGHT THEN DECREASING TO 5 TO 10 MPH. GUSTY MAINLY SOUTHERLT 25 TO 30 MPH WINDS EXPECTED NEAR THUNDERSTORMS IN THE EVENING. RIDGE TOP WINDS.....SOUTHWEST AROUND 25 MPH BECOMING SOUTH AROUND 15 MPH IN THE LATE EVENING AND EARLY MORNING...THEN SHIFTING TO THE SOUTHEAST EARLY IN THE MORNING. LAL.................2 UNTIL 2400...THEN 1. CHC OF WETTING RAIN.5 PERCENT. HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......3700 FT AGL DECREASING TO 800 FT AGL AFTER MIDNIGHT. TRANSPORT WINDS.....SOUTHWEST 20 TO 26 MPH DECREASING TO AROUND 16 MPH AFTER MIDNIGHT. SMOKE DISPERSAL.....GOOD (72400 KNOT-FT) DECREASING TO POOR (10600 KNOT-FT) AFTER MIDNIGHT. .MONDAY... SKY/WEATHER.........MOSTLY CLOUDY (70-80 PERCENT). ISOLATED RAIN SHOWERS IN THE MORNING...THEN SCATTERED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON. MAX TEMPERATURE.....66-68. MIN HUMIDITY........27-29 PERCENT. 20 FOOT WINDS.......UPSLOPE/UPVALLEY 5-9 MPH. SOUTH WINDS 10 TO 15 MPH FROM 0900 TO 1500 THEN BACK TO UPSLOPE/UPVALLEY 5 TO 9 MPH AGAIN. GUSTY SOUTH WINDS EXPECTED NEAR THUNDERSTORMS IN THE AFTERNOON. RIDGE TOP WINDS.....SOUTH 10 TO 15 MPH. LAL.................1 UNTIL 1200...THEN 4. CHC OF WETTING RAIN.14 PERCENT. HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED FIRE GROWTH. MIXING HEIGHT.......3900 FT AGL INCREASING TO 7100 FT AGL IN THE AFTERNOON. TRANSPORT WINDS.....SOUTHWEST 14 TO 16 MPH. SMOKE DISPERSAL.....FAIR (46600 KNOT-FT) INCREASING TO GOOD (98800 KNOT-FT) IN THE AFTERNOON. .FORECAST DAYS 3 THROUGH 5... .MONDAY NIGHT...CLOUDY WITH CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS. LOWS IN THE UPPER 40S. WINDS GENERALLY LESS THAN 10 MPH. .TUESDAY...COOLER. CLOUDY WITH CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS. LOWS IN THE UPPER 40S. HIGHS IN THE LOWER 60S. WINDS GENERALLY LESS THAN 10 MPH. .WEDNESDAY...PARTLY CLOUDY. SLIGHT CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS. LOWS IN THE MID 40S. HIGHS IN THE MID 60S. WINDS GENERALLY LESS THAN 10 MPH. .THURSDAY...PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS. LOWS IN THE MID 40S. HIGHS AROUND 70. WINDS GENERALLY LESS THAN 10 MPH. $$ FORECASTER...LIPSON REQUESTED BY...MCFARLAND REASON FOR REQUEST...WILDFIRE .TAG 20090913.NEWBO.01/RIW