FNUS75 KRIW 092142
FWSRIW

SPOT FORECAST FOR BUTTE FIRE...NPS YNP
NATIONAL WEATHER SERVICE RIVERTON WY
342 PM MDT WED SEP 9 2009

FORECAST IS BASED ON REQUEST TIME OF 1459 MDT ON SEPTEMBER 09.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...
A WEAK UPPER LEVEL RIDGE OF HIGH PRESSURE CENTERED OVER WESTERN
WYOMING WILL GRADUALLY WEAKEN TONIGHT AS A STRONG PACIFIC TROUGH
MOVES EASTWARD ALONG THE CANADIAN BORDER. THE ASSOCIATED DRY
SURFACE BACK-DOOR COLD FRONT WILL MOVE SOUTH/SOUTHEASTWARD THROUGH
WESTERN WYOMING THURSDAY EVENING. COOLER TEMPERATURES...EAST
WIND...AND HIGHER RELATIVE HUMIDITY LEVELS ARE EXPECTED OVER
NORTHWEST WYOMING ON FRIDAY AND SATURDAY AS A RESULT OF THE FRONTAL
PASSAGE. A SLIGHT CHANCE FOR A LIGHT RAIN SHOWER OR TWO IS
POSSIBLE SATURDAY AFTERNOON AND EVENING.

...THUNDERSTORMS IMPLY STRONG GUSTY AND ERRATIC WINDS...
...HAINES INDEX IS HIGH LEVEL HAINES BOTH DAY AND NIGHT...

FORECASTER...CHURCH

.TONIGHT...
SKY/WEATHER.........MOSTLY CLEAR (10-20 PERCENT).
MIN TEMPERATURE.....35-38.
MAX HUMIDITY........79-82 PERCENT.
20 FOOT WINDS.......UPSLOPE 3 TO 6 MPH EARLY IN THE EVENING BECOMING
                    DOWNSLOPE/DOWNVALLEY 4-7 MPH.
RIDGE TOP WINDS.....WEST 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.......3800 FT AGL DECREASING TO 700 FT AGL AFTER
                    MIDNIGHT.
TRANSPORT WINDS.....WEST 10 TO 17 MPH.
SMOKE DISPERSAL.....POOR TO FAIR (6500-46600 KNOT-FT).

.THURSDAY...
SKY/WEATHER.........MOSTLY SUNNY (10-20 PERCENT) THEN BECOMING
                    PARTLY CLOUDY (25-35 PERCENT).
MAX TEMPERATURE.....72-75.
MIN HUMIDITY........19-23 PERCENT.
20 FOOT WINDS.......UPSLOPE/UPVALLEY 5-9 MPH BECOMING WEST-NORTHWEST
                    4 TO 8 MPH WITH GUSTS TO 13 MPH LATE IN THE
                    AFTERNOON.
RIDGE TOP WINDS.....WEST 7 TO 11 MPH...INCREASING AND SHIFTING TO THE
                    WEST-NORTHWEST 10 TO 15 MPH WITH GUSTS TO 18 MPH.                   .
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 INCREASING TO 8500 FT AGL IN THE
                    AFTERNOON.
TRANSPORT WINDS.....WEST-NORTHWEST 12 TO 19 MPH.
SMOKE DISPERSAL.....FAIR (28500-48600 KNOT-FT).

.FORECAST DAYS 3 THROUGH 5...
.THURSDAY NIGHT...MOSTLY CLEAR. LOWS IN THE MID 30S. WINDS
GENERALLY LESS THAN 10 MPH.
.FRIDAY...MOSTLY CLEAR. LOWS IN THE LOWER 30S. HIGHS IN THE UPPER
60S. EAST-NORTHEAST WIND 10 TO 14 MPH WITH GUSTS TO 19 MPH.
.SATURDAY...PARTLY CLOUDY. SLIGHT CHANCE OF SHOWERS. LOWS IN THE
LOWER 30S. HIGHS AROUND 70. EAST-NORTHEAST WIND 10 TO 14 MPH WITH
GUSTS TO 20 MPH.
.SUNDAY...PARTLY CLOUDY WITH SLIGHT CHANCE OF RAIN. LOWS IN THE
MID 30S. HIGHS IN THE UPPER 60S. WINDS SOUTHWEST 15 TO 20 MPH.
.MONDAY...MOSTLY CLEAR. LOWS IN THE MID 30S. HIGHS AROUND 70.
WINDS SOUTHWEST 10 TO 15 MPH.

$$

FORECASTER...CHURCH
REQUESTED BY...EDWIN FOLTS
REASON FOR REQUEST...WILDFIRE
.TAG 20090909.BUTTE.01/RIW