FNUS75 KRIW 242208
FWSRIW

SPOT FORECAST FOR ARNICA FIRE...NPS YNP
NATIONAL WEATHER SERVICE RIVERTON WY
408 PM MDT THU SEP 24 2009

FORECAST IS BASED ON REQUEST TIME OF 1549 MDT ON SEPTEMBER 24.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...
NORTH TO NORTHEAST FLOW WILL REMAIN OVER NORTHWEST WYOMING TONIGHT AND
FRIDAY...WITH CLEAR AND BENIGN WEATHER EXPECTED. A WEAK...DRY TROUGH
WILL MOVE ACROSS MONTANA FRIDAY NIGHT BACKING THE WIND TO THE
NORTHWEST WITH SOME SOUTHWEST TO WEST WINDS DEVELOPING AT THE SURFACE.

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

FORECASTER...T.BAKER

.THIS AFTERNOON AND TONIGHT...
SKY/WEATHER.........MOSTLY CLEAR (5-15 PERCENT).
TEMPERATURE.........MAX 75...MIN 26-29.
MAX HUMIDITY........MIN 10 PERCENT...MIN 80-85 PERCENT.
20 FOOT WINDS.......NORTH 3-6 MPH BECOMING DOWNSLOPE/DOWNVALLEY 2-4 MPH
                    AFTER 2100.
RIDGE TOP WINDS.....NORTH 8 TO 15 MPH GUSTS TO 20 MPH.
LAL.................1.
CHC OF WETTING RAIN.ZERO PERCENT.
HAINES INDEX........5 OR MODERATE POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......9000 FT AGL DECREASING TO 500 FT AGL AFTER
                    2200.
TRANSPORT WINDS.....NORTHEAST 15 MPH.
SMOKE DISPERSAL.....VERY GOOD (135000 KNOT-FT) DECREASING TO POOR (1800
                    KNOT-FT) AFTER 2200.

.FRIDAY...
SKY/WEATHER.........MOSTLY SUNNY (15-25 PERCENT).
MAX TEMPERATURE.....AROUND 75.
MIN HUMIDITY........12-15 PERCENT.
20 FOOT WINDS.......NORTH TO NORTHEAST 5-10 MPH.
RIDGE TOP WINDS.....NORTH TO NORTHEAST 10-15 MPH GUSTS TO 25 MPH.
LAL.................1.
CHC OF WETTING RAIN.ZERO PERCENT.
HAINES INDEX........5 OR MODERATE POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......500 FT AGL INCREASING TO 10000 FT AGL IN THE
                    AFTERNOON.
TRANSPORT WINDS.....NORTH TO NORTHEAST 20 MPH.
SMOKE DISPERSAL.....POOR (10000 KNOT-FT) INCREASING TO EXCELLENT
                    (200000 KNOT-FT) IN THE AFTERNOON.

.FORECAST DAYS 3 THROUGH 5...
.FRIDAY NIGHT...MOSTLY CLEAR. LOWS IN THE UPPER 20S. WINDS
GENERALLY LESS THAN 10 MPH.
.SATURDAY...MOSTLY CLEAR. LOWS AROUND 30. HIGHS IN THE UPPER 60S.
SOUTHWEST TO WEST WINDS 10-15 GUSTS TO 25 MPH.
.SUNDAY...MOSTLY CLEAR. LOWS IN THE UPPER 20S. HIGHS IN THE LOWER
60S. WEST TO NORTHWEST WINDS 10-15 MPH GUSTS TO 25 MPH.
.MONDAY...MOSTLY CLEAR. LOWS IN THE LOWER 30S. HIGHS IN THE MID
60S. WINDS GENERALLY LESS THAN 10 MPH.
.TUESDAY...PARTLY CLOUDY WITH CHANCE OF SHOWERS...THUNDERSTORMS
AND SNOW SHOWERS. LOWS IN THE UPPER 20S. HIGHS IN THE LOWER 60S.
SOUTHWEST WINDS AROUND 11 MPH.

$$

FORECASTER...T.BAKER
REQUESTED BY...ED FOLTS
REASON FOR REQUEST...WILDFIRE
.TAG 20090924.ARNIC.01/RIW