FNUS75 KRIW 301112
FWSRIW

SPOT FORECAST FOR ARNICA FIRE...NPS YNP
NATIONAL WEATHER SERVICE RIVERTON WY
512 AM MDT WED SEP 30 2009

FORECAST IS BASED ON REQUEST TIME OF 1628 MDT ON SEPTEMBER 29.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 PM MDT THIS
EVENING...

.DISCUSSION...A COLD LATE SEPTEMBER STORM SYSTEM WILL MOVE QUICKLY
INTO YELLOWSTONE NATIONAL PARK THIS MORNING WITH RAIN CHANGING OVER
TO SNOW WHICH WILL BE HEAVY AT TIMES TODAY. SNOWFALL OF 3 TO 6 INCHES
IS EXPECTED ACROSS THE AREA BY THIS EVENING. PRECIPITATION WILL TAPER
OFF AND END OVERNIGHT WITH VERY COLD CONDITIONS BY MORNING. TOMORROW
WILL BE COLD WITH A MIX OF SUN AND CLOUDS AND WITH A FEW SNOW SHOWERS
IN THE AREA. ANOTHER COLD STORM SYSTEM WILL MOVE INTO THE AREA LATE
IN THE WEEKEND.

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

FORECASTER...SKRBAC

.TODAY...
SKY/WEATHER.........CLOUDY (95-100 PERCENT). SNOW SHOWERS.
MAX TEMPERATURE.....35-38.
MIN HUMIDITY........60-63 PERCENT...EARLY THEN HIGHER.
20 FOOT WINDS.......UPSLOPE/UPVALLEY 5-9 MPH BECOMING NORTH AROUND
                    10 MPH WITH GUSTS TO AROUND 20 MPH LATE IN THE
                    AFTERNOON.
RIDGE TOP WINDS.....WEST AROUND 15 MPH INCREASING TO NORTH AROUND
                    25 MPH LATE IN THE AFTERNOON.
LAL.................1.
CHC OF WETTING RAIN.100 PERCENT.
HAINES INDEX........2 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......2100-2700 FT AGL.
TRANSPORT WINDS.....NORTHWEST 21 TO 29 MPH.
SMOKE DISPERSAL.....FAIR TO GOOD (43000-62000 KNOT-FT).

.TONIGHT...
SKY/WEATHER.........CLOUDY (85-95 PERCENT). SNOW SHOWERS IN THE
                    EVENING...THEN CHANCE OF SNOW SHOWERS AFTER
                    MIDNIGHT.
MIN TEMPERATURE.....14-17.
MAX HUMIDITY........93-96 PERCENT.
20 FOOT WINDS.......NORTH WINDS 10 MPH WITH GUSTS TO AROUND
                    20 MPH.
RIDGE TOP WINDS.....NORTH 20 TO 25 MPH.
LAL.................1.
CHC OF WETTING RAIN.60 PERCENT.
HAINES INDEX........2 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......2400 DECREASING TO 1000 FT AGL.
TRANSPORT WINDS.....NORTH 25 TO 29 MPH.
SMOKE DISPERSAL.....FAIR (65000 KNOT-FT)...DECREASING TO POOR
                    (27000 KNOT-FT)

.THURSDAY...
SKY/WEATHER.........MOSTLY CLOUDY (55-65 PERCENT) THEN BECOMING
                    PARTLY CLOUDY (50-60 PERCENT). SLIGHT CHANCE OF
                    SNOW SHOWERS.
MAX TEMPERATURE.....34-37.
MIN HUMIDITY........49-52 PERCENT.
20 FOOT WINDS.......NORTHWEST WINDS 8 TO 10 MPH EARLY IN THE
                    MORNING BECOMING UPSLOPE/UPVALLEY 5-9
                    MPH...THEN BECOMING WEST 11 TO 14 MPH IN THE
                    AFTERNOON. GUSTS UP TO 20 MPH.
RIDGE TOP WINDS.....NORTHWEST 15 TO 20 MPH SHIFTING TO THE WEST
                    LATE IN THE AFTERNOON.
LAL.................1.
CHC OF WETTING RAIN.LESS THAN 5 PERCENT.
HAINES INDEX........2 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......2500 FT AGL INCREASING TO 4500 FT AGL IN THE
                    AFTERNOON.
TRANSPORT WINDS.....WEST 21 TO 28 MPH.
SMOKE DISPERSAL.....FAIR (51200 KNOT-FT) INCREASING TO VERY GOOD (112000
                    KNOT-FT) IN THE AFTERNOON.

.FORECAST DAYS 3 THROUGH 5...
.THURSDAY NIGHT...PARTLY CLOUDY. LOWS AROUND 17. WEST WINDS
AROUND 10 MPH.
.FRIDAY...PARTLY CLOUDY. LOWS IN THE LOWER 20S. HIGHS AROUND 40.
WINDS GENERALLY LESS THAN 10 MPH.
.SATURDAY...MOSTLY CLOUDY WITH CHANCE OF SHOWERS AND SNOW
SHOWERS. LOWS IN THE MID 20S. HIGHS AROUND 40. WINDS GENERALLY
LESS THAN 10 MPH.
.SUNDAY...COLDER. SNOW LIKELY. LOWS IN THE LOWER 20S. HIGHS
AROUND 30. EAST WINDS AROUND 11 MPH.

$$

FORECASTER...SKRBAC
REQUESTED BY...ED FOLTS
REASON FOR REQUEST...WILDFIRE
.TAG 20090929.ARNIC.02/RIW