FNUS75 KRIW 262141
FWSRIW

SPOT FORECAST FOR ARNICA FIRE...NPS YNP
NATIONAL WEATHER SERVICE RIVERTON WY
341 PM MDT SAT SEP 26 2009

FORECAST IS BASED ON REQUEST TIME OF 1500 MDT ON SEPTEMBER 26.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

...RED FLAG WARNING IN EFFECT UNTIL 9 PM MDT THIS EVENING...

.DISCUSSION...A RED FLAG WARNING IS IN EFFECT IN ZONE 140 THROUGH 2100 THIS
EVENING DUE TO STRONG WINDS...LOW RELATIVE HUMIDITY AND CRITICALLY
DRY VEGETATION. THE WINDS WILL DIMINISH LATER THIS EVENING.
TEMPERATURES WILL BE AROUND 5 DEGREES COOLER SUNDAY BEHIND A PASSING COLD FRONT.
A RELATIVELY WARM AND DRY DAY IS EXPECTED FOR MONDAY. TEMPERATURES WILL
COOL DURING THE REST OF THE WEEK ALONG INCREASINGLY MOIST CONDITIONS. BY
WEDNESDAY A STRONG PACIFIC TROUGH WILL BRING INCREASING CHANCES OF
RAIN TURNING TO SNOW.

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

FORECASTER...LIPSON

.REST OF TODAY...
SKY/WEATHER.........SUNNY (0-10 PERCENT).
MAX TEMPERATURE.....REMAINING AROUND 67.
MIN HUMIDITY........15 PERCENT.
20 FOOT WINDS.......SOUTHWEST WINDS AROUND 8 TO 13 MPH WITH GUSTS TO AROUND
                    23 MPH.
RIDGE TOP WINDS.....WEST AROUND 25 MPH.
LAL.................1.
CHC OF WETTING RAIN.ZERO PERCENT.
HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED
                    FIRE GROWTH.
MIXING HEIGHT.......5100 FT AGL.
TRANSPORT WINDS.....WEST AROUND 22 MPH.
SMOKE DISPERSAL.....GOOD (90300 KNOT-FT).

.TONIGHT...
SKY/WEATHER.........CLEAR (0-10 PERCENT).
MIN TEMPERATURE.....AROUND 35.
MAX HUMIDITY........64 PERCENT.
20 FOOT WINDS.......SOUTHWEST WINDS 8 TO 13 MPH. GUSTS UP TO 23 MPH.
                    WINDS BECOMING WEST TO 10 MPH WITH GUSTS TO 15 MPH BY 2000.
                    WINDS BECOMING NORTHWEST 10 MPH BY 0300 AND THEN NORTHERLY
                    10 MPH BY 0500.
RIDGE TOP WINDS.....WEST 20 TO 25 MPH.
LAL.................1.
CHC OF WETTING RAIN.ZERO PERCENT.
HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED
                    FIRE GROWTH.
MIXING HEIGHT.......2200-3200 FT AGL.
TRANSPORT WINDS.....WEST 18 TO 24 MPH.
SMOKE DISPERSAL.....POOR TO GOOD (30700-68400 KNOT-FT). BECOMING
                    POOR BY 0300.

.SUNDAY...
SKY/WEATHER.........SUNNY (0-10 PERCENT).
MAX TEMPERATURE.....62.
MIN HUMIDITY........17 PERCENT.
20 FOOT WINDS.......NORTH WINDS DECREASING TO 4 TO 6 MPH BY 0700.
                    WINDS BECOMING SOUTHWEST 10 TO 12 MPH BY 1200.
RIDGE TOP WINDS.....WEST 15 TO 20 MPH INCREASING TO AROUND 25 MPH
                    LATE IN THE AFTERNOON.
LAL.................1.
CHC OF WETTING RAIN.ZERO PERCENT.
HAINES INDEX........3 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......1600 FT AGL INCREASING TO 5800 FT AGL IN THE
                    AFTERNOON.
TRANSPORT WINDS.....WEST 14 TO 23 MPH.
SMOKE DISPERSAL.....POOR (22100 KNOT-FT) INCREASING TO VERY GOOD
                    (107600 KNOT-FT) IN THE AFTERNOON.

.FORECAST DAYS 3 THROUGH 5...
.SUNDAY NIGHT...CLEAR. LOWS IN THE MID 20S. WINDS GENERALLY LESS
THAN 10 MPH.
.MONDAY...MOSTLY CLEAR. LOWS IN THE MID 30S. HIGHS IN THE UPPER
60S. SOUTHWEST WINDS AROUND 10 MPH.
.TUESDAY...MOSTLY CLOUDY. SCATTERED SHOWERS...SNOW SHOWERS AND
ISOLATED THUNDERSTORMS. LOWS IN THE LOWER 30S. HIGHS IN THE MID
60S. SOUTHWEST WINDS AROUND 10 MPH.
.WEDNESDAY...MUCH COLDER. MOSTLY CLOUDY. SHOWERS...SNOW SHOWERS
LIKELY AND ISOLATED THUNDERSTORMS. LOWS AROUND 18. HIGHS IN THE
UPPER 30S. WINDS GENERALLY LESS THAN 10 MPH.

$$

FORECASTER...LIPSON
REQUESTED BY...ED FOLTS
REASON FOR REQUEST...WILDFIRE
.TAG 20090926.ARNIC.01/RIW