FNUS75 KRIW 221059
FWSRIW

SPOT FORECAST FOR ARTHUR 2...NPS YNP
NATIONAL WEATHER SERVICE RIVERTON WY
459 AM MDT SUN AUG 22 2010

FORECAST IS BASED ON REQUEST TIME OF 1940 MDT ON AUGUST 21.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...CLOUDS AND SHOWERS WILL INCREASE THIS MORNING ALONG
WITH THE POSSIBILITY OF AN ISOLATED THUNDERSTORM.  SOUTHWEST WIND
WILL LIKELY INCREASE LATE THIS MORNING WITH A TREND TOWARD COOLER
TEMPERATURES AND HIGHER RELATIVE HUMIDITY. SHOWERS AND THUNDERSTORMS
WILL BECOME MORE NUMEROUS THROUGH THE AFTERNOON AND EVENING WITH THE
HEIGHT OF ACTIVITY EXPECTED FROM 1400L THROUGH 2200L...WITH A
STRONG COLD FRONT MOVING THROUGH 1600L THROUGH 1800L. SHOWERS AND
THUNDERSTORMS WILL DECREASE AFTER MIDNIGHT SUNDAY NIGHT BEHIND THE
COLD FRONT.

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

FORECASTER...MEUNIER

.TODAY...
SKY/WEATHER.........MOSTLY CLOUDY IN THE MORNING (70-80 PERCENT) BECOMING
                    CLOUDY IN THE AFTERNOON (90-100 PERCENT). ISOLATED RAIN
                    SHOWERS IN THE MORNING...THEN SCATTERED SHOWERS
                    AND THUNDERSTORMS IN THE AFTERNOON.  SHOWERS AND
                    AND THUNDERSTORMS BECOMING MORE NUMEROUS 1400L THROUGH
                    1800L.
MAX TEMPERATURE.....RANGING FROM NEAR 72 AT 7500 FEET TO NEAR 67
                    AT 8300 FEET.
MIN HUMIDITY........30-35 PERCENT.
20 FOOT WINDS.......SOUTHWEST WINDS 8 TO 15 MPH WITH GUSTS TO
                    AROUND 30 MPH. GUSTY AND ERRATIC WINDS EXPECTED
                    NEAR THUNDERSTORMS IN THE AFTERNOON.
RIDGE TOP WINDS.....SOUTHWEST AROUND 15-25 MPH WITH GUSTS TO 35 MPH.
LAL.................2 UNTIL 1200...THEN 4.
CHC OF WETTING RAIN.30 PERCENT.
HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED
                    FIRE GROWTH.
MIXING HEIGHT.......3700-4700 FT AGL INCREASING TO 6400-7400 FT AGL
                    IN THE AFTERNOON.
TRANSPORT WINDS.....SOUTHWEST 26 TO 28 MPH.
SMOKE DISPERSAL.....GOOD (97700 KNOT-FT) INCREASING TO EXCELLENT
                    (156100 KNOT-FT) IN THE AFTERNOON.

.TONIGHT...
SKY/WEATHER.........CLOUDY (90-100 PERCENT) THEN BECOMING
                    PARTLY CLOUDY (50-60 PERCENT) AFTER 0300. NUMEROUS
                    SHOWERS AND SCATTERED THUNDERSTORMS IN THE EVENING...SHOWERS
                    DECREASING TO ISOLATED MIDNIGHT TO 0300.
MIN TEMPERATURE.....35-38.
MAX HUMIDITY........87-90 PERCENT.
20 FOOT WINDS.......PREVAILING WEST  WINDS 11 TO 14 MPH WITH GUSTS TO AROUND 25
                    MPH IN THE EVENING WITH GUSTY ERRATIC THUNDERSTORM OUTFLOWS
                    LIKELY TO DOMINATE 1800L THROUGH 2200L.
                    WINDS BECOMING SOUTHWEST OR DOWNSLOPE/DOWNVALLEY 4-7 MPH
                    AROUND 0300
RIDGE TOP WINDS.....WEST 15 TO 20 MPH.
LAL.................4 UNTIL 2200...THEN 2.
CHC OF WETTING RAIN.30 PERCENT.
HAINES INDEX........3 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......4800-5800 FT AGL DECREASING TO 2000-3000 FT AGL
                    AFTER MIDNIGHT.
TRANSPORT WINDS.....SOUTHWEST 16 TO 24 MPH.
SMOKE DISPERSAL.....VERY GOOD (109700 KNOT-FT) DECREASING TO FAIR
                    (42500 KNOT-FT) AFTER MIDNIGHT.

.MONDAY...
SKY/WEATHER.........MOSTLY SUNNY (10 PERCENT).
MAX TEMPERATURE.....63-66.
MIN HUMIDITY........21-24 PERCENT.
20 FOOT WINDS.......UPSLOPE/UPVALLEY 5-9 MPH BECOMING WEST 14 TO 15
                    MPH WITH GUSTS TO AROUND 25 MPH IN THE
                    AFTERNOON.
RIDGE TOP WINDS.....WEST 15 TO 20 MPH.
LAL.................1.
CHC OF WETTING RAIN.ZERO PERCENT.
HAINES INDEX........2 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......3300-4300 FT AGL INCREASING TO 6000-7000 FT AGL
                    IN THE AFTERNOON.
TRANSPORT WINDS.....WEST 18 TO 25 MPH.
SMOKE DISPERSAL.....GOOD (68100 KNOT-FT) INCREASING TO VERY GOOD
                    (129000 KNOT-FT) IN THE AFTERNOON.

.FORECAST DAYS 3 THROUGH 5...

.MONDAY NIGHT...CLEAR. LOWS IN THE LOWER 30S. WINDS GENERALLY
LESS THAN 10 MPH.

.TUESDAY...CLEAR. LOWS IN THE MID 30S. HIGHS IN THE MID 70S.
WINDS GENERALLY LESS THAN 10 MPH.

.WEDNESDAY...MOSTLY CLEAR. LOWS IN THE MID 30S. HIGHS IN THE MID
70S. WINDS GENERALLY LESS THAN 10 MPH.

.THURSDAY...PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS...
THUNDERSTORMS AND SNOW SHOWERS. LOWS IN THE MID 30S. HIGHS IN THE
MID 70S. WINDS GENERALLY LESS THAN 10 MPH.

$$

FORECASTER...MEUNIER
REQUESTED BY...ED FOLTS
REASON FOR REQUEST...WILDFIRE
.TAG 20100821.ARTHU.02/RIW