FNUS75 KRIW 211844
FWSRIW

SPOT FORECAST FOR ANTELOPE...NPS YNP
NATIONAL WEATHER SERVICE RIVERTON WY
1244 PM MDT TUE SEP 21 2010

FORECAST IS BASED ON REQUEST TIME OF 1222 MDT ON SEPTEMBER 21.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...
AFTER A DRY AFTERNOON WITH LIGHT TO BREEZY SOUTHWESTERLY WIND...
A TROUGH OF LOW PRESSURE WILL APPROACH THE AREA FROM THE WEST OVERNIGHT.
THIS WILL TURN THE WIND MORE SOUTHERLY AND EVEN SOUTHEASTERLY WITH MOISTURE
MOVING INTO THE AREA FROM THE SOUTH. THIS MOISTURE WILL BRING SOME
ISOLATED SHOWER ACTIVITY TO THE FIRE AREA LATE WEDNESDAY MORNING.
SHOWERS WILL INCREASE A BIT IN COVERAGE IN THE AFTERNOON WITH A THUNDERSTORM
OR TWO NOT OUT OF THE QUESTION. DRY CONDITIONS RETURN ON THURSDAY
WITH HIGH PRESSURE BEGINNING TO BUILD IN FROM THE WEST.



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

FORECASTER...BERC

.TONIGHT...
SKY/WEATHER.........PARTLY CLOUDY (45-55 PERCENT).
MIN TEMPERATURE.....32-35.
MAX HUMIDITY........85-88 PERCENT.
20 FOOT WINDS.......SOUTHWEST WINDS OF 5 TO 8 MPH
                    BECOMING DOWNSLOPE/DOWNVALLEY 4-7 MPH BY 10 PM. GUSTS UP
                    TO 15 MPH.
RIDGE TOP WINDS.....SOUTHWEST AROUND 15 MPH SHIFTING TO THE SOUTH IN
                    AFTER 9 PM AND BECOMING SOUTHEAST AFTER MIDNIGHT.
LAL.................1.
CHC OF WETTING RAIN.ZERO PERCENT.
HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED
                    FIRE GROWTH.
MIXING HEIGHT.......4400-5400 FT AGL DECREASING TO 800-1800 FT AGL
                    AFTER MIDNIGHT.
TRANSPORT WINDS.....WEST AROUND 16 MPH SHIFTING TO THE SOUTHEAST 13
                    TO 15 MPH IN THE LATE EVENING AND OVERNIGHT.
SMOKE DISPERSAL.....GOOD (75400 KNOT-FT) DECREASING TO POOR (7400
                    KNOT-FT) AFTER MIDNIGHT.

.WEDNESDAY...
SKY/WEATHER.........PARTLY CLOUDY (45-55 PERCENT) THEN BECOMING
                    MOSTLY CLOUDY (60-70 PERCENT). ISOLATED RAIN
                    SHOWERS THROUGH THE DAY. ISOLATED THUNDERSTORMS
                    IN THE AFTERNOON.
MAX TEMPERATURE.....62-67.
MIN HUMIDITY........17-20 PERCENT.
20 FOOT WINDS.......UPSLOPE/UPVALLEY 5-9 MPH BECOMING SOUTHWEST
                    AROUND 11 MPH WITH HIGHER GUSTS LATE IN THE
                    AFTERNOON. GUSTY AND ERRATIC WINDS EXPECTED
                    NEAR THUNDERSTORMS IN THE AFTERNOON.
RIDGE TOP WINDS.....SOUTHEAST AROUND 10 MPH SHIFTING TO THE
                    SOUTHWEST IN THE AFTERNOON.
LAL.................1 UNTIL 1200...THEN 2.
CHC OF WETTING RAIN.3 PERCENT.
HAINES INDEX........5 OR MODERATE POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......3900-4900 FT AGL INCREASING TO 10000-11000 FT
                    AGL IN THE AFTERNOON.
TRANSPORT WINDS.....SOUTHEAST 12 TO 13 MPH SHIFTING TO THE
                    SOUTHWEST 16 TO 20 MPH IN THE AFTERNOON.
SMOKE DISPERSAL.....FAIR (49000 KNOT-FT) INCREASING TO EXCELLENT
                    (152700 KNOT-FT) IN THE AFTERNOON.

.FORECAST DAYS 3 THROUGH 5...
.WEDNESDAY NIGHT...MOSTLY CLOUDY. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS IN THE EVENING...THEN A SLIGHT CHANCE OF RAIN AND
SNOW AFTER MIDNIGHT. WETTING RAIN IS UNLIKELY. LOWS IN THE LOWER
30S. WINDS GENERALLY LESS THAN 10 MPH.
.THURSDAY...PARTLY CLOUDY. LOWS AROUND 30.
HIGHS IN THE MID 60S. WINDS GENERALLY LESS THAN 10 MPH.
.FRIDAY...PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS. LOWS IN
THE LOWER 30S. HIGHS IN THE MID 60S. WINDS GENERALLY LESS THAN
10 MPH.
.SATURDAY...MOSTLY CLEAR. LOWS IN THE MID 30S. HIGHS IN THE LOWER
70S. WINDS GENERALLY LESS THAN 10 MPH.
.SUNDAY...MOSTLY CLEAR. LOWS IN THE MID 30S. HIGHS IN THE LOWER
70S. WINDS GENERALLY LESS THAN 10 MPH.

$$

FORECASTER...BERC
REQUESTED BY...LAURA DOOLEY
REASON FOR REQUEST...WILDFIRE
.TAG 20100921.ANTEL.01/RIW