FNUS75 KRIW 232255
FWSRIW

SPOT FORECAST FOR BEACH...NPS YNP
NATIONAL WEATHER SERVICE RIVERTON WY
455 PM MDT FRI JUL 23 2010

FORECAST IS BASED ON REQUEST TIME OF 1617 MDT ON JULY 23.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...A COLD FRONT COMING DOWN ACROSS NORTHERN YELLOWSTONE
PARK SHOULD BE THROUGH SHORTLY IF NOT ALREADY. UPSTREAM
OBSERVATIONS HAD ALL GONE NORTH...GENERALLY 10 TO 15 MPH WITH
GUSTS TO 20 MPH. SURFACE HIGH PRESSURE WILL BUILD IN OVERNIGHT
WITH NORTH WIND GRADUALLY DIMINISHING AND TURNING NORTHEAST.
A DRY WESTERLY FLOW ALOFT WILL FOLLOW ON SATURDAY WITH WEST
SOUTHWEST SURFACE WIND MIXING OUT IN THE AFTERNOON.

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

FORECASTER...MEUNIER

.TONIGHT...
SKY/WEATHER.........CLEAR (0-10 PERCENT).
MIN TEMPERATURE.....35-38.
MAX HUMIDITY........81-84 PERCENT.
WIND (20 FT)........BECOMING NORTH 8 TO 13 MPH WITH GUSTS
                    TO 20 MPH AROUND 1700...DIMINISHING AT SUNSET
                    AND BECOMING NORTHEAST 4 TO 7 MPH BETWEEN
                    MIDNIGHT AND 0200.
RIDGE TOP WINDS.....NORTHWEST 10 TO 15 MPH BECOMING NORTH AROUND 10 MPH
                    NEAR SUNSET...THEN SOUTHWEST 5 TO 10 MPH AFTER MIDNIGHT.
LAL.................1.
CWR.................ZERO PERCENT.
HAINES INDEX........3 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......5500-6500 FT AGL THIS EVENING...DECREASING TO NEAR
                    1000 FT AGL BY 0400.
TRANSPORT WINDS.....NORTHWEST 20 TO 23 MPH...BECOMING NORTH AROUND 10 MPH
                    BETWEEN 1900 AND 2100 AND THEN SOUTHWEST 5 TO 10 MPH
                    AFTER MIDNIGHT.
SMOKE DISPERSAL.....VERY GOOD (115900 KNOT-FT) DECREASING TO POOR (37100
                    KNOT-FT) AFTER MIDNIGHT.

.SATURDAY...
SKY/WEATHER.........SUNNY (0-10 PERCENT).
MAX TEMPERATURE.....71-74.
MIN HUMIDITY........18-21 PERCENT.
WIND (20 FT)........SOUTHEAST TO SOUTH 4 TO 7 MPH IN THE MORNING BECOMING
                    WEST AROUND 11 MPH LATE IN THE AFTERNOON. GUSTS UP TO 20
                    MPH.
RIDGE TOP WINDS.....SOUTHWEST 5 TO 10 MPH IN THE MORNING...BECOMING WEST
                    SOUTHWEST AROUND 15 MPH IN THE AFTERNOON.
LAL.................1.
CWR.................ZERO PERCENT.
HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED
                    FIRE GROWTH.
MIXING HEIGHT.......3200-4200 FT AGL INCREASING TO 6800-7800 FT AGL
                    IN THE AFTERNOON.
TRANSPORT WINDS.....SOUTHWEST AROUND 10 MPH BECOMING WEST 15
                    TO 20 MPH IN THE AFTERNOON.
SMOKE DISPERSAL.....FAIR (44400 KNOT-FT) INCREASING TO VERY GOOD
                    (112100 KNOT-FT) IN THE AFTERNOON.

.FORECAST DAYS 3 THROUGH 5...
.SATURDAY NIGHT...CLEAR. LOWS AROUND 40. WINDS GENERALLY LESS
THAN 10 MPH.
.SUNDAY...MOSTLY CLEAR. LOWS IN THE LOWER 40S. HIGHS IN THE MID
70S. WINDS GENERALLY LESS THAN 10 MPH.
.MONDAY...PARTLY CLOUDY WITH ISOLATED SHOWERS AND THUNDERSTORMS.
LOWS IN THE MID 40S. HIGHS IN THE LOWER 70S. WINDS GENERALLY LESS
THAN 10 MPH.
.TUESDAY...PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS IN THE LOWER 40S. HIGHS AROUND 70. WINDS
GENERALLY LESS THAN 10 MPH.
.WEDNESDAY...PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS AROUND 40. HIGHS IN THE MID 60S. WINDS
GENERALLY LESS THAN 10 MPH.

$$

FORECASTER...MEUNIER
REQUESTED BY...EDWIN FOLTS
REASON FOR REQUEST...WILDFIRE
.TAG 20100723.BEACH.01/RIW