FNUS75 KRIW 181716
FWSRIW

SPOT FORECAST FOR BEACH FIRE...NPS YNP
NATIONAL WEATHER SERVICE RIVERTON WY
1116 AM MDT SUN JUL 18 2010

FORECAST IS BASED ON REQUEST TIME OF 1023 MDT ON JULY 18.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...

WEAK LOW PRESSURE WILL MOVE ACROSS SOUTHWEST CANADA TODAY THROUGH
MONDAY. WEST WINDS WILL PREDOMINATE THIS AFTERNOON AND AGAIN MONDAY
AFTERNOON...BUT HIGHER ELEVATIONS TO THE WEST WILL SHELTER THE AREA
OF THE FIRE. WEST WIND WILL GUST TO NEAR 20 MPH AFTER 1400
TODAY...AND LIGHTER RIDGE TOP WIND MONDAY SHOULD KEEP AFTERNOON WEST
WINDS AROUND 10 MPH. THERE WILL BE SUFFICIENT INSTABILITY AND
MOISTURE FOR ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS THIS
AFTERNOON AND MONDAY AFTERNOON. THE MAIN THREAT WITH ANY
THUNDERSTORMS WILL BE GUSTY OUTFLOW WINDS...AND THE CHANCE OF
WETTING RAIN WILL BE VERY LOW. MINIMUM RELATIVE HUMIDITY TODAY AND
MONDAY IS EXPECTED TO REMAIN ABOVE 20 PERCENT.

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

FORECASTER...SMITH

.TODAY...
SKY/WEATHER.........MOSTLY SUNNY (25-35 PERCENT) THEN BECOMING
                    PARTLY CLOUDY (45-55 PERCENT). ISOLATED SHOWERS
                    AND THUNDERSTORMS IN THE AFTERNOON.
MAX TEMPERATURE.....70-73.
MIN HUMIDITY........20-23 PERCENT.
WIND (20 FT)........UPSLOPE/UPVALLEY 5-9 MPH...BECOMING SOUTHWEST 10
                    TO 15 MPH WITH GUSTS TO AROUND 20 MPH AFTER 1400 MDT.
                    GUSTY AND ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS
                    IN THE AFTERNOON.
RIDGE TOP WINDS.....WEST 15 TO 20 MPH.
LAL.................1 UNTIL 1400 MDT...THEN 2.
CWR.................3 PERCENT.
HAINES INDEX........5 OR MODERATE POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......4000-5000 FT AGL INCREASING TO 6000-7000 FT AGL
                    IN THE AFTERNOON.
TRANSPORT WINDS.....WEST 15 TO 20 MPH.
SMOKE DISPERSAL.....GOOD (83300 KNOT-FT) INCREASING TO EXCELLENT
                    (166400 KNOT-FT) AFTER 1400 MDT.

.TONIGHT...
SKY/WEATHER.........PARTLY CLOUDY (35-45 PERCENT)...BECOMING MOSTLY
                    CLEAR (10 TO 15 PERCENT) AFTER MIDNIGHT. ISOLATED SHOWERS
                    AND THUNDERSTORMS IN THE EVENING.
MIN TEMPERATURE.....41-44.
MAX HUMIDITY........84-87 PERCENT.
WIND (20 FT)........WEST WINDS 10 TO 15 MPH UNTIL EARLY MORNING...THEN
                    BECOMING DOWN SLOPE/DOWN VALLEY 4-7 MPH. GUSTY AND ERRATIC
                    WINDS EXPECTED NEAR THUNDERSTORMS IN THE EVENING.
RIDGE TOP WINDS.....WEST 15 MPH.
LAL.................2 UNTIL 2400...THEN 1.
CWR.................3 PERCENT.
HAINES INDEX........5 OR MODERATE POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......5000-6000 FT AGL DECREASING TO 1000-1500 FT AGL
                    AFTER MIDNIGHT.
TRANSPORT WINDS.....WEST 15 MPH.
SMOKE DISPERSAL.....VERY GOOD (145700 KNOT-FT) DECREASING TO FAIR
                    (52800 KNOT-FT) AFTER MIDNIGHT.

.MONDAY...
SKY/WEATHER.........MOSTLY SUNNY (20-30 PERCENT) THEN BECOMING
                    PARTLY CLOUDY (40-50 PERCENT). ISOLATED SHOWERS
                    AND THUNDERSTORMS IN THE AFTERNOON.
MAX TEMPERATURE.....AROUND 70.
MIN HUMIDITY........20-23 PERCENT.
WIND (20 FT)........UPSLOPE/UPVALLEY 5-9 MPH BECOMING WEST AROUND
                    10 MPH IN THE AFTERNOON. GUSTY AND ERRATIC WINDS
                    EXPECTED NEAR THUNDERSTORMS IN THE AFTERNOON.
RIDGE TOP WINDS.....WEST 10 TO 15 MPH.
LAL.................1 UNTIL 1200...THEN 2.
CWR.................LESS THAN 5 PERCENT.
HAINES INDEX........5 OR MODERATE POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......2500-3500 FT AGL INCREASING TO 6000-7000 FT AGL
                    IN THE AFTERNOON.
TRANSPORT WINDS.....WEST 15 MPH.
SMOKE DISPERSAL.....FAIR (52300 KNOT-FT) INCREASING TO VERY GOOD
                    (124500 KNOT-FT) IN THE AFTERNOON.

.FORECAST DAYS 3 THROUGH 5...
.MONDAY NIGHT...PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS IN THE UPPER 30S. WINDS GENERALLY LESS THAN
10 MPH.
.TUESDAY...PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS IN THE UPPER 30S. HIGHS IN THE UPPER 60S.
WINDS GENERALLY LESS THAN 10 MPH.
.WEDNESDAY...MOSTLY CLEAR. SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS IN THE UPPER 30S. HIGHS IN THE LOWER 70S.
WINDS GENERALLY LESS THAN 10 MPH.
.THURSDAY...MOSTLY CLEAR. LOWS IN THE UPPER 30S. HIGHS IN THE
LOWER 70S. WINDS GENERALLY LESS THAN 10 MPH.

$$

FORECASTER...SMITH
REQUESTED BY...EDWIN FOLTS
REASON FOR REQUEST...WILDFIRE
.TAG 20100718.BEACH.01/RIW