FNUS75 KRIW 211530
FWSRIW

SPOT FORECAST FOR BLACK...USFS BTF
NATIONAL WEATHER SERVICE RIVERTON WY
930 AM MDT WED AUG 21 2013

FORECAST IS BASED ON IGNITION TIME OF 0840 MDT ON AUGUST 21.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...
CONSIDERABLE CLOUDINESS WILL GIVE WAY TO BUILDING SHOWERS AND A FEW
THUNDERSTORMS BY THIS AFTERNOON. THE STORMS WILL TEND TO BE SLOW
MOVERS TODAY. THE MAIN THREAT WILL OF COURSE BE LIGHTNING AND LOCAL
WIND GUSTS TO 35 MPH WITH A SMALLER CHANCE OF HEAVY RAIN DUE TO THE
SLOW MOVEMENT. THURSDAY WILL BE SIMILAR TO TODAY WITH AN EVEN HIGHER
PROBABILITY OF AFTERNOON THUNDERSTORMS. A FEW SHOWERS WILL LINGER
DURING THE NIGHT ALSO.

WINDS OUTSIDE OF SHOWERS WILL BE RATHER LIGHT AND COULD SHIFT AROUND
QUITE A BIT TODAY MAKING FOR A CHALLENGING WIND FORECAST AT RIDGETOP
AND THROUGH THE MIXED LAYER.

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

FORECASTER...SKRBAC

.TODAY...
SKY/WEATHER.........MOSTLY CLOUDY (60-70 PERCENT). SCATTERED RAIN
                    SHOWERS THROUGH THE DAY. WIDELY SCATTERED
                    THUNDERSTORMS...MAINLY AFTER 1200L.
MAX TEMPERATURE.....65-69.
MIN HUMIDITY........31-35 PERCENT.
20 FOOT WINDS.......UPSLOPE/UPVALLEY 5-9 MPH. GUSTS UP TO 15 MPH IN
                    THE LATE MORNING AND AFTERNOON. GUSTY AND
                    ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS IN
                    THE AFTERNOON.
RIDGE TOP WINDS.....NORTHWEST 5 TO 10 MPH...BECOMING SOUTH IN THE AFTERNOON.
LAL.................1 UNTIL 1200...THEN 3.
CHC OF WETTING RAIN.15 PERCENT.
HAINES INDEX........3 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......2800-3800 FT AGL INCREASING TO 6000-6500 FT AGL
                    IN THE AFTERNOON.
TRANSPORT WINDS.....NORTHWEST 4 TO 8 MPH...BECOMING SOUTH OR SOUTHEAST
                    IN THE AFTERNOON.
SMOKE DISPERSAL.....POOR (19600-39300 KNOT-FT)...BECOMING FAIR FOR A WHILE
                    IN THE AFTERNOON (45000 KNOT-FT).

.TONIGHT...
SKY/WEATHER.........MOSTLY CLOUDY (60-70 PERCENT) THEN BECOMING
                    PARTLY CLOUDY (35-45 PERCENT). SCATTERED
                    SHOWERS AND THUNDERSTORMS EARLY IN THE
                    EVENING...THEN ISOLATED SHOWERS AND
                    THUNDERSTORMS LATE IN THE EVENING.
MIN TEMPERATURE.....43-46.
MAX HUMIDITY........70-80 PERCENT.
20 FOOT WINDS.......DOWNSLOPE/DOWNVALLEY 4-7 MPH. GUSTY AND ERRATIC
                    WINDS EXPECTED NEAR THUNDERSTORMS IN THE
                    EVENING.
RIDGE TOP WINDS.....SOUTHEAST 4 TO 8 MPH...GRADUALLY BECOMING SOUTHWEST
                    BY MORNING.
LAL.................3 UNTIL 2400...THEN 1.
CHC OF WETTING RAIN.10 PERCENT.
HAINES INDEX........3 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......5000-6000 FT AGL DECREASING TO 2700-3700 FT AGL
                    AFTER MIDNIGHT.
TRANSPORT WINDS.....SOUTHEAST 4 TO 8 MPH BECOMING SOUTHWEST GRADUALLY
                    AFTER MIDNIGHT.
SMOKE DISPERSAL.....POOR (23100-39900 KNOT-FT).

.THURSDAY...
SKY/WEATHER.........PARTLY CLOUDY (35-45 PERCENT) THEN BECOMING
                    MOSTLY CLOUDY (60-70 PERCENT). ISOLATED RAIN
                    SHOWERS IN THE MORNING...THEN SCATTERED SHOWERS
                    AND THUNDERSTORMS IN THE AFTERNOON.
MAX TEMPERATURE.....67-72.
MIN HUMIDITY........26-29 PERCENT.
20 FOOT WINDS.......UPSLOPE/UPVALLEY 5-9 MPH WITH GUSTS TO 15 MPH LATE
                    IN THE AFTERNOON. GUSTY AND ERRATIC WINDS EXPECTED
                    NEAR THUNDERSTORMS IN THE AFTERNOON.
RIDGE TOP WINDS.....SOUTH TO SOUTHWEST AROUND 15 MPH.
LAL.................1 UNTIL 1200...THEN 3.
CHC OF WETTING RAIN.10 PERCENT.
HAINES INDEX........3 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......2700-3700 FT AGL INCREASING TO 5400-6400 FT AGL
                    IN THE AFTERNOON.
TRANSPORT WINDS.....SOUTH TO SOUTHWEST 10 TO 15 MPH.
SMOKE DISPERSAL.....POOR TO GOOD (28100-72500 KNOT-FT).

.FORECAST DAYS 3 THROUGH 5...
.THURSDAY NIGHT...PARTLY CLOUDY. ISOLATED SHOWERS AND
THUNDERSTORMS IN THE EVENING. LOWS IN THE MID 40S. WINDS
GENERALLY LESS THAN 10 MPH.
.FRIDAY...PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS IN THE UPPER 40S. HIGHS IN THE MID 70S. WINDS
GENERALLY LESS THAN 10 MPH.
.SATURDAY...PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS IN THE UPPER 40S. HIGHS IN THE LOWER 70S.
WINDS GENERALLY LESS THAN 10 MPH.
.SUNDAY...PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS IN THE UPPER 40S. HIGHS IN THE LOWER 70S.
WINDS GENERALLY LESS THAN 10 MPH.

$$

FORECASTER...SKRBAC
REQUESTED BY...IC
REASON FOR REQUEST...PRESCRIBED
.TAG 20130821.BLACK.01/RIW