FNUS75 KRIW 220025
FWSRIW

SPOT FORECAST FOR NORTH FORK...NPS YNP
NATIONAL WEATHER SERVICE RIVERTON WY
625 PM MDT SAT AUG 21 2010

FORECAST IS BASED ON REQUEST TIME OF 1714 MDT ON AUGUST 21.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

...RED FLAG WARNING IN EFFECT UNTIL MIDNIGHT MDT TONIGHT...

.DISCUSSION...A RED FLAG WARNING REMAINS IN EFFECT UNTIL MIDNIGHT
TONIGHT. SUSTAINED SOUTHWEST WIND AT RIDGETOP LEVEL WILL CONTINUE
TO INCREASE TONIGHT WITH LIGHTER SUSTAINED WINDS WITH OCCASIONAL STRONGER
GUSTS CONTINUING ACROSS THE FIRE OVERNIGHT. RELATIVE HUMIDITY WILL
REMAIN IN THE 20S THIS EVENING WITH SOME RECOVERY AFTER MIDNIGHT.

CLOUDS AND WIND WILL INCREASE SUNDAY MORNING WITH SHOWERS AND
ISOLATED THUNDERSTORMS BEGINNING TO DEVELOP LATE MORNING. THE COLD
FRONT SHOULD PASS THROUGH AROUND 1800L SUNDAY EVENING WITH THE
HEIGHT OF SHOWER AND THUNDERSTORM ACTIVITY CENTERED AROUND THIS
TIME. WINDS WILL SHIFT SOUTHWEST TO WEST WITH THE FRONTAL PASSAGE.
DIMINISHING WIND...RAPID DRYING AND A MUCH COOLER AIRMASS WILL
FOLLOW AFTER MIDNIGHT SUNDAY NIGHT.


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

FORECASTER...MEUNIER

.TONIGHT...
SKY/WEATHER.........MOSTLY CLEAR (5-15 PERCENT).
MIN TEMPERATURE.....50-53.
MAX HUMIDITY........43-46 PERCENT.
20 FOOT WINDS.......SOUTHWEST WIND 10 TO 15 MPH WITH GUSTS OF 30 TO 35 MPH.
RIDGE TOP WINDS.....SOUTHWEST AROUND 25 MPH THIS EVENING INCREASING
                    TO 35 TO 40 MPH AFTER MIDNIGHT.
LAL.................1.
CHC OF WETTING RAIN.ZERO PERCENT.
HAINES INDEX........5 OR MODERATE POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......5700-6700 FT AGL DECREASING TO 2000-2500 FT AGL
                    AFTER MIDNIGHT.
TRANSPORT WINDS.....SOUTHWEST 30 TO 35 MPH.
SMOKE DISPERSAL.....EXCELLENT (178700 KNOT-FT) DECREASING TO GOOD
                    (72900 KNOT-FT) AFTER MIDNIGHT.

.SUNDAY...
SKY/WEATHER.........INCREASING CLOUDS DURING THE MORNING...BECOMING
                    MOSTLY CLOUDY IN THE AFTERNOON (70-80 PERCENT). ISOLATED
                    SHOWERS AND THUNDERSTORMS DEVELOPING BETWEEN 1000 AND NOON
                    AND BECOMING SCATTERED THE AFTERNOON.
MAX TEMPERATURE.....67-70.
MIN HUMIDITY........30-35 PERCENT.
20 FOOT WINDS.......SOUTHWEST WIND 15 TO 20 MPH WITH GUSTS TO NEAR
                    35 MPH. WINDS BECOMING MORE GUSTY AND ERRATIC IN THE
                    AFTERNOON AS THUNDERSTORM COVERAGE INCREASES.
RIDGE TOP WINDS.....SOUTHWEST 30 TO 35 MPH.
LAL.................1 UNTIL 1000...THEN 4 IN THE AFTERNOON.
CHC OF WETTING RAIN.15 PERCENT.
HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED
                    FIRE GROWTH.
MIXING HEIGHT.......3800-4800 FT AGL INCREASING TO 7000-8000 FT AGL
                    IN THE AFTERNOON.
TRANSPORT WINDS.....SOUTHWEST AROUND 35 MPH.
SMOKE DISPERSAL.....VERY GOOD (146000 KNOT-FT) INCREASING TO
                    EXCELLENT (245800 KNOT-FT) IN THE AFTERNOON.

.SUNDAY NIGHT...
SKY/WEATHER.........MOSTLY CLOUDY (80-90 PERCENT) THEN BECOMING
                    PARTLY CLOUDY (50-60 PERCENT) AFTER MIDNIGHT.
                    SCATTERED THUNDERSTORMS IN THE EVENING. SCATTERED RAIN
                    SHOWERS AND ISOLATED THUNDERSTORMS FROM
                    MIDNIGHT UNTIL 0300.
MIN TEMPERATURE.....41-44.
MAX HUMIDITY........77-80 PERCENT.
20 FOOT WINDS.......SOUTHWEST WINDS 17 TO 23 MPH WITH GUSTS UP TO 40
                    MPH EARLY EVENING WITH A SHARP WIND SHIFT FROM THE WEST
                    WITH FRONTAL PASSAGE BETWEEN 1800 AND 2100.  WINDS GRADUALLY
                    DIMINISHING AND BECOMING WEST SOUTHWEST 10 TO 15 MPH
                    AFTER MIDNIGHT.
RIDGE TOP WINDS.....SOUTHWEST 30 TO 35 MPH.
LAL.................4 UNTIL 2400...THEN 2.
CHC OF WETTING RAIN.40 PERCENT.
HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED
                    FIRE GROWTH.
MIXING HEIGHT.......5100-6100 FT AGL DECREASING TO 1700-2700 FT AGL
                    AFTER MIDNIGHT.
TRANSPORT WINDS.....SOUTHWEST 30 TO 35 MPH.
SMOKE DISPERSAL.....EXCELLENT (176600 KNOT-FT) DECREASING TO GOOD
                    (64100 KNOT-FT) AFTER MIDNIGHT.

.FORECAST DAYS 3 THROUGH 5...
.MONDAY...MOSTLY CLEAR. HIGHS IN THE LOWER 60S. WEST WINDS AROUND 12 MPH.
.TUESDAY...MOSTLY CLEAR. LOWS IN THE LOWER 40S. HIGHS IN THE MID
60S. WINDS GENERALLY LESS THAN 10 MPH.
.WEDNESDAY...MOSTLY CLEAR. SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS IN THE LOWER 40S. HIGHS IN THE UPPER 60S.
WINDS GENERALLY LESS THAN 10 MPH.
.THURSDAY...PARTLY CLOUDY WITH CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS IN THE LOWER 40S. HIGHS AROUND 70. WINDS
GENERALLY LESS THAN 10 MPH.

$$

FORECASTER...MEUNIER
REQUESTED BY...GALEN ROESLER
REASON FOR REQUEST...WILDFIRE
.TAG 20100821.NORTH.01/RIW