FNUS75 KRIW 190059
FWSRIW

SPOT FORECAST FOR EAST...NPS YNP
NATIONAL WEATHER SERVICE RIVERTON WY
659 PM MDT WED AUG 18 2010

FORECAST IS BASED ON REQUEST TIME OF 1810 MDT ON AUGUST 18.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...A DRY AIRMASS OVER NORTHERN WYOMING WAS SANDWICHED
BETWEEN THUNDERSTORM ACTIVITY OVER MONTANA AND SOUTHERN WYOMING.
MOSTLY CLEAR SKIES WILL PREVAIL OVERNIGHT. AN UPPER LEVEL
DISTURBANCE WILL MOVE ACROSS WYOMING THURSDAY RESULTING IN A
COOLER AIRMASS WITH HIGHER RELATIVE HUMIDITY. ISOLATED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO MAINLY STAY NORTH NEAR THE MONTANA
BORDER THURSDAY. A DRIER MORE STABLE AIRMASS WILL BUILD IN
THURSDAY NIGHT AND FRIDAY.



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

FORECASTER...MEUNIER

.REST OF TONIGHT...
SKY/WEATHER.........MOSTLY CLEAR (10-20 PERCENT).
MIN TEMPERATURE.....AROUND 40.
MAX HUMIDITY........55-60 PERCENT.
WIND (20 FT)........WEST SOUTHWEST 5 TO 10 MPH...WITH GUSTS TO 15-20 MPH
                    THROUGH SUNSET.
RIDGE TOP WINDS.....WEST SOUTHWEST 15 TO 20 MPH...WITH GUSTS TO 35 MPH THROUGH
                    SUNSET.
LAL.................1.
CWR.................0 PERCENT.
HAINES INDEX........6 OR HIGH POTENTIAL FOR LARGE PLUME DOMINATED
                    FIRE GROWTH.
MIXING HEIGHT.......5600-6600 FT AGL DECREASING TO 600-1400 FT AGL
                    AFTER MIDNIGHT.
TRANSPORT WINDS.....WEST 20 TO 25 MPH UNTIL 2030...BECOMING WEST SOUTHWEST
                    15 TO 20 MPH AFTER MIDNIGHT.
SMOKE DISPERSAL.....VERY GOOD (109700 KNOT-FT) DECREASING TO POOR
                    (21600 KNOT-FT) AFTER MIDNIGHT.

.THURSDAY...
SKY/WEATHER.........PARTLY CLOUDY (35-45 PERCENT). ISOLATED SHOWERS
                    AND THUNDERSTORMS IN THE AFTERNOON...MAINLY NEAR
                    AND NORTH OF TOWER JUNCTION AND THE NORTHEAST
                    ENTRANCE.
MAX TEMPERATURE.....71-74.
MIN HUMIDITY........15-20 PERCENT.
WIND (20 FT)........WEST SOUTHWEST 5 TO 10 MPH...WITH GUSTS OF 15 TO 20 MPH
                    IN THE AFTERNOON.
RIDGE TOP WINDS.....WEST 12 TO 18 MPH IN THE MORNING INCREASING TO 20 TO 25 MPH
                    WITH GUSTS NEAR 30 MPH IN THE AFTERNOON.
LAL.................2.
CWR.................3 PERCENT.
HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED
                    FIRE GROWTH.
MIXING HEIGHT.......3200-4200 FT AGL INCREASING TO 7800-8800 FT AGL
                    IN THE AFTERNOON.
TRANSPORT WINDS.....WEST 20 TO 25 MPH.
SMOKE DISPERSAL.....GOOD (66700 KNOT-FT) INCREASING TO VERY GOOD
                    (145400 KNOT-FT) IN THE AFTERNOON.

.FORECAST DAYS 3 THROUGH 5...
.THURSDAY NIGHT...MOSTLY CLEAR. ISOLATED SHOWERS AND
THUNDERSTORMS UNTIL AROUND SUNSET. LOWS IN THE UPPER 30S. SOUTHWEST
WINDS AROUND 13 MPH.
.FRIDAY...MOSTLY CLEAR. ISOLATED SHOWERS AND THUNDERSTORMS. LOWS
IN THE UPPER 30S. HIGHS IN THE MID 70S. SOUTHWEST WINDS AROUND
11 MPH.
.SATURDAY...PARTLY CLOUDY. SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS AROUND 40. HIGHS IN THE UPPER 70S. WINDS
GENERALLY LESS THAN 10 MPH.
.SUNDAY...PARTLY CLOUDY WITH CHANCE OF SHOWERS AND THUNDERSTORMS.
LOWS IN THE UPPER 30S. HIGHS IN THE MID 70S. SOUTHWEST WINDS
AROUND 10 MPH.
.MONDAY...PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS IN THE MID 30S. HIGHS IN THE LOWER 70S. WINDS
GENERALLY LESS THAN 10 MPH.

$$

FORECASTER...MEUNIER
REQUESTED BY...EDWIN FOLTS
REASON FOR REQUEST...WILDFIRE
.TAG 20100818.EAST_.01/RIW