FNUS75 KRIW 242321
FWSRIW

SPOT FORECAST FOR SOUTH PASS AIRCRAFT ACCIDENT...FREMONT COUNTY
NATIONAL WEATHER SERVICE RIVERTON WY
421 PM MST FRI DEC 24 2010

FORECAST IS BASED ON INCIDENT TIME OF 1536 MST ON DECEMBER 24.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...WITH A VERY STABLE AIRMASS IN PLACE THROUGH CHRISTMAS DAY...THERE
WILL BE A PROPENSITY FOR CONSIDERABLE LOW CLOUDS AND FOG TO FORM IN
THE BASINS AND VALLEYS TONIGHT THROUGH SATURDAY AND SUNDAY...ESPECIALLY OVER
AND WEST OF THE CONTINENTAL DIVIDE...INCLUDING SOUTH PASS...WHERE A FRESH SNOW
COVER IS IN PLACE. THE CLOUD TOPS FROM THE FOG AND LOW CLOUDS WILL REACH UP
TO AROUND 7600 FEET MSL UP THROUGH 1700 THIS AFTERNOON. AFTER 1700 THE CLOUD
TOPS WILL LIKELY INCREASE TO 8300 FEET THIS EVENING. THE FOG AND LOW CLOUDS
WILL LIKELY EXPAND DURING THE NIGHT TONIGHT AND LINGER THROUGH 1200 SATURDAY.
PATCHY FOG COULD ALSO DEVELOP IN THE WIND RIVER BASIN NORTH AND EAST OF LANDER
THIS EVENING BUT LANDER SHOULD STAY IN THE CLEAR. ANY FOG OVER THE WIND RIVER
BASIN WILL EXPAND IN COVERAGE AFTER MIDNIGHT TONIGHT AND LINGER THROUGH 1200
SATURDAY. SOME RESIDUAL PATCHY FOG WILL LINGER AFTER 1200 SATURDAY IN THE
AFOREMENTIONED AREAS. FOG AND LOW CLOUDS ARE EXPECTED TO REDEVELOP SATURDAY NIGHT
AND CONTINUE INTO SUNDAY MORNING. A FAST MOVING PACIFIC WEATHER DISTURBANCE
SUNDAY WILL INCREASE SOUTHWEST WINDS AT 10000 FEET MSL TO SPEEDS OF 35 TO 45 MPH
WITH GUSTS TO 55 MPH BY 1200. THIS WEATHER DISTURBANCE WILL INITIATE
A SLIGHT CHANCE OF SNOW ON SUNDAY. A STRONG TEMPERATURE INVERSION WILL BE IN PLACE
THIS WEEKEND.

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

FORECASTER...LIPSON

.REST OF TODAY...
SKY/WEATHER.........PATCHY FOG AND LOW CLOUDS OVER THE VICINITY OF
                    SOUTH PASS. (40-50 PERCENT).
MAX TEMPERATURE.....25 TO 29.
20 FOOT WINDS.......LIGHT AND VARIABLE.
RIDGE TOP WINDS.....NORTHWEST 5 TO 8 MPH ON THE HIGHEST RIDGES.

.TONIGHT...
SKY/WEATHER.........PARTLY CLOUDY (30-40 PERCENT).
MIN TEMPERATURE.....TEMPERATURES RISING TO 31 DEGREES AT 10000 FEET BY
                    0600. TEMPERATURES FALLING TO 15 DEGREES AT 8000 FEET BY
                    0600.
20 FOOT WINDS.......LIGHT AND VARIABLE.
RIDGE TOP WINDS.....LIGHT AND VARIABLE.

.CHRISTMAS DAY...
SKY/WEATHER.........WIDESPREAD FOG WILL SHROUD SOUTH PASS UP TO AROUND 8300 FEET
                    MSL. THEN SOME PATCHY FOG WILL LIKELY LINGER OVER SOUTH
                    PASS FOR THE REST OF THE AFTERNOON. ABOVE THE FOG INCLUDING
                    ELEVATIONS AT 10000 FEET PARTLY CLOUDY (30-40 PERCENT)
                    WITH SOME HIGH CLOUDS ABOVE THE FOG...THEN BECOMING MOSTLY
                    SUNNY (20-30 PERCENT).
MAX TEMPERATURE.....36 AT 10000 FEET AND 26 AT SOUTH PASS AT 8000 FEET.
20 FOOT WINDS.......LIGHT AND VARIABLE.
RIDGE TOP WINDS.....LIGHT AND VARIABLE BECOMING SOUTHWEST 10 MPH ABOVE
                    10000 FEET IN THE AFTERNOON.

.FORECAST DAYS 3 THROUGH 5...
.SATURDAY NIGHT...FOG OVER SOUTH PASS. OTHERWISE MOSTLY CLEAR. LOWS AROUND 20.
WINDS GENERALLY LESS THAN 10 MPH.
.SUNDAY...SOME MORNING FOG OVER SOUTH PASS. OTHERWISE PARTLY CLOUDY WITH
SLIGHT CHANCE OF SNOW. LOWS AROUND 14. HIGHS IN THE LOWER 30S. WEST WINDS
AROUND 16 MPH.
.MONDAY...PARTLY CLOUDY. LOWS AROUND 11. HIGHS IN THE MID 20S.
WEST WINDS AROUND 11 MPH.
.TUESDAY...MOSTLY CLOUDY. SLIGHT CHANCE OF SNOW. LOWS AROUND 10.
HIGHS IN THE LOWER 20S. WEST WINDS AROUND 18 MPH.

$$

FORECASTER...LIPSON
REQUESTED BY...JASON
REASON FOR REQUEST...SAR
.TAG 20101224.SOUTH.01/RIW