FNUS75 KRIW 181343
FWSRIW

SPOT FORECAST FOR LOWER GROS VENTRE...USFS BTF
NATIONAL WEATHER SERVICE RIVERTON WY
743 AM MDT FRI SEP 18 2009

FORECAST IS BASED ON IGNITION TIME OF 0740 MDT ON SEPTEMBER 18.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...
A WEAK TROUGH WILL MOVE THROUGH THIS AFTERNOON AND EVENING WITH
ISOLATED THUNDERSTORMS POSSIBLE. OTHERWISE...WINDS...TEMPS AND
RH'S WONT BE TOO MUCH DIFFERENT OVER THURSDAY. A STRONGER TROUGH
WILL APPROACH SATURDAY WITH INCREASING SOUTHWEST WINDS AND A
SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS. THE TROUGH WILL MOVE
THROUGH SUNDAY WITH AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS
EXPECTED.


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

FORECASTER...T.BAKER

.TODAY...
SKY/WEATHER.........MOSTLY SUNNY (20-30 PERCENT). ISOLATED SHOWERS
                    AND THUNDERSTORMS IN THE AFTERNOON.
MAX TEMPERATURE.....AROUND 70.
MIN HUMIDITY........20-25 PERCENT.
20 FOOT WINDS.......LIGHT AND VARIABLE...BECOMING UPSLOPE/UPVALLEY
                    5-9 MPH AROUND NOON. GUSTY AND ERRATIC WINDS EXPECTED
                    NEAR THUNDERSTORMS IN THE AFTERNOON.
RIDGE TOP WINDS.....NORTH TO EAST WINDS 4-6 MPH...BECOMING SOUTH TO
                    SOUTHWEST AROUND 5-10 MPH GUSTS TO 15 MPH AFTER 1300.
                    GUSTY AND ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS
                    IN THE AFTERNOON.
LAL.................1 UNTIL 1200...THEN 2.
CHC OF WETTING RAIN.5 PERCENT.
HAINES INDEX........5 OR MODERATE POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......2500 FT AGL INCREASING TO 10000 FT AGL IN THE
                    AFTERNOON.
TRANSPORT WINDS.....SOUTHWEST 10 MPH.
SMOKE DISPERSAL.....POOR (25000 KNOT-FT) BECOMING VERY GOOD (100000
                    KNOT-FT) IN THE AFTERNOON.

.TONIGHT...
SKY/WEATHER.........PARTLY CLOUDY (25-35 PERCENT) IN THE EVENING...THEN
                    CLEARING. ISOLATED SHOWERS AND THUNDERSTORMS IN THE
                    EVENING THROUGH 2000.
MIN TEMPERATURE.....MID TO UPPER 30S VALLEYS...45-50 RIDGETOP.
MAX HUMIDITY........80-85 PERCENT VALLEYS...50-55 PERCENT RIDGETOP.
20 FOOT WINDS.......DOWNSLOPE/DOWNVALLEY 4-7 MPH. GUSTY AND ERRATIC
                    WINDS EXPECTED NEAR THUNDERSTORMS IN THE
                    EVENING.
RIDGE TOP WINDS.....NORTH AROUND 5 MPH. GUSTY AND ERRATIC WINDS EXPECTED
                    NEAR THUNDERSTORMS IN THE EVENING.
LAL.................2 UNTIL 2000...THEN 1.
CHC OF WETTING RAIN.5 PERCENT.
HAINES INDEX........3 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......4000 FT AGL DECREASING TO 600 FT AGL AFTER
                    MIDNIGHT.
TRANSPORT WINDS.....NORTH AROUND 8 MPH SHIFTING TO THE EAST 7
                    TO 8 MPH AFTER MIDNIGHT.
SMOKE DISPERSAL.....POOR (32000 KNOT-FT DECREASING TO 4800 KNOT-FT)
                    AFTER MIDNIGHT.

.SATURDAY...
SKY/WEATHER.........MOSTLY SUNNY (15-25 PERCENT) THEN BECOMING
                    MOSTLY CLOUDY (60-70 PERCENT). SLIGHT CHANCE OF
                    SHOWERS AND THUNDERSTORMS IN THE AFTERNOON.
MAX TEMPERATURE.....65-68.
MIN HUMIDITY........25-30 PERCENT.
20 FOOT WINDS.......UPSLOPE/UPVALLEY 5-9 MPH. GUSTS UP TO 15 MPH IN
                    THE AFTERNOON. GUSTY AND ERRATIC WINDS EXPECTED
                    NEAR THUNDERSTORMS IN THE AFTERNOON.
RIDGE TOP WINDS.....SOUTHWEST 10 TO 15 MPH GUSTS TO 25 MPH.
LAL.................1 UNTIL 1200...THEN 2.
CHC OF WETTING RAIN.6 PERCENT.
HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED
                    FIRE GROWTH.
MIXING HEIGHT.......5100 FT AGL INCREASING TO 9100 FT AGL IN THE
                    AFTERNOON.
TRANSPORT WINDS.....SOUTHWEST 9 TO 15 MPH.
SMOKE DISPERSAL.....FAIR (40300 KNOT-FT) INCREASING TO VERY GOOD
                    (109100 KNOT-FT) IN THE AFTERNOON.

.FORECAST DAYS 3 THROUGH 5...
.SATURDAY NIGHT...PARTLY CLOUDY WITH SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS. LOWS IN THE MID 40S. WINDS GENERALLY LESS THAN
10 MPH.
.SUNDAY...COOLER. PARTLY CLOUDY. CHANCE OF SHOWERS...
THUNDERSTORMS AND SLIGHT CHANCE OF SNOW SHOWERS. LOWS IN THE MID
30S. HIGHS IN THE LOWER 50S. WINDS GENERALLY LESS THAN 10 MPH.
.MONDAY...MOSTLY CLEAR. LOWS IN THE LOWER 30S. HIGHS IN THE LOWER
50S. WINDS GENERALLY LESS THAN 10 MPH.
.TUESDAY...MOSTLY CLEAR. LOWS IN THE UPPER 30S. HIGHS IN THE
LOWER 60S. WINDS GENERALLY LESS THAN 10 MPH.

$$

FORECASTER...T.BAKER
REQUESTED BY...MCFARLAND
REASON FOR REQUEST...PRESCRIBED
.TAG 20090918.LOWER.01/RIW