FNUS75 KRIW 221016
FWSRIW

SPOT FORECAST FOR LOWER GROS VENTRE...USFS BTF
NATIONAL WEATHER SERVICE RIVERTON WY
416 AM MDT TUE SEP 22 2009

FORECAST IS BASED ON IGNITION TIME OF 1920 MDT ON SEPTEMBER 21.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...
UPPER LOW OVER EASTERN COLORADO AND THE WESTERN CENTRAL PLAINS WILL
DRIFT SLOWLY TO THE SOUTH TODAY AND TO THE WEST WEDNESDAY...WHILE A
LARGE UPPER LEVEL HIGH PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST
WILL REMAIN NEARLY STATIONARY. THIS WILL KEEP THE BURN AREA UNDER THE
INFLUENCE OF COOLER THAN NORMAL NORTHERLY FLOW ALOFT. EXPECT COOLER
THAN NORMAL DAYTIME TEMPERATURES TODAY AND WEDNESDAY WITH LOW AFTERNOON
RELATIVE HUMIDITIES. SURFACE HIGH PRESSURE WILL REMAIN IN PLACE TODAY
THROUGH WEDNESDAY WITH DRY WEATHER AND LIGHT WINDS PREDOMINATING.

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

FORECASTER...C.BAKER

.TODAY...
SKY/WEATHER.........SUNNY (5-15 PERCENT).
MAX TEMPERATURE.....58-62.
MIN HUMIDITY........21-24 PERCENT.
20 FOOT WINDS.......UPSLOPE/UPVALLEY 5-9 MPH.
RIDGE TOP WINDS.....NORTH 10 TO 15 MPH.
LAL.................1.
CHC OF WETTING RAIN.ZERO PERCENT.
HAINES INDEX........3 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......4200 FT AGL INCREASING TO 6200 FT AGL IN THE
                    AFTERNOON.
TRANSPORT WINDS.....NORTH 10 TO 15 MPH.
SMOKE DISPERSAL.....BECOMING GOOD BY NOON (39500-72800 KNOT-FT).

.TONIGHT...
SKY/WEATHER.........CLEAR (5-15 PERCENT).
MIN TEMPERATURE.....AROUND 37.
MAX HUMIDITY........60-63 PERCENT.
20 FOOT WINDS.......NORTHEAST WINDS 8 TO 9 MPH IN THE EVENING
                    BECOMING DOWNSLOPE/DOWNVALLEY 4-7 MPH...THEN
                    BECOMING EAST AROUND 8 MPH EARLY IN THE
                    MORNING. GUSTS UP TO 15 MPH.
RIDGE TOP WINDS.....EAST 10 TO 15 MPH.
LAL.................1.
CHC OF WETTING RAIN.ZERO PERCENT.
HAINES INDEX........2 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......700-1700 FT AGL.
TRANSPORT WINDS.....EAST 13 TO 15 MPH.
SMOKE DISPERSAL.....POOR (3700-25400 KNOT-FT).

.WEDNESDAY...
SKY/WEATHER.........SUNNY (5-15 PERCENT).
MAX TEMPERATURE.....AROUND 64.
MIN HUMIDITY........21-24 PERCENT.
20 FOOT WINDS.......UPSLOPE/UPVALLEY 5-9 MPH. GUSTS UP TO 15 MPH
                    IN THE AFTERNOON.
RIDGE TOP WINDS.....NORTHEAST 10 TO 15 MPH.
LAL.................1.
CHC OF WETTING RAIN.ZERO PERCENT.
HAINES INDEX........2 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......4100 FT AGL INCREASING TO 8000 FT AGL IN THE
                    AFTERNOON.
TRANSPORT WINDS.....NORTHEAST 12 TO 14 MPH.
SMOKE DISPERSAL.....BECOMING GOOD BY 11 AM (76000-86000 KNOT-FT).

.FORECAST DAYS 3 THROUGH 5...
.WEDNESDAY NIGHT...MOSTLY CLEAR. LOWS IN THE UPPER 30S. WINDS
GENERALLY LESS THAN 10 MPH.
.THURSDAY...MOSTLY CLEAR. LOWS IN THE UPPER 30S. HIGHS IN THE
LOWER 60S. WINDS GENERALLY LESS THAN 10 MPH.
.FRIDAY...MOSTLY CLEAR. LOWS IN THE UPPER 30S. HIGHS IN THE LOWER
60S. WINDS GENERALLY LESS THAN 10 MPH.
.SATURDAY...MOSTLY CLEAR. LOWS IN THE UPPER 30S. HIGHS IN THE
LOWER 60S. WINDS GENERALLY LESS THAN 10 MPH.

$$

FORECASTER...C.BAKER
REQUESTED BY...PFISTER
REASON FOR REQUEST...PRESCRIBED
.TAG 20090921.LOWER.02/RIW