FNUS75 KRIW 211552
FWSRIW

SPOT FORECAST FOR LOWER GROS VENTRE...USFS BTF
NATIONAL WEATHER SERVICE RIVERTON WY
952 AM MDT MON SEP 21 2009

FORECAST IS BASED ON IGNITION TIME OF 0840 MDT ON SEPTEMBER 21.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...COLD NORTHERLY FLOW ALOFT WILL PRODUCE AN UNSEASONABLY COOL
DAY WITH HIGH TEMPERATURES 8-12 F BELOW NORMAL. SURFACE HIGH PRESSURE WILL
MOVE ACROSS THE REGION TONIGHT WITH SLOWLY DECREASING NORTHERLY WINDS
AND DECENT RELATIVE HUMIDITY RECOVERIES AT NIGHT. SLIGHTLY DRIER LOW
LEVEL AIRMASS AND MILDER...BUT STILL BELOW NORMAL...DAYTIME TEMPERATURES
WILL PREVAIL DURING THE AFTERNOON TUESDAY AS UPPER LEVEL HIGH PRESSURE BUILDS IN
SLOWLY FROM THE WEST.

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

FORECASTER...LIPSON

.TODAY...
SKY/WEATHER.........MOSTLY SUNNY (10-20 PERCENT).
MAX TEMPERATURE.....60 AT 7000 FEET AND 49 AT 9200 FEET.
MIN HUMIDITY........15 PERCENT AT 7000 FEET AND 22 PERCENT AT 9200 FEET.
20 FOOT WINDS.......NORTH NORTHEAST WINDS 6 TO 12 MPH. WINDS WILL GUST TO
                    20 MPH AFTER 1200. ALONG THE WEST FORK WINDS
                    WILL BLOW AT 10 TO 15 MPH WITH GUSTS TO 20 MPH ALL DAY.
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.......4500 FT AGL INCREASING TO 6700 FT AGL IN THE
                    AFTERNOON.
TRANSPORT WINDS.....NORTH 12 TO 17 MPH.
SMOKE DISPERSAL.....FAIR TO GOOD (53400-80700 KNOT-FT).

.TONIGHT...
SKY/WEATHER.........MOSTLY CLEAR (10-20 PERCENT).
MIN TEMPERATURE.....30-33 EXCEPT 25 AT 7000 FEET.
MAX HUMIDITY........42-45 PERCENT EXCEPT 65 PERCENT AT 7000 FEET.
20 FOOT WINDS.......NORTH AROUND 9 MPH LATE IN THE EVENING...THEN
                    BECOMING DOWNSLOPE/DOWNVALLEY 4-7 MPH AFTER
                    MIDNIGHT. WINDS WILL REMAIN NORTH ALONG THE WEST FORK
                    AT 9 MPH ALL NIGHT ALONG WITH SOME GUSTS UP TO 15 MPH.                     .
RIDGE TOP WINDS.....NORTHEAST 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.......2600 FT AGL DECREASING TO 500 FT AGL AFTER
                    MIDNIGHT.
TRANSPORT WINDS.....NORTHEAST 12 TO 15 MPH.
SMOKE DISPERSAL.....POOR (5500-29600 KNOT-FT).

.TUESDAY...
SKY/WEATHER.........MOSTLY SUNNY (10-20 PERCENT).
MAX TEMPERATURE.....71 AT 7000 FEET AND 60 AT 9200 FEET.
MIN HUMIDITY........17 PERCENT AT 7000 FEET AND 19 PERCENT AT 9200 FEET.
20 FOOT WINDS.......NORTH 4 TO 8 MPH EXCEPT 10 TO 15 MPH ALONG WITH
                    WEST FORK. UPSLOPE/UPVALLEY 5-9 MPH IN THE SHELTERED AREAS
                    BELOW 8000 FEET.
RIDGE TOP WINDS.....NORTH AROUND 10 MPH.
LAL.................1.
CHC OF WETTING RAIN.ZERO PERCENT.
HAINES INDEX........3 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......3000 FT AGL INCREASING TO 6200 FT AGL IN THE
                    AFTERNOON.
TRANSPORT WINDS.....NORTH 9 TO 13 MPH.
SMOKE DISPERSAL.....POOR TO FAIR (28100-54600 KNOT-FT).

.FORECAST DAYS 3 THROUGH 5...
.TUESDAY NIGHT...MOSTLY CLEAR. LOWS IN THE UPPER 30S. WINDS
GENERALLY LESS THAN 10 MPH.
.WEDNESDAY...MOSTLY CLEAR. LOWS AROUND 40. HIGHS IN THE LOWER
60S. WINDS GENERALLY LESS THAN 10 MPH.
.THURSDAY...MOSTLY CLEAR. LOWS AROUND 40. HIGHS IN THE LOWER 60S.
WINDS GENERALLY LESS THAN 10 MPH.
.FRIDAY...MOSTLY CLEAR. LOWS IN THE LOWER 40S. HIGHS IN THE LOWER
60S. WINDS GENERALLY LESS THAN 10 MPH.

$$

FORECASTER...LIPSON
REQUESTED BY...PFISTER
REASON FOR REQUEST...PRESCRIBED
.TAG 20090921.LOWER.01/RIW