FNUS75 KRIW 292103
FWSRIW

SPOT FORECAST FOR ARNICA FIRE...NPS YNP
NATIONAL WEATHER SERVICE RIVERTON WY
303 PM MDT TUE SEP 29 2009

FORECAST IS BASED ON REQUEST TIME OF 1420 MDT ON SEPTEMBER 29.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

.DISCUSSION...WARM AND DRY WINDY WEATHER WILL PREVAIL THROUGH EARLY THIS EVENING.
A STRONG PACIFIC TROUGH MAKING LANDFALL ONTO THE PACIFIC COAST WILL
TRACK INLAND TOWARD THE ROCKIES TONIGHT. MOISTURE AHEAD OF THIS SYSTEM
WILL STREAM INTO THE AREA BY EARLY WEDNESDAY MORNING WITH SHOWERS MOVING
INTO THE AREA. A STRONG PACIFIC COLD FRONT ASSOCIATED WITH THIS
TROUGH WILL MOVE INTO THE AREA EARLY WEDNESDAY MORNING. THE
INCREASING RAINFALL WILL MIX WITH AND TURN TO SNOW BY MID MORNING WEDNESDAY.
3 INCHES OF WET SNOW IS EXPECTED WEDNESDAY MORNING AND WILL LIKELY
MELT IN THE AFTERNOON. THEN ANOTHER 2 TO 3 INCHES OF SNOWFALL IS LIKELY
WEDNESDAY NIGHT. THE PRECIPITATION WILL GRADUALLY TAPER OFF LATER WEDNESDAY
NIGHT. SCATTERED RAIN AND SNOW SHOWERS WILL CONTINUE IN THE COLD
UNSTABLE NORTHWEST FLOW BEHIND THE TROUGH THURSDAY. DRY WEATHER IS
EXPECTED FRIDAY BEFORE ANOTHER STRONG WEATHER SYSTEM BRINGS MORE
SIGNIFICANT PRECIPITATION TO THE AREA OVER THE WEEKEND. TEMPERATURES
WILL REMAIN COOL THROUGH THE WEEK.

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

FORECASTER...LIPSON

.REST OF TODAY...
SKY/WEATHER.........PARTLY CLOUDY (35-45 PERCENT). AREAS OF SMOKE.
MAX TEMPERATURE.....66.
MIN HUMIDITY........21 PERCENT.
20 FOOT WINDS.......SOUTHWEST WINDS 12 TO 13 MPH WITH GUSTS TO 20 MPH.
RIDGE TOP WINDS.....SOUTHWEST AROUND 20 MPH.
LAL.................1.
CHC OF WETTING RAIN.ZERO PERCENT.
HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED
                    FIRE GROWTH.
MIXING HEIGHT.......9900 FT AGL.
TRANSPORT WINDS.....SOUTHWEST 21 TO 22 MPH.
SMOKE DISPERSAL.....EXCELLENT (182300 KNOT-FT).

.TONIGHT...
SKY/WEATHER.........PARTLY CLOUDY (50-60 PERCENT) THEN BECOMING
                    CLOUDY (95-100 PERCENT). STEADY RAIN WELL AFTER MIDNIGHT.
MIN TEMPERATURE.....AROUND 34.
MAX HUMIDITY........89-92 PERCENT.
20 FOOT WINDS.......SOUTHWEST WINDS 8 TO 11 MPH WITH GUSTS TO 22 MPH.
                    SOUTHWEST WINDS WILL DIMINISH TO 4 TO 8 MPH BY 0200.
RIDGE TOP WINDS.....SOUTHWEST 15 TO 20 MPH.
LAL.................1.
CHC OF WETTING RAIN.32 PERCENT.
HAINES INDEX........4 OR LOW POTENTIAL FOR LARGE PLUME DOMINATED
                    FIRE GROWTH.
MIXING HEIGHT.......6200 FT AGL DECREASING TO 2400 FT AGL AFTER
                    MIDNIGHT.
TRANSPORT WINDS.....SOUTHWEST 17 TO 20 MPH.
SMOKE DISPERSAL.....GOOD (98300 KNOT-FT) DECREASING TO POOR (32900
                    KNOT-FT) AFTER MIDNIGHT.

.WEDNESDAY...
SKY/WEATHER.........CLOUDY (95-100 PERCENT). RAIN TURNING TO WET SNOWFALL
                    BY 1000. ACCUMULATIONS OF 2 TO 3 INCHES. RAIN AND SNOW
                    THROUGH THE AFTERNOON WITH MOST OF THE SNOW MELTING IN THE
                    AFTERNOON.
MAX TEMPERATURE.....38 TO 40.
MIN HUMIDITY........53-56 PERCENT.
20 FOOT WINDS.......SOUTHWEST 5-9 MPH SHIFTING TO THE NORTH NORTHWEST
                    AROUND 10 TO 14 MPH WITH GUSTS TO AROUND 22 MPH BY 1000.
RIDGE TOP WINDS.....WEST AROUND 15 MPH INCREASING TO NORTH NORTHWEST
                    AROUND 25 MPH LATE IN THE AFTERNOON.
LAL.................1.
CHC OF WETTING RAIN.91 PERCENT.
HAINES INDEX........2 OR VERY LOW POTENTIAL FOR LARGE PLUME
                    DOMINATED FIRE GROWTH.
MIXING HEIGHT.......2100-2700 FT AGL.
TRANSPORT WINDS.....NORTHWEST 16 TO 23 MPH.
SMOKE DISPERSAL.....POOR TO FAIR (28500-44200 KNOT-FT).

.FORECAST DAYS 3 THROUGH 5...
.WEDNESDAY NIGHT...COLDER. NUMEROUS SNOW SHOWERS IN THE EVENING...
THEN SCATTERED SNOW SHOWERS AFTER MIDNIGHT. LOWS AROUND 17. NORTH
WINDS AROUND 13 MPH.
.THURSDAY...PARTLY CLOUDY WITH SCATTERED SNOW SHOWERS AND
ISOLATED SHOWERS. LOWS AROUND 18. HIGHS IN THE MID 30S. WEST
WINDS AROUND 10 MPH.
.FRIDAY...MOSTLY CLOUDY WITH SCATTERED SHOWERS AND SNOW SHOWERS.
LOWS IN THE LOWER 20S. HIGHS AROUND 40. WINDS GENERALLY LESS THAN
10 MPH.
.SATURDAY...MOSTLY CLOUDY WITH CHANCE OF SHOWERS AND SNOW
SHOWERS. LOWS IN THE MID 20S. HIGHS IN THE UPPER 30S. WINDS
GENERALLY LESS THAN 10 MPH.

$$

FORECASTER...LIPSON
REQUESTED BY...ED FOLTS
REASON FOR REQUEST...WILDFIRE
.TAG 20090929.ARNIC.01/RIW