000 FNUS75 KCYS 211554 FWSCYS SPOT FORECAST FOR RAINBOW VALLEY 1.1 BURN......BLM NATIONAL WEATHER SERVICE NWFO CHEYENNE 954 AM MDT MON APR 21 2003 VALID UNTIL 554 PM MDT MON APR 21 2003 IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER SERVICE. DISCUSSION...NARROW UPPER RIDGE OVER EASTERN WYOMING WILL SHIFT EAST TODAY. SOUTHWEST FLOW ALOFT OVER BURN AREA WILL BECOME INCREASINGLY MOIST AHEAD OF STRONG UPPER LOW DIVING INTO SOUTHWEST UNITED STATES. THIS LOW WILL BRING COOL AND WET WEATHER TO BURN AREA MAINLY FOR WEDNESDAY AND THURSDAY. AHEAD OF THIS...THERE WILL BE A FEW SHOWERS AND THUNDERSTORMS BY THIS EVENING WITH A BETTER CHANCE OF THESE TUESDAY AFTERNOON. FOR PLANNED IGNITION TIME OF 1000 MDT 4/21/03 SKY / WEATHER.......SUNNY THIS MORNING. PARTLY CLOUDY IN THE AFTERNOON WITH WIDELY SCATTERED THUNDERSTORMS. TEMPERATURE.........MAX 52 TO 55. RH..................MIN 28 TO 33%. 20 FOOT WIND........SOUTH TO SOUTHEAST INCREASING TO 10 TO 20 MPH. CWR.................10%. LAL.................2. HAINES INDEX........4. MIXING HEIGHT.......8000 FEET AGL. MIXING WINDS........SOUTH 10 TO 15 MPH. SMOKE DISPERSAL.....BECOMING EXCELLENT BY MIDDAY. FOR TONIGHT SKY / WEATHER.......PARTLY CLOUDY WITH WIDELY SCATTERED EVENING SHOWERS AND THUNDERSTORMS. TEMPERATURE.........MIN 29 TO 32. RH..................MAX 90 TO 95%. 20 FOOT WIND........SOUTHEAST 10 TO 20 MPH. CWR.................20%. LAL.................2. HAINES INDEX........4. MIXING HEIGHT.......DECREASING TO 1000 FEET AGL. MIXING WINDS........SOUTHEAST 10 MPH. SMOKE DISPERSAL.....BECOMING POOR BY MIDNIGHT. OUTLOOK FOR TOMORROW SKY / WEATHER.......MOSTLY CLOUDY WITH SCATTERED MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS. TEMPERATURE.........MAX 54 TO 57. RH..................MIN 33 TO 38%. 20 FOOT WIND........SOUTHEAST 15 TO 25 MPH. CWR.................30%. LAL.................2. HAINES INDEX........4. MIXING HEIGHT.......9000 FEET AGL. MIXING WINDS........SOUTHEAST 15 MPH. SMOKE DISPERSAL.....BECOMING EXCELLENT BY LATE MORNING. FORECASTER...JLH $$