FNUS75 KBYZ 131101
FWSBYZ

SPOT FORECAST FOR TWIN BUTTES...USFS BIGHORN
NATIONAL WEATHER SERVICE BILLINGS MT
501 AM MDT MON MAY 13 2013

FORECAST IS BASED ON IGNITION TIME OF 1300 MDT ON MAY 13.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.

...HOT AND DRY TODAY...INCREASING WINDS WITH COLD FRONT TONIGHT...
...ISOLATED EVENING THUNDERSTORMS...DRY AND WINDY TUESDAY...

.DISCUSSION...

UNSEASONABLY HOT AIRMASS WILL BE OVER THE BURN SITE TODAY WHICH
WILL BRING HUMIDITY TO 20 PERCENT. SKIES WILL BE PARTLY CLOUDY WITH
AFTERNOON CUMULUS DEVELOPING WITH ISOLATED THUNDERSTORMS THIS
EVENING. AS TEMPERATURES RISE STRONGER WINDS WILL BEGIN TO MIX
DOWN DURING THE AFTERNOON WITH GUSTS TO 25 MPH POSSIBLE. COLD
FRONT WILL ARRIVE LATE TONIGHT BUT ACTUAL WIND SHIFT COULD COME
EARLIER IF THUNDERSTORMS DEVELOP. TUESDAY WINDS WILL BE STRONGER
BUT IT WILL BE COOLER WITH HUMIDITY STILL LOW. CHANCES FOR
MOISTURE IMPROVE BY WEDNESDAY AND ESPECIALLY THURSDAY. BORSUM

.TODAY...

SKY/WEATHER.........PARTLY CLOUDY WITH AFTERNOON CUMULUS DEVELOPING.
CWR.................ZERO.
LAL.................1...NONE.
MAX TEMPERATURE.....67-72.
MIN HUMIDITY........19-24 PERCENT.
WIND (20 FT)........
 SLOPE/VALLEY.......SOUTHWEST WINDS 5 TO 15 MPH BECOMING 10 TO 20 MPH
                    BY AFTERNOON WITH GUSTS TO 25 MPH.
 RIDGETOP...........WEST 15 TO 25 MPH.
MIXING HEIGHT.......7400 FT AGL.
MIXING WINDS........SOUTHWEST 15 TO 25 MPH.
HAINES INDEX........5.

.TONIGHT...

SKY/WEATHER.........MOSTLY CLOUDY. ISOLATED THUNDERSTORMS IN THE
                    EVENING. SOME THUNDERSTORMS MAY PRODUCE GUSTY
                    WINDS IN THE EVENING.
CWR.................8 PERCENT.
LAL.................2...1 TO 8 STRIKES/15 MIN/CELL.
MIN TEMPERATURE.....43-48.
MAX HUMIDITY........45-50 PERCENT.
WIND (20 FT)........
 SLOPE/VALLEY.......SOUTHWEST WINDS 15 TO 25 MPH. GUSTY AND ERRATIC
                    WINDS EXPECTED NEAR THUNDERSTORMS IN THE
                    EVENING.
 RIDGETOP...........WEST 20 TO 35 MPH.
MIXING HEIGHT.......5300 FT AGL.
MIXING WINDS........WEST 20 TO 35 MPH.
HAINES INDEX........4.

.TUESDAY...

SKY/WEATHER.........MOSTLY SUNNY.
CWR.................0 PERCENT.
LAL.................1...NO THUNDERSTORMS.
MAX TEMPERATURE.....57-62.
MIN HUMIDITY........19-24 PERCENT.
WIND (20 FT)........
 SLOPE/VALLEY.......WEST WINDS 15 TO 25 MPH. GUSTS UP TO 30 MPH IN
                    THE AFTERNOON.
 RIDGETOP...........WEST 15 TO 30 MPH.
MIXING HEIGHT.......5500 FT AGL.
MIXING WINDS........WEST 15 TO 25 MPH.
HAINES INDEX........5.

$$
FORECASTER...BORSUM
REQUESTED BY...ERIC COMSTOCK
TYPE OF REQUEST...PRESCRIBED
.TAG 20130513.TWINB.01/BYZ