004
FNUS75 KBYZ 191518
FWSBYZ
SPOT FORECAST FOR NORTH DERBY RX...USFS
NATIONAL WEATHER SERVICE BILLINGS MT
918 AM MDT THU MAR 19 2026
FORECAST IS BASED ON IGNITION TIME OF 0800 MDT ON MARCH 23.
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER
SERVICE.
PLEASE CONTACT OUR OFFICE IF YOU HAVE QUESTIONS
OR CONCERNS WITH THIS FORECAST.
DISCUSSION
WARM AND DRY CONDITIONS WILL PERSIST THROUGH SATURDAY WHEN A FRONTAL
PASSAGE IS EXPECTED. THERE IS A 40% CHANCE FOR A WETTING RAIN LATE
SATURDAY AFTERNOON THROUGH THE EVENING. MIN RHS WILL GENERALLY BE IN
20-30% RANGE WITH MODERATE OVERNIGHT RECOVERIES. LITTLE TO NO CHANCES
FOR PRECIPITATION THROUGH THE FORECAST PERIOD, BUT A 10-20% CHANCE FOR
PRECIPITATION EXISTS TUESDAY NIGHT. THERE IS STILL A LOT OF
UNCERTAINTY WITH THIS POTENTIAL. THE POTENTIAL FOR STRONG WINDS DOES
LOOK TO PICK UP EARLY WEDNESDAY. THERE IS CURRENTLY ABOUT A 50% CHANCE
FOR GUSTS TO 60 MPH WEDNESDAY.
MONDAY
SKY/WEATHER.........MOSTLY CLOUDY.
CWR.................2 PERCENT.
CHANCE OF LIGHTNING.1 PERCENT.
MAX TEMPERATURE.....56-60.
MIN HUMIDITY........25-29 PERCENT.
WIND (20 FT)........
SLOPE/VALLEY.......SOUTHWEST WINDS UP TO 10 MPH SHIFTING TO THE
NORTHEAST IN THE AFTERNOON WITH GUSTS 15 TO 20 MPH.
RIDGETOP...........WEST 15 MPH
MIXING HEIGHT.......INCREASING TO 4500 FT AGL IN THE AFTERNOON.
TRANSPORT WINDS.....SOUTHWEST 10 MPH
TIME (MDT) 9 AM 12 PM 3 PM
SKY (%).........72 67 71
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CHC OF LTNG (%).0 0 0
TEMP............45 54 57
RH..............40 30 27
20 FT WIND. SW 5G8 NE 5G14 N 8G18
MONDAY NIGHT
SKY/WEATHER.........MOSTLY CLOUDY.
CWR.................3 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MIN TEMPERATURE.....40-44.
MAX HUMIDITY........49-53 PERCENT.
WIND (20 FT)........
SLOPE/VALLEY.......NORTH WINDS 5 TO 7 MPH SHIFTING TO THE
SOUTHWEST 5 TO 6 MPH IN THE LATE EVENING AND
OVERNIGHT.
RIDGETOP...........WEST 20 MPH
MIXING HEIGHT.......DECREASING TO 700 FT AGL OVERNIGHT.
TRANSPORT WINDS.....SOUTHWEST 12 MPH.
TIME (MDT) 6 PM 9 PM MID 3 AM
SKY (%).........80 75 73 71
WEATHER COV.....
WEATHER TYPE....
TSTM COV........
CHC OF LTNG (%).0 0 0 0
TEMP............55 49 47 44
RH..............32 42 45 49
20 FT WIND. N 7G14 SW 6G10 SW 6G8 SW 6G8
TUESDAY
SKY/WEATHER.........MOSTLY CLOUDY.
CWR.................4 PERCENT.
CHANCE OF LIGHTNING.2 PERCENT.
MAX TEMPERATURE.....65-69.
MIN HUMIDITY........26-30 PERCENT.
WIND (20 FT)........
SLOPE/VALLEY.......SOUTHWEST WINDS 5 TO 12 MPH. GUSTS UP TO 30 MPH
IN THE AFTERNOON.
RIDGETOP...........WEST 28 MPH
MIXING HEIGHT.......INCREASING TO 4000 T AGL IN THE AFTERNOON.
TRANSPORT WINDS.....SOUTHWEST 25 MPH.
TIME (MDT) 6 AM 9 AM NOON 3 PM
SKY (%).........77 73 73 71
WEATHER COV.....
WEATHER TYPE....NONE NONE NONE NONE
TSTM COV........
CHC OF LTNG (%).0 0 0 0
TEMP............44 50 61 66
RH..............51 44 33 28
20 FT WIND......SW 6G10 SW 7G14 SW 10G23 SW 12G27
FORECASTER...STETZER
REQUESTED BY...GREG OYLER
TYPE OF REQUEST...PRESCRIBED
.TAG 2606530.0/BYZ
.DELDT 03/19/26
.FORMATTERVERSION 2.0.0
.EMAIL GREGORY.OYLER@USDA.GOV
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page