944  
FNUS75 KBYZ 170943  
FWSBYZ  
 
SPOT FORECAST FOR LONESOMEWOOOD RX...USFS  
NATIONAL WEATHER SERVICE BILLINGS MT  
343 AM MDT THU SEP 17 2026  
 
FORECAST IS BASED ON IGNITION TIME OF 0600 MDT ON SEPTEMBER 17.  
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER  
SERVICE.  
 
PLEASE CONTACT OUR OFFICE IF YOU HAVE QUESTIONS  
OR CONCERNS WITH THIS FORECAST.  
   
DISCUSSION  
 
PERIODIC SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED TO BEGIN EARLY  
THIS MORNING BETWEEN 0500 AND 0700 MDT. PERIODS OF MODERATE TO HEAVY  
RAIN ARE POSSIBLE WITH ANY THUNDERSTORMS. THERE IS SOME UNCERTAINTY ON  
IF SHOWERS WILL CONTINUE INTO THE OVERNIGHT HOURS, BUT HIGHER CONFIDENCE  
EXISTS FOR SHOWERS AND THUNDERSTORMS FRIDAY AFTERNOON AND EVENING WHEN  
HEAVY RAIN AND GUSTY WINDS ARE POSSIBLE UNDER STRONGER THUNDERSTORMS.  
THERE'S ABOUT A 35% CHANCE FOR AT LEAST AN INCH OF PRECIPITATION THURSDAY  
EVENING THROUGH SATURDAY. PRECIPITATION LOOKS TO TAPER OFF SUNDAY EVENING  
WITH MONDAY BEING A DRY DAY. THERE IS SOME UNCERTAINTY IN THE FORECAST  
WITH REGARDS TO POTENTIAL MOISTURE MOVING INTO MID WEEK. CURRENTLY,  
TUESDAY AND WEDNESDAY CARRY ABOUT A 10% CHANCE OF PRECIPITATION.  
   
TODAY  
 
SKY/WEATHER.........MOSTLY CLOUDY. SLIGHT CHANCE OF RAIN SHOWERS  
EARLY IN THE MORNING, THEN CHANCE OF RAIN  
SHOWERS IN THE LATE MORNING AND AFTERNOON.  
CHANCE OF THUNDERSTORMS IN THE AFTERNOON.  
CWR.................40 PERCENT.  
CHANCE OF LIGHTNING.27 PERCENT.  
MAX TEMPERATURE.....67-71.  
MIN HUMIDITY........64-70 PERCENT.  
WIND (20 FT)........  
SLOPE/VALLEY.......NORTH WINDS IN THE MORNING, BECOMING SOUTH UP TO  
6 MPH. GUSTY AND ERRATIC WINDS EXPECTED NEAR  
THUNDERSTORMS IN THE AFTERNOON.  
RIDGETOP...........SOUTH AROUND 10 MPH.  
MIXING HEIGHT.......INCREASING TO 2600 FT AGL IN THE AFTERNOON.  
TRANSPORT WINDS.....EAST 5 TO 6 MPH SHIFTING TO THE SOUTHWEST AT 15 MPH  
IN THE AFTERNOON.  
 
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........64 75 60 57 57 74 75 82 81 81 69 64  
WEATHER COV.....SCH SCH SCH CHC CHC CHC CHC CHC CHC CHC CHC CHC  
WEATHER TYPE....RW RW RW RW RW RW RW RW RW RW RW RW  
TSTM COV........ CHC CHC CHC CHC CHC CHC  
CHC OF LTNG (%).10 10 10 10 10 10 30 30 30 30 30 30  
TEMP............45 43 45 47 53 57 61 65 64 65 67 64  
RH..............81 84 85 85 80 75 65 62 59 56 56 58  
20 FT WIND DIR..N N N N E S S S SW SW S S  
20 FT WIND SPD..3 3 2 2 2 3 4 5 5 6 7 5  
   
TONIGHT  
 
SKY/WEATHER.........MOSTLY CLOUDY THEN BECOMING PARTLY CLOUDY THEN  
BECOMING MOSTLY CLOUDY. PATCHY FOG AFTER 3 AM.  
RAIN SHOWERS LIKELY AFTER 3 AM.  
CWR.................40 PERCENT.  
CHANCE OF LIGHTNING.11 PERCENT.  
MIN TEMPERATURE.....42-46.  
MAX HUMIDITY........98-100 PERCENT.  
WIND (20 FT)........  
SLOPE/VALLEY.......LIGHT WINDS.  
RIDGETOP...........SOUTH AROUND 10 MPH.  
MIXING HEIGHT.......400 FT AGL OVERNIGHT.  
TRANSPORT WINDS.....SOUTH BECOMING WEST AORUND 5 MPH.  
 
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM  
SKY (%).........56 54 54 43 40 54 53 51 61 70 74 70  
WEATHER COV..... LKY LKY LKY  
WEATHER TYPE.... RW RW RW  
TSTM COV........  
CHC OF LTNG (%).10 10 10 10 10 10 10 10 10 10 10 10  
TEMP............63 61 55 53 53 52 51 49 49 48 48 46  
RH..............63 75 78 81 80 81 83 90 91 92 95 96  
20 FT WIND DIR..S S W NW NW NW NW NW W SW SW S  
20 FT WIND SPD..5 5 4 4 4 3 2 2 1 2 2 3  
   
FRIDAY  
 
SKY/WEATHER.........MOSTLY CLOUDY. PATCHY FOG EARLY IN THE MORNING.  
CHANCE OF RAIN SHOWERS IN THE MORNING. RAIN  
SHOWERS AND CHANCE OF THUNDERSTORMS IN THE  
AFTERNOON.  
CWR.................65 PERCENT.  
CHANCE OF LIGHTNING.32 PERCENT.  
MAX TEMPERATURE.....64-68.  
MIN HUMIDITY........67-71 PERCENT.  
WIND (20 FT)........  
SLOPE/VALLEY.......LIGHT WINDS BECOMING SOUTH 3 TO 6 MPH. GUSTY  
AND ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS  
IN THE AFTERNOON.  
RIDGETOP...........SOUTH AROUND 10 MPH.  
MIXING HEIGHT.......INCREASING TO 4200 FT AGL IN THE AFTERNOON.  
TRANSPORT WINDS.....EAST AT 5 MPH BECOMING SOUTH AT 15 MPH.  
 
TIME (MDT) 6 AM 9 AM NOON 3 PM  
SKY (%).........70 73 86 92  
WEATHER COV.....CHANCE CHANCE DEFNTE DEFNTE  
WEATHER TYPE....RNSHWR RNSHWR RNSHWR RNSHWR  
TSTM COV........ CHANCE CHANCE  
CHC OF LTNG (%).10 10 30 30  
TEMP............46 47 60 61  
RH..............97 100 79 69  
20 FT WIND......S 3G4 E 3G5 S 3G6 SW 3G6  
   
FORECAST DAYS 3 THROUGH 7  
   
SATURDAY  
 
SHOWERS AND CHANCE OF THUNDERSTORMS. PATCHY FOG. LOWS IN THE  
LOWER 40S. HIGHS AROUND 60. LIGHT WINDS.    
SUNDAY  
 
MOSTLY CLOUDY. CHANCE OF SHOWERS AND SLIGHT CHANCE OF  
THUNDERSTORMS. PATCHY FOG OVERNIGHT. AREAS OF FOG IN THE MORNING.  
LOWS IN THE UPPER 30S. HIGHS IN THE MID 60S. LIGHT WINDS.    
MONDAY  
 
MOSTLY CLEAR. LOWS IN THE UPPER 30S. HIGHS AROUND 70. LIGHT  
WINDS.    
TUESDAY  
 
MOSTLY CLEAR. LOWS IN THE UPPER 30S. HIGHS AROUND 70.    
WEDNESDAY  
 
MOSTLY CLEAR. LOWS IN THE UPPER 30S. HIGHS AROUND 70.  
 
 
FORECASTER...STETZER  
REQUESTED BY...CHRIS ENRIQUEZ  
TYPE OF REQUEST...PRESCRIBED  
.TAG 2621360.8/BYZ  
.DELDT 09/17/26  
.FORMATTERVERSION 2.0.0  
.EMAIL TYLER.KUHN@USDA.GOV,NICHOLAS.NELSON@USDA.GOV,CHRISTIAN.ENRIQUEZ@USDA.GOV  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab MT Page
The Nexlab WY Page
Main Text Page