443  
FNUS75 KTFX 211203  
FWSTFX  
 
SPOT FORECAST FOR RUGBY...HIDC  
NATIONAL WEATHER SERVICE GREAT FALLS MT  
603 AM MDT FRI AUG 21 2026  
 
FORECAST IS BASED ON FORECAST START TIME OF 0600 MDT ON AUGUST 21.  
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER  
SERVICE.  
   
DISCUSSION
 
 
WARM AND DRY CONDITIONS CONTINUE TODAY WITH INCREASING HIGHER  
LEVEL CLOUDS LATE IN THE DAY. A SUBTLE SHORTWAVE EMBEDDED IN AN  
INCREASINGLY SOUTHWESTERLY FLOW ALOFT WILL SEND A WAVE OF  
WEAKENING ISOLATED SHOWERS AND THUNDERSTORMS INTO THE LITTLE BELTS  
LATE TONIGHT INTO SATURDAY MORNING. THE PRIMARY CONCERN WITH THIS  
ACTIVITY WILL BE WIND GUSTS IN EXCESS OF 25 MPH AND ISOLATED  
LIGHTNING. MORE IMPACTFUL STORMS WILL MOVE THROUGH LATE SATURDAY  
AFTERNOON AND EVENING. WIND GUSTS WITH THESE MAY EXCEED 60 MPH  
WITH THE STRONGEST CORES IN ADDITION TO BRIEF HEAVY DOWNPOURS,  
HAIL, AND CLOUD TO GROUND LIGHTNING. ANOTHER ROUND OF STORMS MAY  
MOVE THROUGH ON SUNDAY, THOUGH THIS IS CONTINGENT ON THE TIMING OF  
THE SURFACE FRONT. OTHERWISE, SUNDAY WILL BE BREEZY AND DRY WITH  
LOCALIZED ELEVATED FIRE WEATHER.  
   
TODAY
 
 
SKY/WEATHER.........MOSTLY SUNNY (25-35 PERCENT).  
CWR.................0 PERCENT.  
CHANCE OF THUNDER...0 PERCENT.  
MAX TEMPERATURE.....78-83.  
MIN HUMIDITY........22-26 PERCENT.  
WIND (20 FT)........  
SLOPE/VALLEY.......NORTHERLY WINDS AROUND 5 TO 10 MPH.  
RIDGETOP...........NORTHWESTERLY AROUND 5 TO 15 MPH.  
MIXING HEIGHT.......5500 FT AGL.  
TRANSPORT WINDS.....NORTHWEST 5 TO 10 MPH.  
 
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........40 45 28 18 20 22 24 11 15 19 22 19  
WEATHER COV.....PTY PTY PTY PTY PTY  
WEATHER TYPE....SMK SMK SMK SMK SMK  
TSTM COV........  
CWR.............0 0 0 0 0 0 0 0 0 0 0 0  
CHC OF THDR (%).0 0 0 0 0 0 0 0 0 0 0 0  
TEMP............59 57 59 63 68 72 74 77 78 79 80 79  
RH..............41 44 49 47 43 41 39 37 30 28 25 24  
20 FT WIND DIR..N N NW NW W NW NW NW NW NW N N  
20 FT WIND SPD..5 0 0 0 0 5 5 5 5 5 5 5  
20 FT WIND GUST. 5 5 5 5 10 10 10 10 10 10  
RIDGE WIND DIR..NW NW W W W W W W W W NW N  
RIDGE WIND SPD..5 5 5 5 5 5 5 5 5 5 5 5  
MIX HGT (KFT)...0.5 0.5 0.5 0.5 1.0 2.5 3.5 4.5 5.0 5.5 5.5 5.0  
TRANSP WIND DIR.NW NW N NW NW NW NW W W W NW N  
TRANSP WIND SPD.5 5 5 5 5 5 5 5 5 5 10 10  
   
TONIGHT
 
 
SKY/WEATHER.........BECOMING MOSTLY CLOUDY (70-80 PERCENT). SLIGHT CHANCE OF  
SHOWERS AND THUNDERSTORMS AFTER 3 AM.  
CWR.................5 PERCENT.  
CHANCE OF THUNDER...15 PERCENT.  
MIN TEMPERATURE.....58-63.  
MAX HUMIDITY........51-56 PERCENT.  
WIND (20 FT)........  
SLOPE/VALLEY.......EASTERLY WINDS 5 TO 15 MPH. GUSTY AND  
ERRATIC WINDS EXPECTED NEAR SHOWERS OR THUNDERSTORMS  
RIDGETOP...........EASTERLY 5 TO 15 MPH.  
MIXING HEIGHT.......500 FT AGL.  
TRANSPORT WINDS.....EASTERLY AROUND 10 TO 15 MPH  
 
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM  
SKY (%).........25 27 52 61 71 63 60 56 66 47 60 91  
WEATHER COV..... SCH SCH  
WEATHER TYPE.... RW RW  
TSTM COV........ SCH SCH  
CWR.............0 0 0 0 0 0 10 10 10 10 10 10  
CHC OF THDR (%).0 0 0 0 0 0 0 10 10 10 20 20  
TEMP............79 78 73 69 67 66 65 64 64 63 62 62  
RH..............33 36 42 46 46 47 46 46 47 48 48 49  
20 FT WIND DIR..N NE NE E E SE SE SE SE SE SE SE  
20 FT WIND SPD..5 5 5 10 5 5 10 10 10 10 10 10  
20 FT WIND GUST.10 15 15 15 15 20 20 20 20 20 15  
RIDGE WIND DIR..NE NE E SE SE SE SE SE S S S S  
RIDGE WIND SPD..5 5 5 10 10 15 15 15 15 15 15 15  
MIX HGT (KFT)...4.0 2.0 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5  
TRANSP WIND DIR.NE E NE E E SE SE SE SE SE SE S  
TRANSP WIND SPD.10 10 10 10 10 10 15 15 15 15 15 15  
   
SATURDAY
 
 
SKY/WEATHER.........CLOUDY (85-95 PERCENT) THEN BECOMING PARTLY  
SUNNY (30-50 PERCENT). SLIGHT CHANCE OF SHOWERS  
AND THUNDERSTORMS IN THE MORNING. SLIGHT CHANCE  
OF SHOWERS AND THUNDERSTORMS IN THE  
AFTERNOON.  
CWR.................5 PERCENT.  
CHANCE OF THUNDER...20 PERCENT.  
MAX TEMPERATURE.....78-83.  
MIN HUMIDITY........20-25 PERCENT.  
WIND (20 FT)........  
SLOPE/VALLEY.......SOUTHEAST WINDS 5 TO 10 MPH SHIFTING TO THE  
SOUTHWEST IN THE AFTERNOON. GUSTY AND ERRATIC  
WINDS EXPECTED NEAR THUNDERSTORMS IN THE  
MORNING. GUSTY AND ERRATIC WINDS EXPECTED NEAR  
THUNDERSTORMS LATE IN THE AFTERNOON.  
RIDGETOP...........SOUTHWEST 15 TO 20 MPH SHIFTING TO THE WEST  
AROUND 10 MPH LATE IN THE AFTERNOON.  
MIXING HEIGHT.......6500 FT AGL.  
TRANSPORT WINDS.....SOUTH 10 TO 15 MPH SHIFTING TO THE WEST LATE IN  
THE AFTERNOON.  
 
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........100 100 100 92 92 92 79 79 79 35 35 35  
WEATHER COV.....SCH SCH SCH SCH SCH SCH SCH SCH  
WEATHER TYPE....RW RW RW RW RW RW RW RW  
TSTM COV........SCH SCH SCH SCH SCH SCH SCH SCH  
CWR.............10 10 10 10 10 10 10 10 10 10 10 10  
CHC OF THDR (%).20 20 20 20 20 20 20 10 10 10 10 20  
TEMP............62 60 61 63 68 71 73 76 78 78 80 78  
RH..............49 55 56 56 48 45 41 38 30 28 25 22  
20 FT WIND DIR..SE SE SE S S S S S S SW SW SW  
20 FT WIND SPD..10 5 5 5 5 5 10 10 10 5 5 5  
20 FT WIND GUST.15 15 15 15 15 20 20 20 20 25 25 25  
RIDGE WIND DIR..S S SW SW SW S S S SW SW SW W  
RIDGE WIND SPD..15 20 20 20 20 20 20 20 20 25 20 20  
MIX HGT (KFT)...0.5 0.5 0.5 1.0 1.5 1.5 2.5 5.5 5.5 6.0 6.5 5.5  
TRANSP WIND DIR.S SE S S S S S S S SW SW W  
TRANSP WIND SPD.15 10 10 10 15 15 15 15 20 15 10 10  
 

 
FORECASTER...GREELY  
REQUESTED BY...RCH  
TYPE OF REQUEST...WILDFIRE  
.TAG 2620058.1/TFX  
.DELDT 08/21/26  
.FORMATTERVERSION 2.0.0  
.EMAIL XAVIER.DELATORRE@USDA.GOV,MTHDC@FIRENET.GOV,RYAN.KOOIKER@USDA.GOV,CLAYBUS2481@GMAIL.COM,  
TFX.OPS@NOAA.GOV  
 
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