568  
FNUS73 KUNR 031017  
FWSUNR  
 
SPOT FORECAST FOR BROKEN JAW...CASPER DISPATCH  
NATIONAL WEATHER SERVICE RAPID CITY SD  
417 AM MDT THU SEP 3 2026  
 
FORECAST IS BASED ON FORECAST START TIME OF 0600 MDT ON SEPTEMBER 03.  
IF CONDITIONS BECOME UNREPRESENTATIVE, CONTACT THE NATIONAL WEATHER  
SERVICE.  
 
...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 8 PM MDT THIS  
EVENING...  
   
DISCUSSION  
CRITICAL FIRE WEATHER CONDITIONS TODAY AND FRIDAY.  
 
AFTER POOR RH RECOVERY OVERNIGHT, CRITICAL FIRE WEATHER IS  
EXPECTED TODAY OVER THE SPOT LOCATION. MIN RH IS EXPECTED AROUND  
10 PERCENT THIS AFTERNOON, WITH WIND GUSTS UP TO 25 MPH IN THE  
SAME TIME PERIOD. WINDS WILL BE OUT OF THE SOUTHWEST TODAY.  
 
TONIGHT EXPECT POOR RH RECOVERY AGAIN, ONLY CLIMBING TO AROUND 35  
PERCENT, WITH CONTINUED SOUTHWEST TO SOUTHERLY WINDS BUT A BIT  
LIGHTER.  
 
FRIDAY WILL BE THE HOTTEST DAY OF THE WEEK (90-92F) ALONG WITH  
GUSTY SOUTHWEST WINDS RESULTING IN CRITICAL FIRE WEATHER  
CONDITIONS AGAIN.  
   
TODAY  
 
SKY/WEATHER.........PARTLY SUNNY (55-65 PERCENT) THEN BECOMING  
SUNNY (5-15 PERCENT).  
MAX TEMPERATURE.....AROUND 85.  
MIN HUMIDITY........10 PERCENT.  
WIND (20 FT)........SOUTHWEST WINDS 10 TO 15 MPH. GUSTS UP TO 16  
MPH INCREASING TO 25 MPH IN THE AFTERNOON.  
CWR.................0 PERCENT.  
MIXING HEIGHT.......9400 TO 9900 FT AGL INCREASING TO 11300 TO  
11800 FT AGL LATE IN THE AFTERNOON.  
TRANSPORT WINDS.....EAST 10 TO 15 MPH SHIFTING TO THE SOUTH 15 TO  
20 MPH LATE IN THE MORNING, THEN SHIFTING TO  
THE SOUTHWEST AROUND 25 MPH IN THE AFTERNOON.  
SMOKE DISPERSAL.....GOOD INCREASING TO EXCELLENT.  
 
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........63 59 20 6 4 8 4 7 8 6 10 19  
WEATHER COV.....  
WEATHER TYPE....  
TSTM COV........  
CWR.............0 0 0 0 0 0 0 0 0 0 0 0  
TEMP............66 65 66 70 74 78 81 83 84 85 85 85  
RH..............33 36 35 32 28 23 18 15 13 12 11 10  
20 FT WIND DIR..S S S S S S SW SW SW SW SW SW  
20 FT WIND SPD..6 6 6 7 8 9 12 13 13 14 14 13  
20 FT WIND GUST.12 10 12 10 14 16 20 21 23 24 24 25  
MIX HGT (KFT)...0.5 0.4 0.5 1.3 2.8 4.8 7.4 9.9 11 12 11 11  
TRANSP WIND DIR.NE E E E SE S S S SW SW SW SW  
TRANSP WIND SPD.10 9 10 12 13 16 18 21 22 23 23 23  
   
TONIGHT  
 
SKY/WEATHER.........MOSTLY CLEAR (15-25 PERCENT).  
MIN TEMPERATURE.....AROUND 64.  
MAX HUMIDITY........30 PERCENT.  
WIND (20 FT)........SOUTH WINDS 10 TO 20 MPH WITH GUSTS TO AROUND  
26 MPH.  
CWR.................0 PERCENT.  
MIXING HEIGHT.......500 TO 1000 FT AGL.  
TRANSPORT WINDS.....SOUTHWEST 20 TO 25 MPH SHIFTING TO THE SOUTH.  
SMOKE DISPERSAL.....EXCELLENT DECREASING TO POOR.  
 
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM  
SKY (%).........14 29 33 33 25 21 22 24 21 17 11 13  
WEATHER COV.....  
WEATHER TYPE....  
TSTM COV........  
CWR.............0 0 0 0 0 0 0 0 0 0 0 0  
TEMP............84 80 76 73 70 68 67 67 67 66 65 64  
RH..............12 14 15 17 19 20 21 22 23 26 28 29  
20 FT WIND DIR..SW SW S S S S S S S S S S  
20 FT WIND SPD..13 12 9 8 8 9 10 12 14 15 16 17  
20 FT WIND GUST.24 21 18 16 17 17 18 21 23 24 25 26  
MIX HGT (KFT)...10 1.8 0.7 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5  
TRANSP WIND DIR.SW S SE SE SE S S S S S S S  
TRANSP WIND SPD.22 20 16 15 15 15 17 20 22 23 24 25  
   
FRIDAY  
 
SKY/WEATHER.........SUNNY (10-20 PERCENT).  
MAX TEMPERATURE.....AROUND 90.  
MIN HUMIDITY........13 PERCENT.  
WIND (20 FT)........SOUTH WINDS 20 TO 25 MPH. GUSTS UP TO 35 MPH  
INCREASING TO 36 MPH LATE IN THE AFTERNOON.  
CWR.................0 PERCENT.  
MIXING HEIGHT.......10000 TO 10500 FT AGL.  
TRANSPORT WINDS.....SOUTH 30 TO 35 MPH SHIFTING TO THE SOUTHWEST 35  
TO 40 MPH LATE IN THE MORNING.  
SMOKE DISPERSAL.....FAIR INCREASING TO EXCELLENT.  
 
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........10 26 12 5 4 7 6 11 8 4 5 5  
WEATHER COV.....  
WEATHER TYPE....  
TSTM COV........  
CWR.............0 0 0 0 0 0 0 0 0 0 0 0  
TEMP............65 67 71 75 80 83 86 89 90 90 90 90  
RH..............30 29 28 26 22 19 18 15 14 13 13 13  
20 FT WIND DIR..S S S S S S S S S S S S  
20 FT WIND SPD..17 18 20 20 21 22 22 22 21 20 20 18  
20 FT WIND GUST.26 28 28 28 30 32 33 35 36 35 35 32  
MIX HGT (KFT)...0.6 0.9 1.2 1.6 3.8 6.1 8.3 9.1 9.8 11 10 10  
TRANSP WIND DIR.S S S S S S SW SW SW SW SW SW  
TRANSP WIND SPD.26 29 31 33 35 36 36 35 33 32 32 31  
 
 
FORECASTER...AD  
REQUESTED BY...MOLLY WARTENBEE  
TYPE OF REQUEST...WILDFIRE  
.TAG 2621124.2/UNR  
.DELDT 09/03/26  
.FORMATTERVERSION 2.0.0  
.EMAIL WYCPC@FIRENET.GOV  
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