285  
FNUS75 KBOU 140135  
FWSBOU  
 
SPOT FORECAST FOR HWY 40 FIRE...JEFFCOM911  
NATIONAL WEATHER SERVICE DENVER/BOULDER CO  
735 PM MDT SAT SEP 13 2025  
 
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER  
SERVICE.  
   
DISCUSSION
 
SCATTERED SHOWERS AND THUNDERSTORMS PRODUCING LIGHT  
TO MODERATE RAIN THROUGH MIDNIGHT TONIGHT. ALTHOUGH, BEST CHANCE  
OF PRECIPITATION MAY STAY NORTH OF WILDFIRE. MAIN THREAT WITH ANY  
STORM WILL BE LIGHTNING AND VARIABLE WIND GUSTS UP TO 40 MPH.  
ASIDE FROM THUNDERSTORM ACTIVITY, WINDS SHOULD BE W/NW UP TO 15  
MPH AT TIMES THROUGHOUT THE NIGHT. RELATIVE HUMIDITY VALUES WILL  
BE BETWEEN 75-85%.  
   
REST OF TONIGHT
 
 
SKY/WEATHER.........MOSTLY CLOUDY (80-90 PERCENT). RAIN SHOWERS  
LIKELY AND CHANCE OF THUNDERSTORMS UNTIL 2100,  
THEN SLIGHT CHANCE OF THUNDERSTORMS UNTIL 2400.  
CHANCE OF RAIN SHOWERS AFTER 2100.  
CWR.................60 PERCENT DECREASING TO 7 PERCENT.  
CHANCE OF THUNDER...25 PERCENT.  
MIN TEMPERATURE.....AROUND 44.  
MAX HUMIDITY........85 PERCENT.  
WIND (20 FT)........WEST WINDS 5 TO 13 MPH UNTIL 0100, THEN 6 TO 11  
MPH. GUSTY AND ERRATIC WINDS EXPECTED NEAR  
THUNDERSTORMS UNTIL 2400.  
MIXING HEIGHT.......1000 FT AGL.  
TRANSPORT WINDS.....WEST 8 TO 13 MPH.  
SMOKE DISPERSAL.....POOR.  
 
TIME (MDT) 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM  
SKY (%).........87 93 85 83 75 79 72 75 80 77  
WEATHER COV.....LKY CHC CHC CHC CHC CHC CHC CHC CHC CHC  
WEATHER TYPE....RW RW RW RW RW RW RW RW RW RW  
TSTM COV........CHC SCH SCH SCH  
CWR.............60 40 40 40 10 10 10 10 10 10  
CHC OF THDR (%).30 10 10 10 10 10 10 0 0 0  
TEMP............53 51 49 48 47 46 46 46 45 46  
RH..............75 80 83 82 85 85 81 84 82 76  
20 FT WIND DIR..NW NW W W W W W W W W  
20 FT WIND SPD..7 8 8 8 8 8 8 8 8 8  
20 FT WIND GUST.12 13 13 13 13 13 13 13 13 13  
MIX HGT (KFT)...1.4 1.1 1.1 1.1 1.0 1.1 1.0 1.2 1.1 1.7  
TRANSP WIND DIR.W W W W W W W W W W  
TRANSP WIND SPD.9 8 8 9 9 9 10 12 13 13  
VRATE KT-FT/1K..12 8 8 9 8 9 9 12 12 19  
SMOKEDISPERSION.P P P P P P P P P P  
   
SUNDAY
 
 
SKY/WEATHER.........MOSTLY CLOUDY (70-80 PERCENT) UNTIL 1100, THEN  
PARTLY CLOUDY (35-45 PERCENT) UNTIL 1500, THEN  
MOSTLY SUNNY (15-25 PERCENT). CHANCE OF RAIN  
SHOWERS UNTIL 0900, THEN SLIGHT CHANCE OF RAIN  
SHOWERS UNTIL 1200.  
CWR.................11 PERCENT.  
CHANCE OF THUNDER...15 PERCENT.  
MAX TEMPERATURE.....AROUND 67.  
MIN HUMIDITY........33 PERCENT.  
WIND (20 FT)........NORTHWEST WINDS 7 TO 12 MPH UNTIL 1100, THEN 9  
TO 14 MPH UNTIL 1500, THEN WEST UNTIL 1700,  
THEN AROUND 9 MPH.  
MIXING HEIGHT.......3000 FT AGL UNTIL 1100, THEN 7200 FT AGL.  
TRANSPORT WINDS.....NORTHWEST 10 TO 16 MPH.  
SMOKE DISPERSAL.....POOR UNTIL 1100, THEN FAIR UNTIL 1200, THEN  
GOOD.  
 
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM  
SKY (%).........80 79 77 72 66 47 37 34 31 21 20 22  
WEATHER COV.....CHC CHC CHC SCH SCH SCH  
WEATHER TYPE....RW RW RW RW RW RW  
TSTM COV........  
CWR.............10 10 10 10 10 10 0 0 0 0 0 0  
CHC OF THDR (%).10 10 10 10 10 10 20 20 20 20 20 20  
TEMP............45 44 45 48 53 58 61 63 63 65 66 65  
RH..............81 85 81 75 63 51 46 42 39 37 33 34  
20 FT WIND DIR..W W W NW NW NW NW NW NW W W W  
20 FT WIND SPD..8 8 9 10 10 10 10 10 12 12 10 9  
20 FT WIND GUST.13 14 16 17 17 17 17 17 18 18 17 15  
MIX HGT (KFT)...1.1 1.3 1.4 2.6 3.5 4.6 6.5 6.9 7.1 7.3 7.3 7.2  
TRANSP WIND DIR.NW NW NW NW NW NW NW NW NW NW W W  
TRANSP WIND SPD.13 12 10 13 13 14 16 15 14 15 14 14  
VRATE KT-FT/1K..12 13 13 29 39 56 91 89 85 95 88 87  
SMOKEDISPERSION.P P P P P F G G G G G G  
 

 
FORECASTER...IDEKER  
REQUESTED BY...ELIZABETH CLARK  
TYPE OF REQUEST...WILDFIRE  
.TAG 2521933.0/BOU  
.DELDT 09/13/25  
.FORMATTERVERSION 2.0.0  
.EMAIL ELIZABETH.CLARK@JEFFCOM911CO.GOV  
 
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