477  
FNUS75 KBOU 182040  
FWSBOU  
 
SPOT FORECAST FOR DEER VALLEY...JEFFCOM  
NATIONAL WEATHER SERVICE DENVER/BOULDER CO  
240 PM MDT FRI SEP 18 2026  
 
IF CONDITIONS BECOME UNREPRESENTATIVE...CONTACT THE NATIONAL WEATHER  
SERVICE.  
   
DISCUSSION
 
 
AS OF 1430, THERE ARE SEVERAL SHOWERS AND THUNDERSTORMS IN THE  
VICINITY OF THE LOCATION WITH LIGHTNING NOTED AS CLOSE AS 2 MILES  
IN THE LAST FEW MINUTES. THE THUNDERSTORM PRODUCING THIS LIGHTNING  
IS NEARLY STATIONARY, BUT SLOWLY MOVING TO THE EAST TOWARDS THE  
LOCATION. WE EXPECT THESE SHOWERS AND THUNDERSTORMS TO BECOME MORE  
ORGANIZED AND MORE NUMEROUS AS THE AFTERNOON PROGRESSES. THERE IS  
A 50-70% CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON WITH  
THE HIGHEST CHANCES THROUGH ABOUT 1800. LOW SHOWER/THUNDERSTORM  
CHANCES (20-30%) CONTINUE THROUGH ABOUT 2100. ANY THUNDERSTORM COULD  
PRODUCE STRONG WINDS UP TO 40 MPH, LIGHTNING, AND BRIEFLY HEAVY  
RAINFALL.  
 
TEMPERATURES ARE PEAKING IN THE LOW 70S FOR THE DAY WITH  
TEMPERATURES FALLING INTO THE 50S AND 60S THROUGH THE EVENING.  
WINDS WILL BE RATHER VARIABLE THIS AFTERNOON AND EVENING, BUT  
GENERALLY NORTH THROUGH THE AFTERNOON AND THEN WEST AT 5-10 MPH.  
WINDS COULD BE DISRUPTED BY ANY THUNDERSTORM CAUSING  
ERRATIC WINDS. WINDS ARE THEN EXPECTED TO TURN NORTH OVERNIGHT,  
BUT REMAIN UNDER 10 MPH. ASIDE FROM WINDS ASSOCIATED WITH  
THUNDERSTORMS, SOME GUSTS AROUND 15 MPH ARE POSSIBLE, MAINLY BEFORE  
MIDNIGHT. MAINLY CLOUDY SKIES ARE IN PLACE WITH SOME CLEARING  
TAKING PLACE AS THE EVENING AND OVERNIGHT PROGRESS.  
   
REST OF TODAY
 
 
SKY/WEATHER.........MOSTLY CLOUDY (75-85 PERCENT). CHANCE OF  
SHOWERS AND THUNDERSTORMS.  
CHANCE OF PCPN......50 PERCENT.  
MAX TEMPERATURE.....AROUND 75.  
MIN HUMIDITY........44 PERCENT.  
SURFACE WINDS (MPH).NORTH WINDS AROUND 6 MPH UNTIL 1600, THEN WEST  
5 TO 7 MPH.  
 
TIME (MDT) 3PM 4PM 5PM  
SKY (%).........80 76 75  
WEATHER COV.....CHC CHC CHC  
WEATHER TYPE....RW RW RW  
TSTM COV........CHC CHC CHC  
CHC OF PCPN (%).70 70 60  
TEMP............72 65 62  
RH..............55 62 67  
SURFACE WND DIR.N NW W  
SURFACE WND SPD.6 6 5  
SURFACE WND GST.9 10 8  
   
TONIGHT
 
 
SKY/WEATHER.........MOSTLY CLOUDY (60-70 PERCENT) UNTIL 2300, THEN  
PARTLY CLOUDY (30-40 PERCENT). CHANCE OF RAIN  
SHOWERS AND THUNDERSTORMS UNTIL 2100.  
CHANCE OF PCPN......30 PERCENT.  
MIN TEMPERATURE.....AROUND 47.  
MAX HUMIDITY........89 PERCENT.  
SURFACE WINDS (MPH).WEST WINDS 5 TO 7 MPH UNTIL 2200, THEN NORTH WINDS 5 TO 6  
MPH.  
 
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM  
SKY (%).........72 68 67 63 57 43 31 29 27 25 22 23  
WEATHER COV.....CHC CHC SCH  
WEATHER TYPE....RW RW RW  
TSTM COV........SCH SCH SCH  
CHC OF PCPN (%).30 30 20 10 10 0 0 0 0 0 0 0  
TEMP............61 58 56 54 53 53 52 50 50 49 49 48  
RH..............72 77 83 86 89 86 86 86 83 83 80 80  
SURFACE WND DIR.W W W W W W N N N NW NW NW  
SURFACE WND SPD.5 5 5 5 3 3 5 5 5 6 5 5  
SURFACE WND GST.7 7 8 7 6 6 7 7 7 8 8 8  
 

 
FORECASTER...VARELA  
REQUESTED BY...DARIAN HORNADAY  
TYPE OF REQUEST...HAZMAT  
.TAG 2622135.0/BOU  
.DELDT 09/18/26  
.FORMATTERVERSION 2.0.0  
.EMAIL DARIAN.HORNADAY@JEFFCOM911CO.GOV  
 
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