199  
FXUS65 KBOU 142054  
AFDBOU  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DENVER/BOULDER CO  
254 PM MDT MON SEP 14 2026  
   
KEY MESSAGES
 
 
- STILL WARM TODAY, WITH ISOLATED TO SCATTERED SHOWERS AND A  
COUPLE STORMS. MOSTLY LIGHT PRECIPITATION AMOUNTS.  
 
- UNSETTLED PATTERN REST OF THIS WEEK, BUT PLENTY OF UNCERTAINTY  
WITH REGARD TO DAILY PRECIPITATION CHANCES. THURSDAY STILL LOOKS  
LIKE THE HIGHEST OPPORTUNITY OF MEASURABLE RAIN (50-70%), AND A  
LOCALLY HEAVY RAINFALL THREAT.  
 
- COOLER WEATHER ARRIVING FOR TUESDAY. TEMPERATURES BOUNCE BACK  
WEDNESDAY, BUT THEN AVERAGE AROUND SEASONAL NORMALS THROUGH NEXT  
WEEKEND.  
 

 
   
DISCUSSION /THROUGH MONDAY/
 
 
ISSUED AT 251 PM MDT MON SEP 14 2026  
 
LIGHT SHOWERS SPRINKLED ACROSS THE AREA AND ABUNDANT CLOUD COVER  
HAVE ALLOWED TEMPERATURES OVER THE DENVER METRO AND PLAINS TO LINGER  
IN JUST THE LOW 80S. THE MOUNTAINS HAVE SEEN A BIT MORE SUNSHINE AS  
A SHORTWAVE CONTINUES PUSH EAST HOWEVER, DAYTIME HEATING AND  
MONSOONAL MOISTURE HAVE QUICKLY PROMOTED THE DEVELOPMENT OF SHOWERS  
AND STORMS OVER THE PEAKS AND RIDGES WITH WINDS OCCASIONALLY GUSTING  
TO 30-40 MPH. THOUGH AN ISOLATED SHOWER CANNOT BE RULED OUT FOR THE  
DENVER METRO LATE THIS AFTERNOON, THE BEST CHANCE OF RAIN AT LOW  
ELEVATIONS WILL BE OVER THE EASTERNMOST COLORADO PLAINS, WHERE  
BETTER INSTABILITY AND MOISTURE ARE IN PLACE.  
 
A COLD FRONT WILL MOVE IN FROM THE NORTH LATE TONIGHT, BRINGING A  
PERIOD OF BREEZY NORTHERLY WINDS IN THE EARLY MORNING HOURS. HIGH-  
RES MODEL GUIDANCE HAS TRENDED DRIER WITH THIS COLD FRONT, LIMITING  
THE DEVELOPMENT OF A PERSISTENT STRATUS LAYER. HOWEVER, PATCHY LOW  
CLOUDS WILL LIKELY STILL DEVELOP EAST OF DENVER AND ERODE JUST AFTER  
SUNRISE. WE EXPECT TEMPERATURES ON TUESDAY TO STAY BELOW NORMAL,  
WITH HIGHS IN THE MID 70S AT LOW ELEVATIONS. EVEN WITH PRECIPITABLE  
WATER (PW) VALUES IN THE 90TH PERCENTILE OVER MUCH OF THE STATE, THE  
POST-FRONTAL AIRMASS OVER THE PLAINS WILL STRUGGLE TO DESTABILIZE  
LEAVING THE BEST CHANCE FOR SHOWERS IN THE MOUNTAINS.  
 
A CLOSED UPPER-LEVEL LOW PRESSURE WILL BEGIN TO SLIDE THROUGH THE  
PACIFIC NORTHWEST AND GREAT BASIN REGION ON WEDNESDAY, TURNING FLOW  
ALOFT SOUTH-SOUTHWESTERLY. MODEST MONSOONAL MOISTURE TRANSPORT WILL  
BRING PW VALUES AS HIGH AS 0.80-1.00" TO THE MOUNTAINS WITH HIGHER  
VALUES POSSIBLE FOR THE EASTERN COLORADO PLAINS, WHERE SOUTHERLY  
SURFACE WINDS MAY ADVECT ADDITIONAL MOISTURE. THEREFORE, THURSDAY  
STILL LOOKS TO BE THE BEST CHANCE FOR MEANINGFUL RAINFALL AMOUNTS  
OVER THE DENVER METRO. THE FLASH FLOODING THREAT APPEARS TO BE  
LOCALIZED IN NATURE GIVEN THE VERY SHALLOW WARM-CLOUD LAYER AND  
MARGINAL STORM MOTIONS (LCL-EL MEAN WINDS ~18KT).  
 
THE EVOLUTION OF A FEW SHORTWAVE TROUGHS OVER THE PACIFIC NORTHWEST  
FRIDAY THROUGH SUNDAY REMAINS UNCLEAR. HOWEVER, THERE WILL LIKELY BE  
ENOUGH MOISTURE FOR DAILY PRECIPITATION CHANCES, PARTICULARLY OVER  
THE HIGH TERRAIN. TEMPERATURES WILL REMAIN NEAR-NORMAL OR EVEN  
COOLER THAN NORMAL, WITH HIGHS IN THE UPPER 70S AND LOW 80S THROUGH  
THE WEEKEND.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
 
 
ISSUED AT 1142 AM MDT MON SEP 14 2026  
 
CURRENT OBSERVATIONS ACROSS THE TAF SITES SHOW SOME CHANNELS OF  
GUSTY WESTERLY WINDS RESIDE EAST OF THE FRONT RANGE THIS MORNING  
WITH SOME MOUNTAIN WAVE ENHANCEMENT. MEANWHILE, THE PREVAILING  
WINDS ARE PREDOMINANTLY SOUTHWESTERLY ACROSS THE TAF SITES. HAVE  
MADE A FEW CHANGES TO THIS TAF PACKAGE TO ACCOUNT FOR THE MORE  
SOUTHWESTERLY WINDS HANGING ON LONGER THAN PREVIOUSLY FORECAST,  
AND ADDED A TEMPO FOR THE NEXT FEW HOURS TO ACCOUNT FOR THE  
WESTERLY GUSTS OCCASIONALLY MAKING THEIR WAY ONTO THE AIRFIELDS.  
THERE IS LOW CONFIDENCE IN TODAY'S WIND FORECAST AS THERE IS  
POTENTIAL WE COULD END UP BECOMING LIGHT AND VARIABLE, BUT WITH  
THE MAJORITY OF GUIDANCE SUGGESTING WE SEE SOUTHWESTERLY WINDS  
INCREASE BY 21/22Z, THERE IS HIGHER CONFIDENCE IN THIS SCENARIO,  
WHICH IS PORTRAYED IN THE TAF. HAVE KEPT THE PROB30 FOR GUSTY  
OUTFLOWS WITH PASSING SHOWERS THIS AFTERNOON, WITH INSTABILITY ON  
THE MARGINAL SIDE FOR TS POTENTIAL HAVE KEPT THE SHRA OVER TSRA,  
BUT CAN'T COMPLETELY RULE OUT A THUNDERSTORM (10-15% CHANCE).  
 
A COLD FRONT IS STILL EXPECTED LATE TONIGHT THAT WILL TURN WINDS  
TO THE NORTH BY ~6Z AT KDEN/KBJC, FOLLOWED BY KAPA ABOUT AN HOUR  
LATER. GUSTS BETWEEN 20-25 KTS CAN BE EXPECTED BEHIND THE FRONT,  
AND HI-RES GUIDANCE IS SHOWING POTENTIAL FOR SOME SHOWERS BETWEEN  
7-9Z, WITH THE BEST CHANCES FOR KBJC/KAPA, THOUGH WE MAY SEE SOME  
AT KDEN TOO, BUT CONFIDENCE IS TOO LOW TO ADD TO THE TAF THERE AT  
THIS TIME. THERE IS ALSO SOME UNCERTAINTY WITH STRATUS POTENTIAL  
WITH THE FRONTAL PASSAGE AS GUIDANCE HAS TRENDED DRIER THIS  
MORNING, BUT WE COULD SEE SOME LOW CLOUDS AT OR AROUND 7,000 FEET  
AGL WITH ANY SHOWERS THAT DEVELOP BETWEEN THAT 7-9Z TIME FRAME.  
 
WINDS ARE EXPECTED TO TURN TO THE SOUTHEAST BY EARLY TUESDAY  
AFTERNOON, WITH POTENTIAL FOR AFTERNOON SHOWERS/THUNDERSTORMS NEAR  
THE TAF SITES IN THE AFTERNOON, ONCE AGAIN.  
 

 
   
BOU WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
DISCUSSION...AA  
AVIATION...9  
 
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