638  
FXUS65 KBOU 112016  
AFDBOU  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DENVER/BOULDER CO  
216 PM MDT FRI SEP 11 2026  
   
KEY MESSAGES  
 
- VERY WARM TODAY WITH ONLY ISOLATED HIGH BASED SHOWERS/VIRGA  
LATE THIS AFTERNOON AND EVENING.  
 
- SLIGHT INCREASE IN SHOWER/STORM COVERAGE THIS WEEKEND. COOLER  
SATURDAY, THEN WARMER SUNDAY.  
 
- UNSETTLED PATTERN NEXT WEEK, WITH MULTIPLE COLD FRONTS EXPECTED  
TO BRING A FEW MORE NOTICEABLE COOLDOWNS.  
 
 
   
DISCUSSION /THROUGH FRIDAY/  
 
ISSUED AT 1245 PM MDT FRI SEP 11 2026  
 
THIS MORNING'S WAVE CLOUD KEPT SOME HEAT RELIEF IN PLACE FOR THE  
NORTHERN CORRIDOR FOR THE FIRST HALF OF THE DAY. NOW THAT THE  
CLOUD HAS DISSIPATED, TEMPERATURES ARE QUICKLY HEATING, WITH KLMO  
SEEING AN EIGHT DEGREE WARMING IN THE PAST HOUR ALONE.  
TEMPERATURES WERE ADJUSTED SLIGHTLY TO ACCOUNT FOR THE COOLER  
MORNING, BUT WE ARE STILL EXPECTING A HOT DAY ACROSS THE LOWER  
ELEVATIONS DUE TO DOWNSLOPING WINDS AND A SLIGHT WARMING IN  
TEMPERATURES ALOFT. WATER VAPOR IMAGERY SHOWS MOISTURE HAS  
SLIGHTLY INCREASED IN THE WESTERLY FLOW ALOFT THROUGH THE MORNING.  
WE STILL EXPECT SOME ISOLATED HIGH-BASED SHOWERS TO DEVELOP THIS  
AFTERNOON OVER THE HIGHER ELEVATIONS, WITH SOME VIRGA SHOWERS  
EXPECTED TO BRING GUSTY OUTFLOWS TO THE LOWER ELEVATIONS. WE MAY  
MANAGE TO SQUEEZE A FEW SPRINKLES OUT OF SOME OF THEM, BUT MOSTLY  
JUST EXPECT 30-40 MPH WINDS AS VIRGA PASSES OVER FOR AREAS EAST OF  
THE MOUNTAINS.  
 
A COLD FRONT IS EXPECTED LATE TONIGHT/EARLY SATURDAY MORNING THAT  
WILL BRING SOME GUSTY NORTHERLY WINDS ACROSS THE PLAINS AND  
COOLER TEMPERATURES FOR SATURDAY. A SLIGHT INCREASE IN MOISTURE  
IS EXPECTED WITH THE FRONT AS WELL. AFTERNOON SHOWERS AND A FEW  
STORMS WILL BE POSSIBLE, WITH THE BEST CHANCES BEING OVER THE  
NORTHERN MOUNTAINS WHERE INSTABILITY WILL BE GREATEST, BUT CAN'T  
RULE OUT SOME HOLDING TOGETHER LONG ENOUGH TO PUSH OFF THE HIGHER  
ELEVATIONS. HAVE ADDED A MENTION OF AT LEAST SLIGHT CHANCE FOR  
POPS TO THE FORECAST ACROSS THE NORTHERN PLAINS AND AREAS ALONG  
THE PALMER DIVIDE.  
 
SUNDAY IS STILL ON TRACK TO BE THE HOTTEST DAY OF THE WEEK IN  
BETWEEN COLD FRONTS. WHILE THE NBM SEEMS TO HAVE A WARM BIAS, MOST  
GUIDANCE DOES SHOW AFTERNOON HIGHS IN THE LOW TO MID 90S, SO  
AFTERNOON HIGHS WERE TRIMMED BACK SLIGHTLY TO BE MORE IN LINE WITH  
THE MAJORITY OF GUIDANCE. EITHER WAY, IT WILL STILL BE HOT FOR THE  
SECOND WEEK OF SEPTEMBER. THERE WILL BE SOME BETTER INSTABILITY  
IN PLACE ACROSS THE NORTHEAST PLAINS THAT IF TAPPED INTO, COULD  
ALLOW FOR SOME STRONGER TO SEVERE STORMS IN THE AFTERNOON/EVENING.  
 
NOT MUCH HAS CHANGED IN THE LONG TERM FORECAST TODAY, WITH THE  
NORTHERN TIER STILL EXPECTED TO REMAIN ACTIVE OVER THE NEXT WEEK.  
A FEW COLD FRONTS ARE STILL PROGGED TO BRING A FEW MORE COOLDOWNS  
THROUGH THE WEEK, AND AFTERNOON SHOWERS AND STORMS WILL BE  
POSSIBLE EACH AFTERNOON.  
 
 
   
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/  
 
ISSUED AT 1206 PM MDT FRI SEP 11 2026  
 
VFR EXPECTED THROUGH THE TAF PERIOD. WINDS OVER THE REGION ARE  
CURRENTLY LIGHT (<10KT) AND NW/N, WITH THE EXCEPTION OF A CHANNEL OF  
STRONGER DOWNSLOPING WNW WINDS NEAR KBJC OCCASIONALLY GUSTING UP TO  
20KT. WE EXPECT NORTHWESTERLY FLOW TO PREVAIL THIS AFTERNOON THROUGH  
SUNSET (01Z-02Z). THERE IS A CHANCE FOR HIGH-BASED SHOWERS TO TAKE  
SHAPE LATE THIS AFTERNOON ALTHOUGH COVERAGE IS EXPECTED TO BE  
SPARSE. NEVERTHELESS, DRY MICROBURSTS AND OUTFLOWS COULD LEAD TO  
ERRATIC WINDS GUSTING UP TO 35KT NEAR THE SHOWERS.  
 
WINDS TONIGHT ARE A BIT UNCERTAIN ALTHOUGH THERE WILL LIKELY BE A  
RETURN TO SW/S DRAINAGE FLOW BY 04Z. A COLD FRONTAL PASSAGE WILL  
BRING A NORTHERLY WIND SHIFT ~10Z.  
 
 
   
BOU WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
DISCUSSION...9  
AVIATION...AA  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab CO Page
Main Text Page