051  
FXUS65 KBOU 181124  
AFDBOU  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DENVER/BOULDER CO  
524 AM MDT THU SEP 18 2025  
   
KEY MESSAGES
 
 
 
- REMAINING DRY TODAY AND TOMORROW, WITH SLIGHTLY MILDER  
CONDITIONS.  
 
- TEMPERATURES WILL WARM BACK TO SEASONAL AVERAGES FOR THE  
WEEKEND, WITH RETURNING POTENTIAL OF AFTERNOON SHOWERS/T-STORMS.  
 

 
   
UPDATE
 
 
ISSUED AT 801 PM MDT WED SEP 17 2025  
 
THE FORECAST REMAINS LARGELY ON TRACK THIS EVENING, WITH ONLY  
MINOR ADJUSTMENTS MADE TO THE POPS. HAVE TRIMMED THEM SLIGHTLY  
ACROSS PARTS OF THE PLAINS, PARTICULARLY SOUTH OF THE CHEYENNE  
RIDGE, WHERE PERSISTENT NORTHERLY WINDS ARE EXPECTED TO LIMIT  
PRECIPITATION POTENTIAL.  
 
DESPITE THE UPPER-LEVEL LOW REMAINING OVER THE REGION, WE ARE  
ALREADY OBSERVING INCREASING ATMOSPHERIC STABILITY, WHICH SHOULD  
FURTHER SUPPRESS CONVECTIVE DEVELOPMENT OVERNIGHT.  
 

 
   
DISCUSSION /THROUGH WEDNESDAY/
 
 
ISSUED AT 259 PM MDT WED SEP 17 2025  
 
THE UPPER LOW OVER SOUTHEAST WYOMING WILL BE DRIFTING SOUTHEAST  
OVERNIGHT. THERE'S A POCKET OF COOLER AIR ALOFT AND A BIT OF QG  
LIFT THAT WILL COME ALONG WITH IT. WE HAD BEEN FAVORING THE  
SOUTHERN PART OF OUR AREA FOR BETTER INSTABILITY AND HIGHER POPS  
OVERNIGHT, BUT THE SITUATION IS MORE COMPLICATED THAN THAT. THE  
SURFACE WILL LIKELY WIND UP WARMER IN THE SOUTH, AND SHOWERS THAT  
FORM OVER THE RELATIVELY WARM FRONT RANGE AND CENTRAL MOUNTAINS  
WILL DRIFT THAT WAY. BUT THE COOLING ALOFT WILL BE BETTER IN THE  
NORTH ALONG WITH THE MOISTURE AND LIFT. SO WE'RE BUMPING UP POPS A  
BIT IN THE NORTH AND DROPPING THEM A BIT IN THE SOUTH. CAPES ARE  
LOWER TODAY, AROUND 400-600 J/KG SO ENOUGH FOR SOME THUNDER BUT WE  
SHOULDN'T HAVE ANYTHING STRONG. WEAK LIFT PERSISTS MUCH OF THE  
NIGHT, SO WE MAY JUST SEE A GRADUAL FADE IN THE SHOWER ACTIVITY.  
 
THURSDAY MORNING DRIER AND WARMER AIR ALOFT WILL BE MOVING OVER,  
BUT THERE WILL STILL BE SOME COOL MOIST AIR AT LOW LEVELS. THERE  
WILL LIKELY STILL BE SOME STRATUS OVER THE PLAINS THAT WILL TAKE  
A WHILE TO BREAK UP. IT'S NOT CLEAR IF DENVER WILL STILL HAVE  
CLOUD COVER OR IF IT WILL BE DRIFTING EAST BY MORNING, BUT WE'LL  
LIKELY HAVE PLENTY OF SUN IN THE CITY MUCH OF THE DAY. THERE MAY  
STILL BE ENOUGH MOISTURE FOR SOME WEAK MOUNTAIN CONVECTION IN THE  
AFTERNOON, BUT THE DRYING WILL BE CONTINUING.  
 
THE MODELS ARE TRENDING LESS AMPLIFIED WITH THE UPSTREAM RIDGE  
OVER THE WEEKEND, BRING A VIGOROUS SHORTWAVE THAT MAY HAVE A  
CLOSED LOW EMBEDDED IN IT DOWN INTO THE PLAINS EARLY NEXT WEEK.  
WHILE THERE'S AN UPWARD TREND IN THE DYNAMIC STRENGTH OF THIS  
SYSTEM AND IT MAY BE NEAR TO US, IT'S IN A RELATIVELY DRY AND  
STABLE ENVIRONMENT. THE NBM HASN'T REALLY RESPONDED TO THIS TREND  
YET, KEEPING POPS LOW WITH ONLY A LITTLE COOLING IN THE  
MONDAY/TUESDAY TIME FRAME. WE'LL HAVE TO KEEP AN EYE ON THE  
POSSIBLE NEED FOR A GREATER IMPACT, BUT GIVEN THE SURROUNDINGS IT  
STILL PROBABLY WON'T BE MUCH. IT STILL LOOKS LIKE THERE WILL BE A  
HIGH AMPLITUDE RIDGE WEST OF US BY THE MIDDLE OF NEXT WEEK, SO  
WE'LL LIKELY CONTINUE TO HAVE DRY WEATHER AND SEASONAL  
TEMPERATURES.  
 

 
   
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
 
 
ISSUED AT 509 AM MDT THU SEP 18 2025  
 
VFR CONDITIONS WILL PREVAIL FOR ALL TERMINALS THROUGH THE TAF  
PERIOD. EXPECT TYPICAL DIURNAL WIND PATTERNS TODAY, WITH LIGHT  
WINDS < 10 KTS ROTATING CLOCKWISE FROM SW DRAINAGE EARLY THIS  
MORNING TO NE FLOW NEAR MIDDAY, RETURNING TO DRAINAGE FLOW IN THE  
EVENING.  
 

 
   
BOU WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
UPDATE...BONNER  
DISCUSSION...GIMMESTAD  
AVIATION...RODRIGUEZ  
 
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