914  
FXUS65 KBOU 151912  
AFDBOU  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DENVER/BOULDER CO  
112 PM MDT SAT AUG 15 2026  
   
KEY MESSAGES
 
 
 
- ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND  
EVENING. HEAVY RAINFALL AND FLASH FLOODING ARE THE MAIN THREATS  
TODAY. A FEW THUNDERSTORMS COULD BECOME SEVERE, WITH STRONG  
WINDS AND HAIL POSSIBLE.  
 
- MONSOON MOISTURE LASTS THROUGH SUNDAY, BRINGING SCATTERED  
SHOWERS AND THUNDERSTORMS AGAIN TOMORROW.  
 
- WARMING AND DRYING TREND FOR MONDAY AND TUESDAY.  
 
- ANOTHER ACTIVE DAY POSSIBLE MIDDLE OF NEXT WEEK.  
 

 
   
DISCUSSION /THROUGH SATURDAY/
 
 
ISSUED AT 103 PM MDT SAT AUG 15 2026  
 
THE WETTER WEATHER PATTERN WILL CONTINUE ON THROUGH THIS WEEKEND.  
FOR TODAY, THERE IS A RISK FOR SEVERE WEATHER AND FLASH FLOODING.  
THE EASTERN PLAINS SHOULD BE LOCATED NEAR THE RIGHT ENTRANCE REGION  
OF A JET OVER THE CENTRAL US WITH A SMALL DISTURBANCE EXPECTED IN  
THE FLOW ALOFT. GOES-19 SATELLITE IMAGERY SHOWS A CIRRUS SHIELD  
CURRENTLY OVER THE MOUNTAINS THAT COULD INITIALLY INHIBIT CONVECTIVE  
DEVELOPMENT. NEVERTHELESS, CONVECTIVE DEVELOPMENT IS STARTING TO  
OCCUR ACROSS THE FOOTHILLS AND IN LARIMER COUNTY. WE EXPECT SHOWERS  
AND THUNDERSTORMS TO DEVELOP ACROSS THE FOOTHILLS EARLY THIS  
AFTERNOON AND MOVE INTO THE I-25 CORRIDOR BY MID-TO-LATE AFTERNOON.  
THESE STORMS WILL THEN MOVE OFF TO THE EAST IN THE LATE AFTERNOON  
AND EARLY EVENING.  
 
THE PREVIOUSLY MENTIONED CIRRUS SHIELD COULD HINDER RAIN COVERAGE  
AND/OR PUSH THIS TIMING A BIT LATER. THE BIGGEST THREAT FOR TODAY  
WILL BE HEAVY RAINFALL WITH SOME EPISODES OF FLASH FLOODING POSSIBLE  
ACROSS THE AREA. THE WEATHER PREDICTION CENTER HIGHLIGHTS THE  
FOOTHILLS, I-25 CORRIDOR, AND THE EASTERN PLAINS IN A SLIGHT (2/4)  
RISK FOR EXCESSIVE RAINFALL FOR TODAY. SEVERAL INGREDIENTS ARE IN  
PLACE FOR THIS THREAT. THUS, A FLOOD WATCH IS IN EFFECT FROM 2PM TO  
10PM THIS AFTERNOON AND EVENING. SEE THE HYDRO DISCUSSION FOR MORE  
DETAILS.  
 
THE STORM PREDICTION CENTER HIGHLIGHTS THE PLAINS IN A  
SLIGHT (2/5) RISK. MLCAPE VALUES ARE FORECAST TO BE AROUND 1000-1200  
J/KG AND 0-6 KM SHEAR WILL BE AROUND 30-40 KTS. LARGE HAIL AND  
DAMAGING WINDS ARE POSSIBLE FROM STORMS TODAY, WITH THE HIGHEST  
CHANCES ALONG THE PALMER DIVIDE.  
 
TOMORROW WILL BRING SIMILAR THREATS AS TODAY, THOUGH WE EXPECT LESS  
COVERAGE OF THUNDERSTORMS. THUS, THE THREATS WILL BE MORE LOCALIZED  
IN NATURE. MLCAPE AND BULK SHEAR VALUES ARE FORECAST TO BE LOWER  
THAN TODAY. THE HIGHEST CHANCES FOR SHOWERS AND THUNDERSTORMS  
TOMORROW SHOULD STAY ALONG/NEAR THE PALMER DIVIDE, BUT THERE WILL  
STILL BE SCATTERED STORMS POSSIBLE FOR MOST OF OUR PLAINS.  
 
HIGH PRESSURE WILL SHIFT CLOSER TO OUR AREA FOR MONDAY AND TUESDAY  
FURTHER LOWERING RAIN CHANCES AND RAISING TEMPERATURES TO AROUND  
90 DEGREES FOR THE PLAINS. BY WEDNESDAY, HIGH PRESSURE SHOULD  
SHIFT OFF TO THE SOUTHWEST, OPENING THE DOOR FOR A DISTURBANCE TO  
MOVE THROUGH THE FLOW ALOFT AND BRINGING BACK SOME ISOLATED TO  
SCATTERED RAIN CHANCES. THIS WILL ONLY BE A BRIEF BREAK AS HIGH  
PRESSURE WILL START TO BUILD OVER THE FOUR CORNERS REGION.  
TEMPERATURES ARE EXPECTED TO RETURN TO THE LOW TO MID 90S ACROSS  
THE PLAINS FOR THE END OF THE WEEK AND INTO NEXT WEEKEND.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z SUNDAY/
 
 
ISSUED AT 1243 PM MDT SAT AUG 15 2026  
 
CURRENT RADAR IMAGERY SHOWS SCATTERED SHOWERS AND THUNDERSTORMS  
DEVELOPING OVER THE FOOTHILLS AND MOVING EAST. WE HAVE OPTED TO  
INCLUDE PROB30S AT ALL THREE AIRPORTS TO REFLECT THE CHANCE FOR A  
ISOLATED STORM OR ERRATIC GUSTY OUTFLOW IN THE VICINITY BEFORE  
21Z, WHEN THE PRIMARY THREAT WINDOW BEGINS. LIGHTNING AND WINDS  
GUSTING UP TO 40KT WILL BE THE MAIN CONCERN, ALTHOUGH RAINFALL  
RATES COULD BE HEAVY ENOUGH TO CAUSE SOME VISIBILITY REDUCTIONS  
(2SM-4SM) IF THE CORE OF A STORM TRACKS OVER THE AIRPORT. SHOWERS  
AND STORMS MAY LINGER UNTIL 03Z, PARTICULARLY IF OUTFLOWS OVER THE  
EASTERN PLAINS INITIATE ADDITIONAL STORMS NEAR KDEN AND KAPA.  
 
WINDS WILL TURN LIGHT AND VARIABLE LATE THIS EVENING BEFORE A VERY  
WEAK S-SW DRAINAGE FLOW TAKES SHAPE AROUND 06Z. THERE IS A 40%  
CHANCE THAT LOW STRATUS AND/OR FOG FROM THE NORTHEAST CO PLAINS  
MAKES IT TO THE DENVER METRO, WITH THE BETTER CHANCE AT KDEN AND  
KBJC. WE HAVE DECIDED TO KEEP LOW CEILINGS OUT OF THE TAFS FOR NOW  
DUE TO UNCERTAINTY, BUT CHANGES MAY NEED TO BE MADE IN THE NEXT TAF,  
PARTICULARLY IF GUIDANCE CONTINUES TO SUGGEST VERY WEAK OR VARIABLE  
SURFACE WINDS ALL NIGHT. THERE WILL BE ANOTHER CHANCE FOR ISOLATED  
SHOWERS AND STORMS SUNDAY AFTERNOON, BETWEEN 21Z AND 00Z.  
 

 
   
HYDROLOGY
 
 
ISSUED AT 103 PM MDT SAT AUG 15 2026  
 
SEVERAL INGREDIENTS ARE IN PLACE FOR THE EXCESSIVE RAINFALL  
THREAT TODAY. PWATS VALUES WILL BE AROUND 150% OF NORMAL. WARM CLOUD  
LAYER HEIGHTS WILL APPROACH 5000 FEET, ALLOWING FOR RATHER EFFICIENT  
WARM RAIN PROCESSES. EASTERLY (UPSLOPE) WINDS ARE OCCURRING WHICH IS  
CONTINUING TO ADVECT MOISTURE INTO THE AREA. DEWPOINTS SHOULD BE IN  
THE 50S FOR THE I-25 CORRIDOR AND LOW TO MID 60S ACROSS THE PLAINS  
THIS AFTERNOON AND EVENING. SIGNIFICANT PORTIONS OF OUR AREA HAVE  
RECEIVED 2 TO 5 INCHES OVER THE LAST 3 DAYS, LOWERING FLASH FLOOD  
GUIDANCE. ALTHOUGH, STORM MOTIONS SHOULD BE A TOUCH FASTER THAN  
YESTERDAY- AROUND 20-25 KTS. ANY STORMS TODAY COULD PRODUCE 1 TO 2  
INCHES IN 30 MINUTES. RAINFALL TOTALS FOR TODAY COULD BE IN EXCESS  
OF 2 TO 4 INCHES. GIVEN THE NATURE OF THESE STORMS, THERE WILL BE  
VARYING RAINFALL TOTALS ACROSS SHORT DISTANCES. A FLOOD WATCH IS IN  
EFFECT FROM 2PM TO 10PM THIS AFTERNOON AND EVENING.  
 
FOR TOMORROW, MOISTURE IS EXPECTED TO DECREASE- PWATS WILL DROP TO  
ABOUT 100 TO 125% OF AVERAGE. THE FLOODING RISK FOR TOMORROW WILL BE  
LOWER THAN TODAY AND MORE ISOLATED IN NATURE. THE WEATHER PREDICTION  
CENTER ONLY HIGHLIGHTS THE PALMER DIVIDE IN A SLIGHT (2/4) RISK FOR  
EXCESSIVE RAINFALL FOR TOMORROW, WHERE STORM COVERAGE SHOULD BE  
HIGHEST.  
 

 
   
BOU WATCHES/WARNINGS/ADVISORIES
 
 
FLOOD WATCH UNTIL 10 PM MDT THIS EVENING FOR COZ036-038>051.  
 

 
 

 
 
DISCUSSION...MV  
AVIATION...AA  
HYDROLOGY...MV  
 
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