590
FXUS65 KBOU 202031 CCA
AFDBOU
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
231 PM MDT THU AUG 20 2026
KEY MESSAGES
- ISOLATED SHOWERS AND STORMS IN THE MOUNTAINS MAINLY SOUTH OF
I-70 ENDING THIS EVENING.
- HOT FRIDAY WITH HIGH TEMPERATURES PUSHING 100F OVER PORTIONS OF
THE PLAINS AND I-25 CORRIDOR. HIGH BASED LATE AFTERNOON AND
EVENING SHOWERS/STORM/VIRGA PRODUCING GUSTY MICROBURST WINDS.
- MONSOON MOISTURE RETURNS THIS WEEKEND AND HOLDS INTO EARLY NEXT
WEEK, WITH INCREASING CHANCE OF STORMS AND SLIGHTLY COOLER
TEMPERATURES.
DISCUSSION /THROUGH THURSDAY/
ISSUED AT 133 PM MDT THU AUG 20 2026
A WARMER AND DRIER AIRMASS IS TAKING HOLD TODAY AS THE RIDGE
STARTS TO AMPLIFY OVER THE FOUR CORNERS INTO THE GREAT BASIN. WE
STILL HAVE ENOUGH MOISTURE PER CURRENT SATELLITE IMAGERY FOR A FEW
SHOWERS AND WEAKER STORMS IN THE MOUNTAINS, MAINLY SOUTH OF I-70.
THOSE WILL END EARLY THIS EVENING AS THE AIRMASS STABILIZES,
WHILE THE PLAINS WILL REMAIN TOO DRY AND STABLE FOR ANY CONVECTIVE
ACTIVITY. OVERNIGHT LOWS WILL BE SEVERAL DEGREES ABOVE NORMAL.
ON FRIDAY, WE'LL BE BACK TO THE FRYING PAN AS THE THERMAL RIDGE
SHIFTS EASTWARD AND CENTERS ITSELF ACROSS COLORADO. 700 MB
TEMPERATURES WARM A COUPLE MORE DEGREES C, WHICH SUPPORTS HIGHS IN
THE MID TO UPPER 90S ACROSS THE PLAINS AND I-25 CORRIDOR, WITH A
FEW SPOTS NEARING 100F FROM DOWNTOWN DENVER TO GREELEY AND FORT
COLLINS. THE RECORD FOR TOMORROW IN DENVER IS 99F SET IN 2023,
AND WE SHOULD BE VERY CLOSE TO THAT AT THE OFFICIAL REPORTING
STATION. THOSE READINGS ALSO BRING US VERY CLOSE TO HEAT ADVISORY
CRITERIA, BUT MOST LOCALES SHOULD STAY JUST BELOW 100F. THERE WILL
BE SOME HEAT RELIEF IN THE FORM OF HIGH BASED CONVECTIVE CLOUDS
LATE IN THE DAY AS MID/UPPER LEVEL MOISTURE STARTS TO SPREAD INTO
THE REGION. GIVEN LARGE DCAPE OF 1500-1700 J/KG AND DEEP
INVERTED-V PROFILES, STRONG MICROBURST WINDS TO 50+ MPH WILL BE
POSSIBLE FROM ANY HIGH BASED SHOWERS.
FOR THE WEEKEND, ENSEMBLES ARE STILL SHOWING THE UPPER LEVEL RIDGE
AXIS TO SHIFT SLOWLY EASTWARD OR FLATTEN, WITH THE FLOW ALOFT
TRENDING MORE WESTERLY. THIS WILL ALLOW FOR AN UPTICK IN MONSOONAL
MOISTURE ACROSS THE FORECAST AREA, LEADING TO SCATTERED THUNDERSTORMS
EACH AFTERNOON. IN THESE MOISTURE AND FLOW PATTERNS, THE MOST
NUMEROUS STORMS ARE EXPECTED OVER THE MOUNTAINS AND EASTERN
PLAINS. MEANWHILE, THE MAJORITY OF THE STORMS ALONG THE I-25
CORRIDOR WILL BE HIGHER BASED AS THE AIRMASS IS STILL QUITE WARM
AND LOW LEVEL MOISTURE IS EXPECTED TO BE LACKING. BUT GIVEN THE
UPTICK IN PRECIPITABLE WATER TO NEAR 150% OF NORMAL, THAT STILL
DOESN'T MEAN WE CAN'T SEE LOCALLY HEAVY RAINFALL.
THERE MAY BE SOME CHANGE IN THIS PATTERN AS FLOW TURNS SLIGHTLY
MORE WEST-NORTHWESTERLY TOWARD TUESDAY OR WEDNESDAY. THAT COULD
ALLOW FOR A WEAK BACKDOOR FRONT OR TWO WITH INCREASING LOW LEVEL
MOISTURE, BUT PLENTY OF UNCERTAINTY EXISTS HERE WITH RESPECT TO
TIMING AND INTENSITY OF ANY SURGE(S). IN ANY CASE, IT APPEARS
TEMPERATURES WILL SETTLE A LITTLE CLOSER TO (STILL ABOVE) NORMAL
FOR THIS WEEKEND THROUGH MUCH OF NEXT WEEK. AND ENOUGH MOISTURE
WILL BE AROUND TO KEEP A CHANCE OF STORMS IN THE FORECAST MOST
DAYS.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1159 AM MDT THU AUG 20 2026
SKIES ARE MOSTLY CLEAR ACROSS THE REGION WITH THE EXCEPTION OF A FEW
CUMULUS CLOUDS OVER THE CENTRAL MOUNTAINS OF COLORADO. THE CHANCE
FOR SHOWERS IN THE VICINITY OF THE AIRPORTS TODAY IS NEAR ZERO. WE
EXPECT WINDS OVER THE AREA TO REMAIN NORTHEASTERLY THROUGH MOST OF
THE AFTERNOON AND GRADUALLY SHIFT TO THE SOUTHEAST AROUND 01Z. FOR
TONIGHT, DRAINAGE S/SSW FLOW WILL BE IN PLACE AT KDEN AND KAPA, AND
A LIGHT WSW (<7KT) WIND AT KBJC.
THE MAIN CONCERN FOR TOMORROW WILL BE THE THREAT FOR DRY MICROBURSTS
PRODUCING ERRATIC WIND GUSTS UP TO 40KT. WE HAVE ALREADY INTRODUCED
A PROB30 FOR KDEN BETWEEN 20Z AND 24Z, ALTHOUGH THE TIMING MAY SHIFT
SLIGHTLY WITH THE NEXT TAF IF MODEL GUIDANCE TRENDS TOWARDS A LATER
START FOR HIGH-BASED SHOWER DEVELOPMENT. LITTLE TO NO PRECIPITATION
IS EXPECTED TO REACH THE SURFACE AS MOISTURE WILL BE EXTREMELY
LIMITED AT THE LOW LEVELS.
BOU WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...20
AVIATION...AA
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