245
FXUS65 KBOU 211830
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1230 PM MDT FRI AUG 21 2026
KEY MESSAGES
- HOT TODAY WITH HIGH TEMPERATURES PUSHING 100F OVER PORTIONS OF
THE PLAINS AND I-25 CORRIDOR.
- HIGH-BASED AFTERNOON AND EVENING SHOWERS/STORMS/VIRGA PRODUCING
GUSTY MICROBURST WINDS, WITH A FEW STRONG TO SEVERE STORMS
POSSIBLE FOR THE FAR EASTERN PLAINS TODAY.
- 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 151 AM MDT FRI AUG 21 2026
ANOTHER HOT DAY IS ON TAP TO END THE WEEK AS UPPER-LEVEL RIDGING
CONTINUES TO DOMINATE THE WEATHER PATTERN, SUPPORTING ABOVE-NORMAL
TEMPERATURES ACROSS THE FORECAST AREA. AFTERNOON HIGH
TEMPERATURES WILL RANGE FROM THE MID TO UPPER 90S ACROSS THE
PLAINS, WITH A FEW LOCATIONS REACHING 100 DEGREES. ASIDE FROM THE
HEAT, THE MAIN CONCERNS FOR TODAY WILL BE WITH THE DEVELOPMENT OF
ISOLATED TO SCATTERED HIGH-BASED SHOWERS AND STORMS AS
NORTHWESTERLY FLOW ALOFT ALLOWS SOME MID-LEVEL PACIFIC MOISTURE
TO SNEAK UNDER THE AMPLIFYING RIDGE. EXPECTING CONVECTION TO
START OVER THE HIGHER ELEVATIONS IN THE AFTERNOON AND
SHOWERS/STORMS TO MOVE SOUTHEAST ONTO THE LOWER ELEVATIONS, WHERE
DEEP EVAPORATIVE COOLING WILL LIKELY LEAD TO MICROBURSTS AND GUSTY
OUTFLOWS, WITH LITTLE TO NO PRECIPITATION EXPECTED. GUSTS BETWEEN
45 TO 55 MPH WILL BE POSSIBLE ALONG THE NORTHERN PORTION OF THE URBAN
CORRIDOR WHERE DCAPE IS EXPECTED TO RANGE FROM 1300-1700 J/KG.
FARTHER EAST, A FEW STRONG TO SEVERE STORMS WILL BE POSSIBLE
ACROSS OUR NORTHEAST CORNER IN THE EVENING, WHERE SLIGHTLY
STRONGER NORTHWEST FLOW, LOW-LEVEL MOISTURE, AND INSTABILITY WILL
BE IN PLACE. WHILE THE MORE ROBUST STORMS ARE EXPECTED TO STAY TO
OUR NORTHEAST, WE CAN'T RULE OUT SEEING A FEW SEVERE GUSTS OR
HAILSTONES WITH ANY STRONGER STORM THAT DEVELOPS. THE SPC HAS
ISSUED A MARGINAL RISK FOR THESE HAZARDS FOR OUR NORTHEAST CORNER,
WHICH SEEMS REASONABLE AT THIS TIME.
LOOKING INTO THE WEEKEND, THE RIDGE IS EXPECTED TO PERSIST, WITH A
GRADUAL EASTWARD PROGRESSION EACH DAY. DESPITE THE RIDGE BEING
OVERHEAD, MID-LEVEL MOISTURE IS EXPECTED TO INCREASE. ENSEMBLES
CONTINUE TO SHOW ABOVE NORMAL PWAT VALUES THROUGH THE WEEKEND,
WITH THE PEAK EXPECTED ON SATURDAY. SURFACE DEWPOINTS ALONG WITH
INSTABILITY BOTH INCREASE ON SATURDAY THAT WILL ALLOW SCATTERED TO
NUMEROUS HIGH-BASED SHOWERS AND STORMS TO DEVELOP IN THE
AFTERNOON, AND WITH FORECAST SOUNDINGS ONLY SHOWING SMALL
IMPROVEMENTS TO DCAPE VALUES, STORMS WILL BE CAPABLE OF PRODUCING
GUSTY OUTFLOWS AND MICROBURSTS ONCE AGAIN. CAN'T RULE OUT A FEW
STRONG TO SEVERE GUSTS WITH THE STRONGEST STORMS. WITH REGARDS TO
QPF, SATURDAY LOOKS TO BE OUR BEST CHANCE FOR MORE WIDESPREAD
ACCUMULATING RAINFALL (A FEW TENTHS), WITH A FEW LOCALIZED
HEAVIER TOTALS POSSIBLE. AFTERNOON HIGH TEMPERATURES WILL COOL BY
FIVE TO TEN DEGREES, WITH 80S AND 90S STILL EXPECTED ACROSS THE
PLAINS AND MOUNTAIN VALLEYS. AFTERNOON SHOWERS AND STORMS ARE
EXPECTED AGAIN ON SUNDAY, THOUGH COVERAGE IS EXPECTED TO DECREASE
COMPARED TO SATURDAY, WITH THE HIGHER ELEVATIONS HAVING THE BEST
CHANCE FOR A FEW HUNDREDTHS TO AROUND A TENTH OF AN INCH. ANOTHER
DAY OF AFTERNOON HIGH TEMPS IN THE 90S IS EXPECTED ACROSS THE
PLAINS, WITH A SLIGHT COOLDOWN FOR THE MOUNTAIN VALLEYS.
A SHORTWAVE PASSING OVER THE NORTHERN ROCKIES ON MONDAY IS
EXPECTED TO FLATTEN THE RIDGE FOR A DAY OR TWO, BRINGING A SLIGHT
COOL DOWN FOR MID-WEEK. AFTERNOON SHOWERS AND STORMS ARE EXPECTED
TO PERSIST EACH AFTERNOON THROUGH THE FORECAST PERIOD, WITH THE
NBM POINTING TO ANOTHER WARMING AND DRYING TREND RETURNING BY THE
SECOND HALF OF THE WEEK.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 1229 PM MDT FRI AUG 21 2026
CONDITIONS REMAIN CALM AT KDEN, WITH WINDS STARTING TO SHIFT MORE
NORTHERLY FROM WHAT WE'VE BEEN SEEING THIS MORNING. THIS AFTERNOON'S
MAIN CONCERN REMAINS HIGH-BASED SHOWERS CAPABLE OF PRODUCING GUSTY
OUTFLOWS AND DRY MICROBURSTS. DCAPE REMAINS HIGH ENOUGH TO SUPPORT
STRONG MICROBURSTS, WITH THE LATEST ACARS SOUNDINGS SHOWING VALUES
OF 1300-1400 J/KG. SHOULD ANY OUTFLOWS REACH THE TAF SITES, WIND
SHIFTS AND GUSTS OF 30-40KTS ARE POSSIBLE. GIVEN THE FAVORABLE
CONDITIONS FOR MICROBURSTS AND THE RECENT FORMATION OF CUMULUS OVER
THE FRONT RANGE, WE'VE DECIDED TO BUMP THE TEMPO UP TO 21Z. SHOWERS
ARE EXPECTED TO MOVE EASTWARD AND BE OUT OF THE AREA BY AROUND 01Z,
WITH WINDS SHIFTING SOUTHERLY TOWARDS DRAINAGE OVERNIGHT AND SKIES
BECOMING CLEAR. WINDS WILL THEN START TURNING NORTHERLY AFTER
SUNRISE, BECOMING N/NW BY 15Z.
TOMORROW'S RAIN CHANCES LOOK BETTER THAN TODAY'S, WITH MOST OF THE
CAMS IN AGREEMENT ON STORMS BUILDING OFF THE FRONT RANGE AND THE
PALMER DIVIDE BY AROUND 22Z. MODEL SOUNDINGS SHOW DECENT DCAPE
VALUES, AROUND 1100-1300 J/KG, INDICATING THAT STRONG GUSTS MAY BE
AN ISSUE TOMORROW, AS WELL, THOUGH PERHAPS NOT AS MUCH AS THIS
AFTERNOON.
BOU WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...9
AVIATION...AGS
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