508
FXUS65 KBOU 192053
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
253 PM MDT MON OCT 19 2026
KEY MESSAGES
- MILD AND MOSTLY DRY CONDITIONS TO START THE WEEK.
- ISOLATED LIGHT RAIN AND SNOW SHOWERS POSSIBLE OVER THE MOUNTAINS
MONDAY AND TUESDAY AFTERNOON.
- A MORE ORGANIZED SYSTEM BY LATE WEDNESDAY, WITH RAIN SHOWERS
BECOMING MORE NUMEROUS OVER THE MOUNTAINS.
DISCUSSION /THROUGH MONDAY/
ISSUED AT 246 PM MDT MON OCT 19 2026
CURRENT OBSERVATIONS SHOW TEMPERATURES IN THE 50S AND 60S, AND
MOSTLY SUNNY SKIES EAST OF THE CONTINENTAL DIVIDE. A FEW SHOWERS
HAVE DEVELOPED OVER WESTERN COLORADO AND PARTS OF PARK COUNTY,
ALTHOUGH THESE SHOULD BE SHORT-LIVED. DECREASING CLOUD COVER OVER
THE MOUNTAINS AND CLEAR SKIES FOR THE PLAINS LATE TONIGHT WILL
GIVE WAY TO ONE MORE CHILLY MORNING (THOUGH STILL ABOVE AVERAGE)
WITH MORNING LOWS IN THE UPPER 30S TO LOW 40S ACROSS THE LOW
ELEVATIONS, AND 30S FOR THE MOUNTAINS.
TOMORROW, A SHORTWAVE WILL CONTINUE TO DRIFT THROUGH THE AREA AND
ALLOW FOR A FEW LIGHT SHOWERS OVER THE HIGH TERRAIN ONCE AGAIN IN
THE AFTERNOON. FOR THE PLAINS AND DENVER METRO, 70-DEGREE AFTERNOON
HIGHS MAKE A RETURN WITH A FEW PATCHES OF MID LEVEL CLOUDS AND
PERHAPS SOME VIRGA. SURFACE WINDS ARE EXPECTED TO GENERALLY REMAIN
LIGHT AT ALL LEVELS THROUGH AT LEAST TOMORROW EVENING DUE TO THE
WEAK PRESSURE GRADIENT AND LIGHT SOUTHWEST FLOW ALOFT.
THE SYNOPTIC PATTERN BECOMES MORE AMPLIFIED ON WEDNESDAY AS AN
UPPER LEVEL RIDGE BUILDS OVER JUST EAST OF OUR AREA AND A STRONG
CUTOFF LOW APPROACHES THE CALIFORNIA COAST. A SUBTROPICAL JET
AHEAD OF THIS CUTOFF LOW WILL STRENGTHEN SOUTHWESTERLY FLOW ALOFT
AND BEGIN ADVECTING PACIFIC MOISTURE TOWARDS THE FOUR CORNERS
WEDNESDAY EVENING INTO THURSDAY. THIS INCREASE IN MOISTURE WILL
ALLOW RAIN SHOWERS TO BECOME MORE NUMEROUS OVER THE MOUNTAINS
WEDNESDAY EVENING, ALTHOUGH THE HEAVIEST RAIN SHOULD REMAIN WELL
OUTSIDE OF OUR CWA, OVER SOUTHWEST COLORADO. IN TERMS OF RAINFALL
AMOUNTS, A TRACE UP TO 0.25" OF QPF SEEMS REASONABLE FOR THE
MOUNTAINS, WITH THE DENVER METRO AND PLAINS REMAINING DRY. THE
AIRMASS APPEARS TO BE TOO WARM FOR ANY TANGIBLE SNOW
ACCUMULATIONS, WITH PERHAPS ONLY SOME DUSTINGS ABOVE 12,000 FT. IT
IS WORTH NOTING THAT MOISTURE TRANSPORT WITH THIS SYSTEM IS QUITE
IMPRESSIVE. LONG-RANGE ENSEMBLE MEANS SHOW PRECIPITABLE WATER
(PW) VALUES REACHING THE 0.60" TO 0.90" RANGE, WHICH IS WELL ABOVE
THEN 90TH PERCENTILE AND EVEN THE DAILY MAXIMUM OF CLIMATOLOGY
FOR THIS TIME OF YEAR. HOWEVER, WITH SUCH LIMITED INSTABILITY
AROUND (IN COMPARISON TO PEAK MONSOON SEASON), WE EXPECT THE BULK
OF THE RAINFALL TO BE OROGRAPHIC IN NATURE, COMING TO FRUITION
OVER AREAS WHERE SOUTHWESTERLY FLOW IS A FAVORABLE UPSLOPE
ORIENTATION (I.E. PRIMARILY SOUTHWEST COLORADO). WITH SO MUCH HIGH
TERRAIN BLOCKING THE BULK OF THIS PLUME OF PACIFIC MOISTURE, HIGH
CLOUDS MAY BE ALL THAT THE FOOTHILLS, DENVER METRO, AND PLAINS
GET OUT OF THIS SYSTEM.
REGARDING TEMPERATURES, THERE IS PRETTY GOOD AGREEMENT IN
TEMPERATURES STAYING WARMER THAN SEASONABLE THROUGH AT LEAST
SATURDAY, WITH THE DENVER METRO AND PLAINS POTENTIALLY REACHING
THE MID TO UPPER 70S WEDNESDAY THROUGH FRIDAY. A COLD FRONT IS
STILL EXPECTED TO PUSH THROUGH THE AREA ON SATURDAY, COOLING
TEMPERATURES DOWN TO NEAR-AVERAGE FOR THE WEEKEND.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1202 PM MDT MON OCT 19 2026
VFR WILL CONTINUE THROUGH THE TAF PERIOD WITH A FEW HIGH CLOUDS
AT TIMES. LIGHT AND VARIABLE WINDS WILL BECOME EASTERLY 18-20Z.
WINDS ARE EXPECTED TO TURN SOUTHEAST AT DEN TOWARDS 00Z, AND
SLIGHTLY SOONER AT APA. WINDS ARE EXPECTED TO STAY A SOUTHERLY
COMPONENT THROUGH TONIGHT. HOWEVER, A DENVER CYCLONE DEVELOPS THIS
AFTERNOON. IF THE MODEL PLACEMENT IS OFF, THERE COULD BE A WIND
SHIFT TO THE NORTH OR NORTHWEST AROUND OR AFTER 00Z (ABOUT A 30
PERCENT CHANCE).
BOU WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...AA
AVIATION...BM
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