864
FXUS65 KBOU 010023
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
523 PM MST SUN NOV 30 2025
KEY MESSAGES
- DETERIORATING MOUNTAIN TRAVEL CONDITIONS ENTERING SUNDAY NIGHT
AS HIGH COUNTRY SNOW INCREASES.
- LIGHT SNOW SUNDAY EVENING FOR THE URBAN CORRIDOR/PLAINS. HIGHLY
LOCALIZED 1-3" ACCUMULATIONS UNDER HEAVIEST BANDS, MAINLY SOUTH
OF I-70.
- REMAINING VERY COLD THROUGH MONDAY.
- INCREASING CONFIDENCE IN RETURN OF SNOW TO MOST AREAS WEDNESDAY,
INCLUDING HIGHEST POTENTIAL FOR LOWER ELEVATION TRAVEL IMPACTS
SO FAR THIS SEASON.
DISCUSSION /THROUGH SUNDAY/
ISSUED AT 1234 PM MST SUN NOV 30 2025
SNOWFALL HAS DEVELOPED ON SCHEDULE IN OUR HIGH COUNTRY AND WILL
CONTINUE TO INCREASE IN THE AFTERNOON UNDER A DEEPENING MOISTURE
COLUMN. UPSTREAM OBSERVATIONS SO WIDESPREAD PRECIPITATION ACROSS
THE WESTERN SLOPE, AND WE CAN EXPECT TRAVEL CONDITIONS IN OUR
MOUNTAINS TO DETERIORATE STEADILY IN THE COMING HOURS AS THIS
MIGRATES EASTWARD. THE OVERALL PICTURE THROUGH TONIGHT REMAINS
RELATIVELY UNCHANGED, WITH SOME BANDED SNOW SHOWERS EXPECTED TO
SPILL INTO THE URBAN CORRIDOR AS EARLY AS 4-5PM, BUT MOSTLY INTO
THE EVENING HOURS. THE BETTER POTENTIAL FOR THESE BANDS WILL BE
ROUGHLY SOUTH OF I-70 AS DESCRIBED IN PREVIOUS DISCUSSIONS, OWING
TO THE MORE FAVORABLE JET STREAK POSITION ALOFT AND DEEPEST
MOISTURE. MOST OF THE LOWER ELEVATIONS WILL RECEIVE LESS THAN 1",
BUT LOCALIZED NARROW CORRIDORS MAY ACCUMULATE 2 OR EVEN 3" UNDER
THE HEAVIEST/MOST PERSISTENT BANDS, ENOUGH FOR SOME ENHANCED
TRAVEL IMPACTS, AND MAY EXTEND INTO PORTIONS OF OUR SOUTHERN AND
EASTERN PLAINS. SNOWFALL ASIDE, TEMPERATURES HAVE BEEN NOTABLY
SLOW TO CLIMB, WITH MOST OF THE LOWER ELEVATIONS BARELY REACHING
INTO THE LOWER 20'S AS OF THIS WRITING. THIS TREND WILL CARRY OVER
INTO THE OVERNIGHT PERIOD, WITH ANOTHER COLD NIGHT AHEAD BRINGING
LOWS INTO THE SINGLE DIGITS TO LOW TEENS FOR MOST AREAS.
TUESDAY'S WARMING WILL BE MODEST AS THE TROUGH AXIS PUSHES EAST,
AND HAVE TRENDED HIGHS DOWNWARD SLIGHTLY KEEPING TEMPERATURES
FIRMLY IN THE 30'S ACROSS THE PLAINS/I-25 CORRIDOR, AND 20'S FOR
MOST MOUNTAIN COMMUNITIES. IT WILL BE AN OTHERWISE DRY DAY PAST
SUNRISE, WITH A DISTINCT LULL IN MOUNTAIN SNOW AND CLEARING SKIES
ACROSS THE REGION.
STRENGTHENING WESTERLY FLOW AHEAD OF A DEVELOPING TROUGH TO OUR
WEST WILL REIGNITE THE POTENTIAL FOR MOUNTAIN SNOW SHOWERS ON
TUESDAY, WITH RECENT RUNS A LITTLE MORE BULLISH ON ACCUMULATING
SNOW POTENTIAL, PARTICULARLY FOR THE PARK AND MEDICINE BOW RANGES.
AMOUNTS SHOULD NONETHELESS BE RATHER MINOR GIVEN STILL LIMITED
MOISTURE.
CONFIDENCE IN THE ARRIVAL OF ANOTHER STORM SYSTEM ON WEDNESDAY HAS
CONTINUED TO INCREASE WITH THE LATEST GUIDANCE, WHICH FAVORS A
SHEARING SHORTWAVE DESCENDING INTO AZ/NM BEFORE LIFTING NE INTO
THE PLAINS COME THURSDAY. THIS PATH EASILY GENERATES THE HIGHEST
POTENTIAL FOR WINTER WEATHER TRAVEL IMPACTS TO THE LOWER
ELEVATIONS YET THIS SEASON, EVEN IF QUESTIONS REMAIN REGARDING
ACCUMULATION AMOUNTS. THERE'S MODERATE CONSENSUS IN A PERIOD OF
MODEST NORTHEASTERLY UPSLOPE FLOW DURING THE DAY WEDNESDAY, WHICH
WOULD PROMOTE QUITE HIGH (~75-80%) PRECIPITATION PROBABILITIES FOR
OUR FOOTHILLS, DENVER METRO AND PALMER DIVIDE IN PARTICULAR.
HOWEVER, THE SYSTEM WON'T LACK SPEED, WITH ITS RAPID EASTWARD
MOTION BEING A LIMITING FACTOR IN SNOWFALL POTENTIAL. ENSEMBLE QPF
SPREAD APPEARS QUITE UNIMODAL AND SYMMETRIC, GENERALLY FAVORING
0.1-0.3" OF QPF FOR THE MOUNTAINS AND I-25 CORRIDOR WITH A SMALL
HANDFUL OF BOTH DRIER AND WETTER SCENARIOS. STILL TIME TO TREND
IN EITHER DIRECTION, OF COURSE.
AS THE LOW MERGES WITH THE BROADER SYNOPTIC FLOW THURSDAY, WE LOOK
TO RETURN TO A MORE PROGRESSIVE PATTERN WITH TROUGHING TO OUR
NORTH AND RIDGING IN THE VICINITY OF THE WEST COAST. THE NUANCES
IN THE PATTERN CAN'T YET BE DISCERNED, BUT THE DOOR WILL REMAIN
OPEN FOR THE PASSAGE OF A FEW SHORTWAVES UNDER NORTHWEST FLOW THAT
WOULD SUSTAIN A FEW WINDOWS FOR PREDOMINANTLY MOUNTAIN SNOWFALL.
WITH THE BULK OF THE TROUGHING EXPECT TO REMAIN TO THE NORTH, OUR
NORTHERN MOUNTAINS WILL BE MOST FAVORABLY POSITIONED FOR SOME
ADDITIONAL HEALTHY SNOWFALL DURING THE LATTER HALF OF THE WEEK.
THIS PATTERN ALSO LENDS ITSELF TO MORE ROBUST PRESSURE GRADIENT-
DRIVEN FLOW AND HENCE STRONGER WINDS ACROSS THE REGION.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
ISSUED AT 523 PM MST SUN NOV 30 2025
CURRENT RADAR SHOWS LIGHT SNOW SHOWERS SPILLING OFF THE
FOOTHILLS. BEST TIMING FOR SNOW TO REACH THE AIRPORTS WILL BE IN
THE NEXT HOUR OR SO, AND LASTING THROUGH 06Z (LINGERING SNOW SHOWERS
POSSIBLE THROUGH 09Z FOR APA). GENERALLY LIGHT SNOW ACCUMULATIONS
ARE EXPECTED ACROSS THE TAF SITES (<1"), ALTHOUGH THERE IS A 20%
CHANCE FOR A NARROW SNOW BAND PRODUCING UP TO 2" FOR APA
(KBJC:15%, KDEN:10%). LOWER CEILINGS DOWN TO 1500 FEET AND VISIBILITIES
DROPPING AS LOW AS 2SM IS POSSIBLE AS THE SHOWERS TRAVEL EAST.
EXPECT CEILINGS TO GRADUALLY IMPROVE TO VFR CATEGORY AFTER
11Z-13Z.
IN TERMS OF WIND, THE BOUNDARY ASSOCIATED THE WITH CYCLONE HAS NOW
STARTED TO SHIFT WEST, SO THE STRONGER SE WINDS WILL GRADUALLY
TURN LIGHT AND VRB FOR DEN IN THE NEXT HOUR (LIGHT NW FOR APA AND
BJC). WINDS ARE EXPECTED TO STAY RELATIVELY LIGHT (<10 KTS) FROM
THE NW, TURNING SW TOMORROW MORNING.
FOR TOMORROW, WINDS SHOULD GRADUALLY TURN NW TO NNE, WITH WINDS
BETWEEN 10-15 KTS AT TIMES FOR KDEN AND KAPA. KBJC IS EXPECTED TO
REMAIN LIGHT AND GENERALLY VRB.
BOU WATCHES/WARNINGS/ADVISORIES
WINTER WEATHER ADVISORY UNTIL 5 AM MST MONDAY FOR COZ031-033-034.
DISCUSSION...BRQ
AVIATION...MAI
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