807
FXUS65 KBOU 140036
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
536 PM MST SAT DEC 13 2025
KEY MESSAGES
- COOLER FOR NORTHEAST PLAINS THIS WEEKEND. OTHERWISE, CONTINUED
MILD AND DRY ACROSS THE REGION THROUGH EARLY NEXT WEEK.
- STRONG DOWNSLOPE WINDS EXPECTED WEDNESDAY, WHICH MAY LEAD TO
FIRE WEATHER CONCERNS FOR THE LOWER ELEVATIONS AND FOOTHILLS.
- INCREASED POTENTIAL FOR MOUNTAIN SNOW LATE WEDNESDAY INTO
THURSDAY.
SHORT TERM /THROUGH SUNDAY/
ISSUED AT 249 PM MST SAT DEC 13 2025
COLD FRONT HAS BACKED SOUTHWEST ACROSS THE NORTHEAST PLAINS AND
URBAN CORRIDOR THIS AFTERNOON. TEMPERATURES REACHED THE LOWER TO
MID 60S ACROSS MUCH OF THE URBAN CORRIDOR BEFORE FALLING IN THE
MID 40S TO LOWER 50S AFTER THE FRONTAL PASSAGE. OVER THE FAR
NORTHEAST CORNER OF COLORADO, TEMPERATURES REMAINED IN THE 20S
MOST OF THE DAY WITH FOGGY CONDITIONS. THE FOG WILL LINGER MUCH OF
THE NIGHT HERE OVER THE FAR NORTHEAST CORNER. THE COLD ARCTIC
HIGH OFF TO THE EAST WILL CONTINUE TO MOVE AWAY FROM COLORADO. THE
PRESSURE GRADIENT SHIFTS TO A SOUTH TO SOUTHWEST LOW LEVEL FLOW
THAT WILL SCOUR THE COLDER AIR OUT LATE TONIGHT AND SUNDAY. THE
COLDER AIR MAY HANG ON FOR A GOOD PART OF THE DAY OVER THE
NORTHEAST PLAINS, BUT EVENTUALLY EXPECT TEMPERATURES TO CLIMB INTO
THE 40S TO MID 50S. FARTHER WEST, ALONG THE URBAN CORRIDOR,
TEMPERATURES SHOULD REACH THE LOWER 60S DURING THE AFTERNOON
HOURS.
LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/
ISSUED AT 249 PM MST SAT DEC 13 2025
ABOVE NORMAL TEMPERATURES ARE EXPECTED EACH DAY OF THE WEEK THIS
WEEK, ALONG WITH THE POTENTIAL FOR ANOTHER HIGH WIND EVENT MIDWEEK
AND ELEVATED FIRE WEATHER CONCERNS. MOST OF THE AREA WILL REMAIN
DRY, ASIDE FROM OROGRAPHIC SNOW SHOWERS IN THE NORTHERN MOUNTAINS.
THE BEGINNING THIS WEEK WILL BE RELATIVELY QUIET, AS WE WILL BE
SITUATED UNDER AN UPPER LEVEL RIDGE. MULTI-RUN ENSEMBLE SOLUTIONS
HAVE CONTINUED TO INDICATE MAXIMUM TEMPERATURES BETWEEN THE HIGH 50S
TO LOW 60S ACROSS THE PLAINS AND 30S/40S IN THE MOUNTAINS/VALLEYS.
WITH THE COMBINATION OF RELATIVE HUMIDITY VALUES AROUND 20% AND
BREEZY WINDS OFF THE CHEYENNE RIDGE, BRIEF PERIODS OF ELEVATED FIRE
WEATHER CONDITIONS ARE POSSIBLE ACROSS THE NORTHERN PLAINS. WINDS
SHOULD STAY RELATIVELY WEAK ACROSS OTHER PORTIONS OF THE FORECAST
AREA, WHICH WILL KEEP FIRE WEATHER CONCERNS AT BAY.
WEATHER BEGINS TO PICK UP ON WEDNESDAY, AS FLOW ALOFT INCREASES WITH
A SHORTWAVE TROUGH TREKKING ACROSS THE NORTHERN UNITED STATES.
CONFIDENCE IS INCREASING OF STRONG WINDS IMPACTING THE HIGH COUNTRY
AND POSSIBLY ADJACENT PLAINS. HOWEVER, IT IS TOO SOON TO GO INTO
SPECIFICS, AS THERE ARE STILL DISCREPANCIES BETWEEN MODELS IN TERMS
OF INGREDIENTS FOR STRONG WINDS TO REACH DOWN TO THE FOOTHILLS. WE
WILL CONTINUE TO MONITOR THE EVOLUTION OF THE SHORTWAVE THAT WILL BE
NORTH OF US, AS THAT WILL DICTATE IF OUR FLOW ALOFT IS MORE ZONAL OR
NORTHWESTERLY. REGARDLESS, EXPECT A WINDY DAY ACROSS THE FORECAST
AREA, WITH NBM INDICATING A 60% FOR WIND GUSTS >70 MPH FOR THE FRONT
RANGE MOUNTAINS, AND A 40-50% FOR GUSTS >50 MPH AT TIMES ALONG
THE FOOTHILLS. EVEN IF RELATIVE HUMIDITY VALUES STAY MARGINAL
(20-25%), STRONG WINDS WILL ALLOW ELEVATED TO BRIEFLY CRITICAL
FIRE WEATHER CONDITIONS ACROSS THE FOOTHILLS AND PLAINS.
AS FOR PRECIPITATION, OUR NORTHERN MOUNTAINS MAY RECEIVE OROGRAPHIC
SNOW SHOWERS WEDNESDAY INTO THURSDAY MORNING. HOWEVER, MINIMAL
ACCUMULATIONS ARE EXPECTED, AS THERE WILL NOT BE A LOT OF MOISTURE
IN OUR AREA. PARK RANGE WILL LIKELY RECEIVE THE MOST SNOW, WITH
ENSEMBLE SOLUTIONS INDICATING <6".
TOWARDS THE END OF THE WEEK, EXPECT WINDY AND DRY CONDITIONS TO
CONTINUE AS FLOW ALOFT REMAINS STRONG AHEAD OF ANOTHER SHORTWAVE TO
OUR NORTH. PERIODS OF ELEVATED FIRE WEATHER CONDITIONS ARE LIKELY,
AS FORECASTED MINIMUM RELATIVE HUMIDITY VALUES SHOULD BE AROUND 20%.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 446 PM MST SAT DEC 13 2025
CURRENT EASTERLY WINDS WILL GRADUALLY TREND TO THE SOUTHEAST AND
SLACKEN IN MAGNITUDE OVER THE NEXT FEW HOURS. A FEW UNCERTAINTIES
REMAIN FOR LATE TONIGHT AND TOMORROW, AS THE CHANCE FOR FOG TO THE
NORTH OF THE TAF SITES TO MAKE IT INTO THE VICINITY (~30%-40%) OF
KDEN AND KBJC, WITH 10-15% CHANCE IT MAKES IT INTO THE AIRFIELDS.
HAVE INTRODUCED VCFG AT BOTH TAF SITES STARTING FROM 12Z-15Z, BUT
IF IT OCCURS, IT WILL LIKELY STICK AROUND LONGER.
WITH SOUTHERLY WINDS COMING OFF THE PALMER DIVIDE, A DENVER
CYCLONE IS EXPECTED TO DEVELOP THAT BRINGS UNCERTAINTIES TO WIND
DIRECTIONS BY LATE MORNING/EARLY AFTERNOON. BY 18Z, WINDS ARE
EXPECTED TO BE FROM THE SOUTH TO SOUTHEAST AT KDEN, BUT THERE WILL
BE A PERIOD (~21Z-22Z) WHERE NNW WINDS WILL START TO PUSH ACROSS
THE AIRFIELD. THIS MAY CAUSE THE NW PORTION OF THE AIRFIELD TO
HAVE NNW WINDS WHILE THE SE PORTION HOLDS ONTO THE SSE. DEPENDING
ON TIMING, THE NORTHERLY WINDS MAY STAY OUT OF KAPA, KEEPING
SOUTHEASTERLY WINDS IN PLACE, BEFORE BOTH TAF SITES TURN TOWARDS
DRAINAGE AROUND 2Z. THE CYCLONE IS EXPECTED TO BRING N TO NE WINDS
TO KBJC THROUGH THE AFTERNOON.
BOU WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...12
LONG TERM...MAI
AVIATION...9
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