460
FXUS65 KBOU 281150
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
450 AM MST Sun Dec 28 2025

.KEY MESSAGES...

- Mountain snow continues this morning, but gradually diminishes
  in intensity by late morning. The heaviest snow totals will be
  in the Park and Gore Ranges where a Winter Storm Warning is in
  effect. Moderate amounts are expected across the Front Range
  mountains with a Winter Weather Advisory in effect. Roads
  through the mountains across the passes are snowpacked and
  slick in spots.

- I-25 corridor could see a dusting to an inch of snow through the
  late morning. Significant travel issues are not expected.

- Much colder today with highs in the 20s and 30s.

- Expect a gradual return to above normal temperatures Tuesday
  through the rest of the week, and dry conditions across our area
  through about Thursday.


&&

.UPDATE...
Issued at 244 AM MST Sun Dec 28 2025

Just a few minor updates to the first 12-18 hours of the
forecast. First, the cold front arrived a bit sooner than
expected across the plains of Colorado, and wind/temperature grids
were updated to reflect the earlier arrival. We have been closely
watching radar and webcams as the band of snow forced by
frontogenesis slides southward across the plains and I-25
corridor. The strongest band is capable of dropping a quick inch
of snow, as evidence by webcams and looking out the window here in
Boulder. Bridges and overpasses that are below freezing could be
slick in spots if untreated, especially through 10 AM. This band
of snow is moving southward, and PoPs/QPF were updated to reflect
the current timing and movement. The band should clear metro
Denver by 5 AM, after which it will mainly impact I-70 eastward
from Elbert into Lincoln Counties. Once the band moves south, it
dries out quickly from north to south, and additional accumulation
behind the snow band is unlikely, but flurries could continue
into the late morning hours. Flurries should end by midday pretty
much everywhere across the I-25 corridor and plains, with
clearing skies by the afternoon hours. It will be cold though,
with breezy northwest winds across the northeast plains and
temperatures warming into only into the low 30s. All forecast
elements were updated slightly to match high res model output and
obs trends.

In the mountains, it continues to snow moderate to heavy in spots
across the Front Range, especially above 9,000 ft. Webcams at ski
areas and across mountain highways show accumulations so far of
4-10 inches, with another 2-4" possible into this afternoon
across the highest ridges/peaks. Elevations between 6-9kft should
see T-3" into early afternoon, with some travel impacts possible
through mid-morning. All travel conditions should improve midday
and into the afternoon with thinning clouds and even some sun. The
mountain forecast was updated mainly for PoPs and snow amounts.
The winter weather highlights look to be in good shape, and they
were updated with the expected additional snowfall through
expiration time.

.DISCUSSION /Through Saturday/...
Issued at 255 PM MST Sat Dec 27 2025

Current water vapor imagery shows a stream of Pacific moisture
moving into the high country, with snow showers ongoing in the Park
Range and northern Front Range mountains. We expect snow to become
more widespread this afternoon/evening as favorable orographics
ahead of an approaching shortwave trough will promote light to
moderate snowfall through tomorrow morning. Short and long range
guidance still favor strong frontogenesis later today and overnight,
which will create snowbands and promote localized heavy snowfall at
times, particularly in the Park Range. Areas of blowing snow will be
a concern, especially across high passes as winds could gust up
to 50 mph. With reduced visiblities and slick roads, expect
difficult to hazardous travel this evening through Sunday
morning. Still think total accumulations will range between 8-18"
in the Park and northern Gore Range and 4-12" along the Front
Range, with highest accumulations north of I-70.

For the plains, the trend is not our friend unfortunately as
expected snowfall amounts have decreased in the last 24 hours. A
strong cold front is progged to enter our forecast area this evening
and tonight, bringing gusty north/northeasterly winds and colder
temperatures. Ahead of this front, light rain and rain/snow mix will
occur before the cold air overcomes warm temperatures and allow
light snowfall. Most short range guidance have all trended towards
a slightly warmer and drier airmass at the lower levels, with
total snowfall accumulations between trace to a couple tenths, and
best area for snowfall across the Palmer Divide. However, long
range guidance has held relatively steady in areas along the lower
foothills/plains receiving a couple of inches by Sunday. Most
likely, the northern and eastern plains will receive a dusting to
an inch of snow by late Sunday morning. Due to favorable upsloping
and frontogenetical forcing, the Denver metro, western urban
corridor, and Palmer Divide could see slightly more
accumulations. Lastly, any banded snowfall will create localized
higher amounts (up to 2-3"). As temperatures are expected to dip
below freezing tonight and Sunday morning, expect slick roads
wherever precipitation falls.

Snow will gradually end late Sunday morning. Temperatures will stay
below freezing throughout the day, with low 30s as expected highs
across the plains, and single digits to mid teens for the high
country.

Quieter conditions are expected Monday and through the rest of the
week. Ensemble guidance has continued to indicate Colorado on the
eastern edge of an upper level ridge with a surface high pressure
settling over the western United States. With weak northwest flow
aloft, dry and warming conditions will prevail. Monday and Tuesday
will see near seasonal temperatures, with highs in the 40s both days
across the plains. Then, as the axis of the upper level ridge shifts
over Colorado towards the later half of the week, temperatures
should warm up to the mid-to-high 50s. Despite dry conditions
allowing relative humidity values to drop to 20% almost each day,
recent precipitation and relatively light winds should keep fire
weather concerns at bay. However, can`t rule out localized elevated
fire weather conditions, particularly in areas that don`t receive
precipitation.

Our next chance of precipitation comes towards the end of the
week/weekend, as ensemble solutions show an upper level trough
trekking over northern Colorado. As of right now, the bulk of the
precipitation is expected to be confined to the high country.
However, will continue to monitor for any changes.

&&


.AVIATION /12Z TAFS through 12Z Monday/...
Issued at 450 AM MST Sun Dec 28 2025

A moderate snow band is currently just south of DEN, and pretty
much on top of APA. The snow band is moving fairly quickly to the
southeast. Conditions have already improved at BJC, and they
should continue to improve at DEN over the next hour. Expect MVFR
conditions at DEN by 1230Z, and just light snow from then on.
Snow should end sometime between 14-16Z at BJC and DEN, for now in
the TAFs best bet is 15Z at both. APA will be about an hour
behind both BJC and DEN in terms of snow ending and improving
CIG/VIS.

Winds in general should be northeast with speeds/gusts
decreasing going forward from right now. Expect them to drop to
8-13 knots after 13Z. Lighter WNW winds are possible at DEN this
afternoon, with VFR conditions returning NLT 19Z. Wind direction
is uncertain this afternoon, but should be variable after 23Z,
then turning to south with drainage winds after 05Z.

APA winds could be gusty from the NW after 18Z. Low confidence in
this occurring, but they could gust to 20 kts. VFR conditions
should return by 18Z or so, maybe as late at 19/20Z. Winds will
also be variable this afternoon after the NW winds decrease, and
southerly drainage will return after 02Z at under 8 kts.

BJC winds are likewise uncertain this afternoon, with stronger NW
winds 15G25KT just 3-5 miles west of the airfield this afternoon.
For now, we are bringing NNW winds to BJC after 18Z but they
could remain south and light between 17-22Z. They should be
variable after 22Z and then south from 03Z onwards. VFR conditions
are expected after 18Z.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 5 AM MST early this morning for
COZ031.

Winter Weather Advisory until 11 AM MST this morning for COZ033-
034.

&&

$$

UPDATE...Schlatter
DISCUSSION...MAI
AVIATION...Schlatter

NWS BOU Office Area Forecast Discussion