181
FXUS65 KBOU 012351
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
451 PM MST Thu Jan 1 2026

.KEY MESSAGES...

- Light mountain snow through Friday, with locally moderate
  accumulations in the Park Range and parts of the northern
  mountains.

- No meaningful precipitation expected for lower elevations
  through at least Wednesday, with continued warm/dry conditions.

- Breezier winds forecast Friday in the high country and plains;
  More widespread Sunday, with increased fire danger for lower
  elevations and foothills.

- Signs of transition to wetter and colder pattern around Thursday
  of next week, but with plenty of uncertainty.

&&

.DISCUSSION /Through Thursday/...
Issued at 141 PM MST Thu Jan 1 2026

Elevated moisture has begun to intrude into the high country,
with some spillover into the foothills and urban corridor. Low-
levels have moistened enough to support development of light snow
showers in the higher elevations, and as expected also some
isolated virga and a few rain drops along and west of I-25. Not
much change is anticipated into the evening, with continued light
snow in the mountains which won`t amount to much accumulation.

Snow will increase in our northern mountains tonight and Friday
with the arrival of more robust flow aloft, leading to 3-9" of
accumulation for most of the Park Range, with a few localized
totals potentially surpassing 10" for the highest elevations.
Forcing will remain too weak for comparable impacts along the
Continental Divide and particularly southward into the I-70
mountain corridor, with the latter expected to receive around 1-3"
for most locations above ~9,500 ft. Breezier conditions will
materialize over the higher terrain through Friday too, extending
into our northeast plains in the afternoon with a weak and dry
frontal passage. Temperatures should be approximately 2-5 degrees
cooler Friday given the cold air advection and cloud cover.

High pressure returns this weekend, pushing low elevation highs
above 60F again Saturday, and peaking Sunday when we`ll be close
to daily records. Dry conditions will be favored, although a few
very light showers can`t be ruled out in our high country Sunday as
a subtle shortwave approaches. Behind said shortwave, enhanced
westerly flow associated with a jet max will increase cross-
barrier winds to around 50 kts by sunrise Sunday. As of yet
there`s no real indication of either a critical or stable layer in
model guidance, but cross-sections do favor limited or even
reverse shear profiles above 600mb. With QG subsidence in place,
at lease some eastward spread of breezier winds into the lower
foothills and adjacent lower elevations appears likely (~70%
chance), with peak gust potential mostly in the 40-60 mph range
outside of the most wind-prone mountain/foothills locations, which
could see a few gusts near 70 mph. The subsident flow regime and
warm temperatures will allow for relatively dry conditions from
the foothills eastward, so there`s potential for a brief window
of near-critical to locally critical fire weather conditions if
there`s sufficient alignment between ingredients.

The strengthening southwest flow aloft will provide for increased
precipitation chances in our mountains Monday and Tuesday, with
just an outside chance (~20%) for some light showers surviving
into the lower elevations. Temperatures should see a steady
decline beginning Monday and continuing through midweek.

Ensembles over the past 24-48 hours have appeared slightly more
excited about the prospect of winter weather returning to the
lower elevations as early as Thursday, January 8th, along with a
transition to a colder pattern thereafter. Is it one of the more
robust signals we`ve seen for low-elevation snow since early
December? Yes. Have we seen such signals fade over the course of a
week only to end up dry? Also yes. In summary: ensemble guidance
suggests that you should keep coming back to read our discussions
and see how things evolve. In the meantime, enjoy the mild
temperatures!

&&

.AVIATION /00Z TAFS through 00Z Saturday/...
Issued at 441 PM MST Thu Jan 1 2026

Light showers are expected to continue around the TAF sites for
the next couple of hours, however most of the precip will
evaporate before reaching the ground. With this activity, we
could see a brief wind gust around 25 kts. But for much of the
next 2 hours, winds will remain light and variable. Winds will
turn more to the south this evening, with SW winds at KAPA and
KDEN overnight and W/SW winds at KBJC. Winds will begin to pick up
from the NW late tomorrow morning and afternoon, with winds
around 10 to 15kts.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 5 PM MST Friday for COZ031.

Winter Weather Advisory from midnight tonight to 5 PM MST Friday
for COZ033.

&&

$$

DISCUSSION...BRQ
AVIATION...AP

NWS BOU Office Area Forecast Discussion