758
FXUS65 KGJT 062207
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
307 PM MST Sat Dec 6 2025

.KEY MESSAGES...

- Moderate to heavy snow rates and strong winds have
  materialized over the Colorado High Country creating hazardous
  travel conditons. Winter Storm Warnings and Winter Weather
  Advisories are in effect through this evening and into Sunday
  morning.

- Unsettled weather continues through the coming work week in
  the northern Colorado mountains with mostly periods of light
  snow showers.

- A general warming trend is expected, but the snow covered
  mountains valleys will see cold inversions set up overnight
  lasting through the days.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 132 PM MST Sat Dec 6 2025

The plume of moisture bringing precipitation to the area now
will drop to our south this evening. Weak cold advection in
northwest flow will keep orographic snow showers going in the
northern mountains and perhaps some of the central mountains.
Increasing snow to liquid ratios could turn this minor QPF into
several inches for the higher terrain especially the Park Range.
Most valleys shut off this evening. Winds decrease tonight but
remain breezy along the peaks and ridges, which may contribute
to blowing snow after the snow ends. Clouds clear out across the
south so sheltered valleys with new snow may get pretty chilly.
Most locations are dry tomorrow as northwest flow continues.
However another weak plume of moisture reaches the northern
mountains so snow showers could develop later in the day. High
temperatures tomorrow do not change much as the cold air
arriving tonight struggles to drop south.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 132 PM MST Sat Dec 6 2025

The beginning of the long term period is characterized by generally
quiet weather for all but the northern Colorado mountains, which are
expected to receive somewhat continuous snowfall while persisting
northwesterly flow supports orographic lift. Atmospheric moisture
amounts through the day Monday are expected to be pretty close to
average for this time of the year, so any snowfall during this time
period should be light.

An atmospheric river looks to move through the Rocky Mountain region
beginning Monday night, and is expected to move into our CWA from
the north overnight Monday into Tuesday. Despite to abundance of
moisture from the atmospheric river, synoptic forcing will be
limited due to a broad region of high pressure over the Pacific
which will keep ridging in place over much of the West. It also
appears there will not be good jet support during the timing of
the moisture advection, but disturbances within the mean flow
should be able to provide a bit of support for snowfall rates to
increase at times. The high pressure to our west keeps our
region under northwesterly flow, which will continue to support
orographic lift in the northern mountains. Thus, the northern
mountains look to be favored for receiving the most snowfall
from this event.

However, there is still a lot of uncertainty
regarding the details. The GFS Ens seems to be suggesting a
stronger atmospheric river than the ECMWF Ens is, so the GFS Ens
is favoring much higher snow totals. There is also significant
disagreement between ensemble members, more so among members of
the ECMWF Ens than the GFS Ens. Another potential concern will
be temperatures during this event, as temperatures are expected
to be well above normal through the long term, potentially
leading to daytime highs near or above freezing in some of the
higher terrain. Once there is better agreement between models on
the strength of this atmospheric river, and temperatures, there
will be greater confidence regarding snow totals.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1044 AM MST Sat Dec 6 2025

Snow showers will continue along the high terrain, ending from
south to north late this afternoon through the evening. Chances
of snow at KTEX, KGUC, and KRIL drop before 00Z, but increased
chances persist at KASE, KEGE, and KHDN through the evening
hours. MVFR to LIFR conditions, and drops below ILS
breakpoints, are possible at these sites as the winter weather
brings lower ceilings and visibility. Gusty winds and wind
shear aloft will may impact some sites as well. Conditions
should improve tonight, but terrain obscuration could prevail
through the overnight hours.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...Winter Storm Warning until 5 AM MST Sunday for COZ004.
     Winter Weather Advisory until 11 PM MST this evening for
     COZ005-008-009-018.
     Winter Storm Warning until 11 PM MST this evening for COZ010-
     012-013.
UT...None.

&&

$$

SHORT TERM...KJS
LONG TERM...GF
AVIATION...TGJT