572
FXUS65 KGJT 201132
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
432 AM MST Thu Nov 20 2025

.KEY MESSAGES...

- 4 to 8 inches of snow across the mountains of southeastern
  Utah and southwestern Colorado is expected through this
  evening, with locally higher amounts possible on the higher
  peaks.

- Snow will spread across the Central and Northern mountains
  this afternoon with areas of 2 to 5 inches of snow possible
  by Friday evening in the higher elevations.

- Temperatures stay near normal through the period.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 300 AM MST Thu Nov 20 2025

Models are in good agreement with each other, but are tracking the
low over the Desert Southwest 50 to 100 miles farther north than
satellite imagery is showing. That this low is tracking more to
the south along the Mexican Border this morning will likely
slow its progress as it lifts to the northeast this afternoon
and evening which is in better agreement with guidance keeping
snow showers in the southern Mountains through this evening and
in the central and northern Colorado mountains overnight into
Friday. Look for this low to become more of a deep trough with a
low in the base as it lifts across Arizona and northern New
Mexico this afternoon and evening, pushing onto the Front Range
overnight. Though the moist plume associated with this system
looks impressive with pwats near 200% of normal, this is
typically a dry period of the year and actual pwats remain below
0.7 inches keeping snow totals on the low end even in the
mountains. As the low moves east of the Divide, snow will taper
off over the southern mountains this evening, but light snow
showers will linger into Friday across the northern and central
Colorado mountains as moisture wraps around the low to the east.


Snow showers will generally be light across across eastern
Utah and Western Colorado, but on the peaks and high mountains
passes of southeastern Utah and southwestern Colorado expect
brief periods of moderate snow reducing visibilities to 1/2 mile.
Winter weather advisories are in effect for the Abajo and La
Sal Mountains above 9500 feet and in San Juan Mountains through
11 PM this evening for up to eight inches snow accumulation. The
primary threat is for snow accumulation on high mountain roads
with the high mountain passes becoming icy and snowpacked.

Another cold low currently moving into the Pacific Northwest will
descend along the West Coast today into Friday becoming cutoff off
the coast of Baja late Friday. This system will bring another
wave of showers to the southern mountains late in the weekend,
but more on that below.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 300 AM MST Thu Nov 20 2025

Kicking off the long-term forecast, we are continuing to monitor the
potential for a closed low to swing through Baja and northeastwards
through the Desert Southwest over the weekend. Though ensembles are
not differing greatly at this time, minor differences in the low`s
track near the southern border of our CWA do hold significant
implications on impacts. Earlier ensemble runs were leaning towards
a more southerly track of the low, likely to miss us entirely or
clip the far southeastern portions of our CWA, leading to more mild
impacts. This is still the favored path of the GEFS. The ECMWF has
began to diverge from this idea over the past couple runs though,
leaning towards a slightly more northerly path through the Four
Corners and nearer to the San Juans. This would yield more notable
precipitation in our CWA and heightened impacts. Timing of when
impacts would begin to be felt appears to be sometime in the early
morning Sunday, but the exact track of the low will certainly have a
heavy influence on this as well. To add to the variability, both the
ECMWF and the GEFS have struggled to pinpoint moisture content of
this storm with PWAT`s increasing 20-30% in both over the past 24
hours. To add, the ECMWF is running notably wetter than the GEFS as
well.

It will be difficult to make confident claims on the details of this
storm until ensembles agree better. To put this uncertainty into
better perspective, the NBM is indicating an uninspiring spread
between the 25th and 75th percentile snow accumulations across the
San Juans, currently sitting at over a half of a foot of spread
across a large swath of the mountain range. This spread is higher
than it has been recently thanks to those models which have been
shifting the low`s track more northwards. When models do re-
converge, we will be able to better estimate timing, coverage, and
accumulations.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 428 AM MST Thu Nov 20 2025

Rain and snow showers continue to affect most of the region.
Prolonged periods of cigs falling below ILS breakpoints can be
expected at most terminals throughout the TAF period. Many
terminals will also reach MVFR to IFR conditions due to these
lowering cigs and decreasing visibility. Dense fog has been
exhibited at, and may continue to be seen at KGJT and KTEX for
the next few hours, dropping visibility to LIFR conditions.
Winds will generally be light and variable.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...Winter Weather Advisory until 11 PM MST this evening for
     COZ019.
UT...Winter Weather Advisory until 11 PM MST this evening for
     UTZ028.

&&

$$

SHORT TERM...DB
LONG TERM...BW
AVIATION...TGJT