024
FXUS65 KGJT 131717
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
1017 AM MST Mon Jan 13 2025

.KEY MESSAGES...

- Weak ascent over the southern CWA will lead to light off and
  on snow shower through the day. Another wave dropping out of
  Wyoming will also bring light snow to portions of northern
  Utah and Colorado this afternoon and evening. Accumulations
  and impacts will be minimal.

- Temperatures will be below normal the next few days as flow
  continues out of the north. The Gunnison Basin and adjacent
  drainages will be especially cold with highs in the single
  digits and lows well below zero.

- Quieter weather expected Tuesday through Thursday with the
  next chance for precipitation arriving at the end of the work
  week.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 236 AM MST Mon Jan 13 2025

Clouds have been increasing and lifting northward across the
southern CWA early this morning but so far webcams and gauges
have been quiet. The southern radar is finally picking up on
some light returns which should expand through sunrise. This
area is in an area of weak upglide just upstream of the parent
trough across southeast Utah. Light snow showers should be
forming in this weak ascent through the morning across SW
Colorado before upglide shuts off with the trough moving
overhead. The trough will be pushed slowly southward through the
afternoon as another wave approaches from Wyoming in this deep
northerly flow pattern. As the trough and embedded PV drops
across the southern mountains this afternoon shower activity
looks to pick up but with minimal accumulations and impacts. The
northern wave will also lead to weak ascent/upglide late this
afternoon and evening with more showery activity breaking out
across the northern zones with the same outcome...very light
snowfall/flurries. There is minimal mositure to work with as
expected in this cold airmass but inflated snow to liquid ratios
could bring a few inches to some of the mountain locations over
the the next 24 hours...but most areas will likely only a
dusting up to an inch. Light snow will linger over the northern
Colorado high peaks tonight into Tuesday which looks to remain
in favorable weak...moist orographic flow with very diffuse
waves continuing to migrate through the flow. Still anticipating
minimal impacts with the best accumulations limited to the the
highest terrain. Temperatures will remain quite chilly in this
pattern with highs 5 to 10 degrees below normal most areas the
next few afternoons. One forecast challenge will also be the
degree of cold stuck in the Gunny basin and associated
drainages...which is not likely to budge for a while. Will aim
below guidance for now and go with single digits for highs the
next few afternoons and double digit lows well into the teens
below zero.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 236 AM MST Mon Jan 13 2025

The influence of the blocking pattern over the West keeps things
quiet here on the West Slope Wednesday. Light, ambivalent winds and
a touch of subsidence should push a slight warming trend in to close
out the week, as that high pressure works slightly east.
Deterministic models are struggling with some finer details of this
pattern as they resolve the breakdown of the ridge later in the
week. It does look like a few clouds may spill over the ridge in our
northern counties Wednesday and Thursday. This will be just some
thin high clouds, but actual weather will be hard to come by until
Friday afternoon. Morning lows and afternoon highs will trend around
climatology and then warmer Thursday. Friday, more cloud cover
arrives with the potential breakdown of the ridge and another
northwesterly wave. Sorry San Juans. This northwest flow will likely
drop some more snow on the Park Range, tapering more as one heads
south. The next storm looks similar to this last weekend`s event. I
suspect snow totals will inch upward through the week as we get
closer to the hi res data that captures orographic details better.
For now, it`s probably best to count on some of the most productive
snow along the front as it drops into the CWA sometime Friday night
and Saturday morning. Post frontal showers will likely continue
through the weekend, potentially stacking some more accumulation on
top of the initial wave. I mention this because snow totals did very
well behind the front on the Park Range this past Saturday night.
Cold air behind the front should drive up those SLR`s too.
Temperatures will respond downward next weekend with the arrival of
more cold air spilling out of the arctic.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1014 AM MST Mon Jan 13 2025

A combination of snow and fog is causing issues at KDRO and
KHDN. Those conditions should improve in the next several hours.
More stratus clouds move in tonight with little to no impact. A
few snow showers are possible around KHDN tonight, but
confidence is low. Relatively light winds are expected through
the period.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...None.
UT...None.

&&

$$

SHORT TERM...15
LONG TERM...LTB
AVIATION...TGJT