Grand Junction, Colorado 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

730
FXUS65 KGJT 221123
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
423 AM MST Sun Dec 22 2024

.KEY MESSAGES...

- Unseasonably warm conditions continue through midweek.

- Several weather systems will move through the area in the
  next 7 days bringing snow mainly to the mountains and perhaps
  some high valleys.

- Snowfall could impact travel in the mountains tonight into
  Monday and again on Wednesday.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 320 AM MST Sun Dec 22 2024

One more dry day is on tap before snow chances return to the
forecast tonight. This pattern change is initiated by a shortwave
trough moving over the Northern Rockies early this morning which
causes the ridge overhead to flatten. This will result in increasing
cloud cover as zonal flow ushers in Pacific moisture with PWATs
climbing to 200% of normal by this evening. The moisture will be met
with a subtle wave that tracks through quickly and looks to favor
the northern mountains. As it does so, mountain snow develops
resulting in up to 4-6" of accumulation along the Park Range in
a 24-hour time frame between midnight tonight and midnight
tomorrow night. Elsewhere, mountain snow up to 2-4" is
possible. Slippery travel is likely on snow-covered roads so
use caution if you are out and about.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 320 AM MST Sun Dec 22 2024

A shortwave ridge moves in for Tuesday before a deeper trough
pushes into the Great Basin Christmas Eve and tracks across
eastern Utah and western Colorado Christmas Day (Wednesday).
Precipitation looks to begin Christmas morning with the bulk of
activity during the afternoon into early evening. Even though
this system is carrying some deeper moisture with PWAT anomalies
up to 200 percent of normal on the leading edge Tuesday evening
but between 160 to 180 percent of normal Christmas Day. This is
also looking like a fairly progressive system with decent
dynamics as 100 to 140 kt jet rounds the base and the H7 and H5
lows align vertically by Wednesday evening over southeast
Colorado. We are looking at a wet Christmas Day with widespread
precipitation but temperatures are not overly cold, keeping snow
levels quite high for much of the day. Looking like around 2 to
5 inches of snow in the mountains at this time with trace
amounts in some higher valleys and rain in the lower valleys.
This could change as we get closer if this system shows any
signs of digging deeper or slowing down so something to watch
since it will have some impacts to holiday travel over the
higher mountain passes, especially along the divide by Wednesday
evening into Thursday morning when the cold air does arrive.

There is a bit of a short break Thursday afternoon with a shortwave
ridge moving in behind this Christmas Day storm system, followed by
another trough moving through Thursday evening through Friday. At
this time, looks like another 2 to 5 inches for most mountain areas
with exception of the Park Range in northwest Colorado that may
continue to snow after this trough exits as orographic northwest
flow continues and yet more shortwaves track across the Northern
Rockies through next weekend, favoring the Park Range for more snow
that could pile up when it`s all said and done. Still a lot to mull
over the next few days as snowfall amounts could change depending on
timing and strength of dynamics with these systems. At this time,
amounts with each system seem to indicate sub-advisory thresholds
but with the holidays and potential changes in dynamics with models,
will keep a close eye on snow amounts and assess potential impacts.
Keep an eye on the latest forecast if you are planning on any travel
this holiday week.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 421 AM MST Sun Dec 22 2024

High level cloudiness will continue to stream in from the west
and as additional moisture is entrained in the flow...clouds
will lower toward mountain top level through the afternoon
hours. Light snow chances increase after 06Z tomorrow in the
northern mountains and their adjacent valleys. Even so, VFR is
forecast for the next 24 hours at our TAF sites with winds
generally remaining light.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...KAA
LONG TERM...MDA
AVIATION...TGJT