521
FXUS65 KGJT 050926
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
326 AM MDT Sun Oct 5 2025

.KEY MESSAGES...

- Light showers will continue across the Colorado/Wyoming
  border and northern mountains today, isolated to widely
  scattered in coverage.

- High temperatures will be cooler with below normal readings
  today but should rebound to near normal values Monday and
  above normal highs by mid week.

- Drier conditions are expected for much of the coming week.
  However, moisture potentially returns late this week into the
  coming weekend.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 326 AM MDT Sun Oct 5 2025

Light showers will continue today across the northern mountains
and areas along the Colorado-Wyoming border due to remnants of
an upper level shortwave trough moving across the Intermountain
West and Northern Rockies...north of the region. The overall
trend however is for drier southwest flow to push into the
region across the southern and central areas with clearing
skies. The shortwave trough pushes across the north Monday but
we remain on the drier side with any isolated showers confined
to the northern Divide mountains. Temperatures today will be
cooler with highs around 5 degrees below normal on average with
cooler temps of up to 10 degrees below normal across the north.
Temperatures will warm to near normal levels by Monday as the
trough lifts out of the region. Winds will be much lighter
today and Monday as well, but still some breezy conditions at
times due to the presence of the upper level jet overhead and
shortwave trough passage.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 326 AM MDT Sun Oct 5 2025

Monday night will see longwave troughing over the Intermountain
West, with a few light showers lingering over the Colorado
Divide. The wave helping to fire these showers sweeps east by
daybreak, and the overall pattern becomes a bit messy. By
Tuesday evening, a Rex block will have set up over the West,
with a cutoff low off the central California coast, and high
pressure over the Northern Rockies. Under this pattern, eastern
Utah and western Colorado will stay high and dry, with near to
below normal PWATs and temperatures climbing to 5-10 degrees
above normal by Wednesday. The cutoff low off the California
coast weakens into an open wave that then gets absorbed into a
trough dropping south out of the Gulf of Alaska. This system
forms a closed low off the Pacific Northwest Coast by Wednesday
evening, and as it strengthens, the ridging over the
Intermountain West amplifies. Southwesterly flow sets up over
the southern Great Basin in the gradient between the deepening
low and amplifying ridge. This could bring some breezier
afternoons during the second half of the week. In addition,
models are hinting that this southwesterly flow will start to
entrain some deeper tropical and subtropical moisture and pull
it north. As a result, mountain showers and thunderstorms will
be back in the forecast starting Wednesday afternoon, mainly
south of I-70. We remain under this southwesterly flow regime
into the coming weekend, with increasing coverage of showers and
storms each afternoon as more and moisture is advected
northward. The above mentioned low remains stagnant through this
period, sitting and spinning off the Pacific Northwest coast.
Current guidance has this low transitioning into an open wave
and finally swinging inland on Saturday, potentially bringing a
return to cooler and wetter conditions for the Western Slope.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1112 PM MDT Sat Oct 4 2025

Skies have become mostly clear across the region, with some mid
and lower level clouds lingering north of the I-70 corridor and
across central-eastern Utah. The clouds over KCNY are expected
to clear in the next 2-4 hours. However, clouds will continue to
linger over KVEL and KHDN through the next 24 hours. Gusty, but
weaker, southwesterly winds will also continue for these two
terminals. Elsewhere, winds will become light and terrain driven
through the period. VFR conditions will prevail.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...MDA
LONG TERM...BGB
AVIATION...TGJT