717
FXUS65 KGJT 071133
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
533 AM MDT Sun Sep 7 2025

.KEY MESSAGES...

- Showers and thunderstorms are expected mostly along and north
  of I-70 through this evening.

- Expect isolated to scattered afternoon showers and
  thunderstorms over the higher terrain daily through mid week.

- Thursday and Friday will see widespread showers and
  thunderstorms return with a passing system.

- Temperatures remain near normal today before a warming trend
  starts Monday.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 337 AM MDT Sun Sep 7 2025

Satellite imagery shows skies have cleared out under the subsidence
of the ridge moving in from the west. There are a few light showers
working their way across the northern area associated with a couple
of weak mid-level disturbances moving through. One line approaching
Hayden will move out of the region in the next few hours while
another batch is just moving into the Uinta Basin and will pass
across the northern area through the morning. Looking at
observations, surface dewpoints remain in the upper 40`s and low
50`s across the region, and with the clear skies, should see strong
diurnal heating this morning across much of the region south of the
I-70 corridor. Guidance and the high-res CAMs have down played
chances for convection to the south  due to a cap forming below
500mb from the subsidence, but still cant rule it out completely.
this will be something to watch today. Otherwise, expect scattered
showers and thunderstorms along and north of the I-70 corridor this
afternoon extending through the evening as another disturbance
passes to the north. There is still a risk for heavier rain on the
northern fire scars causing debris flows this afternoon and evening.
Convection will be mostly isolated over the higher terrain along the
Divide Monday as the atmosphere dries out. Temperatures today will
be near normal and should warm a couple degrees tomorrow.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 126 PM MDT Sat Sep 6 2025

PWAT`s continue to dry out significantly Monday following
northwesterly flow and the stacked ridge amplifying overhead.
Abundant southwesterly flow ahead of a PACNW storm will drive up
heights and temperatures. Afternoon highs will top out a couple
degrees above climatology, pushing 90 degrees in our desert valleys.
This little warmup will be short lived, as the deepening low out
west moves into the Great Basin Tuesday. Height falls and some
prefrontal lift will produce scattered showers and convection by
Tuesday afternoon, likely suppressing an otherwise hot day for much
of the region. The low elevations will be on the warm side of climo,
but the approaching storm is expected to take care of that by late
week. Ridging over the Great Plains runs block for Wednesday and
Thursday as the low drifts across the Intermountain West. This
allows for some additional moisture to get picked up, as return flow
on the high sends some late season monsoonal moisture back across
the Four Corners. Moisture likely gets a helping hand from the low
digging into Baja, sending additional Pacific moisture this way.
PWAT values are into the 150 percent of climatology range Wednesday
and Thursday. This should keep the area under afternoon showers and
thunderstorms both days. Uncertainty creeps in Friday, as the low
lifts northward and east. The monsoonal plume shifts east too. PWAT
values remain high enough for additional shower and storm activity,
but drier northwest flow behind the departing storm could dry things
out for much of the CWA. This solution continues to dry things out
Saturday. Concerns arise in the model`s handling of the decaying
low, as well as the stubborn high pressure anchored over the
Mississippi Valley. These features will have some control over the
monsoon plume and its east/west breadth. There could easily be some
additional showers Saturday on the southern mountains with a slight
shift in the synoptic pattern. Temperatures Thursday, Friday, and
Saturday look cool and fall-like in the wake of this storm.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 525 AM MDT Sun Sep 7 2025

Expect mostly VFR conditions and light terrain driven winds
through the TAF period. There is some patchy low stratus
developing in the Gunnison Valley that should burn off in the
next couple hours as the sun rises. Isolated to scattered
showers and thunderstorms will develop mostly along and north
of the I-70 corridor between 18Z and 00Z with lingering showers
lasting to 06Z producing brief MVFR conditions below ILS
breakpoints at KASE, KEGE and KHDN.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...DB
LONG TERM...LTB
AVIATION...DB