121
FXUS65 KGJT 081132
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
532 AM MDT Wed Oct 8 2025

.KEY MESSAGES...

- High temperatures trend 5-10 degrees above average today and
  tomorrow.

- Isolated showers and thunderstorms develop over the southern
  San Juans this afternoon.

- A surge of tropical moisture is expected across the Southwest
  later this week, peaking Friday and Saturday. Widespread
  showers and storms will be capable of producing flash
  flooding.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 400 AM MDT Wed Oct 8 2025

As southwesterly flow continue to funnel warmer air into
eastern Utah and southwest Colorado, expect unseasonably warm
daytime highs. Much of the region will remain dry today in
advance of the arrival of tropical moisture from the remnants of
Hurricane Priscilla. A few storms cannot be ruled out over the
southern San Juans this afternoon.

The aforementioned moisture arrives tonight into tomorrow
leading to an uptick in coverage of showers and storms. With
PWATs soaring upwards of four standard deviations above normal,
much of the forecast area will see much soggier conditions to
close out the week. The CAMs support periodic showers and storms
spreading northeastward on Thursday. While there will be a
localized flash flooding threat, mainly to the recent burn
scars, a lack of instability will likely prohibit the efficiency
of Thursday`s rains. Rather, they will set the table for a more
active weekend ahead.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Issued at 400 AM MDT Wed Oct 8 2025

The models show remarkable agreement through the extended
forecast period starting with high pressure over West Texas
Thursday evening having pulled deep moisture north out of Sonora
Mexico into the Desert Southwest and into eastern Utah and the
central valleys of Western Colorado. This moisture with pwats
over an inch (300% of normal) will continue to push into the
region through Friday with remnant moisture from Priscilla with
pwats over an inch and a quarter (350% of normal) pushing into
the region Saturday. Temperatures Friday and Saturday will run
ten degrees cooler than Thursday due to the heavy cloud cover
limiting diurnal heating and due to widespread shower activity.
Friday`s precipitation will be more stratified showers due to a
tropical warm rain event with this system having 700 mb temps
near 8C, but can`t rule out possible isolated thunderstorms from
orographic lift and an uncertain passing weak jetstreak through
the afternoon. There is a slight risk for heavy rain Friday in
southeastern Utah and southwestern Colorado with this warm rain
event, but confidence is too low at this time to issue any watch
products, Stay tuned for updated on this.

Widespread showers will continue overnight into Saturday with
heavier shower and stronger thunderstorms possible late Saturday
into the overnight period with increasing upper-level dynamics
and a cold front dropping down out of the Pacific Northwest
moving through the region early Sunday associated with the low
that is off the Pacific Northwest moving inland becoming an
openwave system passing to the north. This deeper surge of
moisture and stronger dynamics push the increased risks for
heavy rain as far north as the Tavaputs and Flat Tops Saturday
afternoon through the overnight. Holding off on a watch through
this period due to current uncertainty, so again, stay tuned for
updates.

Though this cold front will push most of the moisture out of
the region, residual moisture will support scattered afternoon
showers and thunderstorms favoring the higher terrain daily
Sunday through mid week. Behind the cold front, temperatures
will remain about five degrees below normal Sunday, warming to
near normal Monday through Wednesday with more scattered cloud
cover improving diurnal heating. Models are hinting at another
surge of tropical moisture from yet another Eastern Pacific
tropical storm by mid week, but uncertainty is high on this one.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 527 AM MDT Wed Oct 8 2025

Expect mostly VFR conditions with generally light winds through
the TAF period. The exceptions will be westerly winds gusting
20 kts between 18Z and 00Z in the mountains and moisture moving
up from the south spawning afternoon thunderstorms after 20Z
along the southern face of the San Juan Mountains with a chance
for impacts to KDRO. Showers and thunderstorms will push north
to KTEX after 06Z.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...KAA
LONG TERM...DB
AVIATION...DB