704
FXUS65 KGJT 221106
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
506 AM MDT Sat Aug 22 2026

.KEY MESSAGES...

- Monsoonal moisture will cause precipitation chances to become
  more widespread Saturday.

- Heavier rainfall Saturday could lead to localized flash
  flooding over burn scars and susceptible terrain.

- Temperatures gradually cool off for the weekend and into next
  week but still remains above normal.

&&

.DISCUSSION...
Issued at 1014 PM MDT Fri Aug 21 2026

COOLER & WETTER WEATHER THIS WEEKEND:

High pressure will continue to be centered over our region through
the weekend. Clockwise flow around this system will favor moisture
advection into our CWA. Hence, precipitation chances will become
more widespread Saturday under dominant southwesterly flow.
Deterministic models are hinting at PWATs at 150-180% of normal
during this time period. Storms are expected to favor the higher
terrain initially, but adjacent valleys could also get in on the
action as storms begin to move off the terrain. Models also seem to
be hinting at a shortwave disturbing the driving flow Saturday, which
would mean additional lift in an already saturated environment.
This will subsequently increase flash flooding and debris flow
concerns. Continue to be weather aware and have multiple ways to
receive watches and warnings.

Afternoon storm chances will be around Sunday as well while the
increased atmospheric moisture remains in place. However, storm
chances will be mostly confined to the higher terrain as no
additional lift is anticipated from synoptic forcing. With that
being said, flash flooding and debris flow concerns persist through
at least Sunday as localized heavy rainfall remains a possibility.

Daytime highs cool by about 5 degrees for the weekend, but still
remain above normal for this time of year.


NEXT WEEK:

The environment continues to be saturated into next week which will
keep afternoon thunderstorms in the forecast daily for the higher
terrain. It is unclear how precipitation chances will pan out for
the lower valleys at the moment. As more HiRes guidance becomes
available, we will likely have a better grasp on what`s to come.

Daytime highs hold steady as we move into next week with most
locations seeing similar temperatures as the weekend. These values
will still be above normal but not quite into record breaking
territory anymore.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/... Issued at 426 AM MDT
Sat Aug 22 2026

Isolated showers continue to move north across eastern Utah.
Isolated to scattered showers will increase across the region
through the late morning with the higher terrain seeing more
widespread showers and thunderstorms developing around 18Z. Some
of the storms will move off the terrain over the lower valleys
through the afternoon with most TAF sites seeing some impacts.
Lightning, gusts to 45 kts and brief heavy rain producing MVFR
ceilings and visibilities will be the primary threats from
these storms. Otherwise, outside of the storms, expect VFR
conditions through the TAF period with generally light terrain
driven winds.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

DISCUSSION...BS
AVIATION...DB