979
FXUS65 KGJT 291123
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
523 AM MDT Sat Aug 29 2026

.KEY MESSAGES...

- Strong to severe thunderstorms are possible along and north of
  I-70 Saturday, with damaging winds being the primary threat.

- Flash flooding is also possible Saturday as precipitation
  chances become more widespread ahead multiple rounds of
  showers.

- Storm chances remain in the forecast each afternoon through
  next week, as will the threat for flash flooding along
  vulnerable terrain.

- Cooler weather arrives with this current pattern. Daytime
  highs into next week could be hovering near or below normal.

&&

.DISCUSSION...
Issued at 955 PM MDT Fri Aug 28 2026

COOLER AND WETTER WEEKEND:

A substantial pattern change is expected to take place Saturday as
the high pressure previously centered over the Four Corners begins
to break down as a result of an incoming trough to our northwest.
During this transitional period, nocturnal convection is possible
each night as moisture advection begins to intensify under dominant
southwesterly flow aloft. As a result of this, eastern Utah and
western Colorado will likely be waking each morning to cloud cover.
This cloud cover will linger throughout the day, leaving us with
widespread precipitation chances for the CWA this weekend.
Additionally, PWATs are expected to surge to ~150-190% of normal. As
far as temperatures are concerned, this weekend will see daytime
highs within 5 degrees of normal, and they continue to be on the
downward trend as we move towards next week.

SATURDAY:

Strong upper-level winds arriving Saturday will create enhanced wind
shear along and north of I-70, setting the stage for a few strong to
severe thunderstorms. Damaging wind gusts will be the primary threat
with these storms. Gusts upwards of 60 mph were seen with some of
Friday`s storms. Therefore, cannot rule out a similar situation for
Saturday, if not even higher gusts. Additionally, lightning, hail,
and localized heavy downpours should not be ruled out. Flash
flooding will also be a concern if storms slow down, stall, or
repeatedly track over the same area.

SUNDAY:

Scattered to widespread thunderstorms will redevelop on Sunday, but
as the upper-level jet dynamics depart to the northeast, the primary
threat will shift from damaging wind to localized heavy rainfall.
This inherently enhances the risk for flash flooding and debris
flows on recent burn scars and susceptible terrain.

NEXT WEEK:

As we begin next week, ensembles are supporting PWATs >150% of
normal through at least Monday, before a slight downturn in moisture
for Tuesday and Wednesday. Although, models begin to diverge in
outcomes by Wednesday leading to rather low forecast confidence
midweek and beyond. All that being said, there still remains a
signal for another push of monsoonal moisture late next week. This
moisture could also be enhanced by a tropical system situated in the
eastern Pacific, which we will have to see evolve to gain a clearer
picture. As for temperatures, a welcome relief is in store as
daytime highs are expected to fall below normal to start next week.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 517 AM MDT Sat Aug 29 2026

A few showers, maybe a rumble of thunder, will continue this
morning before more widespread convection starts forming. After
18Z, more widespread showers and storms will form with all TAF
sites possibly seeing some convection on station. PROB30 groups
will capture this possibility through much of the afternoon and
evening hours. Under and near the stronger cells, gusty outflow
winds and heavy rain will be the main concerns. Outside of
convection, gusty winds of 20 to 25kts will be possible. Despite
the convection, VFR conditions will remain in place though brief
MVFR can`t be ruled out as stronger storms and showers drop
visbilities to below 3 miles.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

DISCUSSION...BS
AVIATION...TGJT