FXUS65 KGJT 231904
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
104 PM MDT Sun Aug 23 2026

.KEY MESSAGES...

- Monsoonal moisture in place will keep scattered shower and 
  thunderstorm chances in the forecast today.

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

- Temperatures near to around 5 degrees above normal are
  expected through early next week, followed by a gradual warmup
  to close to 10 degrees above normal.

&&

.DISCUSSION...
Issued at 1232 PM MDT Sun Aug 23 2026

Shortwave troughing working across the northern Rockies this
afternoon is providing some lift to the monsoonal moisture in
place across the region. Convection thus far, has been richest
across the San Juans where a concentration of showers and
thunderstorms have developed this morning. This activity is
expected to continue through the afternoon. Some rain is making
its way to the surface, but rainfall remains sporadic. Some
heavier showers could pose flash flooding issues this afternoon,
as afternoon heating amplifies storms. Shortwave energy will
continue to drag across the region into the evening hours,
likely keeping a few isolated showers going into the overnight.
Showers will lose much of their stamina after sunset, so 
expecting for more stratiform shower activity during the late 
evening to overnight hours, winding down before daybreak. While 
moisture takes a slight downturn on Monday, there will still be 
ample fuel for another afternoon of mountain showers and
thunderstorms. Once again, some showers could pose a threat for
flash flooding near burn scars and sensitive slot canyons,
arroyos, etc.

Above normal moisture sticks around Wednesday and beyond, as 
the high gradually shifts back into the Desert Southwest. 
Forcing will be somewhat lacking, with only the occasional 
shortwave rotating around the periphery of the high. This means 
that most afternoons will see isolated to scattered showers and 
thunderstorms develop over the higher terrain, with occasional 
periods of focused convection coinciding with a passing wave. 
So long as surface levels remain saturated, heavy rain and flash
flooding will remain concerns, particularly for burn scars, slot
canyons, and flashy creeks/dry washes. Additionally, gusty 
outflow winds and lightning will be daily threats. Temperatures 
will start around 5 degrees above normal, but will gradually 
warm through the week under the influence of the high. By the 
end of the coming workweek, look for highs to be 5-10 degrees 
above normal.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1145 AM MDT Sun Aug 23 2026

Shower and thunderstorm activity is ongoing, primarily over the
high terrain south of I-70. Coverage of convection will increase
during the afternoon and persist through the evening. Primary 
concerns with this activity is lightning, strong outflow winds, 
and periods of heavy rainfall resulting in drops to MVFR 
conditions. A few sites may experience gusts up to about 20 kts 
outside of shower and storm activity. Winds will become light 
and variable overnight.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

DISCUSSION...TGJT
AVIATION...TGJT