517
FXUS65 KGJT 201118
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
518 AM MDT Sun Sep 20 2026

.KEY MESSAGES...

- Sunday and Monday will see a downward trend in storm activity
  with isolated showers and storms possible over the high
  terrain but overall much drier conditions.

- Another push of moisture on Tuesday and Wednesday brings
  precipitation chances back into the forecast for the region.

- Daytime highs this weekend and into next week will be
  relatively seasonable, if not below at times.

&&

.DISCUSSION...
Issued at 1042 PM MDT Sat Sep 19 2026

Isolated to scattered showers and thunderstorms will continue
late this evening, becoming more isolated in nature overnight
mainly across the north as the upper low that was responsible
for our active weather period pushes eastward across the north.
Overall, storm intensity appears on the downward trend as drier
air continues to advect into the region behind this low and
across the Four Corners.

DRYING OUT SUNDAY AND MONDAY:

Sunday and Monday will see much drier conditions in addition to
cooler more seasonable temperatures as the upper low exits east
onto the Plains and high pressure ridge builds out west over the
Great Basin. Enough moisture may still linger for some isolated
showers and storms over the higher terrain, but those chances
are very low. Overall, Sunday and Monday should provide a brief
break from the stormy pattern with cooler and pleasant
conditions.

PRECIPITATION CHANCES RETURN TUESDAY ONWARD:

Meanwhile, all eyes will be on our next weather maker, an upper
low that will carve out over the Desert Southwest before lifting
across the Great Basin as an open wave trough Tuesday. This will
shift the flow back to a southwest direction and allow moisture
to move back into the region. High pressure sets up over Texas,
which works in concert with the Great Basin trough to draw up
moisture into the Four Corners and across western Colorado. So
it does appear like storm chances and coverage will increase
Tuesday and Wednesday, possibly lingering through late week,
with scattered coverage. We will be in the right entrance region
of the jet, which helps provide dynamic support. The wave will
also provide shear so some of the storms could be strong to
severe. Also, freezing levels may come down enough to coat the
highest peaks with snow. The uncertainty is will the wave push
the moisture to our south or will it linger in portions of the
area. If it does get pushed southward how quick will it return.
Confidence in the forecast mid to late week is low attm.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 517 AM MDT Sun Sep 20 2026

Some stratus hangs over HDN this morning, though cigs are not
anticipated to fall below ILS breakpoints. Otherwise, some
breezy gusts of 18-22 kts may occur across the region today. VFR
conditions prevail throughout the TAF period.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

DISCUSSION...MDA/TGJT
AVIATION...TGJT