929
FXUS65 KGJT 190530
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
1130 PM MDT Fri Sep 18 2026

.KEY MESSAGES...

- Saturday will see isolated to scattered showers and storms
  with moisture on the downward trend for the rest of the
  weekend.

- Another push of monsoonal moisture arrives Tuesday, bringing
  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 1009 PM MDT Fri Sep 18 2026

DRYING OUT FOR THE WEEKEND:

A cold frontal passage will propagate throughout the area late
Friday night into Saturday morning. This will help remove some of
the moisture from the region. With that being said, PWATs are still
forecast to remain ~150% of normal through Saturday. This means that
storm coverage and the threat for heavy rainfall decreases, but
enough moisture is in place to support isolated to scattered
convection Saturday. Current HiRes guidance suggests most of
the storm activity to occur along and north of I-70. In
addition to less coverage of precipitation, temperatures will
cool by a few degrees.

By Sunday, PWATs drop to ~75-125% of normal, which indicates there
may be enough remnant moisture for isolated convection over the
higher terrain. Aside from that, lower elevation areas can expect a
pleasant day with scattered afternoon cloud cover.

RETURN OF PRECIPITATION CHANCES NEXT WEEK:

The aforementioned drier period won`t stick around for long as
another pool of rich moisture is advected into the region. Specific
timing may change in the coming days as more model guidance becomes
available, but it currently looks like this moisture enters the
region by Tuesday and sticks around for a few days. The Euro Ens
appears to be more bullish when it comes to PWAT anomalies, whereas
the GFS Ens seems a little less so. Either way, both models are
hinting at moisture pools favoring the area south of I-70. All that
being said, this event does not appear to be as widespread as what
we have experienced this past week.

On a side note... as moisture returns next week alongside cooler
overnight lows, we could see the first snowflakes of the season over
our highest peaks, particularly in the San Juans and eastern Uintas.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1130 PM MDT Fri Sep 18 2026

Scattered showers and storms will continue to lift northward
across the area through sunrise impacting several of the TAF
sites with light rain and a low probability of MVFR conditions.
This continues again on Saturday across most of the area except
the far southern and western airfields where drier air will be
filtering in...limiting the coverage of storms. VFR should
prevail otherwise over the next 24 hours with area of ILS
possible. Will also continue to monitor the possibility of
stratus in several of our upvalley locations.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

DISCUSSION...BS
AVIATION...GJT