457
FXUS65 KGJT 050518
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
1118 PM MDT Fri Sep 4 2026

.KEY MESSAGES...

- Isolated afternoon showers and storms possible along the
  Divide through Saturday.

- Precipitation chances increase throughout the holiday weekend,
  with peak coverage expected late Sunday into Monday. Storms
  may be capable of producing flash flooding.

&&

.DISCUSSION...
Issued at 927 PM MDT Fri Sep 4 2026

QUIET START TO HOLIDAY WEEKEND:

If you enjoyed Friday`s weather, you will also be a fan of
Saturday`s as the weather pattern remains largely unchanged.
Modest moisture has pooled along the Divide and may spawn
isolated afternoon showers and storms, but the majority of the
forecast area will remain. Temperatures remain seasonable.

PRECIPITATION CHANCES INCREASE LATE SUNDAY INTO MONDAY:

While previous model runs suggested a surge of monsoonal
moisture into the Four Corners region come Sunday, recent trends
have slowed the arrival time of rich moisture to late Sunday
evening into Monday. Hi-res models are in good agreement for
this later arrival time as well. With moisture moving in past
peak heating, this may delay the risk for flash flooding from
heavy rainfall to Monday. Even so, if much of the area is
already blanketed with clouds come Monday morning, it may be
hard to build instability which would also reduce the risk for
flash flooding. While the threat for flash flooding seems to be
on the decline on a broader scale, soils may remain saturated in
some areas after multiple rounds of heavy rainfall last
weekend. It may not take much additional precipitation to
trigger additional debris flows. Recent burn scars and areas
with steep terrain will remain susceptible as well.

LOOKING AHEAD:

Model spread continues to lead to a lower confidence forecast
beyond Monday. The GEFS retains richer moisture along and south
of I-70, while the ECMWF ENS has the moisture receding to the
southeast on Tuesday. However, later in the week much of the
West will likely see an uptick in moisture as the remnants of
Hurricane Marie advect inland. Otherwise, high pressure looks to
drive the forecast through much of the week ahead.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1116 PM MDT Fri Sep 4 2026

Mainly clear skies with light drainage winds can be expected
overnight. A few showers/thunderstorms will again pop over the
southern and eastern mountains on Saturday afternoon but with
limited coverage confidence too low to place in any TAFs attm.
VFR prevails the next 24 hours.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

DISCUSSION...KAA
AVIATION...TGJT