textproduct: Grand Junction

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.