textproduct: Grand Junction

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.