textproduct: Grand Junction

KEY MESSAGES

- Expect showers and thunderstorms through Monday morning. Isolated stronger storms may be capable of producing flash flooding.

- Warmer and drier conditions return Tuesday onward, though a chance for isolated mountain showers remains each afternoon.

DISCUSSION

Issued at 1040 PM MDT Sun Sep 6 2026

Sandwiched between a trough in the Pacific Northwest and a ridge over the Southern Plains, southwesterly flow is dominant aloft over the Desert Southwest. This flow is advecting in a rich plume of tropical Pacific moisture, with PWATs near an inch across the region. The one caveat to this deep moisture are the lingering dry surface layers. This evening's 00z KGJT sounding shows a pronounced inverted-V profile, with the column saturated aloft but quite dry near the surface. As a result, most locations have seen virga showers and strong, gusty winds this evening, rather than heavy rainfall. Areas in northeast Utah where showers have been training for the last 6 hours have finally seen precipitation make it to the surface, but totals have been limited to just a few hundredths. With plenty of moisture but a lack of instability, this type of activity will continue through the night, with gusty winds and light rainfall through daybreak tomorrow.

Drier air moves in after daybreak, bringing an end to any lingering showers and allowing skies to clear, setting the stage for a drier week ahead. The Pacific Northwest trough tracks along the Canadian border over the coming days, while high pressure builds westward into the Desert Southwest, pushing a ridge up along the West Coast. Drier zonal flow will be in control over eastern Utah and western Colorado by midweek, allowing temperatures to warm up a few degrees, running around 5 degrees above normal. Enough surface moisture will linger to fuel a few isolated showers or thunderstorms over the higher terrain Monday and Tuesday, but chances dwindle by midweek.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1150 PM MDT Sun Sep 6 2026

Light showers are possible across the region tonight as an influx of moisture moves in from the south. Showers will shift east through the night with clearing by 12z. Gusty southwest winds of 20-30 knots will impact TAF sites Monday afternoon. VFR conditions will prevail and ceilings will remain above breakpoints.

GJT WATCHES/WARNINGS/ADVISORIES

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