textproduct: Grand Junction

KEY MESSAGES

- Isolated showers, maybe a quick storm, will remain possible over the San Juans and along the Continental Divide this afternoon.

- High temperatures will be around 5 to 10 degrees above seasonal norms through most of the week.

DISCUSSION

Issued at 1216 PM MDT Tue Sep 8 2026

DRY THROUGH THURSDAY:

High pressure building to our south will support a shift from southwesterly to more west/northwesterly flow by tomorrow. The shift to more zonal flow will bring drier air to the region. The drier air will remain in place through Thursday, which makes precipitation unlikely until late in the week. Although, a few light showers are possible over the San Juans and central Divide this afternoon, but most of this convective activity is expected to favor the eastern slopes of these high terrain areas. Temperatures around 5 to 10 degrees above normal are forecast over the next few days.

The drier air will result in relative humidities falling below fire weather thresholds during the late afternoon and early evening, particularly tomorrow and Thursday. However, wind gusts will only be marginal at most, resulting in just localized critical fire weather conditions in the Four Corners region and some areas along the Divide.

POSSIBLE MOISTURE RETURN LATE IN THE WEEK:

Current guidance favors modest moisture advection bringing precipitable water anomalies around 125% to 175% of normal later this week. This moisture advection is reliant on the development of a trough in the Pacific Northwest and a resultant shift in flow over our area. There is good agreement between deterministic models on the development of this trough. However, the reliance on the upstream trough and the absence of any obvious forcing on the synoptic level keeps confidence low regarding the specifics of our potential moisture push. So, be sure to stay tuned to see how the weekend forecast develops over the next few days.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1147 AM MDT Tue Sep 8 2026

VFR conditions are forecast through the TAF period. Winds will gust up to 25 knots this afternoon at most TAF sites with scattered middle to high level clouds. Isolated showers and storms are possible over the San Juans and the Divide during the afternoon. Expect light diurnal winds overnight.

GJT WATCHES/WARNINGS/ADVISORIES

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