textproduct: Grand Junction

KEY MESSAGES

- Hot, dry, windy conditions will develop as temperatures trend 10 to 15 degrees over normal.

- Critical fire weather will become more widespread Thursday and beyond ahead of low pressure dropping into the PACNW.

- Mountain showers and thunderstorms will favor the San Juans and near the Continental Divide northward through much of this week.

DISCUSSION

Issued at 111 PM MDT Tue Jun 2 2026

A weak upper trough continues to work in concert with some return flow moisture working north up the Continental Divide along the backside of high pressure parked over the eastern CONUS. This is producing some high based showers and thunderstorms against the Continental Divide this afternoon. The dry boundary layer is pretty much guaranteeing no wetting rains beneath these clouds unfortunately. A surge of deeper moisture lifts north Wednesday, increasing the chance for wetting rains in the San Juans Wednesday afternoon.

A pattern shift begins to evolve Thursday ahead of a deeper low dropping out of the Gulf of Alaska. Stronger upper level winds associated with this feature will begin to exert some influence on the northern half of the CWA. This could produce critical fire weather conditions for northeast UT and northwest CO on Thursday. While relative humidities remain critical, wind speeds remain on the marginal side, so I held off issuing any headlines. Transitory ridging suppresses winds Friday, while we remain hot and dry, as temperatures climb to near record values this weekend.

Strong southwesterly flow commands our attention this weekend, as a more concrete critical fire weather pattern emerges. Winds increase Saturday and Sunday, as the PACNW low digs into the Intermountain West. Unfortunately, a blocking high over the Plains impedes its inland progress. This increases the chances for us to remain in a critical fire weather pattern heading into the new work week, as hot, dry, windy conditions establish residency on the West Slope. In fact, deterministic models refuse to budge from this regime through the remainder of this extended forecast period next Wednesday. June has arrived.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 532 PM MDT Tue Jun 2 2026

Gusty southwesterly winds will continue through about 03z, then taper off. In many locations, winds will follow typical terrain driven patterns through 15z tomorrow. Winds will become gusty and southwesterly again by 18z. Gusts of 15-25 knots are expected. There is a low chance of showers or thunderstorms around KDRO tomorrow afternoon, with the main concerns being gusty, erratic winds and lightning. VFR conditions will prevail through the period.

GJT WATCHES/WARNINGS/ADVISORIES

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