textproduct: Grand Junction

KEY MESSAGES

- Isolated afternoon showers and storms possible through Saturday.

- Precipitation chances increase throughout the holiday weekend, with peak coverage expected Sunday and Monday. Flash flooding will be the primary threat with periods of heavy rain possible.

DISCUSSION

Issued at 1000 PM MDT Thu Sep 3 2026

ISOLATED SHOWERS AND STORMS FRIDAY AND SATURDAY:

A weak jet accompanied by some modest moisture will nose into the Four Corners region tonight. Some of the hi-res models support the development of showers along the moisture transport gradient, especially in southern foothills of the San Juans. This moisture remains in place for much of Friday and Saturday, especially along the Divide. As a result, afternoon convection favoring the higher terrain will return to the forecast, but most locales will remain dry with seasonable temperatures and breezy afternoon winds.

MONSOONAL MOISTURE SURGES SUNDAY AND MONDAY:

With southwesterly flow remaining in place through the holiday weekend, moisture advection will continue to intensify throughout the holiday weekend. This will result in scattered to widespread convection across the region. PWATs upwards of 200% of normal will support the potential for heavy rainfall and flash flooding, especially around recent burn scars and areas with steep terrain. This threat is particularly heightened where soils have reached peak saturation after multiple rounds of storms this past week.

Beyond Monday, model outcomes begin to diverge from each other. The GFS appears to be heavy handed bringing in a second tropical system over the Baja Peninsula late next week, which most other models do not have a strong signal on. So at this time, there is uncertainty with how long we hold onto moisture chances next week and therefore forecast confidence remains low beyond Monday.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 601 PM MDT Thu Sep 3 2026

Dry weather is ongoing, but after 06Z there is a low chance of showers and thunderstorms over the southern mountains. However, TAF site impacts are unlikely overnight. PROB30 has been included at KTEX after 18Z for thunderstorms. Winds will generally become light tonight, but KGJT and KTEX could see some stronger winds overnight. VFR conditions will prevail.

GJT WATCHES/WARNINGS/ADVISORIES

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