textproduct: Grand Junction

KEY MESSAGES

- Expect terrain-based showers and thunderstorms each afternoon this week, favoring the San Juans, but spreading north by the weekend.

- Localized heavy rainfall will have the ability to produce flash flooding and debris flows in vulnerable terrain, including areas near and downstream of burn scars.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 528 PM MDT Thu Jul 16 2026

Stormy weather continues for the majority of the region. Most terminals (aside from HDN and VEL) may see rainfall this evening and/or tomorrow afternoon. Gusty outflow winds up to 35 kts will be possible, and higher elevation terminals, particularly ASE and EGE could occasionally drop below ILS breakpoints. Heavier rain could also drop vis to MVFR, though areas where this will occur are too uncertain at this time, and thus vis reductions have not been included in any TAF's.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1138 PM MDT Thu Jul 16 2026

The radar is a bit more active late this evening with shower activity but the atmosphere is stabilizing and expect storms to dissipate through the next few hours...leaving convective debris clouds through sunrise. The moisture in place which will once again allow convection to blossom by midday over the terrain with the flow carrying these storms to the Southwest through the evening and impacting the valley/TAF locations. Gusty outflow winds and locally heavy rain will be the main concern with storms. There is a low probability of MVFR occurring due to visibility restrictions in the heavier showers otherwise VFR prevails.

HYDROLOGY

Issued at 1235 PM MDT Thu Jul 16 2026

An anomalous plume of moisture continues to rotate into Utah and western Colorado this afternoon, with a slight uptick compared to yesterday. The San Juans remain a bullseye in precipitation forecasts this afternoon and again on Friday, maintaining flash flood threats redeveloping each afternoon. However, available moisture is higher moving west into Utah, which leaves the potential for isolated storms to produce hourly rainfall rate of 1-2 in. Therefore, areas of concern remain unchanged from the previous forecast for this afternoon.

Storms over the last 24 to 48 hours have only helped prime lower levels of the atmosphere and saturate the ground where rain was observed. Several locations across southwest Colorado reported over 0.5 inches of rain within 30 minutes during yesterday's convection; which is more than sufficient to create issues in our steep, rocky terrain already susceptible to flash flooding. This environment also triggers heightened awareness over recent (or actively burning) fires, due to the burnt ground's inability of absorbing moisture under heavy rainfall. As such, we continue to emphasize the potential for flash flooding and debris flows in this regime.

As a reminder: Keep an eye on our forecasts through the end of the week and stay tuned for updated hydro alerts if visiting or if you reside below vulnerable terrain to flash flooding and/or debris flows. Storms across the west develop quickly, leaving little room for lead time in flashy terrain.

GJT WATCHES/WARNINGS/ADVISORIES

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