textproduct: Grand Junction

KEY MESSAGES

- Isolated to scattered convection is expected each afternoon with gusty outflow winds possible through Wednesday.

- Available moisture increases through the week with an uptick in convection and precipitation coverage and intensity expected Wednesday onwards. - Above normal temperatures will gradually cool closer to normal by late next week.

DISCUSSION

Issued at 1038 PM MDT Sun Aug 9 2026

Some light shower activity is lingering this evening across eastern Utah and is spreading into west-central Colorado as a remnant shortwave moves across the central and northern parts of the CWA. Shower activity could linger overnight but only light rain or gusty winds would be the main concerns since the low levels are still dry. The high pressure will remain overhead but get flattened a bit for Monday, still centered near the Four Corners. So for Monday, we will see moisture recycled under this high in westerly flow with another day of isolated to scattered shower and thunderstorm activity mainly over the higher terrain in the afternoon before drifting eastward into lower valleys late in the day but collapsing as there is little in the way of upper level support to sustain any convection. The high gets nudged a bit east Tuesday but remains overhead so can anticipate more of the same through Tuesday with gusty outflow winds the primary concerns and low chance of wetting rains.

By Wednesday, a low pressure trough moves onto the west coast and nudges the high pressure ridge to the east in a favorable position to advect deeper monsoonal moisture as the flow shifts to the south. The models have been honing in on the mid to late week period for the best moisture availability and increasing chances and coverage of showers and storms with better chances of wetting rain. Several shortwaves will move through the southerly flow ahead of this trough as well Wednesday through Friday with the more robust activity expected Thursday. Convection stands a good chance to last into the overnight hours as well due to this added forcing and lift. Storms during this mid to late week timeframe will be capable of heavy rain, gusty winds and hail with storm motion and speed playing a role with regards to heavy rain. For outdoor enthusiasts, please pay attention to the latest forecasts towards the end of the week. High temperatures will remain about 10 degrees above more normal August values, possibly dropping to below normal towards the end of the week thanks to increased cloud cover and precip.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 514 AM MDT Mon Aug 10 2026

Mid to high level convective debris clouds will drift through this morning as moisture is increasing across the region. This will eventually lead to another round of shower and thunderstorm activity as heating takes place this afternoon. Gusty outflow winds will be the main threat and placed in PROB30 groups at several TAF sites where confidence is the highest. VFR is forecast to prevail over the next 24 hours.

GJT WATCHES/WARNINGS/ADVISORIES

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