textproduct: Grand Junction

KEY MESSAGES

- Isolated showers and thunderstorms increase in coverage on Tuesday and Wednesday, favoring the terrain.

- Chances for wetting rains remain low. Gusty outflow winds and dry lightning pose threats for new/existing wildfires.

- Localized critical fire weather conditions emerge Thursday for southeast UT and southwest CO.

- Afternoon highs could exceed 15 degrees above average this weekend.

DISCUSSION

Issued at 106 PM MDT Mon Jul 6 2026

Details of a pattern shift have come into better focus today. Precipitable water has nearly doubled on the Grand Junction sounding this morning. Unfortunately, this is all confined to the mid levels of the atmosphere, with parched conditions in the lower levels down to the surface. Surface dewpoints have responded. A turnaround of nearly 20 degrees has turned up in surface observations at Blanding and Moab. As extra-tropical plumes go, this one remains inconsistent and will likely be stingy with its measurable rainfall. A couple of gages have picked up some light accumulation, but far from a soaking rain. The threat of dry lightning plagues a moisture starved region impacted by numerous wildfires already. Moisture supplies look more robust on Tuesday and increase the chances for wetting rain, thereby suppressing some of the dry lightning risk. Excessively dry antecedent conditions likely mean the region retains some susceptibility to new fire starts, especially Wednesday when moisture supplies contract again and we return to hotter and drier conditions.

Yet another pattern shift emerges Thursday and Friday. A shortwave trough works across the Intermountain West late Wednesday night. This will bring some stronger winds to the area on Thursday afternoon, along with more widespread critical fire weather conditions around the Four Corners. It looks like fire weather will remain short-lived though. A digging trough offshore of the PACNW will drive heights upward over the West Friday and beyond. Subsidence over the Great Basin will mute winds drastically and send high temperatures upward. Afternoon highs look to surge in excess of 15 degrees over climatology this weekend. This could doom any precipitation chances in the long term. For now we will keep a watchful eye southward in hopes of another trickle of water out of the extra-tropical faucet.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 551 PM MDT Mon Jul 6 2026

Isolated showers and thunderstorms over eastern Utah and southwestern Colorado will continue for the next few hours, diminishing by 06Z. Expect gusty outflow winds and brief periods with these storms. Otherwise, look for terrain driven drainage winds overnight, becoming westerly with a few gusts to 20 kts after 18Z. Expect another round of isolated showers and thunderstorms after 18Z over the higher terrain across the region with more scattered storms possible over the San Juan Mountains and along the Divide. Smoke from local wild fires will continue to have periods of minor impacts to most TAF sites across the region.

FIRE WEATHER

Issued at 106 PM MDT Mon Jul 6 2026

A surge in extra-tropical moisture continues to threaten the region with isolated showers and thunderstorms. As previously discussed, these showers will struggle to saturate the lower layers of a parched atmosphere. Unfortunately, this increases chances for dry lightning, along with gusty outflow winds. Showers will continue to favor the terrain of western CO and eastern UT Tuesday and Wednesday, with a slight uptick in wetting rain chances. Odds remain rather low though that moisture will make it to the surface. High pressure begins to erode Thursday with a weak shortwave traversing the Great Basin. This looks to drive up wind speeds for portions of southeast UT and southwest CO. Localized to more widespread critical fire weather conditions emerge Thursday afternoon around the Four Corners. High pressure returns Friday and beyond, amplifying over the West. Afternoon highs will surge well into the triple digits for the lower desert valleys this weekend. Wind speeds look sub-critical though, below the high. Hot and dry will remain anchored in place heading into next week.

GJT WATCHES/WARNINGS/ADVISORIES

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