textproduct: Grand Junction

KEY MESSAGES

- Scattered showers and thunderstorms (some possibly dry) are expected today. Storms may produce sub-severe hail, gusty outflow winds, and new fire starts.

- Extreme fire weather conditions return tomorrow. Single digit relative humidities and gusts of 45-55 mph may lead to rapid wildfire spread.

- Critical fire weather conditions continue next week.

DISCUSSION

Issued at 138 PM MDT Fri Jun 26 2026

STORMS TODAY:

A moist mid-level environment remains situated over the region ahead of a broad, powerful PacNW trough. Dynamics again look favorable for thunderstorm development, which we are already beginning to see with towering cumulus developing region-wide and multiple isolated thunderstorms. In fact, the 18Z GJT sounding is dramatically outperforming models in regards to instability with CAPE over 1000 J/kg, and some storms have already neared severe hail thresholds. This favorable unstable environment is expected to persist throughout the afternoon and potentially into the evening. Most storms will be capable of small hail and gusty outflow winds, however, based on the ongoing storm behavior, we cannot rule out a storm or two producing 1" hail today. Instability lingers into the evening and overnight, so look for mild convection to continue across the southern CWA before a drier airmass moves overhead around 6 AM local time.

DRY AND WINDY CONDITIONS RETURN:

Rainfall over the past couple days (and expected today) will dampen fire weather threats for some higher elevation locations over the San Juans, central Colorado Mountains, and Roan Cliffs. For most lower elevation areas though, particularly around the Four Corners and within the Grand Valley/Utah Grand Flat, dry surface conditions remain in place as little to no rain fell in these areas. Several lightning strikes in these locations over the past couple days could prompt new fire starts today or over the weekend. And with the low pressure system dipping further south into the western CONUS, a tighter pressure gradient is setting up across the Intermountain West. As such, winds will strengthen Saturday and Sunday, with gusts of 45-55 mph anticipated. This paired with the plummeting relative humidities has led to high confidence in an extreme fire weather day Saturday. Practice wildfire prevention, including avoiding any outdoor activities that may involve flames or sparks, ensuring vehicle chains do not drag on the ground, and obeying all fire weather restrictions.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 506 PM MDT Fri Jun 26 2026

Thunderstorm activity will diminish as sunset approaches, with a few pockets of showers continuing through the overnight period for some terminals. Included PROB30 groups to account for that. Gusty winds will be the main threat for this period, with some terminals seeing gusts through the majority of the TAF period, including the overnight hours. Gusts will be less intense to finish off today, but will ramp back up Saturday afternoon, likely within the 35-40 kt range, with locally higher gusts possible. In the wake of this system, mid to high level clouds will be around to end the TAF period. VFR conditions are expected to prevail.

FIRE WEATHER

Issued at 138 PM MDT Fri Jun 26 2026

Powerful winds and very dry relative humidities again return to the region Saturday and Sunday, setting the stage for an extreme fire weather setup. This follows the extended period of hot, dry, and windy conditions we have been stuck under for multiple weeks now. To add to it, we've seen two days of dry lightning in addition to any lightning we experience today. As things dry out, there is a high potential for new wildfire starts to appear resulting from these thunderstorms. For higher elevation areas in the San Juans, central Colorado Mountains, and Roan Cliffs, recent wetting rains will hinder fire development and spread. The concern lies mostly in lower elevations around the Four Corners and within the Grand Valley/Utah Grand Flat. Most lightning that we've seen over the past few days were along the UT-AZ border and east of the Abajo Mountains. However, with ongoing storms today, additional lightning over the Uncompahgre Plateau and Book Cliffs will also be of concern. Any fires that do develop over the next 48 hours will have the potential to spread rapidly due to the overall atmospheric and fuel conditions.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Red Flag Warning until 9 PM MDT this evening for COZ200-202- 203-207-290. Red Flag Warning from 10 AM Saturday to midnight MDT Saturday night for COZ200>203-205-207-290>295. Red Flag Warning from noon to 10 PM MDT Sunday for COZ202-203- 207-290-292-294. Wind Advisory from 10 AM to 10 PM MDT Saturday for COZ002-008- 020-021. UT...Red Flag Warning from noon to 10 PM MDT Sunday for UTZ487-490- 491. Wind Advisory from 10 AM to 10 PM MDT Saturday for UTZ022-027. Red Flag Warning until midnight MDT Saturday night for UTZ486- 487-490-491.