textproduct: Grand Junction

KEY MESSAGES

- Shower and thunderstorm activity increases today. Gusty outflow winds, small hail, and periods of brief heavy rainfall are possible.

- As the current system exits, gusty winds will stick around each afternoon through the end of the week.

- Red Flag Warnings will be in effect Wednesday 1pm-8pm much of eastern Utah and the Four Corners area.

DISCUSSION

Issued at 1202 PM MDT Tue May 26 2026

Current satellite imagery depicts the trough axis to our west, which will propagate through our area as we move through the day. This will lead to some scattered shower activity and the possibility for thunderstorms. Showers will propagate from south to north during this time period. Locations where the sun was able to peak out this morning may have the best chance for instability as we move into the afternoon hours. It looks like northeast Utah and northwest Colorado did not have as much cloud cover this morning which could indicate an interesting afternoon ahead. A modest jet streak is also forecast to track across the region this afternoon, producing some localized wind shear. PWATs are currently sitting at 200% of normal for most of the region which would indicate plenty of available moisture. All that being said, the best chances for stronger thunderstorms exist northward of I-70. Gusty winds and small hail are the main threats. As mentioned earlier, there is plenty of available moisture fueling this system which would indicate heavy rainfall as a threat as well. Shower activity appears to diminish in most places as we move closer to sunset. With the increasing cloud cover and associated showers, daytime highs will run a few degrees below normal today.

HOT, DRY, WINDY CONDITIONS RETURN:

By Wednesday, a large cutoff low begins to slide down the West Coast which will shift our flow from moist southerly to a more dry southwesterly regime. Cloud cover will begin to diminish, dew points plummet, and temperatures will climb close to above normal by the end of the week. Eastern Utah and western Colorado will then be sandwiched between the aformentioned cutoff low to the west and ridging to the east, which will set up tight pressure gradient contours. This will cause gusts in the 30-40 mph range each afternoon. As a result, critical fire weather conditions make a return for the lower elevations of the Western Slope through at least Friday. See the fire weather section for more information on that. Along the higher terrain, enough available moisture will linger to prompt orographic showers and thunderstorms each afternoon through the end of the week. As previously mentioned, temperatures will hover around 10-15 degrees above normal during this time period, with winds relaxing as we move into the weekend, creating a break from critical fire weather conditions.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1143 AM MDT Tue May 26 2026

Showers are developing across the region, and will continue through the afternoon along with isolated to scattered thunderstorms. The main threats will be lightning and gusty winds, but there is a chance some sites could have brief drops to MVFR conditions. Storms will generally end around sunset, but precipitation should linger overnight across the Divide. Outside of areas with shower and thunderstorm activity, VFR conditions will prevail. Winds will generally become calm overnight.

FIRE WEATHER

Issued at 1202 PM MDT Tue May 26 2026

A deep closed low detaches from the parent flow in the PacNW early this week. By Wednesday, sharp pressure gradients around the low will have set up across our CWA, prompting strong surface winds. We will also be inviting a drier air mass into the region during this time. Relative humidity will drop below 15%, particularly in eastern Utah and the Four Corners region. The previous Fire Weather Watches in place for Wednesday have now been upgraded to Red Flag Warnings for the same zones. The low begins to stall through Friday leading to a few days of critical fire weather concerns. Because of this, Fire Weather Watches have been issued for Thursday for the same fire zones as Wednesday. Winds will begin to decrease through the weekend, which will decrease critical fire weather conditions.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Red Flag Warning from 1 PM to 8 PM MDT Wednesday for COZ207- 290. Fire Weather Watch from Thursday afternoon through Thursday evening for COZ207-290. UT...Red Flag Warning from 1 PM to 8 PM MDT Wednesday for UTZ486- 487-490. Fire Weather Watch from Thursday afternoon through Thursday evening for UTZ486-487-490.