textproduct: Grand Junction

KEY MESSAGES

- Hot and dry conditions persist through the weekend, with near record temperatures possible in some areas. Heat Advisories remain in effect this weekend.

- Isolated storms favoring the high terrain are possible early next week with coverage increasing by late next week with better wetting rain chances.

DISCUSSION

Issued at 1045 PM MDT Fri Aug 7 2026

HOT AND DRY THROUGH THIS WEEKEND:

High pressure will remain anchored over the Four Corners region this weekend. We will see a bit more cloud cover advect into the region from the west as some moisture sneaks in under the ridge, guided by a few shortwaves that will move around the ridge and across the Northern Rockies. This cloud cover comes in a bit later in the day on Saturday, so overnight lows Saturday night appear to be much warmer than we've seen recently due to lack of efficient radiational cooling in the absence of clearer skies. Temperatures during the afternoon will remain hot with a dry air mass remaining in place. Even though a bit of moisture will result in more cloud cover this weekend and some elevated convection over the high terrain, it will take some time for us to overcome this hot and dry air mass in place. So any storms that do form will be more prone to gusty outflow winds and lightning with a very low chance of wetting rain (5 percent or less). Heat advisories remain in place Saturday and Sunday for our east-central and southeast Utah desert valleys with the Grand Valley in west-central Colorado only seeing Heat Advisory for Saturday as Sunday is expected to be below Heat Advisory thresholds.

MOISTURE RETURNS NEXT WEEK:

A pattern change is on the horizon next week as moisture continues to increase from the west underneath the high. Storm coverage as a result is expected to increase but appears like early next week will favor the high terrain with better chances of wetting rain while the lower valleys remain mostly dry. It appears like deterministic and ensemble models are honing in on the mid to late week timeframe for increased storm coverage and precipitation potential. This is likely due to a low pressure trough setting up off the west coast by mid to late week, allowing the high pressure ridge to shift eastward enough to draw a more direct southerly tap of monsoonal moisture. The late week period looks particularly interesting as the GFS is indicating a rather robust shortwave moving through the Four Corners and up through western Colorado next Thursday. With the addition of forcing provided by several shortwaves, this could result in some overnight convection as well in the late week period. These details however are not certain and uncertainty still remains with regards to the magnitude of this moisture push, but models continue to favor a mid to late week jump in QPF, PWAT and PoP.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 506 AM MDT Sat Aug 8 2026

Light winds with passing mid to high cloudiness can be expected through mid day leaving VFR conditions in place. Some high based showers and storms are possible over the higher terrain tomorrow afternoon with breezy outflow the main concern. Impacts at TAFs are very remote and not in the forecast attm.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Heat Advisory from 1 PM this afternoon to 8 PM MDT this evening for COZ006. UT...Heat Advisory from 1 PM this afternoon to 8 PM MDT this evening for UTZ022-027. Heat Advisory from 1 PM to 8 PM MDT Sunday for UTZ022-027.