textproduct: Grand Junction

KEY MESSAGES

- Isolated showers and storms are possible Saturday afternoon, mainly favoring areas across the north. Virga and erratic outflow winds as well as dry lightning will be more prevalent than any wetting rain.

- Widespread critical fire weather conditions will occur Saturday afternoon and evening with gusts 30 to 40 mph at times and relative humidity in the single digits. Red Flag Warnings remain in effect.

- By Sunday, critical fire weather conditions will become more localized, with a return of hot and dry conditions into early next week.

DISCUSSION

Issued at 1024 PM MDT Fri Jun 19 2026

THIS WEEKEND:

Virga showers remain across the north this evening with hi-res CAMs showing virga showers continuing through the overnight, which appears on track. Although winds have become light and terrain driven, could see some occasional breezy conditions near any of these virga showers but overall, conditions appear to remain dry. This activity is attributed to elevated moisture trapped underneath a shortwave ridge that was overhead today. We will transition Saturday to increasing southwest gradient as a shortwave trough approaches from the west across the Great Basin. Winds will increase late Saturday morning with widespread critical fire weather conditions expected by Saturday afternoon through the evening. Therefore, Red Flag Warnings remain in effect Saturday for all areas of western Colorado and eastern Utah where fuels are critical. Wind gusts look to be in the 30 to 40 mph range but some locally higher gusts are possible at times. Relative humidity looks to be in the single digits so the atmosphere will continue to be very dry as deep mixing occurs with an 85 kt jet streak laying across the north. Given the location of the jet and the better moisture and instability remaining north of I-70 at the base of this shortwave trough, isolated showers and thunderstorms are possible mainly favoring the northern areas on Saturday. Given the very dry low levels, virga showers with erratic gusty winds and dry lightning remains a possibility although coverage appears isolated. Temperatures will cool a couple degrees from yesterday and while they will still be hot, triple digits do not appear likely. This shortwave trough will bring in a 5 degree cooldown for Sunday with trailing west flow and less wind as the gradient lessens. This means critical fire weather conditions appear more localized and mainly along the divide and Four Corners. Isolated dry thunderstorms are also possible once again but favoring the northern mountains at this time.

NEXT WEEK:

Looking beyond this weekend, high pressure builds back in over the Southwest early next week, bringing a return to triple digit heat for the desert valleys and highs generally 10+ degrees above normal. Models are hinting at potential introduction of some moisture by late next week as a shortwave trough tries to break down this ridge, possibly resulting in some showers and storms. Given the dry antecedent conditions and ongoing drought, it remains to be seen whether we see any wetting rain from this but dry lightning could be a concern if this comes to fruition.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 526 PM MDT Fri Jun 19 2026

VFR conditions are forecast to prevail over the next 24 hours at all the TAF sites. Winds will be the main concern Saturday afternoon as gusts of 30 to 40 mph develop in this warm and highly mixed environment. Otherwise light terrain based winds will prevail overnight into the mid morning hours.

FIRE WEATHER

Issued at 1024 PM MDT Fri Jun 19 2026

A shortwave trough will move across the area Saturday, resulting in windier conditions in combination with single digit relative humidities. This will lead to widespread critical fire weather conditions so Red Flag Warnings remain in effect from noon until 10 pm MDT Saturday for all Fire Weather zones where fuels are deemed critical (which is all except UTZ485). Non zero chances for terrain based, mostly dry thunderstorms are possible Saturday afternoon as well, with mostly virga and gusty winds as well as isolated dry lightning chances, elevating the chances for new fire starts. Gusts will likely fall within the 30-40 mph range during this time, with locally higher gusts possible. Beyond Saturday, critical fire weather conditions appear to be more localized as triple digit heat returns and minimum relative humidities hang within the 10-15% range. Some virga showers and dry thunderstorms could also develop along the northern mountains Sunday, giving way to the possibility of dry lightning.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Red Flag Warning from noon to 10 PM MDT Saturday for COZ200>203-205-207-290>295. UT...Red Flag Warning from noon to 10 PM MDT Saturday for UTZ486- 487-490-491.