textproduct: Grand Junction

KEY MESSAGES

- Terrain-based showers and thunderstorms expected each afternoon this week, primarily across the San Juans.

- Flash flooding on burn scars will be possible where there is localized heavier rainfall.

- Daytime highs begin to decrease throughout the week, returning to near-normal for most areas by Friday.

DISCUSSION

Issued at 1229 PM MDT Tue Jul 14 2026

Broad high pressure has outstretched across the northern CONUS, but a smaller center of high pressure has developed roughly over Wyoming. Within the western portion of the anticylonic flow around the high resides a strong pool a moisture streaming through the Great Basin. Due to the location of the high, we are sitting on the outskirts of the advected moisture, but this is enough to drive scattered storm development where orographic lift is supported. This is primarily in the southern portions of the CWA where stronger flow exists. As such, we're eying a prolonged period of showers and thunderstorms generally around the San Juans with more modest potential spanning into the central Colorado mountains, Abajos, and La Sal's. Other portions of the region should expect occasional showers and thunderstorms through the week as well, though QPF is less impressive in these areas. The biggest concern with this moisture and expected rainfall will be the flash flooding risk on the most recent burn scars and ongoing wildfires. Although the rain will be beneficial to wildfire suppression, burn scar flooding risk accompanies as heavy rain potential increases.

Per cluster analysis, ensemble members are in strong agreement for the long-term stagnation of high pressure over the region into the weekend. This is cause for the aforementioned extended period of wet weather across the CWA. Expect temperatures to come down a bit due to the increased cloud cover and rainfall this week though. Some guidance suggests a rebuilding of the ridge next week with the axis re-centering itself across the Rockies. Should this occur, the stream of moisture encroaching from the west could push further west away from our CWA. Conversely, tropical disturbances expected to develop offshore of southern Mexico could reinvigorate the moisture supply flowing into the western CONUS. Both these features are worth watching, but it is well too early to speculate how our weather will ultimately be affected next week.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1119 AM MDT Tue Jul 14 2026

Moisture continues to increase across the area and this should lead to another round of scattered showers and thunderstorm development this afternoon. Gusty outflow wind remains the main threat though the atmosphere is beginning to support moderate to heavy rainfall rates as well. Confidence is low for timing and coverage near TAF sites but KTEX...KDRO and KGUC will be favored for storms in the vicinity of the airfield for this forecast cycle.

GJT WATCHES/WARNINGS/ADVISORIES

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