textproduct: Grand Junction

KEY MESSAGES

- Most of the region will generally stay dry throughout the rest of this week, and temperatures will range from 5-15 degrees above normal.

- Isolated and light terrain-based showers across the San Juans are possible daily with Tuesday and Wednesday having the greatest chance for rainfall.

- A stronger storm system may pass through early next week, bringing higher precipitation chances.

DISCUSSION

Issued at 938 PM MDT Sun Oct 4 2026

DRY VALLEYS. ISOLATED RAINFALL IN THE SAN JUANS:

Daily isolated showers and weak thunderstorms continue primarily across the high terrain of the San Juans through Saturday. This is thanks to above normal moisture which has settled in across the region and will persist through the next several days. However, without much in the way of supportive forcing or lift, storm activity should be sparse and on the weaker side. The one caveat to this is a shortwave descending through the Great Basin. By Tuesday, we'll sit in on the eastern edge of the shortwave, and while a slight bolstering of upper- level dynamics has led to an increase in precipitation potential Tuesday and Wednesday, it only appears to modestly boost storm coverage across the high terrain. Otherwise, this pattern keeps temperatures above normal across the CWA, particularly along and north of I-70 where some locations could reach 15 degrees above normal.

PATTERN SHIFTS BEYOND FRIDAY:

We've been eying a stronger system potentially passing through the region sometime early next week. This is being driven by a strong trough expected to skirt across the PacNW and, eventually, parts of the Rockies. Models have struggled to this point to pinpoint the finer details of the system, but consistency between models is improving. We're still seeing too much disagreement to draw any strong conclusions, but clusters have begun to more heavily favor a wetter scenario with precipitation focused around Monday and Tuesday (and perhaps beyond). Jet support looks to be present during this period as well, though its strength is not well agreed upon by models either, so that remains a major question mark as well. Keep an eye on the forecast this week to see how guidance shifts regarding this system.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 510 AM MDT Mon Oct 5 2026

Mostly clear skies and light winds will leave VFR conditions in place the next 24 hours. Isolated mountain showers will be possible again tomorrow afternoon but impacts to nearby TAF sites are extremely low and not placed in the forecast attm.

GJT WATCHES/WARNINGS/ADVISORIES

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