textproduct: Grand Junction

KEY MESSAGES

- Flooding is ongoing across portions of southeast Utah and southwest Colorado, and is expected to continue through this evening.

- Rivers continue to run full, with a few cresting already and some expected to crest later this evening.

- Scattered showers and storms will be capable of producing moderate to heavy rainfall that could result in additional local flooding through Sunday.

- Mountain passes could see some snow on roadways late Saturday and Sunday night.

DISCUSSION

Issued at 1235 PM MDT Sat Oct 24 2026

The slow moving low pressure system drifting over the Southwest continues to pump tropical moisture across the region. Water logged soils and bank full rivers continue to pose a flash flood risk. Many rivers have begun to recede today. However, portions of the San Juan and Dolores Rivers will see additional runoff from smaller basins impact their flows through this evening. Flood Watches and Warnings were left active until this runoff threat has safely passed. An area of convection continues to train northward along the state line. This has produced some steep precipitation rates in a few isolated storms. Hi res models are keen to keep this activity going into the overnight hours as the low begins to lift northeast towards the Four Corners. While some drier air begins to wrap into the low, the threat of flash flooding from training storms will continue overnight due to the vulnerability of saturated watersheds in southeast UT and southwest CO. A few rivers that receded today could see a return upward as additional runoff increases their flows. Snow levels drop to around 9 to 10K overnight, which could leave some snow on mountain passes at road level.

The low will finally begin to lift out of the region on Sunday. Forcing along the frontal boundary is expected to produce another round of showers and thunderstorms. Some drier air noses into the region from the southwest. This is expected to chip away at rain rates, but a few productive thunderstorms with stronger rainfall could easily overwhelm this dry signature. While severe storms are not expected, a few strong storms will be capable of strong winds, hail, and torrential rainfall, given the frontal dynamics on Sunday. Models eject the low out of the Rockies by early Monday morning. Colder air wrapped behind this system will keep some snow flying on our mountain passes early Monday. Commuters and travelers on Rabbit Ears and Vail Passes can expect some snow early Monday. Accumulations don't look to be a problem, but motorists should keep abreast of forecast updates.

Drier conditions and broad zonal flow develop Monday and Tuesday across the West. A frontal boundary draped across the West will deliver a weak clipper wave to our northern counties, including some light rain and snow for the Uintas and northern mountains of CO. A storm digging south out of British Columbia on Wednesday will send heights upward, as southwest flow returns across the Four Corners. Temperatures return to near normal under this warmer regime Wednesday and Thursday. Models are introducing some stronger winds late next week too, as another system develops. This system will potentially bring another round of active weather to the region by next weekend.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1119 AM MDT Sat Oct 24 2026

Showers and storms are expected across the most of the area through tonight. Showers may result in IFR/MVFR conditions briefly if a stronger shower/cell moves overhead and drops vis/cigs. Despite that, do anticipate VFR conditions to remain predominant. Gusty outflow winds can also be expected near and under any convection. Low stratus and fog is possible as the showers dissipate late tonight.

HYDROLOGY

Issued at 1044 PM MDT Fri Oct 23 2026

Hydrologic concerns remain elevated through Saturday due to the widespread excessive rainfall. Some locations in the southern San Juan mountains have received 3-6 inches of rain since Wednesday afternoon. Potential hazards through Saturday include localized flash flooding from thunderstorms producing heavy rainfall rates and river flooding due to a prolonged period of widespread moderate to heavy rainfall. Several river gauges are near or past crest, but a few downstream locations are not expected to reach crest until Saturday.

There is a marginal risk of excessive rainfall Saturday across eastern Utah and western Colorado, mainly along and south of I-70. Precipitation amounts of 1-2 inches will be possible over the San Juans with 0.5 to 1 inch across the southern valleys. An additional concern is of rain on snow leading to more runoff making it into the waterways. Snow levels are forecast around 11-13 kft, which will likely result in melting of some of the existing early-season snow pack. The combined runoff from rain and rain-on-snow will result in a rapid rise in many of our creeks, streams and rivers. If heavy rainfall occurs many of the streams and rivers could experience additional crests.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Flood Watch through Sunday morning for COZ017>023. UT...Flood Watch through Sunday morning for UTZ022-027>029.