textproduct: Grand Junction

KEY MESSAGES

- The Flood Watch continues for southeast Utah and southwest Colorado as an atmospheric river brings rain, rainshowers, and snowfall to the area.

- Several rivers across southwest Colorado are forecast to reach minor flooding stage.

- The San Juan River at Pagosa Springs is forecast to reach major flood stage which has prompted a Particularly Dangerous Situation Flood Warning for that area.

- Winter weather highlights have been issued for the San Juans and central Colorado mountains for accumulating snow Sunday morning through Monday evening.

DISCUSSION

Issued at 1148 AM MST Sun Nov 1 2026

A substantial stream of atmospheric river moisture continues to spread across the region this afternoon. Widespread rainfall persists below 11000 feet. This has already produced a streamflow response on rivers in southwest CO. Well over an inch of rain has fallen across southwest CO in the past 24 hours and more is on the way. Flood warnings are in place for the La Plata, Mancos, San Juan and Navajo rivers due to the forecasted volume of water that's expected to pass through these basins. Widespread rain showers, including some embedded thunderstorms, will bring valley rainfall to near an inch for the central valleys, and 2 to 2.5 inches for the Four Corners valleys eastward, with less up north. 1.5 to 2.5 inches is likely for the Book Cliffs/Tavaputs and central mountains while the San Juans may see 3 to 4 inches of liquid precipitation. The Flood Watch remains in effect for southeast Utah and southwest Colorado accounting for saturated soils and excessive rainfall producing additional localized flooding and debris flows near susceptible washes, arroyos and burn scars.

Winter Weather Conditions:

Snow levels will remain above 10K feet, before dropping late this afternoon onwards. Amounts remain in the 12 to 18 inch range with locally higher amounts possible keeping Winter Storm Warnings in effect. The Advisories also remain in place for the central mountains, Grand Mesa, and Flat Tops where 5 to 10 inches of snow are expected. As snow levels lower late Sunday night into Monday morning, some of this snow will reach pass level. Be prepared for winter driving conditions during the Monday morning commute along US-550, US-50, and along I-70 over Vail Pass, with lighter impacts north on highway 40 west of Rabbit Ears Pass.

NEXT WEEK:

Behind this system, conditions dry out for a few days as high amplitude ridging moves overhead. We'll see a slight warm up through the mid-week period, although highs remain 5-10 degrees below normal for early November. Looking further out, a quick moving clipper system has the potential to bring some light showers to the region mid-to-late next week, although model agreement is poor.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 414 PM MST Sun Nov 1 2026

MVFR/IFR conditions are expected at most TAF sites for the rest of today, with periodic conditions below ILS breakpoints through the TAF period. Gusty winds will be around this evening and through the overnight hours at some TAF sites. Winds will begin to settle down after ~03Z, but showers will continue through ~12Z with rain changing over to snow at higher elevation TAF sites overnight. Therefore, lowered ceilings and persistent precipitation will continue to impact terminals through the TAF period.

HYDROLOGY

Issued at 1148 AM MST Sun Nov 1 2026

An atmospheric river will produce widespread rainfall with stronger rain rates across southeast Utah and southwest Colorado this afternoon through Monday, mostly below 10,000 feet. A growing concern lies in the potential for runoff around steep terrain in the region. This could produce rock, mud, and debris flows onto roadways, as well as flash flood prone burn scars, washes, slot canyons, and arroyos. Current guidance supports 1 to 3 inches of rainfall for far southeast Utah and portions of southwest Colorado, with locally higher amounts close to 4 inches possible. As a result, a Flood Watch remains in effect 5 AM Sunday through 11 AM Monday. Latest forecast guidance has a number of rivers in southwest Colorado climbing above minor flood stage, with the gage at Pagosa Springs now expected to hit Major flood stage. As a result, targeted River Flood Warnings along the La Plata, Mancos, Navajo, and San Juan rivers are in effect.

Of note, the River Flood Warning for Pagosa Springs is a Particularly Dangerous Situation due to the significant and possibly historic flooding along the San Juan River. Excessive runoff in these basins will exacerbate historic rainfall totals. That region should prepare for a dangerous and impactful flood event.

Outdoor enthusiasts, motorists, and residents of areas recently impacted by flooding are encouraged to remain tuned to the forecast in the coming days.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Winter Weather Advisory until 6 PM MST Monday for COZ009-010- 012-013. Winter Storm Warning until noon MST Monday for COZ018-019. Flood Watch through Monday morning for COZ019-021>023. UT...Flood Watch through Monday morning for UTZ022-028-029.