002
FXUS65 KGJT 011154
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
454 AM MST Sun Nov 1 2026

.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 909 PM MDT Sat Oct 31 2026

CALM BEFORE THE STORM:

A weak shortwave moved across the area today with only a few
showers and storms noted on radar. A few showers remain across
the area at this hour but are trending downwards and this will
continue. Good news for the trick or treaters this evening.
Satellite is showing plenty of cloud cover to our southwest,
poised to move into the area very shortly.

RAIN, SNOW, FLOODING POTENTIAL:

More widespread precipitation will begin falling between
midnight and 3am thanks to a potent Atmospheric River (AR). This
AR remains forecast to bring anomalous precip to our CWA for
the next 24 to 36 hours. PWATs from the ensemble GFS and EC
remain in the 250 - 350% range for this time of year, no change
there. Widespread rain and rainshowers, possibly some embedded
thunderstorms, will bring valley rainfall to near/at an inch for
the central valleys, and 2 to 2.5 inches for the Four Corners
valleys eastward, less up north. 1.5 to 2.5 is likely for the
Book Cliffs/Tavaputs and central mountains while the San Juans
may see 3 to 4 inches of liquid precip. The Flood Watch remains
in effect for southeast Utah and southwest Colorado as already
saturated soils, along with this rainfall, may result in flash
flooding and debris flow issues, not to mention river flooding.
Rivers are expected to respond quickly to this additional
rainfall, especially in the Pagosa Springs area.

As far as snow is concerned, snow levels will remain above 10K
feet, if not a bit higher, before dropping Sunday afternoon
onwards. Amounts remain in the 12 to 18 inch range with locally
higher amounts still possible so the Winter Storm Warning
remains in effect. The Advisories also remain in effect for the
central mountains, Grand Mesa, and Flat Tops where 5 to 10
inches are expected. As snow levels lower late Sunday night into
Monday morning, some of this snow will reach pass level. Be
prepared for sloppy driving conditions during the Monday
morning commute along US-550, US-50, and along I-70 over Vail
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 /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 443 AM MST Sun Nov 1 2026

Widespread rain across the region west of the Continental Divide
this morning with some embedded heavier showers has lowered
ceilings and visibilities at many TAF sites. Expect MVFR/IFR
conditions at most TAF sites after 15Z with conditions below
ILS breakpoints through the TAF period. Stronger winds aloft
will produce areas of Low-Level-Wind-Sheer (LLWS) through the
morning before these winds start mixing down to the surface with
southerly surface winds gusting 20 to 40 kts from late morning
well into the evening hours (past 00Z). Expect isolated to
scattered thunderstorms mostly on the higher terrain between 18Z
and 06Z. Winds will settle down after about 03Z, but rain and
showers will continue through 12Z with rain changing over to
snow at the higher elevation TAF sites after about 09Z.

&&

.HYDROLOGY...
Issued at 1226 PM MDT Sat Oct 31 2026

Deeper moisture develops later tonight into early Sunday. This
will produce widespread rainfall with stronger rain rates
across southeast Utah and southwest Colorado Sunday and 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 Moderate to Major
flood stage. As a result, targeted River Flood Warnings along
the La Plata 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 will also increase flooding risks. 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 from noon today to 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.

&&

$$

DISCUSSION...TGR/TGJT
AVIATION...DB
HYDROLOGY...TGJT