554
FXUS65 KGJT 301912
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
112 PM MDT Wed Sep 30 2026

.KEY MESSAGES...

- Widespread rainfall continues through the evening across
  southeast Utah and southwest Colorado. Isolated storms cannot
  be ruled out.

- Flooding concerns continue over the rain-soaked terrain,
  especially within and adjacent to the southern San Juans. A
  Flood Watch remains in effect through 6AM Thursday.

&&

.DISCUSSION...
Issued at 1257 PM MDT Wed Sep 30 2026

WET WEATHER WITH FLOODING POTENTIAL THROUGH TONIGHT:

Satellite imagery currently shows the low pressure system
responsible for our recent bout of wet weather centered in
northwest New Mexico. The low will continue to eject
east/northeast as the day wears on, leading to one final round
of precipitation through this evening. With an overcast stratus
cloud deck in place, organized convection will not be favored
for most locations. Instead, steady light to moderate rain with
pockets of locally heavy rainfall will persist.

Given much of Southwest Colorado has already received well over
an inch of rainfall over the last 48 hours, additional rain
will have the potential to produce localized flooding. As a
result, the Flood Watch will continue for the San Juan Mountains
and San Juan River Basin through 6 AM Thursday morning.

Most shower and storm activity will decrease in coverage this
evening as the low moves east and drier air moves in behind it
from the northwest.

WARM AND DRY THURSDAY THROUGH THE WEEKEND:

High pressure moves into the region on Thursday. This pattern
shift will bring dry and warmer weather through at least the
weekend. High temperatures are forecast to climb from near
normal on Thursday to 5 to 10 degrees above normal by the
weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1130 AM MDT Wed Sep 30 2026

Showers are ongoing for areas south of I-70. MVFR conditions
are occurring within heavier showers. Expect this to continue
for the rest of the afternoon with some clearing this evening.
Overnight, showers will diminish, skies will continue to clear,
and ceilings over southern Colorado will begin to raise. Due to
the rainfall and moisture, stratus and fog may develop around
sunrise Thursday in mountain valleys particularly at KDRO and
KGUC but confidence is low at this time. Otherwise expect
improving conditions area wide.

&&

.HYDROLOGY...
Issued at 1257 PM MDT Wed Sep 30 2026

One last surge of tropical moisture will lead to widespread
rain and isolated storms through this evening. As a result, our
concerns for flash flooding and rises on local rivers remains
elevated through the overnight hours.

RFC guidance maintains a second peak at several sites, peaking
late this evening after another day of continuous rainfall
across southeast Utah and for the San Juan Mountains and
  part of the San Juan River Basin southwest Colorado. Fortunately,
water levels are not anticipated to exceed previous high water
marks. That being said, localized flooding and flash flooding
continue to pose a threat to our southwestern Colorado
communities until remnant moisture from Hurricane Polo and the
closed low completely exit our region.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...Flood Watch through late tonight for COZ018-019-023.
UT...None.

&&

$$

DISCUSSION...TGJT
AVIATION...TGJT
HYDROLOGY...ERW