272
FXUS65 KGJT 142332
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
532 PM MDT Mon Sep 14 2026

.KEY MESSAGES...

- There is a chance for strong storms over the next few days,
  capable of producing hail, gusty winds, and heavy rainfall.

- Moderate to heavy rainfall could lead to localized flash
  flooding, rockfalls, and mudslides at times this week.

- Temperatures return to near-normal through the week.

&&

.DISCUSSION...
Issued at 1246 PM MDT Mon Sep 14 2026

High pressure anchored over the southeast CONUS will continue to
block eastward progression of the troughing over the West this
week. A resident jet streak will continue to provide upper level
support for shower and storm development. Moisture supplies
become the pivotal variable in the equation as the week
progresses. The CWA remains under a marginal risk for excessive
rainfall as well. With the lower atmosphere sufficiently moist,
storms should have no problem producing measurable rainfall this
week. This will continue to pose a flash flood risk around the
region. Guidance continues to suggest the best moisture will
focus on the Four Corners region, holding south of I-70.

This afternoon, storms will continue to take advantage of the
overhead jet, which was sampled well on the morning Grand
Junction sounding. Convective parameters remain bullish on the
sounding too. Storms have been training southwest to northeast
thus far today. Flash flood prone locales will remain a concern
should we see sufficient storm training this afternoon and this
evening. Hi res models are keeping shower activity lively again
through the overnight hours. With little opportunity to dry
back out, Tuesday will see the return of flash flooding risk.
High pressure nudges back westward, allowing some richer
subtropical moisture to get entrained into the upper level flow
on Tuesday afternoon. Much of southeast UT and southwest CO get
upgraded into a Slight Risk area for flash flooding on Tuesday.

The synoptic pattern sees little change as the week progresses.
Subtropical moisture remains persistent and forcing aloft will
sustain thunderstorms each day. The flash flood risk remains in
play Wednesday and Thursday, as we never really dry out. On
Friday, models are trying to eject the low out of the PACNW,
with a transitional ridge behind it perhaps drying us out a
smidge...or at least suppressing the subtropical moisture tap
enough to limit rainfall. Forecast confidence wanes rather
quickly this weekend, as models are trying to grapple with the
pattern shift. While it does look like moisture does contract,
the upper level pattern looks busy enough to keep some
orographic showers present through the extended period of this
forecast. With the Vernal Equinox approaching quickly and
daylight fading, it seems apropos to discuss fall weather.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 529 PM MDT Mon Sep 14 2026

Scattered showers and thunderstorms continue today and tomorrow
afternoon with lighter showers expected overnight. Gusty winds
and light to moderate rainfall are the main hazards. Locally
heavier rainfall may decrease vis to MVFR at some locations,
though certainty on where this will occur has led to decreased
visibility being left out of all TAF`s. Cigs may fall below ILS
breakpoints as storms pass by, particularly at ASE, EGE, and
RIL.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

DISCUSSION...LTB
AVIATION...TGJT