Thompson, Utah Weather Forecast Discussion

769
FXUS65 KGJT 291122
AFDGJT
Area Forecast Discussion
National Weather Service Grand Junction CO
522 AM MDT Mon Sep 29 2025
.KEY MESSAGES...
- Showers and storms will favor the Southern and Divide
  mountains tomorrow as the last piece of the system moves
  through.
- Another passing trough on Tuesday will bring more showers and
  thunderstorms to the elevations of western Colorado and
  eastern Utah.
- Drier and warmer conditions then move in for the mid to late
  week period with another system moving through Friday into the
  Saturday.
&&
.SHORT TERM /THROUGH TUESDAY/...
Issued at 255 AM MDT Mon Sep 29 2025
Satellite imagery and hand analysis is showing a fairly large
trough advancing through the EPac toward the Pacific coastline
early this morning. This has finally kicked the closed low out
of SoCal which is now lifting into the 4 Corners region as an
opening wave. Most of the shower and thunderstorm activity has
waned with only some isolated returns popping up. Water vapor
imagery is showing the main lobe of energy in this wave lifting
across northwest New Mexico toward out southern border attm.
This PVU advection will help fire more showers and thunderstorms
today with the highest chances across the southern to central
mountains this afternoon. The main upstream trough axis will be
swinging through and will likely help force more isolated
activity over the western and northern CWA but drier air will
also be sweeping in. The upstream trough will be progressive and
energy in the leading edge will arrive here by tomorrow morning
with the trough swinging through during the PM hours into early
Wednesday. Overall forcing is broad and weak and moisture
advection limited so most of the activity will favor terrain
forcing tomorrow afternoon. Temperatures look to hover right
near seasonal normal the next few days as well.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 255 AM MDT Mon Sep 29 2025
A weak shortwave is expected to swing through eastern Utah and
western Colorado late Tuesday, keeping shower activity going
through the night. This wave is a quick mover, however, ejecting
east into the Plains by daybreak Wednesday. Southwesterly flow
aloft sets up on Wednesday as high pressure builds into the
center of the country, and a deep trough of low pressure lingers
along the West Coast. We remain under this southwesterly flow
regime through the end of the week, resulting in temperatures
gradually climbing 5-10 degrees above normal. Model guidance
wants to keep above normal moisture around through the end of
the week, although with limited forcing this will just keep a
slight chance of a shower or thunderstorm over the higher
terrain in the forecast through the end of the week.
Friday sees the West Coast trough start to track inland. There is
still a significant amount of model disagreement with the evolution
of this trough as it drops into the Great Basin. Some solutions
develop a cutoff low over the southern Great Basin, slowing the
whole system down, while other solutions maintain an open and
progressive trough. Guidance should come into better alignment over
the next few model runs. Regardless of which solution verifies, the
coming weekend is shaping up to be a cooler and wetter one, with
below normal temperatures and widespread showers. Looking out into
early next week, models seem keen to keep this cooler and wetter
pattern around for a little while longer.
&&
.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 520 AM MDT Mon Sep 29 2025
Mid and high level clouds continue to stream across the area
this morning, but ceilings remain above breakpoints. Skies will
continue to clear from west to east through the day today.
Mountain showers and thunderstorms are expected east of a line
stretch from roughly KHDN to KTEX. These showers and storms will
be capable of producing heavy rain, gusty winds, and lightning.
Winds will be light and terrain driven, and VFR conditions will
prevail.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...None.
UT...None.
&&
$$
SHORT TERM...15
LONG TERM...BGB
AVIATION...TGJT

NWS GJT Office Area Forecast Discussion