Thompson, Utah Weather Forecast Discussion

940
FXUS65 KGJT 092334
AFDGJT
Area Forecast Discussion
National Weather Service Grand Junction CO
534 PM MDT Tue Sep 9 2025
.KEY MESSAGES...
- Showers and thunderstorms continue Wednesday, with more
  widespread wetting rains and localized flash flooding
  concerns.
- Thursday and Friday will see widespread showers and
  thunderstorms return with additional wetting rains.
- Temperatures will trend cooler Thursday and beyond with fall-
  like conditions expected.
&&
.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 352 PM MDT Tue Sep 9 2025
The collapsing ridge, ample moisture, and a series of shortwaves are
producing an active weather pattern here on the West Slope this
afternoon. Despite some dry air at the surface, storms have been
productive with small hail and brief, localized downpours. Wetting
rains are welcome in the dry conditions most locales remain under.
This wavy pattern will continue this evening and overnight, with a
few isolated showers possible in the overnight hours, given
the likelihood of a shortwave rolling through.
Strong southwesterly flow remains in charge Wednesday as the West
Coast low digs south and the jet slides overhead. This will bring
winds up around the region. Gusts on the terrain will run 25 to 35
mph through the afternoon, with sheltered valleys a bit lighter.
Given the wet antecedent conditions, widespread critical fire
weather is not expected. A few localized spots in eastern Utah and
along the Colorado line could hit critical thresholds briefly. Jet
streak exit forcing comes into play Wednesday afternoon, along with
additional moisture. PWAT values surge north of 150 percent of
climatology across the Four Corners tomorrow, with higher values
likely. This should keep the atmosphere will fueled for more
widespread convection. Given today`s activity, better forcing and
moisture, I would expect a few stronger storms with gusty winds,
hail, and localized flash flooding concerns on burn scars and flashy
drainages.
Wednesday night, the low sits over the Great Basin, which keeps the
jet in residence over the CWA. This will keep forcing active
overnight. Rainshowers and embedded thunderstorms are likely through
the night and into Thursday morning across the region.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 352 PM MDT Tue Sep 9 2025
Moisture continues to funnel into western Colorado, and eastern Utah
to a lesser extent, Thursday and Friday leading to elevated
precipitation chances, cooler temperatures, and the potential for
burn scar flash flooding. A stronger pressure gradient also sets up
by Friday bringing breezy winds to the region. We`ll be keeping an
eye on the potential for small perturbations in the upper level flow
to enhance the coverage of convection on Friday PM but this will be
easier resolved in the CAMs as they are integrated into the forecast
blends.
Drier air works in from the west, but there`s a timing discrepancy
between global ensembles. The GEFS brings drier air in on Saturday,
24-36 hours faster than the ECMWF which wants to slowly evacuate
mositure from the forecast area from south to north throughout the
weekend. This will be something to keep an eye on over the next few
days, especially if you have outdoor plans. Seasonal temperatures
return Sunday. Afternoon thunderstorm chances pick back up again
next week with a troughy pattern aloft.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 534 PM MDT Tue Sep 9 2025
A few strong showers and thunderstorms remain across the area
this evening and a few more may develop throughout the night.
Winds with these storms could gust up to 20 kts. More showers
and storms are expected tomorrow afternoon as well, particularly
near KMTJ, KTEX, KDRO, and KGUC.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...None.
UT...None.
&&
$$
SHORT TERM...LTB
LONG TERM...KAA
AVIATION...TGJT

NWS GJT Office Area Forecast Discussion