Dutch John, Utah Weather Forecast Discussion

139
FXUS65 KGJT 040539
AFDGJT
Area Forecast Discussion
National Weather Service Grand Junction CO
1139 PM MDT Fri Oct 3 2025
.KEY MESSAGES...
- Breezy southwesterly winds with gusts of 30-40 mph are
  occurring today and expected tomorrow.
- Showers and storms associated with the approaching low
  pressure have begun over the higher terrain today, and will
  become widespread by tomorrow morning. Light snow is possible
  above 9k feet.
- Temperatures drop below normal tomorrow and Sunday, then
  rebound to near normal values Monday as warmer and more
  seasonable conditions return.
&&
.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 246 PM MDT Fri Oct 3 2025
Showers and some thunderstorms have begun, primarily in the
southern half of the CWA, where moisture is beginning to advect
into the region ahead of the incoming low pressure system. Water
vapor satellite imagery shows that the low pressure system is
currently centered over California. As the low moves across the
Intermountain West overnight, bringing increasing amounts of
upper level support to the region, PoPs will increase across
most of the CWA. The moisture transport associated with this
system will elevate PWAT values to above 200% of normal in some
areas. Given the abundance of moisture and sufficient forcing,
widespread rain is expected overnight tonight and tomorrow
morning. Snow is possible above 9kft, but really only an inch or
two is expected at most. Perhaps a few very localized areas may
see a bit more. Once the system moves east of the Rockies
tomorrow night dry air moves in from the southwest. So, PoPs
will decrease from southwest to northeast through the day
Saturday as both upper level support and moisture decrease.
Gusty winds are ongoing this afternoon, partially from mixing
with stronger winds aloft, but also from strong wind gusts
associated with showers and thunderstorms. Tomorrow
synoptically driven wind gusts of up to 30 to 40 mph are
possible, potentially even greater in some areas, especially
southwest Colorado where Wind Advisories are in effect from 10
AM to 5 PM MDT tomorrow.
A cold front moves across the region during the day tomorrow,
dropping high temperatures significantly. Today high
temperatures will be about 10 degrees above normal, but highs
will drop down to around 5 degrees below normal tomorrow, a
decrease of nearly 15 degrees for many locations. Overnight low
temperatures tonight into tomorrow will be much warmer than
Saturday night into Sunday. This is a result of drier air
clearing cloud cover Saturday night for all but the northern
border of our CWA.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 246 PM MDT Fri Oct 3 2025
The long term period will start out with a long wave trough draped
across much of the Intermountain West. The best support will remain
over Wyoming, Idaho and Montana so while there will be a slim chance
for a few isolated showers over the northern mountains, quiet
conditions will be the rule. Upper level support will then shift to
the Plains which will cause the trough to remain in place.
Eventually, a closed low will form in the base of the trough, Monday
into Tuesday. By Wednesday, the system will start tracking eastward
causing flow to become more southwesterly. While available moisture
to the south will be entrained by this flow and bring increasing
chances for precipitation, especially over the San Juans up into the
central mountains. Finally, Wednesday into Thursday the now open
wave to our west will move through the area bringing some isolated
chances for precip across the CWA. PWATs will remain at or below
normal, thus those isolated chances. High temps will be a few
degrees above normal for the most part.
&&
.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1135 PM MDT Fri Oct 3 2025
Showers and thunderstorms continue to race northward mainly east
of the Colorado/Utah border, although activity is beginning to
fill in across northeast Utah. With the speed that these showers
and storms are moving, the main concerns are lightning and gusty
winds, with a lesser concern of very brief heavy rain. Winds
remain elevated and south to southwesterly, with sustained winds
forecast tonight to be 10-20 knots, and gust of 25-35 knots.
These winds increase through the morning tomorrow, and finally
start to diminish after 00z tomorrow evening. Ceilings remain
lowered and will flirt with breakpoints at times, especially at
KASE, KEGE, KRIL, and KTEX. VFR conditions are expected to
prevail, but drops to MVFR/IFR will be possible, especially at
higher elevation terminals.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...Wind Advisory from 10 AM to 5 PM MDT Saturday for COZ020-021.
UT...None.
&&
$$
SHORT TERM...GF
LONG TERM...TGR
AVIATION...TGJT

NWS GJT Office Area Forecast Discussion