893
FXUS65 KGJT 011732
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
1132 AM MDT Tue Jul 1 2025

.KEY MESSAGES...

- Increasing moisture will keep afternoon showers and storms in
  the forecast each day, favoring the higher terrain initially,
  before spreading over adjacent valleys.

- Main threats with showers and storms remain outflow winds
  capable of gusts upwards of 50 mph, small hail, frequent
  lightning, and brief heavy rain.

- Temperatures remain above normal through midweek, then will
  cool to near normal value into the holiday weekend.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 244 AM MDT Tue Jul 1 2025

A ridge of high pressure remains overhead, while a closed low spins
off the coast of California. The flow around these two features
continues to draw moisture northward into the Four Corners region.
This increasing moisture has helped to keep temperatures mild. A
little wave rounding the ridge has contributed to lingering clouds
and even a few light showers as well. This activity should diminish
over the next few hours as that wave tracks east. A few hours of
sunshine this morning will give way to showers and thunderstorms
developing over the terrain this afternoon. The deepest moisture,
and therefore highest chances of wetting precipitation, will be over
the southern mountains. In this area, brief heavy rainfall will be
possible, in addition to the more widespread threats of gusty
outflow winds, small hail, and frequent lightning. Fire starts from
lightning will be a concern over the next few days. With the
expected uptick in afternoon clouds and convection, temperatures
will run a couple degrees cooler today, though still 3-5 degrees
above normal. Convection will slowly taper off tonight into tomorrow
morning, with another mild night expected. By tomorrow morning, the
low to our west will have moved onshore, nudging the ridge slightly
to the east. This will direct the bulk of the moisture plume more
directly into the Four Corners, keeping moisture increasing through
the day tomorrow. Another shortwave in the flow will act on this
moisture, bringing an uptick in coverage tomorrow afternoon. The
main threats with any showers or thunderstorms will remain gusty
winds, frequent lightning, small hail, and localized brief heavy
rain.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Issued at 244 AM MDT Tue Jul 1 2025

Low pressure over California and high pressure over the Gulf will
keep deeper moisture moving into the CWA thanks to flow around these
two features. This is corroborated by forecast NAEFS PWATs
indicating values of 2 to 2.5 standard deviations above normal early
July values. Thursday, the low pressure that was out west will
become an open wave and start moving across the CWA. Models continue
to indicate Thursday being the day with the most widespread and
heaviest precip. Highly anomalous PWATs will remain across the area
and the added lift from the open wave will be the impetus for this
precip. The only fly in the ointment will be cloud cover that may
limit convection. If this occurs, we can expect a more stratiform,
soaking type rain event with some embedded storms being more likely.
Still have plenty of time to work out these finer details.

Friday onward, model discrepancies start to crop up as different
models handle another approaching shortwave differently. In some
guidance, this wave acts on lingering moisture to bring another
round of widespread precipitation. In others, the precipitation is
confined largely along the divide. And models do seem to be flip-
flopping from run to run on this detail. This uncertainty lingers
through the weekend, although there is some consensus that high
pressure tries to reassert itself by the beginning of next week. All
together, the holiday weekend looks continue cooler and
unsettled.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1132 AM MDT Tue Jul 1 2025

Scattered mid-level cloud cover and isolated showers are
beginning to pop up near KASE, KEGE, and KTEX late this morning.
More widespread showers and thunderstorms are expected to
develop over the next couple hours. All higher elevation
terminals have the potential to see some precipitation this
afternoon into the evening. Gusty, erratic winds are possible
near any storms that do form. However, VFR conditions should
prevail.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...BGB
LONG TERM...TGR/BGB
AVIATION...TGJT