532
FXUS65 KGJT 041125
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
525 AM MDT Fri Jul 4 2025

.KEY MESSAGES...

- Drier air works in today, bringing clearing skies, slightly
  warmer temperatures, and a decrease in afternoon thunderstorm
  coverage.

- Areas along and north of I-70 will have the highest chance to
  see scattered showers and thunderstorms today, with gusty
  winds, lightning, and small hail the main threats.

- High pressure sets up this weekend and lingers into the coming
  week, with temperatures climbing to 5-10 degrees above normal
  by mid next week and generally dry conditions dominating.

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 228 AM MDT Fri Jul 4 2025

The shortwave trough is currently tracking through the Western
Slope, providing just enough lift to keep showers going over the
last several hours. As this trough lifts to the north east, flow
aloft will gradually transition to westerly or southwesterly through
the morning hours. This will start to advect drier air in aloft,
leading to clearing skies with abundant sunshine and temperatures 5-
10 degrees warmer than we saw yesterday. This drier air will also
start to eat away at the moisture pooled at the surface, leading to
a distinct downturn in convective coverage this afternoon. Areas
along and north of I-70 will be most favored to see afternoon
showers and thunderstorms develop over the higher terrain, although
isolated to scattered showers will be possible along the southern
Divide mountains as well. The threat for heavy rain with any showers
or storms will gradually decrease through the day as the moisture
pool is eroded and drier air infiltrates the surface levels. Main
threats with storms are more likely to be frequent lightning, gusty
outflow winds, and maybe some small hail. Shower and storm activity
should quickly taper off after sunset. High pressure builds in for
tomorrow, bringing much drier conditions and high temperatures
running around normal for early July. A few isolated to widely
scattered showers and thunderstorms are possible along the Divide
tomorrow. Otherwise, quiet and sunny conditions are expected.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 228 AM MDT Fri Jul 4 2025

The long term period brings a return of warm and dry conditions
with daily chances of afternoon convection along the Divide and
in the San Juans. Dry air is in place by Sunday, bringing an
end to the widespread showers and thunderstorms we have received
during the latter half of the workweek. Model disagreement on
atmospheric moisture introduces some uncertainty in regard to
the precipitation forecast in the long term. Over the weekend
both the ECMWF Ens and the GFS Ens keep PWATs below or near
normal in the southern mountains, but the ECMWF Ens keeps the
northern half of our CWA more moist than the GFS Ens. During the
workweek the ECMWF Ens is consistently drier than the GFS Ens,
keeping PWAT anomalies 10-30% of normal lower than the GFS Ens.
However, even considering the differences between models,
moisture ultimately looks limited through the long term. Despite
the dry conditions, weak winds are expected to keep the CWA
from meeting critical fire weather thresholds.

A center of high pressure to our south will set up southwesterly
flow and subsidence. As a result, temperatures will gradually warm
each day Sunday through Thursday. High temperatures climb from a
degree or two above normal on Sunday to 5-10 degrees above normal on
Thursday. This could mean temperatures exceeding 100 degrees for the
desert valleys during the workweek.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 522 AM MDT Fri Jul 4 2025

Most shower activity has tapered off, although patches of low
stratus have developed at higher elevation terminals such as
KGUC and KTEX. Periods of MVFR to IFR ceilings will continue
through the next 3 hours, before finally lifting. Showers and
thunderstorms will develop over the higher terrain this
afternoon, favoring areas along and north of I-70. Gusty outflow
winds, lightning, and brief heavy rain are the main concerns.
Outside of shower activity, westerly winds will be gusting up to
20 knots in the afternoon. Skies will gradually clear through
the day from south to north. VFR conditions will prevail.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...BGB
LONG TERM...GF
AVIATION...TGJT