604
FXUS65 KGJT 132202
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
402 PM MDT Sun Jul 13 2025

.KEY MESSAGES...

- Above-normal temperatures remain status quo through the seven-
  day forecast.

- Outflow winds and dry lightning remain a threat tomorrow as
  thunderstorm coverage increases across the western Colorado
  terrain.

- Coverage of afternoon showers and storms will continue to gradually
  increase as the week wears on.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 357 PM MDT Sun Jul 13 2025

Not much change to the synoptic environment tomorrow as high
pressure centered off to the southwest continues to promote hot
and dry conditions across eastern Utah and western Colorado.
Tomorrow`s high temperature forecast is almost a carbon copy of
today`s with overnight lows dropping into the 50s (mountains)
and 60s (valleys). The risk for heat-related illness remains
elevated during the heat of the day, so be sure to stay hydrated
and take sufficient shade breaks if you are working or
recreating outside tomorrow afternoon.

Moisture transport continues along the western slope of the
Divide supporting another round of afternoon showers and storms
tomorrow afternoon. We expect the coverage of showers and storms
to increase over the Colorado mountains with dry lightning and
gusty outflow winds being the main thunderstorm hazards. The
passage of a subtle wave along our northern border with Wyoming
tomorrow afternoon/evening will also produce a dry lightning
threat.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 357 PM MDT Sun Jul 13 2025

High pressure will continue to support hot and dry conditions,
with increased PoPs in the afternoon. The coverage of showers
and thunderstorms vary each day as weak moisture advection
elevates PWAT anomalies in different parts of our CWA.
Unsurprisingly, the greatest chances for precipitation tend to
be over the high terrain. On Tuesday PWATs are near or below
normal, which may allow for convection over the high terrain,
including dry thunderstorms. On Wednesday shower and
thunderstorm coverage looks to increase as some moisture makes
its way into our region, particularly north of I-70. However, at
this point in time ensembles begin to differ on timing,
placement, and magnitude of moisture advection. The ECMWF Ens
favors stronger moisture advection later this week than the GFS
Ens, which puts maximum PWAT anomalies at above 150% of normal
and around 130% of normal, respectively. So, there is a chance
for a push of monsoon moisture later this week, but differences
in the guidance lowers confidence on this. High temperatures
remain 5 to 10 degrees above normal for the first few days of
the long term, but should begin decreasing towards normal as a
trough from the Pacific Northwest propagates eastward. Despite
dry weather, Red Flag conditions are expected to only be
localized at times as winds generally stay below critical fire
weather thresholds, with the exception of local areas.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1143 AM MDT Sun Jul 13 2025

Mid and upper level cloud cover will increase through the
afternoon. There is a chance of isolated to scattered showers
and thunderstorms in our central and southern mountains. The
main concerns with showers and thunderstorms are gusty winds
and lightning. The southern half of our region may see smoke
moving downstream of the ongoing wildfires. Winds will generally
be light today, although gusts of up to 25 mph are possible at
some sites or around showers and thunderstorms. VFR conditions
will continue to prevail.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...KAA
LONG TERM...GF
AVIATION...TGJT