449
FXUS65 KGJT 212327
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
527 PM MDT Mon Jul 21 2025

.KEY MESSAGES...

- Terrain based showers and thunderstorms continue this week,
  with wetting rains and gusty outflows possible.

- A warmer, drier airmass gradually moves in for the latter
  half of the week.

- Localized critical fire weather conditions in low elevation
  desert valleys become more widespread by week`s end.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 356 PM MDT Mon Jul 21 2025

The resident monsoonal plume of moisture continues to produce
terrain based showers and thunderstorms around the region.
Generous stratiform cloud cover this morning stalled storm
initiation a bit today, but daytime mixing and some breaks in
cloud cover have helped get things going across the San Juans
and some of the Central Mountains. Storms are producing a few
outflows in the 45 mph range too. The mid-day sounding here at
Grand Junction registered a hike in PWAT`s, but a mid level cap
is clearly producing some resistance to convection. Storms will
trail off again around dark tonight. A digging trough out west,
will tighten the upper level gradient, thereby continuing a
steady supply of moisture along the well defined monsoonal
plume. Leftover cloud debris Tuesday morning will likely pose
some delay in storm initiation Tuesday too. However, a little
sunshine will go a long way and send us another round of terrain
convection on Tuesday. Temperatures will remain in line with
today`s as we hold on to a rather stagnant isoheights pattern
Tuesday. Dry boundary layers are expected to persist in the
lower valleys Tuesday and will likely abet gusty outflow winds
again. Quiet overnight conditions will return again early
Wednesday morning.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 356 PM MDT Mon Jul 21 2025

Persistent southwesterly flow highlights the extended forecast. As
moisture ebbs and flows across the region, coverage of afternoon
convection over the high terrain will shift but otherwise conditions
will remain fairly consistent from day to day. The biggest shift in
moisture comes late in the week when dry air is progged to build in.
Fire weather concerns may pick back up during this timeframe,
although winds do not look to exceed Red Flag thresholds anytime
this week. Dry thunderstorms will be our bigger concern. Gradual
warming is expected this week as a drier airmass moves in, but we
remain in the seasonable range for much of the week ahead. Afternoon
thunderstorms will be capable of producing gusty winds and small
hail at times.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 524 PM MDT Mon Jul 21 2025

Widespread showers with a few embedded thunderstorms will
continue to impact terminals mainly north of I-70 over the next
2-4 hours. An additional round of showers and storms is tracking
over the San Juans, and will impact KTEX and KGUC during the
same period. Activity will begin to taper off after 03z, with
ceilings lifting, although broken to scattered skies will
persist. Drier air moves in from the southwest tomorrow,
limitingafternoon storm activity to the higher terrain of the
San Juans and along the central Divide. Winds will be gusty and
erratic near storms, but will otherwise follow typical terrain
patterns tonight. Afternoon winds tomorrow will be westerly and
gust up to 25 knots.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...LTB
LONG TERM...KAA
AVIATION...TGJT