Arapahoe Basin

000
FXUS65 KGJT 011131
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
531 AM MDT Sat Aug 1 2026

.KEY MESSAGES...

- Record heat and predominately dry conditions move in for the
  weekend and early next week with localized critical fire
  weather conditions.

- Chance for showers return to the southern mountains and
  valleys mid to late next week.

&&

.DISCUSSION...
Issued at 1059 PM MDT Fri Jul 31 2026

HOT AND DRY THIS WEEKEND INTO NEXT WEEK:

High pressure will strengthen and anchor itself across the
Desert Southwest this weekend, reinforcing this drier air mass
and allowing temperatures to climb a bit higher well into the
triple digits for the valleys of eastern Utah and lower western
Colorado. We will be under a northerly flow and a more stable
regime, so it will be pretty hard pressed to get much convection
or shower activity going. Storm activity seems to favor areas
east of the divide, with the eastern and far southern San Juans
standing the best chance of isolated storms potentially 
drifting south off the terrain Saturday afternoon and again on 
Sunday afternoon. Given the much drier air mass, lack of upper
level support and lack of forcing...do not expect any activity
to last very long and will be more conducive to gusty outflow
winds and lightning rather than any wetting rain. Regarding the
heat, record high temperatures are possible for many locations
with low relative humidity in the teens and single digits for
the lower valleys, giving us a bit of a reprieve from the
monsoonal moisture through at least early next week. On Monday,
a trough will track across the Northern Rockies into the Plains,
which could introduce some clouds and a brief suppression of the
high pressure. It appears like storms would favor areas east of
the divide while the western slope remains hot and dry, but the
higher terrain of the divide could see some isolated afternoon
storm activity. Extreme Heat Warnings and Heat Advisories remain
in effect this weekend through Monday for our eastern Utah
valleys and Grand Valley in west-central Colorado. See product
for details and exact timing for those particular locations. 

MOISTURE POTENTIAL MID TO LATE NEXT WEEK:

Looking ahead in the week, the pattern becomes a bit
disorganized with the high pressure remaining across the Desert
Southwest and Great Basin but becoming a bit squashed and not as
strong mid to late next week. It appears that we will slowly
introduce some moisture across the Four Corners as it seeps in
underneath this ridge from Arizona and New Mexico. This will
allow for a bit more afternoon thunderstorm development over the
southern mountains at first with that moisture and storm
coverage potentially slowly creeping northward by late next
week. The northern stream will also become more active with a
few passing shortwaves across the northern tier of states that
could help provide the needed forcing. This is a low confidence
forecast on this moisture return and extent of storm activity.
Otherwise, temperatures look to remain hot around 10 degrees
above normal.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 530 AM MDT Sat Aug 1 2026

High pressure will dominate through the TAF period with VFR
conditions at all terminals. Afternoon winds will gust to around
20 mph in a few locales, but return light and variable by early
this evening. Clouds will be minimal, but a few mid and high 
clouds will stream across the ridge of high pressure through the
afternoon, clearing after dark again.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...Heat Advisory from noon Sunday to 9 PM MDT Monday for COZ006.
UT...Heat Advisory from noon Sunday to 9 PM MDT Monday for UTZ022.
     Heat Advisory from noon to 9 PM MDT Sunday for UTZ024.
     Extreme Heat Warning from noon today to 9 PM MDT Monday for 
     UTZ027-029.

&&

$$

DISCUSSION...MDA/TGJT
AVIATION...TGJT