245
FXUS65 KGJT 121128
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
528 AM MDT Sat Jul 12 2025

.KEY MESSAGES...

- Hot and dry conditions continue with chances for afternoon
  showers and thunderstorms today against the Divide.

- Gusty outflows and dry lightning will continue to pose threats
  to wildfire management today and tomorrow.

- Hot and dry conditions persist into next week, as terrain
  based shower and thunderstorm chances spread.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 327 AM MDT Sat Jul 12 2025

Hot and dry conditions will persist today and Sunday as high
pressure remains parked across the West. This will keep temperatures
near and above the century mark for our desert locales this weekend.
Elsewhere, temperatures will trend nearly 5 degrees above
climatology. Wildfires will continue to produce smoke across
southwest Colorado and portions of Utah. Northwest flow aloft is
expected to push some of that smoke into the southern counties of
the CWA each afternoon as fire activity increases. Given the
shifting position of the high, smoke transport will be inconsistent
through the period.

This afternoon, extra-tropical moisture works northward along the
Continental Divide. How much of this weak plume penetrates westward
is up in the air at the moment. Guidance lacks conviction on a
meaningful push. Nonetheless, it looks like afternoon instability on
the terrain against the Divide will produce showers and
thunderstorms today and tomorrow. The dry airmass will take a lot to
produce measurable rainfall. Gusty outflows and dry lightning
continue to cause concern for fire and outdoor activities.

Sunday afternoon, the breadth of the high increases eastward,
opening the door for a bit more subsidence around the state line and
thus raising highs a degree or two from Saturday. This should also
open up the area for moisture to work north and allow thunderstorm
chances to expand along the Divide too.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 251 PM MDT Fri Jul 11 2025

On Sunday high pressure will be positioned over the Desert
Southwest leaving us under weak northwest flow aloft through
early next week. As a result temperatures look to run about 5
degrees above normal. Given the weak flow moisture should linger
in the region mainly across the southern half of the forecast
area. Therefore there is a chance for diurnally driven showers
over the high terrain each afternoon with a focus in and around
the San Juans. Rainfall rates will generally be light given the
warm temperatures, and showers will be capable of producing
strong outflow winds. It is evident now that some places are
very susceptible to lightning fire starts, and that potential
will continue until temperatures cool and moisture arrives.
Over the course of next week models want to migrate the high
pressure eastward, which should not change the sensible weather
here much. Although by late week that high gets situated to our
east opening the door to southerly flow. This flow will allow
moisture to spread into our area, so we should see an uptick in
the convection. Hopefully this moisture can give us some relief
from the hot and dry conditions in place.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 527 AM MDT Sat Jul 12 2025

Mostly clear skies and VFR conditions will continue at
terminals, as high pressure pushes in from the west today. Non
zero chances for showers and thunderstorms will continue against
the Divide, but confidence is low in storms forming far enough
west to impact terminals. KGUC, KASE, and KEGE are favorable for
a VCSH, but held off on PROB30 storms. Showers/storms will
produce gusty outflows and lightning, but not much else with the
dry air in place. Wildfire smoke will continue to ebb and flow
across southwest Colorado. Mentioned reduced visibility in KMTJ,
KGUC, KTEX, and KDRO thanks to smoke. Northerly flow will
likely keep other terminals out of the path of smoke plumes.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...LTB
LONG TERM...KJS
AVIATION...TGJT