Area Forecast Discussion
Issued by NWS Grand Junction, CO

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068
FXUS65 KGJT 121721
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
1121 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 /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1119 AM MDT Sat Jul 12 2025

Mostly clear skies and VFR conditions will continue at
terminals. Isolated chances (<20%) for showers and
thunderstorms will continue against the Divide, but confidence
is low in storms forming far enough west to impact terminals.
Showers/storms will be capable of producing 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 for 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