813
FXUS65 KGJT 122342
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
542 PM MDT Sat Jul 12 2025

.KEY MESSAGES...

- Hot and dry conditions continue to highlight the forecast for
  the first half of the week ahead.

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

- Gusty outflow winds and dry lightning are the primary concerns
  for tomorrow`s round of convection over the central and
  southern Divide mountains.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 356 PM MDT Sat Jul 12 2025

High pressure continues to build in from the southwest tomorrow
helping triple-digit temperatures return to the lower valleys.
We`ll see an uptick in moisture building in along the Divide
over the next 24 hours helping to spawn afternoon convection
over the central and southern Divide mountains. PWATs around
125% of normal will be high enough to see an uptick in storm
coverage, but likely not high enough to produce much-needed
wetting rains. However, storms will be capable of producing
gusty outflow winds and dry lightning which could lead to fire
starts in areas where fuels are critical.

Speaking of fires, with 3 large and many small wildfires
burning across eastern Utah and southwest Colorado, smokey/hazy
skies will continue to impact communities across the southern
half of the forecast area. Synoptic winds will remain out of the
northwest tomorrow meaning much of the smoke will advect
southeastward.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 356 PM MDT Sat Jul 12 2025

They synoptic pattern really doesn`t change much through the
seven- day forecast with high pressure being the driving force
behind much of our weather for the week to come. We`ll be
following two main storylines throughout much of the upcoming
week.

1. Unseasonably Warm Temperatures

Temperatures remain 5-10 degrees above normal for mid-July
through at least mid week. At that time, a shortwave trough is
progged to move track across the Pacific Northwest into the
Northern Plains. Locally, this wave will flatten out the ridge
overhead and could help temperatures cool off a few degrees.
Despite this, the current forecast calls for normal to above-
normal temperatures through the work week.

2. Increasing Moisture

Global ensembles continue to show signs of moisture slowly
seeping back into the region, first along the Divide from the
southeast, then from the north as the aformentioned shortwave
leads to zonal flow aloft, and then from the south once more
late in the period. PWAT anomalies of 100-125% of normal will
not support the widespread rains we need, but will support
convection over the high terrain each afternoon. Storms will
continue to be capable of producing gusty outflow winds, fire
starts, and small hail at times. There are hints of stronger
moisture advection late in the week/next weekend, but it is
still too early to tell if this will be the pattern that ushers
in the monsoon. There`s too much spread between global ensembles
to have much forecast confidence come next weekend.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 542 PM MDT Sat Jul 12 2025

Showers and storms will continue mainly along the western
Colorado Divide but terminals not expected to be impacted at TAF
sites through this evening aside from gusty outflow winds with
not much in the way of wetting rain. Gusty winds of 25 to 35
mph are still possible through the evening with winds becoming
light and terrain driven after sunset. 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. Afternoon storms are possible Sunday
across the higher terrain. Included PROB30 groups at KASE, KTEX
and KGUC where confidence is higher.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

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