106
FXUS65 KGJT 051114
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
514 AM MDT Sat Jul 5 2025

.KEY MESSAGES...

- Near-normal temperatures today will climb to 5-10 degrees
  above normal by Wednesday, remaining above normal for the rest
  of the week.

- High pressure will usher in a much drier period, although a
  slight chance of daily showers or storms remains along the
  Divide.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 240 AM MDT Sat Jul 5 2025

Moisture is starting to come down across the region as drier air
advects in from the southwest. However, as of last night`s 00z
sounding, PWAT values are still right around the 90th percentile for
that day, indicating there`s still quite a bit of surface based
moisture up for grabs along and north of I-70. And that moisture has
been, in concert with a passing wave, a line of showers and
thunderstorms tracking across northeast Utah and northwest Colorado.
This area of showers and storms should track north and east of the
region by daybreak, with clear skies dominating behind it. High
pressure will dominate today, with strong subsidence really limiting
any afternoon convection that could develop. Additionally, deep
mixing under the strong daytime heating will continue to mix down
that much drier air aloft, scouring out the surface based moisture.
The best chance to see a shower or thunderstorm will be along the
Divide, but even that is a less than 10% chance. Temperatures
rebound to near-normal values today, with highs in the mid to upper
90s across the desert valleys and highs in the 70s for the mountain
towns.

High pressure remains with us tomorrow, promising mostly clear skies
and temperatures climbing to 3-5 degrees above normal. Some moisture
tries to sneak in from the south, increasing the chances of isolated
showers and thunderstorms along the southern and central Divide
mountains during the afternoon. The main threats with this activity
will be gusty outflow winds, frequent lightning, and small hail. Any
showers that do form will taper off after sunset, with a quiet,
seasonal night on tap.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 240 AM MDT Sat Jul 5 2025

A center of high pressure to our south will set up our region for a
series of hot and dry days, with chances for precipitation over the
terrain each afternoon. Despite elevated PoPs over the Divide and
San Juans each day of the long term, the actual quantitative amount
of precipitation in the forecast is very little. The GFS Ens has
been trending drier, finding agreement with the ECMWF Ens. Although,
the ECMWF Ens is still forecasting less moisture available than the
GFS Ens. Overall PWAT anomalies look to be 70-100% of normal through
the end of the workweek. With these dry conditions in place, showers
and thunderstorms over the terrain are generally not expected to be
efficient producers of rain that reaches the ground. Single digit
afternoon relative humidity values return to the forecast through
the long term. Despite the anticipated dry conditions, calm winds
from high pressure should keep us from meeting critical fire weather
conditions. However, a closed low off the coast of California looks
to make its way across the West through the week, passing to the
north of our CWA on Thursday as a weak trough. As the pressure
gradient increases with the passing trough, there is potential for
stronger afternoon gusts. High temperatures will be above normal,
with Wednesday looking to be the hottest day.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 513 AM MDT Sat Jul 5 2025

A patch of showers and low level clouds is working northeastward
through northwest Colorado, bringing some showers to KHDN.
Outside of that, skies are mostly clear and winds are light and
terrain driven. This pattern will persist through the day, with
VFR conditions prevailing. Some westerly wind gusts up to 20
knots will be possible in the afternoon.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...BGB
LONG TERM...GF
AVIATION...TGJT