756
FXUS65 KGJT 140430
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
1030 PM MDT Fri Sep 13 2024

.KEY MESSAGES...

- Expect dry and warm temperatures Saturday before unsettled
  conditions return Sunday.

- Above normal temperatures persist through Monday before a cold
  front moving through the region on Tuesday brings cooler than
  normal readings for the latter part of the week.

- Aside from Wednesday, off and on showers can be expected
  across eastern Utah and western Colorado next week.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 247 PM MDT Fri Sep 13 2024

Conditions remain quiet tonight and tomorrow with dry,
seasonable weather on tap. The most notable forecast feature
will be continued hazy skies from across the western CONUS.
West/southwesterly flow aloft will continue allow smoke...mostly
elevated...to ebb and flow through the forecast period. Limited
reduction to visibilities and air quality may result at times.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 247 PM MDT Fri Sep 13 2024

The weather takes a bit of turn Sunday according to better than
average model consensus, as all operational runs depicted a
shallow short wave trough lifting northeastward from the Desert
Southwest. A shift to a more southerly mid-level trajectory
aloft carries mid-level moisture over the region ahead of the
trough. The arrival of moisture combined with mid-level
vorticity advection and diurnal warming is expected to result in
scattered showers and thunderstorms with the southern mountains
favored.

That won`t be the end of it though, as models remained in good
agreement with the next system, which will be digging southward
over the West Coast and forming a deep closed low over the Bay
Area by 12Z/Monday. This system then moves slowly across the
northern Great Basin Monday before lifting to the northern
Rockies on Tuesday. During this time, south to southwest flow
aloft will continue to feed moisture into the region where broad
difluence over the region generates off and on showers across
the region with the best chances of precipitation coming Monday
and Monday night. Meanwhile, a cold front associated with this
system moves eastward across the forecast Tuesday generating
breezy/windy prefrontal winds ahead of it. Showers ahead of and
along the front combined with falling mid-level temperatures
should bring cooler temperatures to the area. Highs are expected
to dip below seasonal norms, though the temperature forecast
hinges on time of frontal passage so there is some uncertainty
with respect to highs on Tuesday.

Showers linger into Tuesday evening, but will be shutting down
overnight in response to subsidence and diurnal cooling on the
back side of the mid-level trough extending southward from the
closed low mentioned previously. Drier air in the wake of this
system looks likely to deliver a brief break in the action on
Wednesday. However, to the West on Wednesday another closed low
forms over the western Great Basin and by Thursday this system
will be just west of the Green River having evolved into a
positive tilt long wave trough extending from the northern High
Plains to the southern tip of California. There doesn`t appear
to be much moisture for this system to work with, but it does
seem reasonable to expect dynamic forcing will be capable of
generating some scattered moist convection, with areas north of
the I-70 corridor favored. Temperatures for Wednesday and
Thursday are expected to remain a bit below normal.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1030 PM MDT Fri Sep 13 2024

Expect mostly clear skies over the next 24 hours with terrain
driven winds, becoming breezy at times during the afternoon.
VFR conditions will prevail.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

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