290
FXUS65 KGJT 162056
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
256 PM MDT Sun Jun 16 2024

.KEY MESSAGES...

- Gusty southwest winds, single digit relative humidities, and
  warm temperatures this evening and again on Monday. Red Flag
  Warnings remain in effect.

- Cold frontal passage Monday night will bring cooler
  conditions Tuesday and Wednesday. Light cloud cover and no
  precipitation is expected with the front.

- Unsettled conditions return Wednesday, with afternoon/evening
  showers and thunderstorms expected through the weekend.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 256 PM MDT Sun Jun 16 2024

Strong southwest winds developed across the region from late
morning into the early afternoon south of a cold front over
northern Utah. Dry air from the Desert Southwest has inhibited
shower/thunderstorm development which models indicated was
unlikely late this afternoon.

The cold front remains quasi-stationary tonight and Monday as
the closed low over the Pacific Northwest deepens, then tracks
east to the northern Rockies late in the day. As the pattern
evolves, the height gradient aloft as well as the surface
pressure gradient increase, leading to strong southwest winds
from late Monday morning through Monday evening. Wind gusts are
expected to be close to advisory level, especially for the
eastern Uinta Basin and the northwest plateau. However, at this
point, feel higher gusts will be localized so held off issuing
a Wind Advisory. Advection of slightly cooler temperatures aloft
is expected to bring temperatures down a few degrees, but
hotter than normal conditions persist Monday afternoon.

The cold front finally moves south and southeastward across the
forecast area Monday night as the northern Rockies low shifts
to the northern High Plains late. Models continued to suggest
that moisture will be insufficient to generate
showers/thunderstorms with passage of the front despite modest
forcing. More notably, winds will be decreasing in the front`s
wake. Lows are expected to dip by close to 10 degrees along and
north of the I-70 corridor Tuesday morning, but by closer to 5
degrees to the south.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Issued at 256 PM MDT Sun Jun 16 2024

Behind the cold front, Tuesday`s temperatures across the region
will run about ten degrees below normal for mid June in the
lower elevations to near normal in the mountains. Midweek the
synoptic pattern continues with the longwave trough over the
western CONUS and high pressure along the Atlantic Seaboard
keeping the region under a dry southwesterly flow. Temperatures
will warm about five degrees Wednesday and another five degrees
Thursday in the lower elevations under mostly clear skies.
Though we only warm to near normal, the intense sunshine will
make it feel much hotter.

Weak shortwave disturbances dropping into the longwave trough
will pull it westward with the whole longwave pattern
retrograding for the latter half of the week. As the high
pressure slides west, the mid-level flow becomes more
southeasterly Thursday to draw the moist gulf air up through
New Mexico into southern Colorado and southeastern Utah. Expect
scattered showers and thunderstorms developing over the San
Juan, Abajo and La Sal Mountains through the afternoon with
showers and likely thunderstorms spreading north over the
central mountains overnight as a shortwave disturbance moves
overhead. By Friday, the high pressure will have pushed into
Texas shifting the moist gulf flow farther west into Arizona
where the southwesterly flow from the troughing along the West
Coast picks it up and carries it to the northeast over eastern
Utah and western Colorado bringing widely scattered showers and
thunderstorms to the lower elevations across the region and
widespread storms to the higher elevations through the
afternoon. With mostly cloudy skies, Friday will stay a few
degrees cooler than Thursday.

Going into the weekend, confidence in the model solutions drops,
but the general consensus is for the high pressure slide to
the south across New Mexico settling in over the Desert
Southwest Sunday. This cuts off the tap off the Gulf of Mexico
bringing the return of a dry airmass over eastern Utah and
western Colorado. Convective activity will become widely
scattered over the higher terrain Saturday favoring the Colorado
mountains and more isolated Sunday favoring the Continental
Divide. Diurnal heating with residual moisture will generate
afternoon cumulus across the region to keep temperatures near
normal for the weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1133 AM MDT Sun Jun 16 2024

Expect VFR conditions through the TAF period with a few high
clouds invading late in the period from the northwest.
Southwest winds with gusts of 30 to 40 mph across much of the
region will run through the afternoon and early evening with
the strongest winds favoring northeast UT and northwest CO. Look
for winds to decouple from the flow aloft, becoming light
drainage winds at the surface. This creates a risk for Low-Level
Wind Sheer at the mountain TAF sites.

&&

.FIRE WEATHER...
Issued at 256 PM MDT Sun Jun 16 2024

Red Flag Warnings remain in place for southeast Utah, southwest
Colorado, and west-central Colorado through 10 PM this evening.
Relative humidity recovers overnight as winds subside bringing
a break in critical conditions through Monday morning. However,
strong prefrontal southwest winds gusting from 30 to 40 mph,
single digit relative humidities, and above normal temperatures
will cause critical fire weather conditions to redevelop from
late Monday morning through Monday evening. Cold frontal passage
Monday night is expected to bring subcritical fire weather
conditions overnight Monday night through Tuesday.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...Red Flag Warning until 10 PM MDT this evening for COZ203-207-
     290>293.
     Red Flag Warning from 11 AM to 10 PM MDT Monday for COZ203-207-
     290>293.
UT...Red Flag Warning until 10 PM MDT this evening for UTZ490-491.
     Red Flag Warning from 11 AM to 10 PM MDT Monday for UTZ490-491.

&&

$$

SHORT TERM...NL
LONG TERM...DB
AVIATION...TGJT
FIRE WEATHER...NL/TGJT