246
FXUS65 KGJT 161745
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
1145 AM MDT Sun Jun 16 2024

.KEY MESSAGES...

- Gusty southwest winds, single digit relative humidities, and
  warm temperatures today and Monday. Red Flag Warnings are in
  effect both days.

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

- Unsettled conditions return Thursday, with afternoon
  convection expected through the extended period.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 334 AM MDT Sun Jun 16 2024

A trailing frontal boundary dragging behind a Saskatchewan low is
pulling some weak Pacific moisture across the northern portion of
the Great Basin and to our north along the Wyoming state line this
morning. These are the only clouds showing up on satellite here in
the CWA this morning. The inverted v sounding at Grand Junction last
night sums up the very dry surface conditions well. This trend will
continue today and tomorrow as the upper level flow pretty much
holds steady at a southwesterly reach for the next 36 hours. Single
digit relative humidities, gusty winds, and temperatures well above
climatological averages can be expected today and Monday ahead of
the aforementioned frontal boundary that swings through in the
extended term(more on that below). Meanwhile, winds will ratchet up
this afternoon out of the southwest with gusts 30 to 40 mph and
steady winds of 20-30 mph. Winds south of the Colorado River will be
a touch lighter, but still high enough to warrant our Red Flag
Warnings. Winds will temper towards sunset and relative humidities
are expected to recover back above Red Flag thresholds by around
10pm MDT. Monday will pretty much rinse and repeat today. However,
winds will strengthen in the tightening gradient ahead of the front.
Our northern counties can expect gusts closer to 45 mph Monday
afternoon, as well as a few invading mid/high level clouds along the
front. Have held off on a Wind Advisory Monday afternoon with
coverage in question, but the northern zones of the CWA are expected
to be close as the front approaches. Surface conditions remain
extremely dry and Red Flag Warnings are in place for Monday as well
for the zones included in today`s product.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 334 AM MDT Sun Jun 16 2024

Winds finally subside as the system and upper level support
responsible shift to our east and a dry, cold front moves across the
area. By Tuesday morning, the front will have moved across the
entire CWA bringing cooler temps to the region. High temps will be
10 to 15 degrees cooler from the central valleys northward and 5 to
10 degrees cooler farther south. Tuesday and Wednesday will be
pleasant but the rest of the long term period gets interesting. A
broad trough will set up across the western US while a large area of
high pressure sets up along the East Coast. The location of the high
will tap into deep tropical moisture and anti-cyclonic flow will
cause this moisture from the Gulf of Mexico to move northwestward
across Texas and eventually move into our CWA allowing an uptick in
convection Thursday onwards. Some subtle minor disturbances will
move through UT and CO during this timeframe and will work on this
moisture allowing said convection to fire. This chance for
convection will fire each afternoon and evening through Saturday. As
of now, the widest coverage looks to occur on Thursday and Friday
but some isolated to scattered convection will continue into the
weekend. Forecast dewpoints and RH values are forecast to increase
during this timeframe so the chance for some wetting rains looks
promising. Clouds and precip will also temper high temperatures as
well as convection so we`ll have to see how this all plays out. For
now, the NBM has a 40 to 60% chance PoPs for mainly the southern
half of the CWA as well as along the Divide for both Thursday and
Friday but we`ll see how things end up once the short range models
get involved. Enjoy Tuesday and Wednesday as unsettled weather
returns after that.

&&

.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 334 AM MDT Sun Jun 16 2024

Red Flag Warnings are in place for southeast Utah, southwest
Colorado, and west-central Colorado today and tomorrow. Strong
southwest winds gusting 30-40 mph, single digit relative
humidities, and well above normal temperatures will keep
critical fire weather conditions locked in. RH values will
recover during the overnight hours and winds are expected to
subside some as well. A frontal passage on Monday night is
expected to return fire weather conditions to subcritical on
Tuesday. Wetting rains are not expected.

&&

.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...LTB
LONG TERM...TGR
AVIATION...TGJT
FIRE WEATHER...TGJT