Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 272122 CCA
AFDGJT

Area Forecast Discussion...CORRECTED
National Weather Service Grand Junction CO
322 PM MDT Wed Mar 27 2024

.KEY MESSAGES...

- Gusty southwest winds will arrive ahead of the next
  disturbance Thursday afternoon. Warmer temperatures will
  accompany the southwesterly flow.

- A few inches of new snowfall expected in the high country by
  Friday morning, mostly after midnight Thursday night.

- Unsettled conditions will continue through the weekend and
  into Tuesday morning. Sunday and Monday and look like the core
  of the storm, with the greatest snowfall accumulations for
  the period.

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 246 PM MDT Wed Mar 27 2024

Moisture continues to spill into the Pacific Northwest and Great
Basin this afternoon ahead of the next storm system to impact the
West Slope. Much of this is riding a jet streak nosing into the
Great Basin along the southern perimeter of a stacked low sitting in
the northeast Pacific. A dirt, transitory ridge passes by tonight,
before breaking down in the height falls ahead of the digging low in
the Pacific. This will keep a few clouds streaming across the CWA
overnight, mostly up north. While down south, clearer skies will
allow things to cool a bit more efficiently. Some patchy fog turns
up in a few cold spots overnight, taking advantage of the surface
moisture hanging around. Some dense fog formed in the Grand Valley
this morning and I wouldn`t rule out another round Thursday morning.
This will be very localized, adjacent to the river, and bears
watching overnight. Moisture settling southward under the collapsing
ridge will spark a few showers over the eastern Uintas and northern
mountains of Colorado Thursday. Snow accumulations will remain
confined mostly to areas above 7000 feet. Winds are expected to
increase Thursday afternoon with the tightening pressure gradient in
the southwesterly flow ahead of the storm pushing ashore up in the
Northwest. Winds will be gusty in the 25-35 mph range across the
region. Richer moisture will arrive as the jet scoops up more
Pacific moisture  and delivers it into the region late Thursday and
early Friday morning. Snow accumulations will answer early Friday
morning, with a few inches of new snow expected on the terrain from
the Central Mountains and northward. The protracted nature of
snowfall keeps this event in sub-advisory criteria. Breezy,
southwest winds will pump more warm air in Thursday and temperatures
will respond upward. Desert valleys will climb back into the 60`s
and lower 70`s, with mountain locales in the 40`s. This will chew
into some of the early snowfall that comes down Thursday evening.
Overnight lows tonight will remain chilly again, but Friday morning
will trend warmer under a blanket of clouds and higher
dewpoints.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 246 PM MDT Wed Mar 27 2024

A tight, closed low will continue to spin just off the Oregon coast
at the start of the long term period. A stronger piece of energy
originating from that low will support a surface boundary that will
be spread across our northern valleys/mountains first thing Friday
morning. This weak boundary will slowly slip southward through the
day and will be the focus for some valley rain and mountain snow. As
of now, NBM and other models are suggesting an inch or two of new
snow for the Flat Tops and Park Range with less amounts elsewhere
dropping to around an inch for the afternoon hours. Upper level
support will wane during the day Friday but as the next jet streak
approaches from the southwest, this weak(er) boundary will lift up
into Wyoming.

As far as the weekend is concerned, the low off the Oregon coast
will become absorbed by another area of low pressure as it drops
south along the California coast. This trajectory will allow broad
southwesterly flow to set up across the area for Saturday and
continue advecting moisture into the region...yup, a weak AR event.
In addition to the moisture, H7 winds aloft are progged to reach
between 35 to 45 kts and with deeper mixing, look for some gusty
winds Saturday. The strongest winds will be over the Four Corners
region with some gusts reaching near 45 mph, if not a bit above
though any cloud cover could temper these values. Speaking of,
plenty of cloud cover is expected. Despite that, most locations will
see some gusts of 25 to 35 mph. Some precip is likely over the
highest elevations of the eastern Uintas Saturday while some
favorable orographics allow some showers to fire along the Divide
Saturday evening.

Things get much more interesting Sunday as the low comes ashore near
San Diego. Flow around the low will keep pumping in the moisture and
we can expect some light precip Sunday morning, slowly increasing
coverage through the day with heavier rain/snow moving in by Sunday
evening and continuing through Monday morning. Actually, the precip
doesn`t really end until Tuesday morning but that shot from Monday
into Tuesday will be from a secondary wave dropping down from the
north. Total snowfall amounts from Sunday morning through Tuesday
morning, for all higher terrain in the CWA, ranges from 6 to 8
inches...maybe a bit more for the northern mountains and heading up
to Wolf Creek Pass. These amounts over a 48 hour period don`t
warrant any highlights especially as roads will be warm with only
minor impacts expected.  Even so, we`ll see how things pan out as we
get closer to the event. The long and short of it: cloudy, warm
temps for the weekend dropping to normal Monday onwards, unsettled
weather for much of the long term.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1115 AM MDT Wed Mar 27 2024

Clouds linger across the Colorado mountains this afternoon
though mostly VFR conditions are being reported. KGUC is seeing
some low clouds with occasional snow dropping them to MVFR
briefly. Kept a tempo group there for the next few hours to
cover this on and off snow. Remaining TAF sites will see
scattered skies, maybe occasionally broken for KASE, KEGE,
KHDN, and KTEX. Some high clouds will move in overnight but pose
no aviation threats.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...LTB
LONG TERM...TGR
AVIATION...TGJT


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