028
FXUS65 KGJT 120915
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
315 AM MDT Sun May 12 2024

.KEY MESSAGES...

- Mountain snow and valley rain will continue through the
  morning hours for the central and southern areas with 2 to 4
  inches of additional accumulation mainly above 11,000 feet.
  Steadier precipitation should come to an end by late morning
  as this low moves southeast of the area.

- Daily showers and thunderstorms, favoring the mountains along
  the Divide, are expected this afternoon and continuing each
  day through the coming week. More widespread activity returns
  Tuesday into Wednesday.

- A gradual warming trend will bring near normal temperatures
  today, and above normal temperatures from Monday onward.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 315 AM MDT Sun May 12 2024

At this early morning hour, wraparound precipitation is
occurring on the northern and western sides of the low pressure
system that appears to be centered somewhere around Salida,
southeast of the Leadville area. This is resulting in an
easterly flow on the north side of the low with the Front Range
easterly upslope areas seeing the best snowfall rates. It should
be noted that easterly upslope flow does not particularly favor
the western slope areas with significant snowfall and this is
evident when looking at observations around the area. Webcams
indicate primarily wet roads at this time with snow accumulating
at elevations above 11,000 feet as snow levels still remain
high. The ski resorts around Aspen and Snowmass seem to indicate
about 6 inches of snow has accumulated thus far since yesterday
and the rest of the area appears to have had 2 to 4 inches on
average, which is about what we expected. Webcams indicate
snow rates are lessening with light snow falling in the Elks
with little additional accumulation at Aspen and Snowmass ski
areas since midnight. This is due to the precipitation band
shifting southward as the low continues to progress
southeastward, projected to end up in southeast Colorado by late
this morning. The wraparound precipitation will move out of
here with the southeast movement of the low. Valleys are still
too mild where rain is the likely precipitation type but limited
impacts are being seen on our highways across the western slope
and expect this to remain the case through the morning with the
best accumulating snow above 11,000 feet in the realm of an
additional 2 to 5 inches through noon, with the highest
elevations of the West Elks and Sawatch Range seeing the locally
higher amounts. The higher impacts appear to be further east
over the easterly upslope areas and Front Range though with
minimal impacts on the western side.

Conditions improve by late morning as the low shifts southeast
of the area and takes the better precipitation banding with it.
Drier northerly flow moves in on the backside of this trough
this afternoon but enough moisture will remain along the divide
areas to combine with daytime diurnal heating to produce some
isolated to scattered showers and thunderstorms this afternoon.
Snow levels also rise as a result with maybe another 1 to 2
inches of snow at the higher elevations above 11,000 feet.
Temperatures are projected to be milder with a decent increase
of about 4 to 8 degrees higher than yesterday. Lower elevations
across eastern Utah, northwest and west-central Colorado should
be closer to normal with below normal readings elsewhere, about
5 degrees below normal. Showers and storms come to an end
shortly after sunset with clearing skies for Sunday night. A
shortwave ridge of high pressure moves in for Monday for drier
and warmer conditions for much of the area, although lingering
moisture along the western Colorado divide will spark some
afternoon convection once again. Otherwise, much of the area
will see a return to above normal temperatures by Monday with
highs around 4 to 8 degrees above normal.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 315 AM MDT Sun May 12 2024

Monday night sees eastern Utah and western Colorado on the
backside of a transient ridge, with the next trough dropping
south through the Pacific Northwest. In addition, an area of
low pressure will be located just off the southern California
coast. Models are in decently good agreement that the cutoff
low and the approaching trough will phase as they move east,
creating a weak but extensive area of dynamic lift that will
slowly move across the region. This lift will begin acting on
above average moisture pooled across eastern Utah and western
Colorado starting Tuesday, and is expected to be maximized
Wednesday afternoon. This means scattered to widespread shower
and thunderstorm activity each day, with the higher terrain
most favored. Current QPF forecasts remain modest, with most
spots seeing between 0.01" and 0.10" of liquid, while the
mountains could see up to 0.20" each afternoon. This will
likely change as higher resolution guidance begins to come in.
Warm air ahead of this trough, and very modest cooling behind
it, will keep snow levels high, with forecast accumulations of
2-3 inches expected only above 11000 feet, and therefore only
limited impacts to travel for Tuesday and Wednesday. The trough
axis shifts east of the Divide by Thursday morning.

From Thursday onward, a ridge tries to nudge in and brings
drier and warmer conditions. Mountains and adjacent high
elevation valleys can still expect isolated to scattered showers
most afternoons as daytime heating acts on residual moisture
pooled across the region, but otherwise most of eastern Utah and
western Colorado can expect mostly sunny skies. Overnight lows
will remain fairly mild, with near to a few degrees above normal
values expected. Daytime highs will start out near normal for
Tuesday and Wednesday as showers and clouds keep things cooler,
but a warming trend will kick in for Thursday onward under clear
skies and warm air advection. Look for highs running around 5
degrees above normal by the end of the week, with desert
valleys once again seeing low 80s, and higher valleys seeing
70s. Mountain towns can expect upper 50s to low 60s. So, if
this forecast verifies, it looks as though we`ll finally see a
bit of a break from this cool and unsettled pattern we`ve been
stuck in.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1129 PM MDT Sat May 11 2024

An area of light to moderate rainfall is moving southeast
through the region at this hour. Reduced visibility and low
ceilings associated with this area have led to MVFR to IFR
conditions at KASE, with KEGE and KRIL remaining below ILS
breakpoints. This area will bring potential showers to KGJT,
KMTJ, KTEX, and KGUC over the next 6 hours before tapering off.
Skies will clear behind this area of showers, with ceilings
rising above ILS breakpoints. VFR conditions will prevail after
12z. Gusty afternoon winds up to 20 knots will be possible.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...MDA
LONG TERM...BGB
AVIATION...TGJT