000
FXUS65 KGJT 152301
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
501 PM MDT Mon Apr 15 2024

.KEY MESSAGES...

- Gusty winds up to 50 mph from showers or virga will continue
  to be a threat along with isolated thunderstorms through the
  evening.

- Significant snowfall will impact the northern and central
  mountains, including Vail and Rabbit Ears passes through
  Tuesday afternoon.

- Breezy, milder, and unsettled conditions linger through the
  end of the week.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 322 PM MDT Mon Apr 15 2024

Satellite imagery is showing a classic Springtime mid-lat
cyclone moving into the central Rockies this afternoon. The dry
conveyor belt is wrapping into the High Plains driving the high
fire danger conditions and enhancing the dry line which should
pops strong convection later. This dry line is heading under the
warm conveyor belt shown well in the ALPW imagery with Gulf
moisture beginning to wrap back toward the West toward the Black
Hills region of S.Dakota. It is this moisture source that will
continue to wrap around the backside of the cyclone as it
emerges onto the lee of Rockies this evening and take aim at our
northern CWA. A strongly convective environment is in place
attm with the upper low overhead. Various PV lobes rotating
around the low are helping to release instability...in addition
to the northward driving cold front which should clear the
northeast CWA over the next few hours. Snow impacts have been
minimal in the first part of the storm...but some decent snow
rates we seen coming down behind the fropa over parts of SE Utah
this morning. Now it looks like the spine of the northern Utah
mountains are seeing some decent convectively driven snow rates
and some coverage of snow on the roads. The bigger impacts
through the afternoon will most likely be wind related with
gusts of 40 to 50 mph being brought down to the surface by the
convective mixing/virga/showers. Snow rates will pick up and
travel hazards across the central and northern mountains post
sunset as the above mentioned moisture meets northwest
orographics and mid level frontogenesis overnight. 1-2 inch per
snow rates are possible over the Park/Elkheads to the Elks for
several hours overnight and travel impacts appear imminent over
Rabbit Ears and Vail Passes and adjacent mountain corridors
through tomorrow morning. The stacked Plains cyclone will lift
into the Upper MO Valley by tomorrow afternoon allowing
transitory ridging and WAA to into our CWA and shut off the snow
from late morning onward. The cyclone will be accelerating
eastward Tuesday night as the already the next high latitude
system digs across the Northern Rockies/High Plains early
Wednesday morning. So the break from precipitation will be short
lived as moisture and dynamics dip back into the northern CWA
by daybreak. Temperatures will rebound tomorrow behind this
system and hover back to near or a bit above normal outside the
eastern mountains.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 322 PM MDT Mon Apr 15 2024

A confluent weather pattern will be setting up over eastern
Great Basin and Rockies to end out the week. This mid latitude
region will be squeezed between a large vortex to the
north...centered over the Canadian Prairies and the northern
periphery of the SubTrop High to the South. This basically will
set up a thermal gradient across the CWA with cooler conditions
and over-running precipitation over the north and warmer/drier
conditions to the south. This thermal gradient and the
moderately strong zonal flow aloft means windy conditions each
afternoon as the mixing deepens with Wednesday looking to be
about the windiest of the week. Any dry fuels combined with the
winds and warmer temperatures in the southern CWA will continue
to keep fire danger in the higher end of comfortable. This
pattern will begin to break down later on Friday as yet another
strong high latitude system sweeps across the EPac. This shift will
force a weak and broad trough through the southern stream. Right
now this wave looks more likely to bring more wind from mixing
than moisture for precipitation but some afternoon showers/virga
looks to become a bit more widespread. Lingering moisture and
instabiliy look to keep mountain showers in place through the
weekend. Snow levels will be high and looks like the highest
amounts remain limited to the high peaks of the Park Range
through the latter part of the week into the weekend.
Temperatures look to settle around 5 to 10 degrees above normal
in the south and near to slightly below normal up north.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 458 PM MDT Mon Apr 15 2024

A strong system and associated cold front is lifting northward
across eastern Utah and western Colorado. Scattered showers are
producing MVFR conditions. These showers will persist for the
northern and eastern sites into the morning. Winds will remain
gusty with this strong system and gusts in the 25 to 40 mph
range will occur through the early morning hours. There may some
improvement towards the end of the period.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...Winter Weather Advisory until noon MDT Tuesday for COZ004-010-
     013.
UT...None.

&&

$$

SHORT TERM...15
LONG TERM...MMS
AVIATION...TGJT