387
FXUS65 KGJT 280955
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
355 AM MDT Sun Apr 28 2024

.KEY MESSAGES...

- A disturbance will move over the area today bringing some
  showers and a few storms this afternoon and evening.

- High temperatures start warming up day by day.

- The next chance for more widespread precipitation looks to
  occur Wednesday afternoon through Thursday afternoon.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 254 AM MDT Sun Apr 28 2024

The system that brought all the snow and rain yesterday has
shifted to the Plains where severe weather is ongoing. Some
light snow continues at the highest elevations of the CO
mountains though it looks to have really died down for the
Uintas. Went ahead and cancelled the advisory there but will
keep them going through 12Z for the CO mountains. The next
question for the overnight hours will be fog. Dewpoint spreads
for many locations are fairly close together and local obs are
showing low broken to overcast skies so some fog is very likely.
Will be interesting to see if we get any sunrise surprises this
morning. Sunday will bring one more day of unsettled weather as
a shortwave drops in from the northwest. This shortwave will
work on cold air aloft and with plenty of midlevel instability
across the area, another round of showers and storms will be
possible this afternoon and evening. Another inch or two of snow
is also possible along the higher terrain of the Continental
Divide. Variable cloudiness will be the rule with more cloudy
skies over and around the mountains with clearing skies for
eastern UT and far western CO through the day. With less precip
and cloud cover, high temps should rebound about 4 to 8 degrees
from yesterday.

Zonal flow sets up across the CWA Monday as the next system
moves across the PacNW. Favorable windflow may allow some
showers to form over the northern mountains during the day but
that should be about it. Heading towards the late
afternoon/evening hours, said system to our north will drag a
cold front far enough south that it could bring some showers to
our northern valleys/mountains. Elsewhere, dry conditions
expected with some of the usual afternoon gusts of 20 to 25 mph
with higher gusts up north. Clouds will also increase in the
afternoon in response to the approaching front but they should
remain partly cloudy...with plenty of sun south of the San
Juans. The warmup continues as highs jump another 4 to 8
degrees.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 254 AM MDT Sun Apr 28 2024

A broad area of cyclonic flow stretching from the PACNW all the way
to the Northern Plains will continue to play a part in this week`s
extended forecast. Kicking off the period Monday night is a pocket
of northeast Pacific moisture working through the Intermountain West
on the shoulders of a strong jet streak digging out a trough into
the north of the Great Basin. As this feature works east, it is
expected to clip our northern Mountains early Tuesday with enough
moisture to drop additional snowfall on the Flat Tops, Elk Heads,
and Park Range. This clipper will be an afterthought though, as most
of its moisture is gone before your second cup of coffee Tuesday
morning. Temperature advections will remain neutral to warm Tuesday
afternoon and afternoon highs will rebound into the 70`s for our
warm desert valleys and perhaps 80`s for our southeast Utah deserts.
Reinforcements to the low pressure occupying the Intermountain West
up north arrive Wednesday, as another pulse of the jet digs deeper
into the Great Basin. Gradients tighten and southwesterly winds kick
up Wednesday afternoon in front of a pending cold front. Presently,
some additional moisture wrapping around the low to our north will
generate some cloud cover and a shower or two across our northern
counties Wednesday afternoon. This will likely check afternoon highs
down a bit and hopefully take a bite out of fire weather concerns in
the gusty regime ahead of the incoming front. The passing front
early Thursday morning will send us back below climatology for
temperatures Thursday through Friday morning. It will also bring
some more valley rain and mountain snow to much of the northern half
of the CWA. Post-frontal showers and thunderstorms will likely
present themselves Thursday afternoon before we scour out the
remaining moisture late Thursday night. Model solutions are not in
lockstep with the depth of the trough on this late week system.
There is a chance this system fails to dig south enough for any
impacts beyond far north Colorado. Mean flow flattens out Friday and
Saturday ahead of a weak transitory ridge models are trying to paint
over the Great Basin. This looks good enough for another warm up
next weekend. Still time to rework this forecast, given spring time
model discontinuities.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1159 PM MDT Sat Apr 27 2024

Lingering cloud cover and shower activity will keep some IFR
conditions in place during the early morning hours. However, by
daybreak ceilings are expected to improve. Afternoon showers
will develop once again on the terrain, with a few drifting out
over the valleys. Gusty outflows, brief downpours and small hail
can be expected Sunday afternoon around these showers.
Intermittent IFR conditions will be expected at terminals again
Sunday afternoon. Flying conditions will improve towards sunset
as shower activity winds down for the day.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...Winter Weather Advisory until 6 AM MDT early this morning for
     COZ004-009-010-012-013-018-019.

UT...None.

&&

$$

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