224
FXUS65 KGJT 032333
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
533 PM MDT Mon Jun 3 2024

.KEY MESSAGES...

- A surface front will bring some showers and a few embedded
  storms to northern portions of the forecast area. The CO/WY
  border will see this precip first before shifting to the
  northern mountains and Flat Tops later this evening.

- Some high clouds will persist tomorrow with a clearing trend
  Tuesday afternoon onwards.

- Temperatures will remain above normal into the coming week.
  The warmest temperatures of the season thus far will be
  Thursday and Friday at 10 to 15 degrees above normal.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 256 PM MDT Mon Jun 3 2024

Plenty of high clouds continue to stream into the area ahead of the
next system. Currently, the surface front is located in southern
Idaho down into northern Nevada and will keep moving eastward
through the afternoon. Some showers and a few embedded thunderstorms
will accompany frontal passage later this evening.
The cloud cover and weak cap may limit the convection and the latest
NAMNEST and HRRR guidance is also showing some slight decrease in
activity. That being said, isolated to scattered showers and storms
remain in the forecast with the most coverage from 6PM through
midnight. Favored areas will be along the CO/WY border in the early
evening hours shifting to the northern mountains and Flat Tops as
the evening progresses. After that, some residual showers will
continue mainly for the northern and central mountains but these
will decrease through the early morning hours.

By Tuesday morning, a stray rain shower may persist over the higher
terrain but better chances are for all precip having ended.
Northwest through northwesterly flow sets up over the area on
Tuesday bringing drier air to the region though neutral advection
will keep high temps very similar to what we saw today...maybe a few
degrees cooler. Some high clouds will be moving overhead during the
day becoming mostly clear heading into the early evening hours.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 256 PM MDT Mon Jun 3 2024

High pressure building overhead will continue the heat streak across
the Western Slope. By Wednesday temperatures are progged to rise ten
degrees above normal for early June and continue to climb through
Friday. Looks like Moab, Grand Junction and areas down to Delta will
likely reach their first 100 degree day this year. NBM probabilities
suggest over a 90 percent chance of a 100 degree day in Moab on
Friday, with GJ not trailing far behind (80% chance of max T`s
exceeding 99 degrees). Stay hydrated, my friends, summer is here,
just a little early this year.

Forecast highs are expected to peak on Friday, while the ridge`s
axis sets up directly overhead. A low pressure system spinning off
the Baja Peninsula will eventually nudge the high eastward. However,
there are discrepancies amongst deterministic guidance with regard
to how soon and where the low becomes embedded with stirring flow to
our north. More specifically, the trajectory of the low this weekend
will influence how much moisture is pulled from the southern Pacific
and Gulf of Mexico into the Western Slope. Precipitation
probabilities definitely favor the front range this weekend, though
the spine of the Rockies may bode well under this regime, as well.
Afternoon showers and thunderstorms would favor higher terrain on
Saturday, with adjacent valleys showing less than a 20 percent of
measurable precipitation. Fortunately, if the aformentioned low
crosses the area as an open wave on Sunday, that will boost the
chance for showers across high valley floors by the afternoon/
evening. Desert floors may not feel a spit of rain Saturday or
Sunday, although, passing clouds would bring some relief to this
early June heat wave.

Concerns for a blocking pattern developing upstream may maintain
this stagnant, and warmer than usual, weather pattern for early
June. Climate Prediction Center`s latest 6 to 10 and 8 to 14 day
outlooks both show temperatures likely above normal through the long
term period...and beyond.|

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 530 PM MDT Mon Jun 3 2024

Cloud cover and pockets of stable atmospheric conditions haven`t
favored thunderstorm activity thus far along the front`s
boundary. Even rain reaching the ground has been difficult to
detect upstream. Thus, have removed VCTS and replaced with VCSH
for evening TAFs. Gusty winds along and ahead of the boundary is
the main concern for most terminals. However, KHDN, KASE and
KEGE still have the greater potential for seeing measurable
precipitation and/or conditions dipping below ILS breakpoints
later this evening. Still anticipate clearing conditions in the
wake of today`s front, with widespread VFR conditions expected
tomorrow.

&&

.HYDROLOGY...
Issued at 530 PM MDT Mon Jun 3 2024

High pressure building overhead through the end of the week will
result in an unseasonably warm period across the Western Slope.
Simultaneously, as those temperatures rise, so will the rate of
snowmelt across our high terrain. Even though low to mid elevations
have already melted out, there`s still an abnormally high amount of
snow left over basins generally at and above 11,000 ft. As a result,
we`ll see creeks, streams and major tributaries along the Upper
Colorado River Basin rise. Seasonal peak flows are expected over the
next 10 days, with the Upper Gunnison, Upper Yampa and Colorado
Headwaters basins potentially peaking this weekend. Current
guidance oscillates diurnal peaks cresting the Action Stage for
portions of Gore Creek and Eagle River in Eagle County and the
Elk River in Routt County Colorado. We will continue to monitor
these evolving forecasts to see if any Flood products are
warranted. But for now, we just want to pass on the message:

As scorching temperatures lure folks to the water, please
remember the potential hazards associated with high flows during
the snowmelt season. Fast flows are not just dangerous for
those choosing to float the rivers. In addition, high diurnal
swings may drastically change the depth and flow for normally
small creeks and streams. Swift currents and cold water
temperatures can catch you off guard, so please be vigilant with
current conditions and look for forecast updates when
recreating or working near the water`s edge.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...TGR
LONG TERM...ERW
AVIATION...TGJT
HYDROLOGY...ERW