593
FXUS65 KGJT 032105
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
305 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 SUNDAY/...
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 /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1138 AM MDT Mon Jun 3 2024

Cloud cover will continue to drift southeast across the forecast
area, as a predecessor to this evening`s cold front. Expect
gusty southwest winds, 20 to 30 kts, ahead of the front as well,
which is progged to dip into northeast Utah and northwest
Colorado by mid afternoon. Showers and thunderstorms are most
prominent along the Upper Yampa Basin, with VCTS and periods of
rain most likely impacting KHDN by 6PM. Elsewhere, showers and
storms will favor higher terrain, with KRIL, KASE and KEGE
falling within the path of potential showers and storms after 8PM.
The front will clear from west to east tonight with VFR
conditions expected by sunrise....that being said, low clouds
may linger along the Upper Yampa and Roaring Fork basins.

&&

.HYDROLOGY...
Issued at 256 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.

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 and forecast conditions 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