161
FXUS65 KGJT 082018
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
218 PM MDT Sat Jun 8 2024

.KEY MESSAGES...

- Afternoon showers and storms will favor the north today, but
  will expand to include all terrain features Sunday and Monday.
  Main threats will be gusty winds and lightning.

- Temperatures will cool to near normal values by Monday before
  warming back to 10-15 degrees above normal mid to late next
  week.

- High pressure from Tuesday onward will keep conditions hot,
  dry, and quiet.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 212 PM MDT Sat Jun 8 2024

A weak shortwave moved across the north this morning and is now
sparking convection along the Front Range. Sufficient moisture is
still present north of I-70 and lapse rates remain steep. Convection
is developing in the higher terrain and will most likely struggle
leaving these spots. Given the dew points and pwats some downpours
are possible in the northern mountains. Due to the relatively dry
low levels wind gusts of 40-60 mph are possible under these showers
in some of the valleys. The models are hinting at another wave
tracking behind the one this morning. Although there are no obvious
features associated with that on satellite attm. Either way that
wave may help force some of the showers and storms as well. By
sunset or shortly after the convection should come to an end. These
two waves push the moisture around a bit but the high pressure to
our south allows it to advect back northward tomorrow. The remnants
of the Baja cutoff low will be an open wave over the Desert
Southwest tomorrow afternoon, providing some modest lift across the
southern portion of the CWA, while yet another passing wave to the
north will help with convection over Northeast Utah and northwest
Colorado. Expect to see activity fire along the terrain first before
drifting off over adjacent valleys. Multiple days of uninterrupted
moisture across the north will see increasing chances of heavy rain
with afternoon convection, along with the usual threats. Gusty winds
and lightning remain the main threat across the south. All of these
waves are helping to keep the ridge down therefore temperatures
remain fairly steady. Also, for a few locations the presence of
clouds and rain will keep it cooler.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 212 PM MDT Sat Jun 8 2024

The synoptic pattern heading into next week holds onto a vague
familiarity Monday, with a cutoff low sitting offshore of SOCAL and
a flattened ridge dominating the pattern in the West. A weak
shortwave to our north works through Monday, while the cutoff low
ejects a lobe of vorticity into the southern reaches of the CWA.
This should be enough moisture and forcing to see another round of
convection on the terrain Monday afternoon. The resultant cloud
cover and wind shift will see temperatures trend down a notch from
their summer-like highs on Monday and Tuesday. Unfortunately, this
will only ease the temperatures a few degrees in our hot desert
valleys, while the mountain towns will see more appreciable
decreases. The subsident effects of the ridge take the reins again
Wednesday and temperatures respond accordingly with highs expected
to push more than 10 degrees above early June averages. Models try
to eject our offshore low  into the Great Basin by Thursday
afternoon, when strong southwesterly flow is expected to push more
warm air into the region. Breezy, hot conditions will potentially
introduce some marginal critical fire weather conditions Thursday.
The progress of the low gets called into question by deterministic
models Thursday, with GFS the most aggressive in speed. Model
confidence also wanes here. For now it looks like another push of
storms and showers along a frontal boundary Thursday into Friday is
a safe bet. Late week temperatures come back down in the wake of
this front Friday and Saturday, with high pressure and dry
northwesterly influence bringing back warm and dry for next weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1137 AM MDT Sat Jun 8 2024

Scattered cloud cover and VFR conditions will hold on across
much of the region, especially south of I-70 and the lower
elevation valleys. Elsewhere, on the terrain along the Divide
and northwest Colorado, showers and thunderstorms will form
this afternoon. Brief heavy showers and gusty winds will pose
the biggest challenges to aviation at the mountain terminals.
Winds will pick up mostly westerly this afternoon at 10-20 mph
with a few stronger terrain influenced gusts and the occasional
outflow gusting to around 50 mph in the vicinity of showers and
storms. Storm activity will diminish around sunset and VFR
conditions with light winds will close out this period.

&&

.HYDROLOGY...
Issued at 332 PM MDT Fri Jun 7 2024

High elevation snow will continue to melt under these anomalously
warm spring conditions. Following current guidance and river
trends, we`re expecting an increase in flows along the Colorado
Headwaters. More specifically, Gore Creek, Eagle River and the
Roaring Fork River Basin have all shown an increasing trend over
the last 24 hours. Current advisories all remain in place
through the weekend, and we`ll continue to monitor for any
expansions to highlights or for any chance these could upgrade
to a warning. Improving conditions are anticipated following
this weekend, as large diurnal swings taper off next week.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...KJS
LONG TERM...LTB
AVIATION...TGJT
HYDROLOGY...ERW