454
FXUS65 KCYS 061735
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1135 AM MDT Sat Jul 6 2024

.KEY MESSAGES...

- Near critical to critical fire weather conditions expected on
  Saturday for parts of Carbon and Albany County. Red Flag
  Warnings are in effect.

- Chances for showers and thunderstorms will exist through the
  weekend as a series of weak disturbances impact the region.

- Gradual warming trend expected through next week with limited
  precipitation chances.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 418 AM MDT Sat Jul 6 2024

Currently, a weak surface low sits just south of the
Colorado/Wyoming border along the Front Range. This has
contributed to both weak south to southeast flow and moisture
advection into the southern Nebraska panhandle. As the surface
low moves eastward throughout the morning along the Colorado
border, the weak moisture stream will get cut off, capping
dewpoints off in the 40s. Although these dewpoints likely aren`t
high enough for severe weather, it still is enough for storm
development, especially with forcing from a modest upper-level
shortwave passing across the area. For the most part, weather
during the day looks fairly quiet with Hi-Res guidance showing a
few isolated showers and storms, mainly across the far northern
zones. Storm chances actually look better tonight behind an
incoming cold front. Hi-Res guidance and the GFS show
instability increasing behind the front and 0-6 km shear in the
sweet spot for potentially organized convection. However, most
guidance show storm clusters across most of the CWA overnight.
Cannot rule out an isolated strong to severe storm, especially
with MUCAPE values around 1500 J/kg and DCAPEs in some locations
exceeding 1000 J/kg. Therefore, wind gusts over 60 MPH could be
possible, as well as quarter-size hail.

Could see a brief break in storms early to mid-Sunday morning before
the next round arrives late Sunday morning. Continued pulses of
upper-level energy into the CWA will contribute to the prolonged
stormy period Saturday afternoon through Sunday afternoon. Luckily,
not a whole lot of strong instability present on Sunday, so most
likely looking at sub-severe thunderstorms throughout the day.
Besides storms, Sunday will be post-frontal, so looking at cooler,
below average daytime highs. Most locations will be in the 70s, with
perhaps a few isolated high valley locations staying in the 60s.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 418 AM MDT Sat Jul 6 2024

Long Range models in excellent agreement with the gradual warm
up and shift in the weather pattern coming up this week through
next weekend. A few more days of northerly to northwesterly
flow early in the week as the exiting potent upper level trough
axis digs further south into the southern Great Plains states
before ejecting eastward. Expect a slow warming trend to start
off the week as the upper level high over the Great Basin Region
slowly drifts east and amplifies over the southwest United
States. Although it should remain a few degrees below normal on
Monday, afternoon high temperatures will return to normal by
Tuesday as 700mb temperatures climb towards 10c to 15c across
the region. Chances for showers and thunderstorms will be tricky
to nail down, but expect mainly dry conditions on Monday with a
slight chance for thunderstorms along the Laramie Range and the
I-25 corridor Tuesday. Models do show a few weak upper level
disturbances moving clockwise around the main upper level high
pressure to our west. However, low level moisture is lacking
with dewpoints likely in the 30s to low 40s until Wednesday,
where they approach seasonal averages. Kept a mention of
thunderstorms for the mountains and Albany and Laramie counties
for now Tuesday and Wednesday.

All models indicate the strong upper level high (598dm) and
ridge axis drifting further east into the four corners area
with the ridge axis extending northeast towards the Dakotas late
this week. Ensembles are in excellent agreement and show very
little spread in POP and temperatures. Kept POP below 10 percent
for most areas...with the exception of the Snowy and southern
Laramie Range where mountain showers and thunderstorms are
possible each day. The warming trend will continue with a
potential heat wave starting Friday and Saturday of next
week...with highs in the 90s to around 100 degrees over far
eastern Wyoming and western Nebraska. PWAT do creep up by next
weekend, which may result in a slightly better coverage for
showers and thunderstorms.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1128 AM MDT Sat Jul 6 2024

VFR conditions expected for the forecast period. Afternoon
convection will be more active today than the last few days,
kicking off after about 21-22z. Maintained VCSH for all
terminals, except for VCTS at KCDR and KAIA where higher
instability will lead to a better thunderstorm chance.
Thunderstorms should wane by around 06z, but scattered showers
are expected to continue through the night and into Sunday
morning.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning until 8 PM MDT this evening for WYZ425-428.
NE...None.

&&

$$

SHORT TERM...SF
LONG TERM...TJT
AVIATION...MN