154
FXUS65 KCYS 111003
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
403 AM MDT Sat May 11 2024

.KEY MESSAGES...

- Trending warmer through the weekend, but remaining unsettled
  with daily chances for showers and storms. Severe weather is
  not expected.

- Colder with widespread precipitation chances expected across
  much of SE Wyoming the Nebraska Panhandle on Wednesday.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 340 AM MDT Sat May 11 2024

Warmer temperatures and mostly clear skies today will bring a
welcome change from the chilly last few days. High temperatures
in the 60s to low 70s are expected across southeast Wyoming and
western Nebraska. While there are precipitation chances,
confidence is low in much accumulating rainfall as conditions
will be mostly dry across the High Plains. Any thunderstorms
that do develop will likely be relatively weak as HiRes guidance
is only showing CAPE values 100-300 J/kg and bulk shear 10-20
knots. The best chances for thunderstorm development is expected
to be along and south of the Interstate-80 corridor.

Sunday brings similar conditions to Saturday with high
temperatures just a few degrees warmer. However, as the low
pressure system currently positioned near the Four Corners
region drifts east, there is an additional push of low- level
moisture into far southeast Wyoming and the southern Nebraska
panhandle that will aid in the precipitation chances. Any
thunderstorms that do develop are still expected to be weak,
mainly tied to higher terrain and areas along and south of the
Interstate-80 corridor.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 340 AM MDT Sat May 11 2024

The long term forecast continues to show chances for isolated
afternoon thunderstorms, with better chances for more scattered to
widespread precipitation chances Tuesday and Wednesday. Temperatures
will continue to be warm Monday and Tuesday with temperatures likely
remaining in the upper 60s to low 70s. By midweek, we are tracking a
cold storm system that will push a potent cold front through the
region that will increase precipitation chances across the region as
well as bring cooler temperatures. We should trend toward drier
conditions with gradually warming temperatures toward the end of the
week.

By Sunday night, the slow churning upper level low pressure system
will be pushing east across western Nebraska/Kansas with the bulk of
the wrap around moisture and precipitation should be coming to an
end from west to east as the evening progresses. With the position
of the low pressure system we could see some easterly winds develop
that may keep some low clouds and drizzle in place across the
typical upslope regions during the early morning hours on Monday.

Monday looks be quiet day across the region as a weak upper level
ridge axis moves but this too will quickly move east of the region
throughout the day on Monday. We will see the benefits of some
warmer 700mb temperatures which will allow for temperatures to jump
into the 70s across much of SE Wyoming and the Nebraska Panhandle.

Heading into Tuesday models have shifted a bit on the overall
pattern across the region. Models are now showing a deeper trough
developing across western Montanta which will have a downstream
transition to to a SW flow across much of Wyoming, this deeper
trough also means the ridge will hold in place longer before getting
ejected to the east. The evolution of this trough becomes quite
messy with models initially pushing this feature in as a positively
tilted trough before pinching off a weak closed low over central
Utah with strong shortwave pushing out of eastern Montanta on
Wednesday. This secondary shortwave looks to push a cold front north
to south across the region bringing with it colder temperatures and
more widespread precipitation chances with the potential for some
high elevation mountain snow showers. This system looks to move
through the region quickly and it is looking like Wednesday may be
the only day of cold, wet weather as in the wake of this passing
shortwave, a ridge axis begins to nose eastward from the western
CONUS into our region that should dry the region out and bring back
some warmer temperatures.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 340 AM MDT Sat May 11 2024

VFR conditions expected to persist through the 12Z TAF period
with mostly clear skies and generally light winds overnight.
Saturday afternoon southeast Wyoming may see wind gusts 20 to 25
knots, weakening near sunset. In addition, there`s a chance for
an isolated shower/thunderstorm near KCYS, KLAR, and KSNY
between 18Z and 03Z, but confidence is low in direct TSRA at
the terminals.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.

&&

$$

SHORT TERM...LEG
LONG TERM...AW
AVIATION...LEG