206
FXUS65 KCYS 070445
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1045 PM MDT Sat Jun 6 2026

.KEY MESSAGES...

- Near record high temperatures and elevated to critical fire
  weather conditions are anticipated this weekend.

- A Marginal Risk (1/5) of severe weather expected on Sunday for
  east-central Wyoming and the Nebraska Panhandle, with gusty
  winds and large hail the main threats.

- Expect a quick cool down on Monday before heat builds back into
  the area towards the middle of next week.

- There is potential for widespread critical fire weather conditions
  on Tuesday and Wednesday.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 240 PM MDT Sat Jun 6 2026

Current observations across the region show a pleasant and very
warm Saturday afternoon with temperatures well into the 80s for
most of the area, and low to mid 90s over the lower elevations
east of Interstate 25. A few lines of light showers are
currently on KCYS radar (likely not reaching the ground), with
some observations over Carbon and Albany counties showing wind
gusts over 40 MPH. Decided to get ahead of this and issue a
Special Weather Statement for brief gusty winds over 50 MPH.
This will mainly impact travel through the afternoon. Otherwise,
kept isolated thunderstorms in the forecast for the eastern
plains through this evening, mainly along and east of the
Laramie Range where the "better" moisture profiles are located.
Primary threat will be locally strong gusty winds into late this
evening. Windy conditions will continue over parts of western
Nebraska late this evening, mainly due to the low level jet
across the plains.

Another very warm day expected on Sunday and only a few degrees
cooler, at best, with highs in the 80s to near 90 along and west
of the I-25 corridor...and widespread mid 90s east of I-25 into
western Nebraska. Expect mostly dry weather, but can`t rule out
a few thunderstorms across the higher terrain and the western
Nebraska Panhandle. There is Marginal Risk of strong to severe
thunderstorms north of the North Platte River valley with the
best chance located north of Highway 20 over east central
Wyoming and the northern Nebraska Panhandle. Not seeing much of
a threat during the day with inverted-V soundings in the
afternoon, but it may end up being a late evening/overnight show
up north with outflow boundary interaction and MUCAPE>1500 j/kg
resulting in elevated thunderstorms after 1000 pm. In addition,
a weak to moderate low level jet across the plains may linger
into late Sunday evening. However, other than outflow boundary
interaction, there is not much forcing present as any shortwave
will likely eject eastward earlier in the day with the afternoon
t-storm activity.

For Monday, a weak cool front (likely thunderstorm outflow) will
push south early in the morning with winds briefly shifting to
the north. High temperatures will be around 5 to 10 degrees
cooler compared to this weekend. Thunderstorm activity is
expected to shift southwest, closer to where the remnant cool
front boundary will be located through the afternoon. Kept POP
around 20 to 35 percent for widely scattered/scattered thunderstorm
activity along and near the Laramie Range and across most of
the I-80 and I-25 corridors. With increasing low to midlevel
shear, will have to monitor the potential for another afternoon
of strong to marginally severe thunderstorms, mainly east of
I-25.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 203 PM MDT Sat Jun 6 2026

Monday night into Tuesday, A negatively tilted trough
pushes through the Rocky mountains giving us some weak jetstream
dynamic support while in southwest flow. The system will advect in
some moisture at the mid-levels during this time giving us some
shower potential in the afternoon. However, the model soundings
aren`t to convincing as they show a stout residual dry layer near
the surface and a capped environment that may put a pause to any
convection and prevent any rain from reaching the surface. As this
low pressure system begins to become stacked Tuesday into Wednesday,
the Intermountain West switches from southerly flow to a downsloping
westerly flow. This will lead to the continuation of warmer
temperatures, but also a more likely chance to break the cap when
combined with the progged frontal boundary moving through in the
afternoon. Our windiest day looks to be Wednesday as the 700mb ramps
up to about 50 knots by the afternoon giving us gusty winds but not
enough to meet the high wind criteria. By Thursday and area of high
pressure looks to build in that may stay through the weekend. Fire
Weather remains a concern throughout the long term as RH values look
to bounce between 15 and 20 percent and some isolated places
dropping as low as 10 percent. The severe chances look minimal
through the long term as the stout dry layer looks to stick around
with minimal CAPE when glancing at the global model soundings.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 1044 PM MDT Sat Jun 6 2026

Showers and thunderstorms are winding down this evening into the
overnight period as the boundary layer stabilizes and decouples. VFR
conditions will prevail throughout the TAF period with CIGs aoa 20
kft with mostly dry conditions. There is a 35-40 knot SE low-level
jet impacting the Nebraska terminals, and have mentioned LLWS mainly
for KBFF where there is the greatest directional shear. For the
Wyoming terminals, winds are expected to increase to 20-25 knots
mainly at KLAR and KRWL, with gusts as high as 40 knots after 15Z.
This is in response to lee cyclogenesis occurring east of the I-25
corridor, increasing gradient flow.

&&

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

&&

$$

SHORT TERM...TJT
LONG TERM...MM
AVIATION...NB