346
FXUS65 KCYS 270513
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1113 PM MDT Thu Jun 26 2025

.KEY MESSAGES...

- Fire weather conditions are probable for Western portion of
  the forecast area tomorrow.

- Warm temperatures and daily coverage of scattered afternoon
  and evening showers and thunderstorms expected for the weekend
  through Thursday.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 235 PM MDT Thu Jun 26 2025

Looking at Water Vapor imagery, there`s a lot of dry air at the
lower levels that keeps us from getting some scattered showers as a
small shortwave pushes through the intermountain west later this
afternoon/evening. There may be quick isolated showers as some
moisture floats in from the midlevels as seen on water vapor, but
it`s uncertain if it will be enough to spark anything. Most of the
more abundant water vapor is still shown to be in the Pacific
Northwest. As the shortwave moves through there may be around a
couple hundred joules of CAPE still left but doesn`t look like it
may be enough to produce anything strong or severe. A few bolts of
lightning may still be generated along with some thunder and light
rain. Models depict most of these showers will be contained in the
mountains if they were to develop. Friday, Looks to be almost the
same scenario as a weak shortwave looks to push through the
Intermountain West. Friday, will also be a little bit warmer with
temperatures in the 80`s east of I-25 and in the 70`s possibly 80`s
in the mountains. There is a little more CAPE especially in the
Panhandle with progged values around 1000-1500 j/kg. However, most
models have the storms developing mostly in the Panhandle where the
moisture is a little better with the higher CAPE values. SPC did
issue a Marginal risk for the southern panhandle as most of the
convection seems to develop late, strengthen quickly but also move
out of our CWA quickly as well. There are some embedded vort-maxes
that will move with the shortwave but it`s uncertain if the timing
of the forcing will line up with our diurnal heating and moisture.
The winds will be a little gusty and the RH values are forecasted to
be below 15 percent so a fire weather watch was also issued for
Carbon county Friday as well since their fuels were reported to be
turned over already due to the lack of rain in that county.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 235 PM MDT Thu Jun 26 2025

Saturday...Zonal flow aloft continues. Another warm day expected
with 700 mb temperatures near 15 Celsius, yielding high temperatures
from the mid 80s to mid 90s. With a shortwave trough overhead, and
low level convergence noted near the Wyoming and Nebraska state
line, we anticipate isolated to scattered afternoon and evening
showers and thunderstorms along and east of I-25.

Sunday...Somewhat cooler temperatures in the wake of a cold front
and with an increase in cloud cover. Looks like adequate low and mid
level moisture for scattered late day showers and thunderstorms,
mainly east of I-25.

Monday...Temperatures about the same as on Sunday, with low level
upslope east winds and 700 mb temperatures near 11 Celsius. Despite
adequate low and mid level moisture, we may see a decrease in
coverage of showers and thunderstorms due to ridging aloft.

Tuesday...A warming trend develops as 700 mb temperatures rise to
near 13 Celsius. Adequate moisture aloft for isolated to scattered
late day showers and thunderstorms, mainly east of I-25.

Wednesday...The warming trend continues as 700 mb temperatures reach
14 Celsius. Moisture looks a bit more prevalent than Tuesday, thus
we should see an increase in convective coverage, including west of
I-25.

Thursday...Similar temperatures to Wednesday with 700 mb
temperatures near 14 Celsius. Adequate low and mid level moisture
again, thus scattered late day showers and thunderstorms
expected.&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1112 PM MDT Thu Jun 26 2025

Calm conditions overnight through the early morning hours as
light winds and clear skies prevail. With residual moisture
remaining across western Nebraska, some light fog will be
possible at KBFF, KCDR, and KAIA overnight, though confidence
remains low given the relatively stronger surface winds. Cloud
cover increases through the late morning and early afternoon
hours with isolated showers and storms drifting across much of
southeast Wyoming and western Nebraska. Confidence is low at
this time in any of these showers impacting terminals, but
included best estimate for timing on any showers that develop
this afternoon.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Fire Weather Watch Friday afternoon for WYZ421>423-425-427.
NE...None.

&&

$$

SHORT TERM...MM
LONG TERM...RUBIN
AVIATION...AM