588
FXUS65 KCYS 012336
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
536 PM MDT Tue Jul 1 2025

.KEY MESSAGES...

- There is a Marginal to Slight Risk of strong to severe thunderstorms
  this afternoon for portions of western Nebraska and far
  eastern Wyoming.

- Warm temperatures and daily chances for PM showers and
  thunderstorms will continue late this week and into next
  weekend.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 1249 PM MDT Tue Jul 1 2025

A mid to upper level shortwave will kick off thunderstorms this
afternoon. Most of the Panhandle is in a Marginal Risk as
dewpoints and shear are more favorable in that area. The far
eastern portion of the panhandle of our CWA is in a slight as
the thunderstorms are likely to intensify the further east the
storms travel. Effective shear looks to range between 25 to
35kts with 1000-2000 joules of CAPE. These storms if they do
develop are likely to be messy and pulsy as the shear and mid
level lapse rates of 7.5C are quite lackluster. However,
looking at model soundings severe winds and hail look to be the
main threats as the classic inverted v soundings are displayed
by the models. Later in the evening, a developing low level jet
may enhance this thunderstorm activity, but most of the
activity may be moving into central Nebraska by then.

For Wednesday and Thursday, a pretty typical summer weather
pattern sets up across the region as a slow moving upper level
ridge moves east of the area. High temperatures will remain in
the 80s west of I-25, and upper 80s to mid 90s east of I-25.
Secondary 590 dm ridge axis will push into the area Wednesday.
With increasing midlevel subsidence and the lack of any notable
forcing, kept mention of precipitation west of the Laramie
Range. Showers and thunderstorms will return to most of the
region on Thursday as a broad eastern Pacific trough moves into
the Great Basin Region and finally into the Intermountain West
Thursday afternoon. This feature is expected to bring some
subtropical moisture to the area as PWATs increase between 1.00
to 1.50 inches. Continued to increase POP across southeast
Wyoming with some heavy rainfall possible. High temperatures
will be slightly cooler Thursday afternoon due to cloud cover,
but still near or slightly above average for this time of the
year.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Issued at 455 AM MDT Tue Jul 1 2025

Models show the pacific upper level trough continuing to lift
northeast across the area Friday with another round of showers
and thunderstorms. Thunderstorm coverage is forecast to lower
this weekend due to the lack of forcing as weak zonal flow
develops across the Intermountain west and across the Rocky
Mountain Region.

Temperatures remain in the upper 70`s to the mid 80`s across the
forecast area. 700mb temperatures stay around 16 celsius which
translate surface temperatures into the low to mid 80`s for the
lower elevations and upper 70`s to low 80`s for our more mountainous
regions.

As we head into next week, models show another slow warming
trend as a 595 to 600dm upper level high develops near the four
corners region. The position of this high is a bit far south, so
any shortwave activity digging south of of Canada will be enough
to trigger showers and thunderstorms each afternoon. Kept
thunderstorms in the forecast Monday and Tuesday as all models
do not show this upper level high drifting northward until the
middle of next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 524 PM MDT Tue Jul 1 2025

Wyoming Terminals...

Lingering shower activity is expected through 03Z near KCYS and 01z
near KLAR, with southeast wind gusts to 20kts in the showers. Gusty
southeast winds will then continue for a few more hours at KLAR
before easing. VFR conditions will prevail. Main concern for
Wednesday will be a return of gusty winds around 20kts at the WY
terminals.

Nebraska Terminals...

Isolated to scattered showers and thunderstorms are ongoing
across the Panhandle this evening with gusty and erratic winds
in and around these storms. Storms will continue for the next 1
to 4 hours, though confidence is low that any storm will
directly impact a terminals. Therefore, kept PROB30 groups in
for the Nebraska TAF sites. Skies clear overnight with winds
decreasing. Winds increase once more late morning into the
afternoon tomorrow ahead of another round of isolated showers
and storms.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...High Wind Watch until 6 PM MDT this evening for WYZ109-110.
NE...None.

&&

$$

SHORT TERM...TJT/MM
LONG TERM...TJT/MM
AVIATION...AM/RJM