Special Weather Statement, NWS Cheyenne, WY

Area Forecast Discussion
National Weather Service Cheyenne WY
516 PM MDT Fri May 29 2026

.KEY MESSAGES...

- An unsettled weather pattern will continue into the weekend
  with daily chances for afternoon/evening showers and
  thunderstorms.

- Strong to severe thunderstorms could be possible on Saturday.
  Storms may produce damaging winds and large hail.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 231 PM MDT Fri May 29 2026

Much of the low-level moisture we woke up to this morning has mixed
out, as dewpoints across SE Wyoming have dropped into the 40s east
of the Laramie Range thanks to heating/insolation. At the time of
this discussion, sites across the Nebraska Panhandle are seeing
surface dewpoints in the mid-50s and are beginning to see shallow
cumulus develop based on visible satellite imagery. SPC Mesoanalysis
currently shows MLCAPE of 500-1000 J/Kg east of the I-25 corridor
with some deeper reflectivity returns along and just north of the
Cheyenne Ridge. However with effective bulk shear of around 20
knots, supercells today are unlikely and storms are expected to be
rather short-lived. With plenty of near-surface vorticity combined
with 0-3 km lapse rates of 9.5 degC/km (nearly dry adiabatic), would
not be surprised to see a landspout tornado occur if a developing
updraft manages to sit atop a localized, terrain-induced boundary
under prevailing SE flow in the lee of the Cheyenne Ridge.
Otherwise, the main hazards with any stronger thunderstorms will be
gusty winds of 50-60 knots, small hail, and frequent lightning. We
should see most of the shower and thunderstorm activity move east of
Wyoming and the Nebraska Panhandle by 06Z as any rain-cooled air and
nocturnal cooling after sunset should erode most of our instability.

GOES-19 mid-level water vapor imagery is showing a robust negatively-
tilted shortwave trough located over the Desert Southwest that is
ejecting north and east and will become the main feature of interest
on Saturday, particularly for the Nebraska Panhandle, hence the
Storm Prediction Center placing much of Dawes County in a Day 2
slight risk for severe weather. A 45 knot 500 mb speed maximum is
expected to pivot around the base of the wave located over SE
Wyoming and Western Nebraska on Saturday afternoon, providing a
source for deep-layer vertical wind shear and the potential for
organized deep convection. Low-level theta-e advection will take
place during the day across the eastern Nebraska Panhandle ahead of
a weak dryline, with the strongest isodrosothermal gradient located
south of the Kansas-Nebraska border. In the warm sector, surface
dewpoints are expected to remain in the mid-50s per high resolution
ensemble guidance with temperatures expected to reach the upper 70s
to low 80s. The upstream shortwave trough is expected to initiate
showers and thunderstorms over the higher terrain around 18-20Z
before moving NE over lower elevations. With an effective bulk wind
difference of 25-30 knots combined with 1500-2000 J/Kg MLCAPE in the
warm sector, supercells remain possible across the Nebraska
Panhandle late afternoon into the evening hours. Forecast soundings
indicate LCLs around 1500m across the northern Nebraska Panhandle,
which is well within the realm (near the 50th percentile) of tornado
climatology. The main failure mode for tornadoes tomorrow will be
the lack of low-level shear, as 850 mb flow remains weak around 10-
15 knots before gradually ramping up to 20 knots after 03Z with the
onset of a weak low-level jet, however storms look to be elevated at
this time, therefore limiting the tornado threat. The main threats
tomorrow will be large hail and damaging winds, especially with any
sustained rotating updrafts where hail has a longer residence time
within the cloud (to allow for maximum accretion and growth). Storms
should begin to exit the Nebraska Panhandle after 06Z Sunday.

Focus shifts to high winds for our wind-prone areas of Wyoming late
Saturday night into Sunday morning. 700 mb cross-barrier flow
increases to 50 knots overnight, with in-house guidance continuing
to show Arlington with 65% probabilities of exceeding high wind
criteria into Sunday morning, with Bordeaux at about 40%. Model
cross-sections show a mountain-top stable layer with strong downward
omega signatures in the lee of the Snowy and Laramie Ranges, so
these probabilities for high winds seem appropriate at this
time.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 231 PM MDT Fri May 29 2026

The long term will remain as unsettled as the short term with near
daily chances of precipitation through at least mid-week. With
the upper-level trough responsible for Saturday's storm expected
to eject northeastward out if the area Sunday, precipitation
chances on Sunday will be rather slim. Lingering showers could
be possible for the northern Wyoming and Nebraska zones of the
forecast area as the system ejects into the Dakotas, but even
these chances look rather slim.

Precipitation chances will increase for the start of the work week
as the upper-level trough/low begins to retrograde back towards the
northwest. The rough location of the low over the Montana/Canada
border, will allow the CWA to once again tap into moisture from the
Gulf. Moisture-rich mid-level southerly flow will usher in the
necessary humidity to fuel storm develop during the afternoon and
evening. Lift will come in the form of vorticity maxes streaming
through the area from the trough to the north, as well as another
trough the enters the picture during the middle of next week. At
this point, global models seem fairly consistent on showing daily
storm chances east of the Laramie Range Monday through Thursday. A
quick look at model soundings for areas east of the Laramie Range
show moderate amounts of CAPE each afternoon as well as decent shear
most days. As a result, severe weather cannot be ruled out each
afternoon.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 514 PM MDT Fri May 29 2026

Isolated to scattered showers and thunderstorms are ongoing
across southeast Wyoming and western Nebraska. These showers and
storms are expected to continue for the next several hours,
though confidence is low in any specific terminal seeing
impacts. There is a line of storms just east of KCYS that is
slowly moving northwest and new storms continue to develop east
of KCYS. Confidence in these storms moving far enough west to
impact KCYS is low, as they have remained just off to the east.
After storms depart tonight, low ceilings are possible at KBFF,
KSNY, and KAIA due to excess moisture in these regions. Isolated
to patchy fog is also possible near these terminals, but
confidence is very low in it developing.

&&

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

&&

SHORT TERM...NB
LONG TERM...SF
AVIATION...AM

Special Weather Statement
National Weather Service Cheyenne WY
530 PM MDT Fri May 29 2026

WYZ108-300015-
Goshen County WY-
530 PM MDT Fri May 29 2026

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL GOSHEN COUNTY THROUGH
615 PM MDT...

At 529 PM MDT, Doppler radar was tracking a strong thunderstorm
capable of producing a landspout near Southern Hills Estates, or 7
miles southwest of Torrington, moving northwest at 25 mph.

HAZARD...Landspouts, wind gusts up to 50 mph, and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to outdoor objects is possible. Gusty winds
         could knock down tree limbs and blow around unsecured
         objects.

Locations impacted include...
Torrington, Lingle, Yoder, Huntley, Southern Hills Estates,
Torrington Municipal Airport, Veteran, and Goshen County Fairgrounds.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4195 10406 4187 10426 4213 10460 4227 10436
      4212 10416
TIME...MOT...LOC 2329Z 154DEG 20KT 4199 10427

LANDSPOUT...POSSIBLE
MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

Natoli

Special Weather Statement
National Weather Service Cheyenne WY
547 PM MDT Fri May 29 2026

NEZ020-300015-
Banner NE-
547 PM MDT Fri May 29 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN KIMBALL AND CENTRAL
BANNER COUNTIES THROUGH 615 PM MDT...

At 546 PM MDT, Doppler radar was tracking a strong thunderstorm
southeast of Harrisburg, moving northwest at 25 mph.

HAZARD...Wind gusts up to 40 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Harrisburg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4160 10393 4165 10355 4139 10345 4140 10372
TIME...MOT...LOC 2346Z 151DEG 21KT 4147 10362

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...40 MPH

Natoli

Special Weather Statement
National Weather Service Cheyenne WY
555 PM MDT Fri May 29 2026

WYZ107-108-300030-
East Platte County WY-Goshen County WY-
555 PM MDT Fri May 29 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHWESTERN GOSHEN AND
NORTHEASTERN PLATTE COUNTIES THROUGH 630 PM MDT...

At 555 PM MDT, Doppler radar was tracking a strong thunderstorm over
Fort Laramie, or 17 miles northwest of Torrington, moving northwest
at 20 mph.

HAZARD...Wind gusts up to 40 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Fort Laramie, Pine Ridge Estates, and Fort Laramie National Historic
Site.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4246 10449 4216 10432 4211 10448 4222 10466
      4241 10465
TIME...MOT...LOC 2355Z 143DEG 16KT 4219 10447

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

Natoli

Special Weather Statement
National Weather Service Cheyenne WY
600 PM MDT Fri May 29 2026

NEZ019-020-300030-
Scotts Bluff NE-Banner NE-
600 PM MDT Fri May 29 2026

...A STRONG THUNDERSTORM WILL IMPACT SOUTH CENTRAL SCOTTS BLUFF AND
NORTH CENTRAL BANNER COUNTIES THROUGH 630 PM MDT...

At 600 PM MDT, Doppler radar was tracking a strong thunderstorm near
Harrisburg, or 18 miles south of Scottsbluff, moving northwest at 20
mph.

HAZARD...Wind gusts up to 40 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Harrisburg and Wildcat Hills State Recreation Area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4156 10353 4151 10371 4163 10385 4180 10386
      4181 10359
TIME...MOT...LOC 0000Z 154DEG 18KT 4161 10366

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...40 MPH

Natoli

Special Weather Statement
National Weather Service Cheyenne WY
615 PM MDT Fri May 29 2026

NEZ003-095-096-300100-
Box Butte NE-North Sioux NE-South Sioux NE-
615 PM MDT Fri May 29 2026

...A STRONG THUNDERSTORM WILL IMPACT WESTERN BOX BUTTE...SOUTHERN
SIOUX AND NORTHEASTERN GOSHEN COUNTIES THROUGH 700 PM MDT...

At 614 PM MDT, Doppler radar was tracking a strong thunderstorm
capable of producing a landspout 11 miles southwest of Flahertys
Corner, or 25 miles north of Scottsbluff, moving north at 20 mph.

HAZARD...Landspouts, wind gusts up to 50 mph, and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to outdoor objects is possible. Gusty winds
         could knock down tree limbs and blow around unsecured
         objects.

Locations impacted include...
Agate Fossil Beds National Monument.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4217 10344 4211 10389 4238 10406 4246 10405
      4252 10350
TIME...MOT...LOC 0014Z 168DEG 18KT 4223 10364

LANDSPOUT...POSSIBLE
MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

Natoli

Special Weather Statement
National Weather Service Cheyenne WY
621 PM MDT Fri May 29 2026

NEZ019-300045-
Scotts Bluff NE-
621 PM MDT Fri May 29 2026

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL SCOTTS BLUFF AND
NORTHERN BANNER COUNTIES THROUGH 645 PM MDT...

At 621 PM MDT, Doppler radar was tracking a strong thunderstorm near
Gering, or near Scottsbluff, moving north at 20 mph.

HAZARD...Wind gusts up to 50 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

Locations impacted include...
Scottsbluff, Gering, Mitchell, Terrytown, Morrill, Wildcat Hills
State Recreation Area, Hubbard Hill, Lake Alice Number 2, Scotts
Bluff County Fairground, Scottsbluff Airport, Scotts Bluff National
Monument, and Lake Alice.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4169 10366 4170 10377 4196 10394 4200 10370
      4200 10355 4171 10352
TIME...MOT...LOC 0021Z 168DEG 17KT 4177 10366

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH

Natoli