Severe Thunderstorm Warning 39, NWS Cheyenne, WY

483 
WWUS55 KCYS 012344
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Severe Weather Statement
National Weather Service Cheyenne WY
544 PM MDT Mon Jun 1 2026

NEC013-123-020045-
/O.CON.KCYS.SV.W.0039.000000T0000Z-260602T0045Z/
Box Butte NE-Morrill NE-
544 PM MDT Mon Jun 1 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM MDT
FOR SOUTHEASTERN BOX BUTTE AND MORRILL COUNTIES...

At 543 PM MDT, severe thunderstorms were located along a line
extending from 9 miles southwest of Berea to 11 miles east of Angora
to Northport, moving east at 50 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Public.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Alliance, Bridgeport, Bayard, Broadwater, Northport, Bridgeport State
Recreation Area, Angora, Morrill County Fairgrounds, Chimney Rock
National Historic Site, Courthouse And Jail Rock, Redington, Alliance
Municipal Airport, The Intersection Of Highway 385 And 92, The
Intersection Of Highway 385 And L62, and South Bayard Junction.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

For your protection move to an interior room on the lowest floor of a
building.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

&&

LAT...LON 4183 10323 4186 10311 4215 10322 4222 10274
      4210 10274 4209 10271 4201 10270 4200 10267
      4179 10268 4174 10266 4174 10264 4149 10264
      4159 10337 4180 10336 4182 10323
TIME...MOT...LOC 2343Z 267DEG 43KT 4208 10308 4190 10292 4171 10310 

TORNADO...POSSIBLE
HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Natoli

299 
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Severe Weather Statement
National Weather Service Cheyenne WY
609 PM MDT Mon Jun 1 2026

NEC013-123-020045-
/O.CON.KCYS.SV.W.0039.000000T0000Z-260602T0045Z/
Box Butte NE-Morrill NE-
609 PM MDT Mon Jun 1 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM MDT
FOR SOUTHEASTERN BOX BUTTE AND NORTHEASTERN MORRILL COUNTIES...

At 609 PM MDT, severe thunderstorms were located along a line
extending from Alliance to 12 miles south of Alliance Municipal
Airport to 7 miles east of Northport, moving east at 30 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Alliance, Broadwater, and Alliance Municipal Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

For your protection move to an interior room on the lowest floor of a
building.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

&&

LAT...LON 4184 10293 4219 10297 4220 10289 4220 10287
      4218 10274 4210 10274 4209 10271 4201 10270
      4200 10267 4179 10268 4174 10266 4174 10264
      4157 10264 4159 10293 4164 10307 4181 10308
TIME...MOT...LOC 0009Z 262DEG 27KT 4211 10286 4187 10280 4171 10296 

TORNADO...POSSIBLE
HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Natoli

618 
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Severe Weather Statement
National Weather Service Cheyenne WY
631 PM MDT Mon Jun 1 2026

NEC013-020041-
/O.CAN.KCYS.SV.W.0039.000000T0000Z-260602T0045Z/
Box Butte NE-
631 PM MDT Mon Jun 1 2026

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN BOX BUTTE COUNTY
IS CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 800 PM MDT for
the Panhandle of Nebraska.

&&

LAT...LON 4159 10292 4166 10283 4179 10280 4200 10282
      4201 10268 4178 10268 4174 10266 4174 10264
      4158 10264
TIME...MOT...LOC 0031Z 256DEG 16KT 4188 10270 4173 10270 4161 10279 

$$

NEC123-020045-
/O.CON.KCYS.SV.W.0039.000000T0000Z-260602T0045Z/
Morrill NE-
631 PM MDT Mon Jun 1 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM MDT
FOR NORTHEASTERN MORRILL COUNTY...

At 631 PM MDT, severe thunderstorms were located along a line
extending from 13 miles southeast of Alliance Municipal Airport to 15
miles west of Crescent Lake National Wildlife Refuge to near
Broadwater, moving east at 20 mph.

HAZARD...Ping pong ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Broadwater.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

For your protection move to an interior room on the lowest floor of a
building.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. These storms may cause serious injury and significant
property damage.

&&

LAT...LON 4159 10292 4166 10283 4179 10280 4200 10282
      4201 10268 4178 10268 4174 10266 4174 10264
      4158 10264
TIME...MOT...LOC 0031Z 256DEG 16KT 4188 10270 4173 10270 4161 10279 

TORNADO...POSSIBLE
HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Natoli

890 
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Severe Weather Statement
National Weather Service Cheyenne WY
642 PM MDT Mon Jun 1 2026

NEC123-020052-
/O.EXP.KCYS.SV.W.0039.000000T0000Z-260602T0045Z/
Morrill NE-
642 PM MDT Mon Jun 1 2026

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN MORRILL COUNTY
WILL EXPIRE AT 645 PM MDT...

The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.  However, heavy
rain is still possible with these thunderstorms.

A Severe Thunderstorm Watch remains in effect until 800 PM MDT for
the Panhandle of Nebraska.

&&

LAT...LON 4159 10292 4166 10283 4179 10280 4200 10282
      4201 10268 4178 10268 4174 10266 4174 10264
      4158 10264
TIME...MOT...LOC 0042Z 270DEG 33KT 4190 10258 4175 10258 4163 10267 

$$

Natoli

Area Forecast Discussion
National Weather Service Cheyenne WY
1233 PM MDT Mon Jun 1 2026

.KEY MESSAGES...

- Monday & Tuesday bring another chance for strong to severe
  thunderstorms in the afternoon and evening. There is a slight
  risk (level 2 of 5) across the eastern high plains on both
  days. Large hail, severe wind, and an isolated tornado
  possible.

- A warming and slight drying trend appears likely after
  Wednesday with temperatures climbing into the 80s by later in
  the week and during next weekend.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 1230 PM MDT Mon Jun 1 2026

After some morning showers and thunderstorms that produced hail,
storminess will continue into the afternoon as daytime heating
begins to further destabilize the atmosphere. A stagnant upper-level
low over the Montana/Canada border will allow the CWA to tap into
moisture from the Gulf. Moisture-rich low-level southerly flow will
usher in the necessary humidity needed to fuel storm development
during the afternoon and evening. Lift will come in the form of
vorticity maxes streaming through the area from the trough to the
north. Moderate instability this afternoon with MUCAPE values around
1500 J/kg will create an environment capable of producing severe
storms east of the Laramie Range. Hi-Res guidance shows initially
discrete cells, with effective shear and steep mid-level lapse rates
supporting a large hail threat. As the afternoon progresses into
evening, more outflow dominant storms will lead to a severe wind
threat. Storms will move out of the Nebraska panhandle rather
quickly this evening, with most storms expected to be out of the
area by 9 PM. A few lingering storms could be possible overnight,
but the severe threat will be long gone by then.

With the upper-level low still stuck over the Montana/Canada border,
a similar set up is forecast for Tuesday. The environment remains
largely the same, although with a few small, but important changes.
Model soundings show a lot more instability in the Nebraska
panhandle Tuesday afternoon with MUCAPE values of 2500 J/kg and
higher. However, shear values are rather unimpressive with weak low-
level and effective shear. On top of that, a strong capping
inversion seems to persist through most of the afternoon. Hi-Res
guidance shows storms forming off the high terrain per usual, but
not necessarily strengthening as they enter the more favorable
environment. They are likely also catching onto the cap that
may be in place. Soundings do show the cap eroding by the
evening hours. This is also when the HRRR shows another round of
convection developing off the high terrain and pushing eastward
into the Wyoming high plains, and into the Nebraska panhandle
overnight. These storms do appear stronger, as instability will
persist into the overnight hours. As a result, cannot rule out
severe nocturnal convection from about 8 PM Tuesday through 1 AM
Wednesday. Primary hazards will once again be large hail in
initial discrete cells, transitioning to more of a wind threat
as convection becomes a bit more organized.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 150 PM MDT Sun May 31 2026

We remain under SW flow aloft upstream of a high amplitude
positively-tilted ridge centered over Ontario and the Great Lakes
region, resulting in mostly dry and above-average temperatures
heading into the second half of the week. Thanks to trajectories
stemming from the Gulf of Mexico, PWAT over SE Wyoming and W
Nebraska will be in the 80th-90th percentile relative to
climatology. This will allow for daily chances of showers and
thunderstorms despite the absence of any large-scale forcing for
ascent. Despite anomalously high PWAT, long range ensemble
forecast soundings continue to show large dewpoint depressions
at the surface and inverted-V profiles, so any showers or storms
will likely produce far more wind than any beneficial moisture.
The threat for any severe weather looks to remain low towards
the end of the week as deep-layer shear is weak due to the lack
of mid and upper level flow. Going into the weekend, high
temperatures are expected to push 80 degrees west of the I-25
corridor, with even a few 90s for our Nebraska counties as we
remain under longwave ridging through the end of the long term
period.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1145 AM MDT Mon Jun 1 2026

Primary forecast concern today will be the potential for strong and
severe thunderstorms for the high plains terminals. Upper level
disturbance over the Great Basin region will rapidly eject eastward
over the area this afternoon and this evening. Scattered showers and
thunderstorms are expected ahead of this disturbance with strong
winds, hail, heavy rainfall, and frequent lightening possible.

HAZARDS/WEATHER TRENDS: VFR conditions will prevail until 09z late
tonight (low CIGS). Brief IFR or LIFR conditions expected with the
heaviest thunderstorms, but will keep in PROB30 groups until
convection develops over the next few hours with increasing
confidence.

For tonight, attention shifts to low CIGS and possibly some fog,
depending on how much rain (and how widespread) falls today. Added
IFR CIGS for KSNY, KAIA, KBFF after 09z Tuesday. These conditions
are possible at KCDR and KCYS as well, but confidence is lower.

&&

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

&&

SHORT TERM...SF
LONG TERM...NB
AVIATION...MM

Special Weather Statement
National Weather Service Cheyenne WY
336 PM MDT Mon Jun 1 2026

WYZ117>119-012230-
Central Laramie County WY-South Laramie Range Foothills WY-
East Laramie County WY-
336 PM MDT Mon Jun 1 2026

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN LARAMIE COUNTY
THROUGH 430 PM MDT...

At 336 PM MDT, Doppler radar was tracking a strong thunderstorm over
Natural Fort, or 13 miles south of Cheyenne, moving northeast at 40
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...
Cheyenne, Burns, Egbert, Laramie County Fairgrounds at Archer,
Hillsdale, Fox Farm-College, Cheyenne Regional Airport, Winchester
Hills, South Greeley Highway, Ranchettes, Warren AFB, Frontier Park,
North Cheyenne, South Cheyenne, Bison Crossing, Grass Hills, and
Cowboy Ranch South.

This includes the following highways...
 Interstate 25 in Wyoming between mile markers 1 and 17.
 Interstate 80 in Wyoming between mile markers 356 and 390.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 800 PM MDT for
southeastern Wyoming.

&&

LAT...LON 4100 10502 4140 10471 4118 10423 4100 10460
TIME...MOT...LOC 2136Z 219DEG 34KT 4096 10489

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

Natoli

Preliminary Local Storm Report
National Weather Service Cheyenne WY
351 PM MDT Mon Jun 1 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0350 PM     Hail             8 SW South Greeley High 41.00N 104.91W
06/01/2026  M1.00 Inch       Laramie            WY   Trained Spotter

            Trained spotter reports quarter sized hail
            along Interstate 25.

&&

Preliminary Local Storm Report
National Weather Service Cheyenne WY
359 PM MDT Mon Jun 1 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0356 PM     Hail             1 S Cheyenne            41.13N 104.80W
06/01/2026  E1.00 Inch       Laramie            WY   Public

            Report from mPING: Quarter (1.00 in.).

&&

Preliminary Local Storm Report
National Weather Service Cheyenne WY
408 PM MDT Mon Jun 1 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0359 PM     Hail             1 SW Cheyenne           41.13N 104.81W
06/01/2026  E0.75 Inch       Laramie            WY   Public

            Report from mPING: Dime (0.75 in.).

0400 PM     Hail             2 E Cheyenne            41.15N 104.76W
06/01/2026  E1.00 Inch       Laramie            WY   Public

            Report from mPING: Quarter (1.00 in.).

0402 PM     Hail             2 NW South Greeley High 41.12N 104.83W
06/01/2026  E1.00 Inch       Laramie            WY   Public

            Report from mPING: Quarter (1.00 in.).

0404 PM     Hail             7 E North Cheyenne      41.18N 104.67W
06/01/2026  E0.50 Inch       Laramie            WY   Public

            Report from mPING: Half-inch (0.50 in.).

&&

Preliminary Local Storm Report
National Weather Service Cheyenne WY
437 PM MDT Mon Jun 1 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0433 PM     Tornado          9 NE Mitchell           42.03N 103.68W
06/01/2026                   Sioux              NE   Storm Chaser

            Storm chaser reports broad circulation on
            the ground. Another spotter in the area
            reported a brief funnel around the same
            time.

&&

Preliminary Local Storm Report
National Weather Service Cheyenne WY
524 PM MDT Mon Jun 1 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0441 PM     Tstm Wnd Gst     4 WNW Terrytown         41.87N 103.74W
06/01/2026  M61 MPH          Scotts Bluff       NE   Mesonet

            UPR site gust 61 MPH.

&&