Tornado Warning 18, NWS Cheyenne, WY

902 
WWUS55 KCYS 220240
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
840 PM MDT Fri Aug 21 2026

NEC033-105-220300-
/O.CON.KCYS.TO.W.0018.000000T0000Z-260822T0300Z/
Cheyenne NE-Kimball NE-
840 PM MDT Fri Aug 21 2026

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 900 PM MDT FOR
SOUTHWESTERN CHEYENNE AND EASTERN KIMBALL COUNTIES...

At 839 PM MDT, a severe thunderstorm capable of producing a tornado
was located near Potter, or 16 miles east of Kimball, moving south at
30 mph.

HAZARD...Tornado and tennis ball size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This tornadic thunderstorm will remain over mainly rural areas of
southwestern Cheyenne and eastern Kimball Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4136 10347 4135 10325 4100 10315 4100 10331
      4101 10353
TIME...MOT...LOC 0239Z 357DEG 24KT 4114 10336 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...2.50 IN

$$

Natoli

814 
WWUS55 KCYS 220247
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
847 PM MDT Fri Aug 21 2026

NEC033-105-220300-
/O.CON.KCYS.TO.W.0018.000000T0000Z-260822T0300Z/
Cheyenne NE-Kimball NE-
847 PM MDT Fri Aug 21 2026

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 900 PM MDT FOR
SOUTHWESTERN CHEYENNE AND SOUTHEASTERN KIMBALL COUNTIES...

At 846 PM MDT, a severe thunderstorm capable of producing a tornado
was located 8 miles south of Potter, or 18 miles southeast of
Kimball, moving south at 25 mph.

HAZARD...Tornado and tennis ball size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

This tornadic thunderstorm will remain over mainly rural areas of
southwestern Cheyenne and southeastern Kimball Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

&&

LAT...LON 4118 10343 4119 10325 4100 10317 4100 10331
      4101 10350
TIME...MOT...LOC 0246Z 355DEG 21KT 4110 10335 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...2.50 IN

$$

Natoli

328 
WWUS55 KCYS 220258
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
858 PM MDT Fri Aug 21 2026

NEC033-105-220308-
/O.EXP.KCYS.TO.W.0018.000000T0000Z-260822T0300Z/
Cheyenne NE-Kimball NE-
858 PM MDT Fri Aug 21 2026

...THE TORNADO WARNING FOR SOUTHWESTERN CHEYENNE AND SOUTHEASTERN
KIMBALL COUNTIES WILL EXPIRE AT 900 PM MDT...

The tornado threat has diminished and the Tornado Warning has been
cancelled. However, large hail and damaging winds remain likely and a
Severe Thunderstorm Warning remains in effect for the area.

A Severe Thunderstorm Watch remains in effect until 1100 PM MDT for
the Panhandle of Nebraska.

&&

LAT...LON 4118 10343 4119 10325 4100 10317 4100 10331
      4101 10350
TIME...MOT...LOC 0258Z 355DEG 21KT 4104 10334 

$$

Natoli

Area Forecast Discussion
National Weather Service Cheyenne WY
525 PM MDT Fri Aug 21 2026

.KEY MESSAGES...

- Precipitation chances return by this weekend, with the
  possibility of widespread rain on Saturday.

- Daily shower and storm chances continue Monday through the
  end of the week with slightly above average temperature
  expected until Thursday.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 131 PM MDT Fri Aug 21 2026

A bit of uncertainty in the forecast for this afternoon and evening
regarding storm chances. Upper-level ridging over the west continues
to shift eastward into Wyoming today. This will produce strong
subsidence which will work to counteract storms. However, model
soundings and mesoanalysis show quite a bit of instability,
especially east of the Laramie Range. Satellite thus far has
been unimpressive, showing flat topped cumulus fields mainly
around Cheyenne and Laramie. A few isolated instances of
vertical growth have been observed, but have quickly fallen
apart due to the presence of MLCIN. Mesoanalysis does have CIN
eroding away within the next few hours, so it is possible that
by late afternoon and evening, storms could develop given the
instability and lift from a weak upper-level disturbance. Most
CAMs aren't too exited about storms today. The HRRR has been the
most bullish, but also the most uncertain, flip flopping back
and forth between lots of storms and barely any storms. However,
newest runs of the HRRR seem to be more believable, showing
convection developing this evening over the high terrain and
pushing into the panhandle where it strengthens due to higher
instability. If this is the case, a severe thunderstorm or two
could be possible. Both strong winds and large hail cannot be
ruled out in storms with DCAPE over 1000 J/kg and MUCAPE around
1500 J/kg. Any storms that develop will move out of the area by
midnight tonight, however, cannot rule out nocturnal convection
developing in the panhandle after this. Increased moisture into
the area from precipitation as well as weak southeast flow,
could cause low stratus and patchy fog east of the Laramie Range
early Saturday morning.

The forecast for Saturday looks more certain, with greater chances
for precipitation. Another weak shortwave moving through the ridge
will provide the needed lift and monsoon moisture for storms to
develop. Model soundings show decent instability once again, which
could lead to marginally severe storms. Hi-Res guidance shows widely
scattered storms developing during the mid-afternoon and continuing
through the evening hours. Most hazards will be possible in storms,
including heavy rain due to PWATs in the 90th percentile, large
hail, and strong winds. Hi-Res guidance does show lingering showers
across the area Saturday night, however these should not cause
impacts. Similar conditions are expected on Sunday with another
round of scattered storms. PWATs and instability are weaker on
Sunday, so severe storms are unlikely at this time. Due to less
moisture, models are also hinting at lower coverage of storms on
Sunday.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 131 PM MDT Fri Aug 21 2026

Monday...Coverage of afternoon and evening showers and thunderstorms
increases somewhat by an increase in monsoonal moisture and lowering
700 mb temperatures providing less convective inhibition, CIN,
compared to Sunday. As is this type of pattern, afternoon convection
will be over and near the mountains due to differential heating and
orographic effects, with the activity spreading across the rest of
the forecast area before dissipation by late evening. Warmer
temperatures compared to the previous day due to less cloud cover
and convective coverage.

Tuesday...Similar pattern synoptically to Monday with minor
perturbations in the flow aloft aiding in lift of monsoonal moisture
to produce widely scattered to scattered afternoon convection over
and near our Snowy, Sierra Madre and northern Laramie Ranges, with
the activity spreading eastward across the rest of the forecast area
in the evening. Some lowering of mid level temperatures suggests
daytime maximum temperatures will be a little cooler.

Wednesday...The primary change compared to Tuesday, will be a
reinforcement of the ridge aloft axis over Wyoming, inducing a
return to upslope mechanical lift aiding the areal increase of
showers and thunderstorms, especially east of the mountains and
along the I-25 corridor and eastward. Slight warming trend with 700
mb temperatures near 13 Celsius yielding high temperatures in the
80s.

Thursday-Friday...Monsoonal moisture becomes a bit more scant with
decent westerly flow aloft and with warm temperatures aloft
producing more convective inhibition, CIN, to limit development. A
slight warming trend continues based on mid level, 700 mb
temperature trends.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 525 PM MDT Fri Aug 21 2026

Tricky aviation forecast for this period, especially across the
Nebraska Panhandle with showers and thunderstorms rolling through
and the possibility for further development. Do to low confidence on
placement and coverage, kept TS out of the TAFs for the most part
and expect AMDs if further development occurs. For the southeast
Wyoming terminals, scattered showers and storms are pushing
southeast across the region and will continue for the next several
hours. In any storm activity, winds could become erratic and gusty.
There is also the threat for GR in any thunderstorm activity, this
could bring additional aviation hazards. After everything
clears, with the added moisture and wind direction, VIS and CIG
reduction is possible overnight for the Nebraska sites.

&&

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

&&

SHORT TERM...SF
LONG TERM...RUBIN
AVIATION...RZ

Preliminary Local Storm Report
National Weather Service Cheyenne WY
616 PM MDT Fri Aug 21 2026

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

0602 PM     Tstm Wnd Gst     10.1 ESE Box Butte Dam  42.39N 102.90W
08/21/2026  M62 MPH          Box Butte          NE   Public

            Personal weather station.

&&

Preliminary Local Storm Report
National Weather Service Cheyenne WY
617 PM MDT Fri Aug 21 2026

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

0537 PM     Tstm Wnd Gst     7 SE Chadron State Park 42.61N 102.90W
08/21/2026  M58 MPH          Dawes              NE   Public

            Personal weather station.

&&

Special Weather Statement
National Weather Service Cheyenne WY
622 PM MDT Fri Aug 21 2026

WYZ117-118-220045-
Central Laramie County WY-South Laramie Range Foothills WY-
622 PM MDT Fri Aug 21 2026

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN LARAMIE COUNTY
THROUGH 645 PM MDT...

At 622 PM MDT, Doppler radar was tracking a strong thunderstorm over
North Cheyenne, or near Cheyenne, moving east at 30 mph.

HAZARD...Wind gusts up to 50 mph and pea 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, 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.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 4115 10503 4132 10487 4126 10444 4100 10462
      4100 10482
TIME...MOT...LOC 0022Z 292DEG 26KT 4122 10484

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

Natoli

Special Weather Statement
National Weather Service Cheyenne WY
640 PM MDT Fri Aug 21 2026

WYZ107-108-220130-
East Platte County WY-Goshen County WY-
640 PM MDT Fri Aug 21 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHWESTERN GOSHEN AND EAST
CENTRAL PLATTE COUNTIES THROUGH 730 PM MDT...

At 639 PM MDT, Doppler radar was tracking a strong thunderstorm near
Hartville, or 28 miles northeast of Wheatland, moving east at 25 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...
Fort Laramie, Hartville, Pine Ridge Estates, Guernsey State Park,
Fort Laramie National Historic Site, and Hwy 85 At Dry Rawhide Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4232 10482 4243 10469 4245 10417 4211 10437
TIME...MOT...LOC 0039Z 283DEG 22KT 4237 10462

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

Natoli

Preliminary Local Storm Report
National Weather Service Cheyenne WY
718 PM MDT Fri Aug 21 2026

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

0650 PM     Hail             8 NE Bayard             41.84N 103.21W
08/21/2026  M2.75 Inch       Morrill            NE   Storm Chaser

0707 PM     Hail             2 NNE Bayard            41.78N 103.31W
08/21/2026  M2.75 Inch       Morrill            NE   Trained Spotter

&&

Preliminary Local Storm Report
National Weather Service Cheyenne WY
726 PM MDT Fri Aug 21 2026

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

0721 PM     Hail             4 E Bayard              41.76N 103.25W
08/21/2026  M2.00 Inch       Morrill            NE   Trained Spotter

&&