Alert archive / Nebraska / Severe Thunderstorm Warnings in 2025

Severe Thunderstorm Warning 21, NWS Cheyenne, WY

May 18, 2025Box Butte County, Sioux County, Nebraska

NWS Cheyenne, WY issued this severe thunderstorm warning at May 18, 2025, 5:05 PM MDT for Box Butte County, Sioux County, Nebraska. It was in force for 19 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: May 18, 2025, 5:05 PM MDT (23:05 UTC)
Expired: May 18, 2025, 5:24 PM MDT
In force: 19 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

Counties Box Butte County, NE, Sioux County, NE

The radar

The Cheyenne radar (KCYS), 172 km from the middle of the area, began a volume at 23:08 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 11.1 hours before the alert went out and 428 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1656 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 67 m²/s²
0-3 km storm-relative helicity: 146 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

823 
WUUS55 KCYS 182305
SVRCYS
NEC013-165-182345-
/O.NEW.KCYS.SV.W.0021.250518T2305Z-250518T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
505 PM MDT Sun May 18 2025

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  Western Box Butte County in the Panhandle of Nebraska...
  East central Sioux County in the Panhandle of Nebraska...

* Until 545 PM MDT.

* At 505 PM MDT, a severe thunderstorm was located near Kilpatrick
  Lake, or 22 miles west of Alliance, moving northwest at 25 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...
  Kilpatrick Lake and Flahertys Corner.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4211 10313 4202 10335 4236 10366 4244 10321
TIME...MOT...LOC 2305Z 147DEG 20KT 4216 10331 

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

$$

Natoli

1 follow-up statement

681 
WWUS55 KCYS 182324
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
524 PM MDT Sun May 18 2025

NEC013-165-182333-
/O.CAN.KCYS.SV.W.0021.000000T0000Z-250518T2345Z/
Box Butte NE-Sioux NE-
524 PM MDT Sun May 18 2025

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN BOX BUTTE AND EAST
CENTRAL SIOUX COUNTIES IS CANCELLED...

The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However, gusty winds are
still possible with this thunderstorm.

&&

LAT...LON 4211 10313 4202 10335 4236 10366 4244 10321
TIME...MOT...LOC 2322Z 147DEG 20KT 4225 10339 

$$

Natoli

The office that day

Everything else NWS Cheyenne, WY issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 18, 3:46 PM MDT	Severe Thunderstorm Warning Considerable damage threat	CYS	Banner, Cheyenne, Kimball, Morrill	44 min
May 18, 4:08 PM MDT	Severe Thunderstorm Warning	CYS	Banner, Kimball	37 min
May 18, 4:14 PM MDT	Severe Thunderstorm Warning Considerable damage threat	CYS	Cheyenne	46 min
May 18, 4:26 PM MDT	Severe Thunderstorm Warning Considerable damage threat	CYS	Banner, Cheyenne, Kimball, Morrill	49 min
May 18, 4:50 PM MDT	Tornado Warning	CYS	Cheyenne, Morrill	25 min
May 18, 4:55 PM MDT	Severe Thunderstorm Warning	CYS	Cheyenne, Morrill	50 min
May 18, 4:57 PM MDT	Severe Thunderstorm Warning	CYS	Banner, Scotts Bluff	48 min
May 18, 5:14 PM MDT	Severe Thunderstorm Warning Considerable damage threat	CYS	Box Butte, Morrill, Scotts Bluff, Sioux	46 min
May 18, 5:18 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte, Dawes	42 min
May 18, 5:36 PM MDT	Severe Thunderstorm Warning	CYS	Cheyenne, Morrill	24 min
May 18, 5:51 PM MDT	Special Weather Statement	CYS	Sioux	24 min
May 18, 5:54 PM MDT	Special Weather Statement	CYS	Dawes	36 min

Nearby

Severe Thunderstorm Warnings in Nebraska, 2025 Every severe thunderstorm warning in 2025

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.