Alert archive / Nebraska / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 26, NWS Cheyenne, WY

May 28, 2021Sioux County, Nebraska; Niobrara County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at May 28, 2021, 9:05 PM MDT for Sioux County, Nebraska; Niobrara County, Wyoming. It was in force for 40 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: May 28, 2021, 9:05 PM MDT (03:05 UTC)
Expired: May 28, 2021, 9:45 PM MDT
In force: 40 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

Counties Sioux County, NE, Niobrara County, WY

The radar

The Cheyenne radar (KCYS), 179 km from the middle of the area, began a volume at 03:07 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.

What was reported inside it

Time	Report	Where	Remark
May 28, 9:15 PM MDT	HAIL 1.5	6 W Van Tassell, WY	LATE REPORT ON SOCIAL MEDIA. NEAR THE CORNER OF HIGHWAY 20 AND MCMASTER ROAD.
May 28, 9:30 PM MDT	HAIL 0.5	17 E Lusk, WY	HAIL COVERING US HIGHWAY 20.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Rapid City, SD (KUNR), launched 00:00Z, 3.1 hours before the alert went out and 187 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: 1505 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 151 m²/s²
0-3 km storm-relative helicity: 132 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

552 
WUUS55 KCYS 290305
SVRCYS
NEC165-WYC027-290345-
/O.NEW.KCYS.SV.W.0026.210529T0305Z-210529T0345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
905 PM MDT Fri May 28 2021

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  West central Sioux County in the Panhandle of Nebraska...
  Southeastern Niobrara County in east central Wyoming...

* Until 945 PM MDT.

* At 904 PM MDT, a severe thunderstorm was located 8 miles southeast
  of Lusk, moving east at 15 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.

* This severe thunderstorm will remain over mainly rural areas of
  west central Sioux and southeastern Niobrara Counties, including
  the following locations... Van Tassell.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in Cheyenne.

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 4264 10439 4277 10436 4285 10401 4264 10401
TIME...MOT...LOC 0304Z 268DEG 13KT 4270 10430 

HAIL...1.25IN
WIND...60MPH
 
$$

Jamski

2 follow-up statements

539 
WWUS55 KCYS 290324
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
924 PM MDT Fri May 28 2021

NEC165-WYC027-290345-
/O.CON.KCYS.SV.W.0026.000000T0000Z-210529T0345Z/
Sioux NE-Niobrara WY-
924 PM MDT Fri May 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 945 PM MDT
FOR WEST CENTRAL SIOUX AND SOUTHEASTERN NIOBRARA COUNTIES...

At 923 PM MDT, a severe thunderstorm was located 13 miles east of
Lusk, moving east at 15 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.

This severe thunderstorm will remain over mainly rural areas of west
central Sioux and southeastern Niobrara Counties, including the
following locations... Van Tassell.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
Cheyenne.

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4264 10428 4277 10423 4285 10401 4264 10401
TIME...MOT...LOC 0323Z 268DEG 13KT 4270 10420 

HAIL...1.50IN
WIND...60MPH
 
$$

Jamski

194 
WWUS55 KCYS 290341
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
941 PM MDT Fri May 28 2021

NEC165-WYC027-290351-
/O.EXP.KCYS.SV.W.0026.000000T0000Z-210529T0345Z/
Sioux NE-Niobrara WY-
941 PM MDT Fri May 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL SIOUX AND
SOUTHEASTERN NIOBRARA COUNTIES WILL EXPIRE AT 945 PM MDT...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.  However gusty winds and heavy rain are still
possible with this thunderstorm.

LAT...LON 4264 10428 4277 10423 4285 10401 4264 10401
TIME...MOT...LOC 0341Z 268DEG 13KT 4270 10414 

$$

Jamski

The office that day

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

Issued	Product	Office	Counties	Lasted
May 28, 9:45 PM MDT	Special Weather Statement	CYS	Sioux	45 min
May 28, 10:12 PM MDT	Special Weather Statement	CYS	Sioux	33 min
May 28, 10:25 PM MDT	Special Weather Statement	CYS	Sioux	35 min
May 28, 6:58 PM MDT	Special Weather Statement	CYS	Niobrara	47 min
May 28, 8:44 PM MDT	Special Weather Statement	CYS	Niobrara	46 min
May 28, 9:15 PM MDT	Areal Flood Advisory	CYS	Niobrara	72 min
May 28, 9:21 PM MDT	Special Weather Statement	CYS	Laramie	24 min
May 29, 1:37 PM MDT	Special Weather Statement	CYS	Laramie	38 min
May 29, 2:06 PM MDT	Special Weather Statement	CYS	Laramie	24 min
May 29, 2:17 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	28 min
May 29, 5:55 PM MDT	Special Weather Statement	CYS	Platte	35 min

Nearby

Severe Thunderstorm Warnings in Nebraska, 2021 Severe Thunderstorm Warnings in Wyoming, 2021 Every severe thunderstorm warning in 2021

Sources

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