Alert archive / Nebraska / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 2, NWS Cheyenne, WY

May 20, 2021Scotts Bluff County, Sioux County, Nebraska; Goshen County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at May 20, 2021, 7:07 PM MDT for Scotts Bluff County, Sioux County, Nebraska; Goshen County, Wyoming. It was in force for 38 min. 8 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 20, 2021, 7:07 PM MDT (01:07 UTC)
Expired: May 20, 2021, 7:45 PM MDT
In force: 38 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

Counties Scotts Bluff County, NE, Sioux County, NE, Goshen County, WY

The radar

The Cheyenne radar (KCYS), 124 km from the middle of the area, began a volume at 01:07 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 20, 7:07 PM MDT	HAIL 1.5	1 Ne Torrington, WY
May 20, 7:10 PM MDT	HAIL 0.7	4 E Lingle, WY	MEASURED PEA TO DIME SIZED HAIL.
May 20, 7:12 PM MDT	HAIL 0.7	1 E Torrington, WY	MEASURED HAIL PEA TO DIME SIZED. WINDS 12 MPH WITH GUSTS TO 38 MPH.
May 20, 7:12 PM MDT	HAIL 1.75	4 E Lingle, WY	ESTIMATED PING PONG TO GOLF BALL SIZED HAIL ON THE GROUND.
May 20, 7:12 PM MDT	HAIL 1.75	4 E Lingle, WY	MEASURED PING PONG TO GOLF BALL SIZED HAIL.
May 20, 7:16 PM MDT	HAIL 1	5 Ese Lingle, WY
May 20, 7:25 PM MDT	HAIL 1.75	Torrington, WY
May 20, 7:26 PM MDT	HAIL 1.5	1 N Torrington, WY	ESTIMATED BASED ON PICTURE.

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, 1.1 hours before the alert went out and 237 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: 296 J/kg
Mixed-layer CIN: -70 J/kg
Mixed-layer LCL: 2384 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 0 m²/s²
0-3 km storm-relative helicity: 9 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

994 
WUUS55 KCYS 210107
SVRCYS
NEC157-165-WYC015-210145-
/O.NEW.KCYS.SV.W.0002.210521T0107Z-210521T0145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
707 PM MDT Thu May 20 2021

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  Northwestern Scotts Bluff County in the Panhandle of Nebraska...
  Southwestern Sioux County in the Panhandle of Nebraska...
  Northeastern Goshen County in southeastern Wyoming...

* Until 745 PM MDT.

* At 707 PM MDT, a severe thunderstorm was located near Torrington,
  moving north at 40 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...
  Torrington, Huntley, Agate Bed National Monument, Henry and Hwy 85
  At Dry Rawhide Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4190 10406 4195 10429 4251 10435 4241 10368
TIME...MOT...LOC 0107Z 192DEG 41KT 4202 10415 

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

Claycomb

2 follow-up statements

929 
WWUS55 KCYS 210120
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
720 PM MDT Thu May 20 2021

NEC157-210129-
/O.CAN.KCYS.SV.W.0002.000000T0000Z-210521T0145Z/
Scotts Bluff NE-
720 PM MDT Thu May 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN SCOTTS BLUFF
COUNTY IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4203 10402 4206 10427 4251 10435 4241 10368
TIME...MOT...LOC 0119Z 192DEG 41KT 4216 10411 

$$

NEC165-WYC015-210145-
/O.CON.KCYS.SV.W.0002.000000T0000Z-210521T0145Z/
Sioux NE-Goshen WY-
720 PM MDT Thu May 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM MDT
FOR SOUTHWESTERN SIOUX AND NORTHEASTERN GOSHEN COUNTIES...

At 719 PM MDT, a severe thunderstorm was located 7 miles northeast of
Torrington, moving north at 40 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Torrington, Agate Bed National Monument and Hwy 85 At Dry Rawhide
Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4203 10402 4206 10427 4251 10435 4241 10368
TIME...MOT...LOC 0119Z 192DEG 41KT 4216 10411 

HAIL...1.00IN
WIND...60MPH
 
$$

Claycomb

816 
WWUS55 KCYS 210139
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
739 PM MDT Thu May 20 2021

NEC165-WYC015-210147-
/O.EXP.KCYS.SV.W.0002.000000T0000Z-210521T0145Z/
Sioux NE-Goshen WY-
739 PM MDT Thu May 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN SIOUX AND
NORTHEASTERN GOSHEN COUNTIES WILL EXPIRE AT 745 PM MDT...
                
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 will be allowed to expire. Another severe 
thunderstorm warning is in effect northwest of this warning in 
northern Goshen County.

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

LAT...LON 4203 10402 4206 10427 4251 10435 4241 10368
TIME...MOT...LOC 0137Z 192DEG 41KT 4232 10406 

$$

Claycomb

The office that day

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

Issued	Product	Office	Counties	Lasted
May 20, 6:10 PM MDT	Special Weather Statement	CYS	Banner	50 min
May 20, 6:49 PM MDT	Special Weather Statement	CYS	Scotts Bluff	41 min
May 20, 6:54 PM MDT	Special Weather Statement	CYS	Kimball	51 min
May 20, 7:15 PM MDT	Severe Thunderstorm Warning	CYS	Banner, Cheyenne, Kimball	45 min
May 20, 7:55 PM MDT	Severe Thunderstorm Warning	CYS	Banner, Cheyenne, Kimball, Morrill	39 min
May 20, 8:36 PM MDT	Severe Thunderstorm Warning	CYS	Banner, Cheyenne, Kimball	24 min
May 21, 4:10 PM MDT	Special Weather Statement	CYS	Dawes	50 min
May 21, 4:28 PM MDT	Special Weather Statement	CYS	Box Butte	47 min
May 21, 4:38 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte, Dawes	52 min
May 21, 5:26 PM MDT	Severe Thunderstorm Warning	CYS	Box Butte, Morrill, Scotts Bluff, Sioux	49 min
May 21, 5:32 PM MDT	Severe Thunderstorm Warning	CYS	Dawes	43 min
May 20, 7:27 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Niobrara, 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.