Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 30, NWS Cheyenne, WY

June 5, 2021Goshen County, Niobrara County, Wyoming; Sioux County, Nebraska

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 5, 2021, 7:53 PM MDT for Goshen County, Niobrara County, Wyoming; Sioux County, Nebraska. It was in force for 22 min. 1 report 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
Jun 5, 2021, 7:53 PM MDT (01:53 UTC)
Expired
Jun 5, 2021, 8:15 PM MDT
In force
22 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Sioux County, NE, Goshen County, WY, Niobrara County, WY

The radar

The Cheyenne radar (KCYS), 169 km from the middle of the area, began a volume at 01:57 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

TimeReportWhereRemark
Jun 5, 7:55 PM MDTTSTM WND GST 558 Sse Lusk, WY30 MPH SUSTAINED GUSTS TO 55 MPH.

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, 1.9 hours before the alert went out and 197 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-pSkew-T log-p diagram, Rapid City, SD at 00:00Z on 2021-06-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1645 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Rapid City, SD at 00:00Z on 2021-06-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
1645 J/kg
Mixed-layer CIN
-84 J/kg
Mixed-layer LCL
2622 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
48 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

296 
WUUS55 KCYS 060153
SVRCYS
NEC165-WYC015-027-060215-
/O.NEW.KCYS.SV.W.0030.210606T0153Z-210606T0215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
753 PM MDT Sat Jun 5 2021

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  Northwestern Sioux County in the Panhandle of Nebraska...
  Southeastern Niobrara County in east central Wyoming...
  North central Goshen County in southeastern Wyoming...

* Until 815 PM MDT.

* At 752 PM MDT, a severe thunderstorm was located 8 miles northwest
  of Prairie Center, or 12 miles southeast of Lusk, moving northeast
  at 35 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  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.

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

&&

LAT...LON 4249 10437 4262 10447 4286 10407 4262 10405
TIME...MOT...LOC 0152Z 239DEG 32KT 4260 10433 

HAIL...0.88IN
WIND...60MPH
 
$$

Claycomb
2 follow-up statements
188 
WWUS55 KCYS 060207
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
807 PM MDT Sat Jun 5 2021

NEC165-WYC015-027-060215-
/O.CON.KCYS.SV.W.0030.000000T0000Z-210606T0215Z/
Sioux NE-Niobrara WY-Goshen WY-
807 PM MDT Sat Jun 5 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM MDT
FOR NORTHWESTERN SIOUX...SOUTHEASTERN NIOBRARA AND NORTH CENTRAL
GOSHEN COUNTIES...

At 807 PM MDT, a severe thunderstorm was located 11 miles north of
Prairie Center, or 15 miles southeast of Lusk, moving northeast at 35
mph.

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

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
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.

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

&&

LAT...LON 4254 10430 4264 10436 4286 10407 4262 10405
TIME...MOT...LOC 0207Z 239DEG 32KT 4267 10417 

HAIL...0.88IN
WIND...60MPH
 
$$

Claycomb
610 
WWUS55 KCYS 060212
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
812 PM MDT Sat Jun 5 2021

NEC165-WYC015-027-060220-
/O.EXP.KCYS.SV.W.0030.000000T0000Z-210606T0215Z/
Sioux NE-Niobrara WY-Goshen WY-
812 PM MDT Sat Jun 5 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN SIOUX...
SOUTHEASTERN NIOBRARA AND NORTH CENTRAL GOSHEN COUNTIES WILL EXPIRE
AT 815 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.  However heavy rain
is still possible with this thunderstorm.

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

LAT...LON 4254 10430 4264 10436 4286 10407 4262 10405
TIME...MOT...LOC 0210Z 239DEG 32KT 4267 10417 

$$

Claycomb

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 5, 7:16 PM MDTSevere Thunderstorm WarningCYSGoshen, Niobrara, Platte28 min
Jun 6, 3:24 PM MDTSpecial Weather StatementCYSLaramie36 min
Jun 6, 5:21 PM MDTSevere Thunderstorm WarningCYSLaramie39 min
Jun 6, 5:32 PM MDTSevere Thunderstorm WarningCYSLaramie, Platte43 min
Jun 6, 5:02 PM MDTSpecial Weather StatementCYSKimball43 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 2021Severe Thunderstorm Warnings in Nebraska, 2021Every 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.