Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 11, NWS Cheyenne, WY

May 23, 2021Goshen County, Niobrara County, Platte County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at May 23, 2021, 1:59 PM MDT for Goshen County, Niobrara County, Platte County, Wyoming. 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 23, 2021, 1:59 PM MDT (19:59 UTC)
Expired: May 23, 2021, 2:18 PM MDT
In force: 19 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Goshen County, WY, Niobrara County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 162 km from the middle of the area, began a volume at 20:02 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 23, 12:06 PM MDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 8.0 hours before the alert went out and 218 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: 549 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 271 m²/s²
0-3 km storm-relative helicity: 339 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

704 
WUUS55 KCYS 231959
SVRCYS
WYC015-027-031-232045-
/O.NEW.KCYS.SV.W.0011.210523T1959Z-210523T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
159 PM MDT Sun May 23 2021

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  Southwestern Niobrara County in east central Wyoming...
  Northwestern Goshen County in southeastern Wyoming...
  Northeastern Platte County in southeastern Wyoming...

* Until 245 PM MDT.

* At 158 PM MDT, a severe thunderstorm was located 12 miles east of
  Two Moon Campground, or 21 miles southwest of Lusk, moving north at
  30 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...
  Lusk, Manville and Keeline. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM MDT for southeastern
and east central Wyoming.

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

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

&&

LAT...LON 4245 10465 4250 10487 4286 10478 4279 10443
TIME...MOT...LOC 1958Z 198DEG 27KT 4253 10473 

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

Cox

1 follow-up statement

825 
WWUS55 KCYS 232018
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
218 PM MDT Sun May 23 2021

WYC015-027-031-232027-
/O.CAN.KCYS.SV.W.0011.000000T0000Z-210523T2045Z/
Niobrara WY-Goshen WY-Platte WY-
218 PM MDT Sun May 23 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN NIOBRARA...
NORTHWESTERN GOSHEN AND NORTHEASTERN PLATTE COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has weakened.
Therefore, the warning has been cancelled. However heavy rain is 
still possible with this thunderstorm.

A Tornado Watch remains in effect until 800 PM MDT for southeastern
and east central Wyoming.

LAT...LON 4245 10465 4250 10487 4286 10478 4279 10443
TIME...MOT...LOC 2015Z 198DEG 27KT 4267 10467 

$$

Cox

The office that day

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

Issued	Product	Office	Counties	Lasted
May 23, 12:54 AM MDT	Dense Fog Advisory	CYS	Albany, Laramie	7 hr
May 23, 2:04 AM MDT	High Wind Warning	CYS	Albany, Carbon	18 hr
May 23, 1:18 PM MDT	Special Weather Statement	CYS	Laramie	42 min
May 23, 1:28 PM MDT	Special Weather Statement	CYS	Platte	47 min
May 23, 1:35 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Platte	29 min
May 23, 2:03 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Laramie	42 min
May 23, 2:38 PM MDT	Severe Thunderstorm Warning	CYS	Goshen	24 min
May 23, 3:22 PM MDT	Areal Flood Advisory	CYS	Laramie	3 hr

Nearby

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.