Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 10, NWS Cheyenne, WY

May 23, 2021Goshen County, Platte County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at May 23, 2021, 1:35 PM MDT for Goshen County, Platte County, Wyoming. It was in force for 29 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, 1:35 PM MDT (19:35 UTC)
Expired
May 23, 2021, 2:04 PM MDT
In force
29 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Goshen County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 129 km from the middle of the area, began a volume at 19:39 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.

IssuedProductOfficeLasted
May 23, 12:06 PM MDTTornado WatchSPC8 hr

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 7.6 hours before the alert went out and 248 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 12:00Z on 2021-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2021-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 271 square meters per square second.19395878Sfc1 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
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.

048 
WUUS55 KCYS 231935
SVRCYS
WYC015-031-232015-
/O.NEW.KCYS.SV.W.0010.210523T1935Z-210523T2015Z/

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

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  Northwestern Goshen County in southeastern Wyoming...
  Northeastern Platte County in southeastern Wyoming...

* Until 215 PM MDT.

* At 134 PM MDT, a severe thunderstorm was located near Guernsey
  Campground, or 17 miles northeast of Wheatland, moving north at 20
  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...
  Guernsey, Guernsey Campground and Hartville. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM MDT for southeastern
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 4217 10472 4223 10495 4254 10486 4245 10452
TIME...MOT...LOC 1934Z 199DEG 17KT 4228 10481 

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

Cox
2 follow-up statements
338 
WWUS55 KCYS 231948
SVSCYS

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

WYC015-031-232015-
/O.CON.KCYS.SV.W.0010.000000T0000Z-210523T2015Z/
Goshen WY-Platte WY-
148 PM MDT Sun May 23 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 215 PM MDT
FOR NORTHWESTERN GOSHEN AND NORTHEASTERN PLATTE COUNTIES...

At 148 PM MDT, a severe thunderstorm was located 8 miles north of
Guernsey Campground, or 27 miles southwest of Lusk, moving north at
25 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...
Guernsey Campground and Hartville. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM MDT for southeastern
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 4228 10467 4233 10492 4254 10486 4245 10452
TIME...MOT...LOC 1948Z 197DEG 23KT 4244 10475 

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

Cox
870 
WWUS55 KCYS 232004
SVSCYS

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

WYC015-031-232014-
/O.CAN.KCYS.SV.W.0010.000000T0000Z-210523T2015Z/
Goshen WY-Platte WY-
204 PM MDT Sun May 23 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN GOSHEN AND
NORTHEASTERN PLATTE COUNTIES IS CANCELLED...
        
The storm which prompted the warning has moved out of the area.
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
Wyoming.

LAT...LON 4228 10467 4233 10492 4254 10486 4245 10452
TIME...MOT...LOC 2002Z 199DEG 17KT 4251 10472 

$$

Cox

The office that day

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

IssuedProductOfficeCountiesLasted
May 23, 12:54 AM MDTDense Fog AdvisoryCYSAlbany, Laramie7 hr
May 23, 2:04 AM MDTHigh Wind WarningCYSAlbany, Carbon18 hr
May 23, 1:18 PM MDTSpecial Weather StatementCYSLaramie42 min
May 23, 1:28 PM MDTSpecial Weather StatementCYSPlatte47 min
May 23, 1:59 PM MDTSevere Thunderstorm WarningCYSGoshen, Niobrara, Platte19 min
May 23, 2:03 PM MDTSevere Thunderstorm WarningCYSGoshen, Laramie42 min
May 23, 2:38 PM MDTSevere Thunderstorm WarningCYSGoshen24 min
May 23, 3:22 PM MDTAreal Flood AdvisoryCYSLaramie3 hr

Nearby

Severe Thunderstorm Warnings in Wyoming, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.