Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 33, NWS Cheyenne, WY

June 6, 2021Laramie County, Platte County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 6, 2021, 6:11 PM MDT for Laramie County, Platte County, Wyoming. It was in force for 34 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
Jun 6, 2021, 6:11 PM MDT (00:11 UTC)
Expired
Jun 6, 2021, 6:45 PM MDT
In force
34 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Laramie County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 51 km from the middle of the area, began a volume at 00:12 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 6, 6:35 PM MDTHAIL 11 Ne Chugwater, WYREPORT RELAYED FROM FIRE CHIEF OF HEAVY HAIL DAMAGE TO NORTH BOUND VEHICLES AROUND INTERSTATE 25 MILE MARKER 57 NORTH OF CHUGWATER.
Jun 6, 6:40 PM MDTHAIL 11 Ne Chugwater, WYDELAYED REPORT, NICKEL TO QUARTER SIZED HAIL.

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

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 0.2 hours before the alert went out and 240 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, Denver, CO at 00:00Z on 2021-06-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 60 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 2021-06-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 square meters per square second.1939Sfc1 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
60 J/kg
Mixed-layer CIN
-139 J/kg
Mixed-layer LCL
2807 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
113 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted.

246 
WUUS55 KCYS 070011
SVRCYS
WYC021-031-070045-
/O.NEW.KCYS.SV.W.0033.210607T0011Z-210607T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
611 PM MDT Sun Jun 6 2021

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  Northwestern Laramie County in southeastern Wyoming...
  South central Platte County in southeastern Wyoming...

* Until 645 PM MDT.

* At 610 PM MDT, a severe thunderstorm was located 11 miles southwest
  of Chugwater, or 29 miles south of Wheatland, moving northeast 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...
  Chugwater.

This includes Interstate 25 in Wyoming between mile markers 39 and
57, and near mile marker 61.
 
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 4151 10501 4160 10513 4183 10482 4157 10467
TIME...MOT...LOC 0010Z 227DEG 20KT 4162 10497 

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

Claycomb
1 follow-up statement
339 
WWUS55 KCYS 070027
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
627 PM MDT Sun Jun 6 2021

WYC021-031-070045-
/O.CON.KCYS.SV.W.0033.000000T0000Z-210607T0045Z/
Laramie WY-Platte WY-
627 PM MDT Sun Jun 6 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM MDT
FOR NORTHWESTERN LARAMIE AND SOUTH CENTRAL PLATTE COUNTIES...

At 627 PM MDT, a severe thunderstorm was located near Chugwater, or
24 miles south of Wheatland, moving northeast at 25 mph.

HAZARD...Golf 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...
Chugwater.

This includes Interstate 25 in Wyoming between mile markers 43 and
57, and near mile marker 61.
 
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 4160 10492 4167 10500 4183 10482 4157 10467
TIME...MOT...LOC 0027Z 225DEG 21KT 4170 10486 

HAIL...1.75IN
WIND...60MPH
 
$$

Claycomb

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 6, 6:37 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte38 min
Jun 6, 7:39 PM MDTSevere Thunderstorm WarningCYSGoshen36 min
Jun 7, 3:39 PM MDTSpecial Weather StatementCYSConverse51 min
Jun 7, 4:17 PM MDTSpecial Weather StatementCYSConverse43 min
Jun 7, 5:37 PM MDTSpecial Weather StatementCYSNiobrara53 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.