Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 35, NWS Cheyenne, WY

June 6, 2021Goshen County, Platte County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 6, 2021, 6:37 PM MDT for Goshen County, Platte County, Wyoming. It was in force for 38 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 6, 2021, 6:37 PM MDT (00:37 UTC)
Expired: Jun 6, 2021, 7:15 PM MDT
In force: 38 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

Counties Goshen County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 74 km from the middle of the area, began a volume at 00:40 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
Jun 6, 6:40 PM MDT	HAIL 1	1 Ne Chugwater, WY	DELAYED 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, 0.6 hours before the alert went out and 249 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: 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.

413 
WUUS55 KCYS 070037
SVRCYS
WYC015-031-070115-
/O.NEW.KCYS.SV.W.0035.210607T0037Z-210607T0115Z/

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

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  West central Goshen County in southeastern Wyoming...
  Southeastern Platte County in southeastern Wyoming...

* Until 715 PM MDT.

* At 637 PM MDT, a severe thunderstorm was located over Chugwater, or
  21 miles southeast of Wheatland, moving northeast at 25 mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Chugwater and Slater. 

This includes Interstate 25 in Wyoming between mile markers 56 and
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 4173 10476 4179 10487 4198 10466 4184 10449
TIME...MOT...LOC 0037Z 224DEG 22KT 4177 10478 

HAIL...1.25IN
WIND...60MPH
 
$$

Claycomb

1 follow-up statement

756 
WWUS55 KCYS 070109
SVSCYS

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

WYC015-031-070118-
/O.EXP.KCYS.SV.W.0035.000000T0000Z-210607T0115Z/
Goshen WY-Platte WY-
709 PM MDT Sun Jun 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL GOSHEN AND
SOUTHEASTERN PLATTE COUNTIES WILL EXPIRE AT 715 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 4173 10476 4179 10487 4198 10466 4184 10449
TIME...MOT...LOC 0108Z 227DEG 19KT 4184 10465 

$$

Claycomb

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 6, 6:11 PM MDT	Severe Thunderstorm Warning	CYS	Laramie, Platte	34 min
Jun 6, 7:39 PM MDT	Severe Thunderstorm Warning	CYS	Goshen	36 min
Jun 7, 3:39 PM MDT	Special Weather Statement	CYS	Converse	51 min
Jun 7, 4:17 PM MDT	Special Weather Statement	CYS	Converse	43 min
Jun 7, 5:37 PM MDT	Special Weather Statement	CYS	Niobrara	53 min

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