Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 39, NWS Cheyenne, WY

June 8, 2021Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 8, 2021, 7:27 PM MDT for Laramie County, Wyoming. It was in force for 48 min. 9 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 8, 2021, 7:27 PM MDT (01:27 UTC)
Expired: Jun 8, 2021, 8:15 PM MDT
In force: 48 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

County Laramie County, WY

The radar

The Cheyenne radar (KCYS), 1 km from the middle of the area, began a volume at 01:27 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 8, 7:35 PM MDT	HAIL 0.7	1 Ne Cheyenne, WY
Jun 8, 7:36 PM MDT	TSTM WND GST 67	8 Wsw Hillsdale, WY	CORRECTS PREVIOUS NON-TSTM WND GST REPORT FROM 8 WSW HILLSDALE. MESONET STATION WY46 9.7 E CHEYENNE (WYDOT).
Jun 8, 7:36 PM MDT	NON-TSTM WND GST 67	8 Wsw Hillsdale, WY	MESONET STATION WY46 9.7 E CHEYENNE (WYDOT).
Jun 8, 7:39 PM MDT	HAIL 1	8 Sw Hillsdale, WY	51-53 MPH WINDS.
Jun 8, 7:40 PM MDT	HAIL 1	3 Ne Cheyenne, WY	REPORT RECEIVED VIA FACEBOOK. DELAYED REPORT.
Jun 8, 7:40 PM MDT	HAIL 1	5 Ene Cheyenne, WY
Jun 8, 7:42 PM MDT	TSTM WND GST 60	8 Sw Hillsdale, WY
Jun 8, 7:54 PM MDT	HAIL 0.5	3 E Cheyenne, WY	RECORDED PEA TO HALF INCH SIZED HAIL.
Jun 8, 8:10 PM MDT	TSTM WND DMG	6 Ne Cheyenne, WY	PEA TO QUARTER SIZE HAIL ALONG WITH 60 MPH WIND GUSTS. 3-4 INCHES OF HAIL COVERED GROUND. GREENHOUSE DESTROYED. LIVESTOCK LOST INCLUDING A GOAT AND CHICKENS. FLASH FLOODING OBSERVED AS WELL.

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, 1.5 hours before the alert went out and 196 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: 424 J/kg
Mixed-layer CIN: -54 J/kg
Mixed-layer LCL: 3769 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 92 m²/s²
0-3 km storm-relative helicity: 155 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.2

Open this sounding in Storm Lab

The text

As transmitted.

266 
WUUS55 KCYS 090127
SVRCYS
WYC021-090215-
/O.NEW.KCYS.SV.W.0039.210609T0127Z-210609T0215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
727 PM MDT Tue Jun 8 2021

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  Southwestern Laramie County in southeastern Wyoming...

* Until 815 PM MDT.

* At 726 PM MDT, a severe thunderstorm was located over Cheyenne,
  moving east at 10 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Cheyenne, South Greeley, Ranchettes, Warren AFB, Frontier Park,
  North Cheyenne, Warren Af Base, Fox Farm-College and South Greeley
  High.

This includes the following highways...
 Interstate 25 in Wyoming between mile markers 5 and 20.
 Interstate 80 in Wyoming between mile markers 351 and 380.

This replaces the Severe Thunderstorm Warning which was previously 
in effect for the warned area. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.

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

&&

LAT...LON 4104 10500 4119 10505 4141 10457 4112 10444
TIME...MOT...LOC 0126Z 252DEG 7KT 4116 10480 

HAIL...1.00IN
WIND...<50MPH
 
$$

Hammer

3 follow-up statements

836 
WWUS55 KCYS 090136
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
736 PM MDT Tue Jun 8 2021

WYC021-090215-
/O.CON.KCYS.SV.W.0039.000000T0000Z-210609T0215Z/
Laramie WY-
736 PM MDT Tue Jun 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM MDT
FOR SOUTHWESTERN LARAMIE COUNTY...

At 735 PM MDT, a severe thunderstorm was located over Cheyenne,
moving east at 10 mph.

HAZARD...70 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

Locations impacted include...
Cheyenne, South Greeley, Ranchettes, Warren AFB, Frontier Park, North
Cheyenne, Warren Af Base, Fox Farm-College and South Greeley High.

This includes the following highways...
 Interstate 25 in Wyoming between mile markers 5 and 20.
 Interstate 80 in Wyoming between mile markers 351 and 380.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.

Wind damage with this storm will occur before any rain or lightning.
Do not wait for the sound of thunder before taking cover. SEEK
SHELTER IMMEDIATELY inside a sturdy structure and stay away from
windows.

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

&&

LAT...LON 4104 10500 4119 10505 4141 10457 4112 10444
TIME...MOT...LOC 0135Z 252DEG 7KT 4117 10478 

HAIL...1.00IN
WIND...70MPH
 
$$

Hammer

969 
WWUS55 KCYS 090202
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
802 PM MDT Tue Jun 8 2021

WYC021-090215-
/O.CON.KCYS.SV.W.0039.000000T0000Z-210609T0215Z/
Laramie WY-
802 PM MDT Tue Jun 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM MDT
FOR SOUTH CENTRAL LARAMIE COUNTY...

At 802 PM MDT, a severe thunderstorm was located near Hillsdale, or
12 miles northeast of Cheyenne, moving east at 10 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
East Cheyenne and Ranchettes. 

This includes Interstate 80 in Wyoming between mile markers 365 and
380.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4108 10475 4124 10478 4137 10455 4112 10444
TIME...MOT...LOC 0202Z 251DEG 10KT 4122 10458 

HAIL...0.75IN
WIND...60MPH
 
$$

Hammer

461 
WWUS55 KCYS 090212
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
812 PM MDT Tue Jun 8 2021

WYC021-090222-
/O.EXP.KCYS.SV.W.0039.000000T0000Z-210609T0215Z/
Laramie WY-
812 PM MDT Tue Jun 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL LARAMIE COUNTY
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 small 
hail, gusty winds and heavy rain are still possible with this 
thunderstorm. A Flash Flood Warning remains in effect for central 
Laramie County including the city of Cheyenne until 1030 PM MDT this 
evening. 

LAT...LON 4108 10475 4124 10478 4137 10455 4112 10444
TIME...MOT...LOC 0212Z 252DEG 7KT 4122 10456 

$$

Hammer

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 8, 6:14 PM MDT	Special Weather Statement	CYS	Laramie	31 min
Jun 8, 6:45 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	45 min
Jun 8, 7:30 PM MDT	Flash Flood Warning	CYS	Laramie	3 hr
Jun 8, 8:21 PM MDT	Special Weather Statement	CYS	Niobrara	54 min
Jun 8, 8:29 PM MDT	Special Weather Statement	CYS	Laramie	46 min
Jun 8, 8:35 PM MDT	Severe Thunderstorm Warning	CYS	Niobrara	55 min
Jun 8, 8:36 PM MDT	Special Weather Statement	CYS	Laramie	39 min
Jun 8, 9:03 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Laramie	42 min
Jun 8, 9:08 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	52 min
Jun 8, 9:33 PM MDT	Special Weather Statement	CYS	Niobrara	57 min
Jun 8, 10:20 PM MDT	Areal Flood Advisory	CYS	Laramie	3 hr
Jun 8, 10:26 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	49 min
Jun 8, 11:15 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	45 min
Jun 9, 2:11 PM MDT	High Wind Watch	CYS	Albany, Converse, Goshen, Laramie, Niobrara, Platte	12 hr
Jun 9, 2:11 PM MDT	High Wind Warning	CYS	Albany, Carbon, Converse, Goshen, Laramie, Niobrara and 1 more	39 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.