Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 61, NWS Cheyenne, WY

June 18, 2021Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 18, 2021, 7:54 PM MDT for Laramie County, Wyoming. It was in force for 51 min. 8 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 18, 2021, 7:54 PM MDT (01:54 UTC)
Expired: Jun 18, 2021, 8:45 PM MDT
In force: 51 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

County Laramie County, WY

The radar

The Cheyenne radar (KCYS), 7 km from the middle of the area, began a volume at 01:53 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 18, 7:58 PM MDT	HAIL 1	3 E Cheyenne, WY	NICKEL TO QUARTER SIZE HAIL AT CONVERSE AND LINCOLNWAY.
Jun 18, 7:58 PM MDT	HAIL 1	3 Nnw Cheyenne, WY
Jun 18, 7:59 PM MDT	HAIL 1.25	Cheyenne, WY	QUARTER AND HALF DOLLAR HAIL.
Jun 18, 8:00 PM MDT	HAIL 1.25	1 Se Cheyenne, WY
Jun 18, 8:00 PM MDT	HAIL 1.25	6 Ne Cheyenne, WY
Jun 18, 8:00 PM MDT	HAIL 1.5	3 Ene Cheyenne, WY	HALF DOLLAR TO PING PONG BALL HAIL.
Jun 18, 8:05 PM MDT	HAIL 1.5	2 Nnw Cheyenne, WY
Jun 18, 8:10 PM MDT	HAIL 0.88	2 Ese Cheyenne, WY	SUN VALLEY DRIVE.

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, 1.9 hours before the alert went out and 188 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: 580 J/kg
Mixed-layer CIN: -27 J/kg
Mixed-layer LCL: 2917 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 78 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted.

339 
WUUS55 KCYS 190154
SVRCYS
WYC021-190245-
/O.NEW.KCYS.SV.W.0061.210619T0154Z-210619T0245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
754 PM MDT Fri Jun 18 2021

The National Weather Service in Cheyenne has issued a

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

* Until 845 PM MDT.

* At 753 PM MDT, a severe thunderstorm was located over Cheyenne,
  moving east at 15 mph.

  HAZARD...Ping pong 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...
  Cheyenne, South Greeley, Frontier Park, Ranchettes, Warren AFB, Fox
  Farm-College and South Greeley High.

This includes the following highways...
 Interstate 25 in Wyoming between mile markers 10 and 15.
 Interstate 80 in Wyoming between mile markers 360 and 374.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 4107 10485 4121 10484 4120 10458 4105 10455
TIME...MOT...LOC 0153Z 284DEG 11KT 4117 10477 

HAIL...1.50IN
WIND...60MPH
 
$$

Cox

4 follow-up statements

095 
WWUS55 KCYS 190202
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
802 PM MDT Fri Jun 18 2021

WYC021-190245-
/O.CON.KCYS.SV.W.0061.000000T0000Z-210619T0245Z/
Laramie WY-
802 PM MDT Fri Jun 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM MDT
FOR SOUTH CENTRAL LARAMIE COUNTY...

At 802 PM MDT, a severe thunderstorm was located near Cheyenne,
moving east at 15 mph.

HAZARD...Ping pong 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...
Cheyenne, South Greeley, Ranchettes, Fox Farm-College and South
Greeley High.

This includes Interstate 80 in Wyoming between mile markers 361 and
374.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and 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 4107 10484 4121 10480 4120 10458 4105 10455
TIME...MOT...LOC 0202Z 284DEG 11KT 4116 10473 

HAIL...1.50IN
WIND...60MPH
 
$$

Cox

691 
WWUS55 KCYS 190215
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
815 PM MDT Fri Jun 18 2021

WYC021-190245-
/O.CON.KCYS.SV.W.0061.000000T0000Z-210619T0245Z/
Laramie WY-
815 PM MDT Fri Jun 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM MDT
FOR SOUTH CENTRAL LARAMIE COUNTY...

At 814 PM MDT, a severe thunderstorm was located near Cheyenne,
moving southeast at 15 mph.

HAZARD...Ping pong 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...
Cheyenne and Ranchettes. 

This includes Interstate 80 in Wyoming between mile markers 365 and
374.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and 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 4107 10477 4120 10474 4120 10458 4105 10455
TIME...MOT...LOC 0214Z 296DEG 14KT 4112 10468 

HAIL...1.50IN
WIND...60MPH
 
$$

Cox

648 
WWUS55 KCYS 190224
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
824 PM MDT Fri Jun 18 2021

WYC021-190245-
/O.CON.KCYS.SV.W.0061.000000T0000Z-210619T0245Z/
Laramie WY-
824 PM MDT Fri Jun 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM MDT
FOR SOUTH CENTRAL LARAMIE COUNTY...

At 824 PM MDT, a severe thunderstorm was located 9 miles east of
Cheyenne, moving east at 20 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...
Cheyenne.

This includes Interstate 80 in Wyoming between mile markers 368 and
374.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and 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 4107 10472 4120 10468 4120 10458 4105 10455
TIME...MOT...LOC 0224Z 282DEG 19KT 4111 10461 

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

Cox

991 
WWUS55 KCYS 190236
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
836 PM MDT Fri Jun 18 2021

WYC021-190245-
/O.EXP.KCYS.SV.W.0061.000000T0000Z-210619T0245Z/
Laramie WY-
836 PM MDT Fri Jun 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL LARAMIE COUNTY
WILL EXPIRE AT 845 PM MDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However small hail
and heavy rain are still possible with this thunderstorm.

LAT...LON 4107 10472 4120 10468 4120 10458 4105 10455
TIME...MOT...LOC 0235Z 284DEG 11KT 4110 10457 

$$

Cox

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 18, 7:18 PM MDT	Red Flag Warning	CYS		25 hr
Jun 18, 7:21 PM MDT	Special Weather Statement	CYS	Laramie	39 min
Jun 18, 7:35 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	40 min
Jun 18, 8:13 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	47 min
Jun 18, 8:29 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	46 min
Jun 18, 8:30 PM MDT	Special Weather Statement	CYS	Laramie	45 min
Jun 19, 12:54 PM MDT	Fire Weather Watch	CYS		7 hr
Jun 19, 1:18 PM MDT	Special Weather Statement	CYS	Laramie	42 min
Jun 19, 1:51 PM MDT	Special Weather Statement	CYS	Laramie	24 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.