Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 100, NWS Cheyenne, WY

July 14, 2021Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jul 14, 2021, 3:11 PM MDT for Laramie 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: Jul 14, 2021, 3:11 PM MDT (21:11 UTC)
Expired: Jul 14, 2021, 3:45 PM MDT
In force: 34 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 1.75 in
Wind: 60.0 mph

County Laramie County, WY

The radar

The Cheyenne radar (KCYS), 20 km from the middle of the area, began a volume at 21:12 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

Time	Report	Where	Remark
Jul 14, 3:13 PM MDT	HAIL 1.75	8 Sse Federal, WY
Jul 14, 3:20 PM MDT	HAIL 1.25	7 W Warren Af Base, WY	REPORTS OF QUARTER TO HALF DOLLAR-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 12:00Z, 9.2 hours before the alert went out and 207 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2082 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -9 m²/s²
0-3 km storm-relative helicity: -20 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

583 
WUUS55 KCYS 142111
SVRCYS
WYC021-142145-
/O.NEW.KCYS.SV.W.0100.210714T2111Z-210714T2145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
311 PM MDT Wed Jul 14 2021

The National Weather Service in Cheyenne has issued a

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

* Until 345 PM MDT.

* At 311 PM MDT, a severe thunderstorm was located near Crystal Lake
  Reservoir, or 14 miles west of Cheyenne, moving southeast 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...
  Warren AFB.

This includes the following highways...
 Interstate 25 in Wyoming between mile markers 1 and 8.
 Interstate 80 in Wyoming between mile markers 344 and 359.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

&&

LAT...LON 4119 10518 4122 10495 4100 10476 4100 10514
TIME...MOT...LOC 2111Z 331DEG 20KT 4117 10507 

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

Trudel

2 follow-up statements

705 
WWUS55 KCYS 142125
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
325 PM MDT Wed Jul 14 2021

WYC021-142145-
/O.CON.KCYS.SV.W.0100.000000T0000Z-210714T2145Z/
Laramie WY-
325 PM MDT Wed Jul 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM MDT
FOR SOUTHWESTERN LARAMIE COUNTY...

At 324 PM MDT, a severe thunderstorm was located 8 miles west of
Warren AFB, or 12 miles west of Cheyenne, moving southeast 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.

This severe thunderstorm will remain over mainly rural areas of
southwestern Laramie County.

This includes the following highways...
 Interstate 25 in Wyoming between mile markers 1 and 6.
 Interstate 80 in Wyoming between mile markers 345 and 357.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail up to ping pong balls. SEEK 
SHELTER NOW inside a sturdy structure and stay away from windows.

&&

LAT...LON 4115 10513 4117 10494 4100 10476 4100 10514
TIME...MOT...LOC 2124Z 331DEG 20KT 4111 10502 

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

Trudel

706 
WWUS55 KCYS 142142
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
342 PM MDT Wed Jul 14 2021

WYC021-142152-
/O.EXP.KCYS.SV.W.0100.000000T0000Z-210714T2145Z/
Laramie WY-
342 PM MDT Wed Jul 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN LARAMIE COUNTY
WILL EXPIRE AT 345 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 gusty 
winds up to 55 MPH and very heavy rain still possible with this 
thunderstorm.

LAT...LON 4115 10513 4117 10494 4100 10476 4100 10514
TIME...MOT...LOC 2142Z 331DEG 20KT 4103 10496 

$$

Trudel

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 13, 6:42 PM MDT	Special Weather Statement	CYS	Converse	33 min
Jul 13, 7:13 PM MDT	Special Weather Statement	CYS	Converse	32 min
Jul 14, 1:52 PM MDT	Special Weather Statement	CYS	Laramie	38 min
Jul 14, 2:43 PM MDT	Special Weather Statement	CYS	Laramie	47 min
Jul 14, 2:46 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	29 min
Jul 14, 2:57 PM MDT	Special Weather Statement	CYS	Laramie	48 min
Jul 14, 3:41 PM MDT	Special Weather Statement	CYS	Laramie	34 min
Jul 14, 4:13 PM MDT	Special Weather Statement	CYS	Laramie	32 min
Jul 14, 5:08 PM MDT	Special Weather Statement	CYS	Laramie	37 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.