Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 105, NWS Cheyenne, WY

July 15, 2021Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jul 15, 2021, 4:22 PM MDT for Laramie County, Wyoming. It was in force for 38 min. 4 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 15, 2021, 4:22 PM MDT (22:22 UTC)
Expired: Jul 15, 2021, 5:00 PM MDT
In force: 38 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), 16 km from the middle of the area, began a volume at 22:23 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 15, 4:24 PM MDT	HAIL 1	4 Ese North Cheyenne, WY	NICKELS TO QUARTERS REPORTED.
Jul 15, 4:27 PM MDT	HAIL 1	4 Ese North Cheyenne, WY
Jul 15, 4:30 PM MDT	HAIL 1	5 Ese North Cheyenne, WY
Jul 15, 4:37 PM MDT	HAIL 0.7	6 E Cheyenne, WY

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, 10.4 hours before the alert went out and 186 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: 6 J/kg
Mixed-layer CIN: -427 J/kg
Mixed-layer LCL: 1726 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 23 m²/s²
0-3 km storm-relative helicity: 45 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

304 
WUUS55 KCYS 152222
SVRCYS
WYC021-152300-
/O.NEW.KCYS.SV.W.0105.210715T2222Z-210715T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
422 PM MDT Thu Jul 15 2021

The National Weather Service in Cheyenne has issued a

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

* Until 500 PM MDT.

* At 422 PM MDT, a severe thunderstorm was located near Ranchettes,
  or 7 miles northeast of Cheyenne, moving southeast at 10 mph.

  HAZARD...Quarter size hail.

  SOURCE...Law enforcement.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Cheyenne, Hillsdale and Ranchettes. 

This includes Interstate 80 in Wyoming between mile markers 367 and
381.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4111 10472 4120 10474 4126 10465 4127 10460
      4123 10447 4113 10443 4101 10458
TIME...MOT...LOC 2222Z 315DEG 7KT 4119 10467 

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

Mokry

2 follow-up statements

441 
WWUS55 KCYS 152244
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
444 PM MDT Thu Jul 15 2021

WYC021-152300-
/O.CON.KCYS.SV.W.0105.000000T0000Z-210715T2300Z/
Laramie WY-
444 PM MDT Thu Jul 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM MDT
FOR SOUTH CENTRAL LARAMIE COUNTY...

At 444 PM MDT, a severe thunderstorm was located 8 miles east of
Cheyenne, moving southeast at 10 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Cheyenne and Hillsdale. 

This includes Interstate 80 in Wyoming between mile markers 368 and
381.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4110 10471 4120 10471 4123 10466 4126 10459
      4122 10448 4113 10443 4101 10458
TIME...MOT...LOC 2244Z 315DEG 7KT 4116 10463 

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

Mokry

559 
WWUS55 KCYS 152252
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
452 PM MDT Thu Jul 15 2021

WYC021-152302-
/O.EXP.KCYS.SV.W.0105.000000T0000Z-210715T2300Z/
Laramie WY-
452 PM MDT Thu Jul 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL LARAMIE COUNTY
WILL EXPIRE AT 500 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.

LAT...LON 4110 10471 4120 10471 4123 10466 4126 10459
      4122 10448 4113 10443 4101 10458
TIME...MOT...LOC 2252Z 315DEG 7KT 4116 10462 

$$

Mokry

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 14, 6:03 PM MDT	Special Weather Statement	CYS	Albany	27 min
Jul 14, 6:17 PM MDT	Severe Thunderstorm Warning	CYS	Albany	43 min
Jul 14, 6:19 PM MDT	Special Weather Statement	CYS	Albany	26 min
Jul 14, 6:34 PM MDT	Severe Thunderstorm Warning	CYS	Albany	26 min
Jul 14, 6:59 PM MDT	Severe Thunderstorm Warning	CYS	Albany	46 min
Jul 14, 7:13 PM MDT	Special Weather Statement	CYS	Carbon	32 min
Jul 14, 7:45 PM MDT	Special Weather Statement	CYS	Carbon	45 min
Jul 14, 7:53 PM MDT	Special Weather Statement	CYS	Albany	37 min
Jul 14, 8:48 PM MDT	Special Weather Statement	CYS	Carbon	27 min
Jul 14, 8:51 PM MDT	Severe Thunderstorm Warning	CYS	Carbon	24 min
Jul 15, 3:55 PM MDT	Special Weather Statement	CYS	Laramie	35 min
Jul 15, 4:42 PM MDT	Areal Flood Advisory	CYS	Laramie	3 hr
Jul 15, 4:59 PM MDT	Special Weather Statement	CYS	Laramie	46 min
Jul 15, 5:00 PM MDT	Special Weather Statement	CYS	Laramie	15 min
Jul 15, 5:33 PM MDT	Special Weather Statement	CYS	Laramie	12 min
Jul 15, 5:46 PM MDT	Special Weather Statement	CYS	Laramie	29 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.