Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 129, NWS Cheyenne, WY

August 14, 2021Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Aug 14, 2021, 7:12 PM MDT for Laramie County, Wyoming. It was in force for 48 min. 3 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: Aug 14, 2021, 7:12 PM MDT (01:12 UTC)
Expired: Aug 14, 2021, 8:00 PM MDT
In force: 48 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Damage threat: Considerable
Hail: 1.75 in
Wind: 60.0 mph

County Laramie County, WY

The radar

The Cheyenne radar (KCYS), 14 km from the middle of the area, began a volume at 01:11 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
Aug 14, 7:25 PM MDT	HAIL 1	3 E Cheyenne, WY	WIND GUSTS UP TO 50 MPH WAS ALSO REPORTED WITH THIS STORM.
Aug 14, 7:25 PM MDT	HAIL 1	4 E Cheyenne, WY
Aug 14, 7:52 PM MDT	HAIL 1	9 Se 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 00:00Z, 1.2 hours before the alert went out and 191 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: 666 J/kg
Mixed-layer CIN: -45 J/kg
Mixed-layer LCL: 3335 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: -22 m²/s²
0-3 km storm-relative helicity: 81 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

As transmitted.

109 
WUUS55 KCYS 150112
SVRCYS
WYC021-150200-
/O.NEW.KCYS.SV.W.0129.210815T0112Z-210815T0200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
712 PM MDT Sat Aug 14 2021

The National Weather Service in Cheyenne has issued a

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

* Until 800 PM MDT.

* At 711 PM MDT, a severe thunderstorm was located near Ranchettes,
  or 9 miles northeast of Cheyenne, moving south at 15 mph.

  HAZARD...Golf ball size hail and 60 mph wind gusts.

  SOURCE...Public. At 710 PM...Golfball sized hail was reported by a 
           NWS employee 8 miles northeast of Cheyenne. 

  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 366 and
378.
 
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.

&&

LAT...LON 4131 10474 4132 10459 4103 10444 4104 10473
TIME...MOT...LOC 0111Z 348DEG 12KT 4122 10464 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Claycomb

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 14, 7:01 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	44 min
Aug 14, 7:36 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	39 min
Aug 15, 12:42 PM MDT	Areal Flood Advisory	CYS	Albany, Carbon	3 hr
Aug 15, 1:03 PM MDT	Special Weather Statement	CYS	Platte	42 min
Aug 15, 1:06 PM MDT	Areal Flood Advisory	CYS	Albany	3 hr
Aug 15, 1:42 PM MDT	Areal Flood Advisory	CYS	Albany, Carbon, Converse	2 hr
Aug 15, 2:10 PM MDT	Special Weather Statement	CYS	Albany	35 min
Aug 15, 2:21 PM MDT	Special Weather Statement	CYS	Albany	24 min
Aug 15, 3:47 PM MDT	Special Weather Statement	CYS	Albany	28 min
Aug 15, 3:49 PM MDT	Special Weather Statement	CYS	Albany	26 min
Aug 15, 4:25 PM MDT	Special Weather Statement	CYS	Albany	50 min
Aug 15, 4:46 PM MDT	Flash Flood Warning Considerable damage threat	CYS	Albany	95 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.