Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 131, NWS Cheyenne, WY

August 14, 2021Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Aug 14, 2021, 7:36 PM MDT for Laramie County, Wyoming. It was in force for 39 min. 1 report 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, 7:36 PM MDT (01:36 UTC)
Expired: Aug 14, 2021, 8:15 PM MDT
In force: 39 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

County Laramie County, WY

The radar

The Cheyenne radar (KCYS), 19 km from the middle of the area, began a volume at 01:35 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, 7:52 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, 1.6 hours before the alert went out and 180 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.

033 
WUUS55 KCYS 150136
SVRCYS
WYC021-150215-
/O.NEW.KCYS.SV.W.0131.210815T0136Z-210815T0215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
736 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 815 PM MDT.

* At 736 PM MDT, a severe thunderstorm was located 7 miles southwest
  of Hillsdale, or 10 miles east of Cheyenne, moving south at 25 mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Cheyenne and Carpenter. 

This includes Interstate 80 in Wyoming between mile markers 366 and
384.
 
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 4117 10471 4125 10454 4101 10415 4100 10481
TIME...MOT...LOC 0136Z 337DEG 21KT 4114 10460 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Claycomb

1 follow-up statement

982 
WWUS55 KCYS 150209
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
809 PM MDT Sat Aug 14 2021

WYC021-150218-
/O.EXP.KCYS.SV.W.0131.000000T0000Z-210815T0215Z/
Laramie WY-
809 PM MDT Sat Aug 14 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 has exited the warned area. Therefore, the warning will
be allowed to expire.

LAT...LON 4117 10471 4125 10454 4101 10415 4100 10481
TIME...MOT...LOC 0208Z 337DEG 21KT 4099 10451 

$$

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, 7:12 PM MDT	Severe Thunderstorm Warning Considerable damage threat	CYS	Laramie	48 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.