Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 40, NWS Cheyenne, WY

June 8, 2021Niobrara County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 8, 2021, 8:35 PM MDT for Niobrara County, Wyoming. It was in force for 55 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: Jun 8, 2021, 8:35 PM MDT (02:35 UTC)
Expired: Jun 8, 2021, 9:30 PM MDT
In force: 55 min
Issued by: NWS Cheyenne, WY
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Niobrara County, WY

The radar

The Rapid City radar (KUDX), 169 km from the middle of the area, began a volume at 02:35 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
Jun 8, 8:35 PM MDT	HAIL 1	1 Ne Lance Creek, WY

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Rapid City, SD (KUNR), launched 00:00Z, 2.6 hours before the alert went out and 162 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: 2269 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 2498 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 49 m²/s²
0-3 km storm-relative helicity: 162 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 9.2

Open this sounding in Storm Lab

The text

As transmitted.

799 
WUUS55 KCYS 090235
SVRCYS
WYC027-090330-
/O.NEW.KCYS.SV.W.0040.210609T0235Z-210609T0330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
835 PM MDT Tue Jun 8 2021

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  Niobrara County in east central Wyoming...

* Until 930 PM MDT.

* At 835 PM MDT, severe thunderstorms were located along a line
  extending from Morrisey to near Manville, moving east at 20 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

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

* Severe thunderstorms will be near...
  Lusk around 900 PM MDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4277 10406 4273 10477 4350 10469 4350 10406
TIME...MOT...LOC 0235Z 248DEG 18KT 4353 10439 4281 10464 

HAIL...1.00IN
WIND...60MPH
 
$$

Rubin

2 follow-up statements

933 
WWUS55 KCYS 090253
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
853 PM MDT Tue Jun 8 2021

WYC027-090330-
/O.CON.KCYS.SV.W.0040.000000T0000Z-210609T0330Z/
Niobrara WY-
853 PM MDT Tue Jun 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 PM MDT
FOR EASTERN NIOBRARA COUNTY...

At 852 PM MDT, severe thunderstorms were located along a line
extending from 6 miles east of Morrisey to 6 miles northeast of
Manville, moving east at 25 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated. At 835 PM MDT, quarter size hail was 
         reported 1 mile northeast of Lance Creek. 

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

These severe thunderstorms will remain over mainly rural areas of
eastern Niobrara County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4277 10406 4274 10463 4350 10446 4350 10406
TIME...MOT...LOC 0252Z 250DEG 20KT 4356 10427 4284 10452 

HAIL...1.00IN
WIND...60MPH
 
$$

Rubin

849 
WWUS55 KCYS 090328
SVSCYS

Severe Weather Statement
National Weather Service Cheyenne WY
928 PM MDT Tue Jun 8 2021

WYC027-090337-
/O.EXP.KCYS.SV.W.0040.000000T0000Z-210609T0330Z/
Niobrara WY-
928 PM MDT Tue Jun 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN NIOBRARA COUNTY WILL
EXPIRE AT 930 PM MDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However small
hail, gusty winds and heavy rain are still possible with these
thunderstorms.

LAT...LON 4277 10406 4274 10463 4350 10446 4350 10406
TIME...MOT...LOC 0327Z 248DEG 18KT 4362 10405 4290 10430 

$$

Rubin

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 8, 6:14 PM MDT	Special Weather Statement	CYS	Laramie	31 min
Jun 8, 6:45 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	45 min
Jun 8, 7:27 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	48 min
Jun 8, 7:30 PM MDT	Flash Flood Warning	CYS	Laramie	3 hr
Jun 8, 8:21 PM MDT	Special Weather Statement	CYS	Niobrara	54 min
Jun 8, 8:29 PM MDT	Special Weather Statement	CYS	Laramie	46 min
Jun 8, 8:36 PM MDT	Special Weather Statement	CYS	Laramie	39 min
Jun 8, 9:03 PM MDT	Severe Thunderstorm Warning	CYS	Goshen, Laramie	42 min
Jun 8, 9:08 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	52 min
Jun 8, 9:33 PM MDT	Special Weather Statement	CYS	Niobrara	57 min
Jun 8, 10:20 PM MDT	Areal Flood Advisory	CYS	Laramie	3 hr
Jun 8, 10:26 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	49 min
Jun 8, 11:15 PM MDT	Severe Thunderstorm Warning	CYS	Laramie	45 min
Jun 9, 2:11 PM MDT	High Wind Watch	CYS	Albany, Converse, Goshen, Laramie, Niobrara, Platte	12 hr
Jun 9, 2:11 PM MDT	High Wind Warning	CYS	Albany, Carbon, Converse, Goshen, Laramie, Niobrara and 1 more	39 hr

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.