Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 42, NWS Cheyenne, WY

June 8, 2021Laramie County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 8, 2021, 9:08 PM MDT for Laramie County, Wyoming. It was in force for 52 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
Jun 8, 2021, 9:08 PM MDT (03:08 UTC)
Expired
Jun 8, 2021, 10:00 PM MDT
In force
52 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Laramie County, WY

The radar

The Cheyenne radar (KCYS), 8 km from the middle of the area, began a volume at 03:08 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

TimeReportWhereRemark
Jun 8, 9:29 PM MDTHAIL 0.71 N Fox Farm-College, WY
Jun 8, 9:30 PM MDTHAIL 0.71 N Fox Farm-College, 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, 3.1 hours before the alert went out and 189 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-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2021-06-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 424 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 2021-06-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 92 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
424 J/kg
Mixed-layer CIN
-54 J/kg
Mixed-layer LCL
3769 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
92 m²/s²
0-3 km storm-relative helicity
155 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

Open this sounding in Storm Lab

The text

As transmitted.

295 
WUUS55 KCYS 090308
SVRCYS
WYC021-090400-
/O.NEW.KCYS.SV.W.0042.210609T0308Z-210609T0400Z/

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

The National Weather Service in Cheyenne has issued a

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

* Until 1000 PM MDT.

* At 908 PM MDT, a severe thunderstorm was located near South
  Greeley, or near Cheyenne, moving east at 10 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.

* Locations impacted include...
  South Cheyenne, South Greeley, Warren AFB, Frontier Park, Warren 
  Af Base, Ranchettes, Fox Farm-College and South Greeley High.

This includes the following highways...
 Interstate 25 in Wyoming between mile markers 1 and 12.
 Interstate 80 in Wyoming between mile markers 355 and 372.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4113 10494 4122 10464 4101 10458 4100 10468
      4100 10496
TIME...MOT...LOC 0308Z 262DEG 10KT 4108 10489 

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

Hammer
2 follow-up statements
843 
WWUS55 KCYS 090347
SVSCYS

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

WYC021-090400-
/O.CON.KCYS.SV.W.0042.000000T0000Z-210609T0400Z/
Laramie WY-
947 PM MDT Tue Jun 8 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM MDT
FOR SOUTH CENTRAL LARAMIE COUNTY...

At 947 PM MDT, a severe thunderstorm was located near South Greeley,
or near Cheyenne, moving east at 10 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.

Locations impacted include...
Cheyenne.

This includes Interstate 80 in Wyoming between mile markers 366 and
372.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4122 10464 4101 10458 4100 10468 4100 10480
      4116 10473
TIME...MOT...LOC 0347Z 262DEG 10KT 4110 10475 

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

Hammer
573 
WWUS55 KCYS 090357
SVSCYS

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

WYC021-090406-
/O.EXP.KCYS.SV.W.0042.000000T0000Z-210609T0400Z/
Laramie WY-
957 PM MDT Tue Jun 8 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL LARAMIE COUNTY
WILL EXPIRE AT 1000 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 small hail 
and heavy rain are still possible with this thunderstorm.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Cheyenne.

LAT...LON 4122 10464 4101 10458 4100 10468 4100 10480
      4116 10473
TIME...MOT...LOC 0356Z 262DEG 10KT 4110 10472 

$$

Hammer

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 8, 6:14 PM MDTSpecial Weather StatementCYSLaramie31 min
Jun 8, 6:45 PM MDTSevere Thunderstorm WarningCYSLaramie45 min
Jun 8, 7:27 PM MDTSevere Thunderstorm WarningCYSLaramie48 min
Jun 8, 7:30 PM MDTFlash Flood WarningCYSLaramie3 hr
Jun 8, 8:21 PM MDTSpecial Weather StatementCYSNiobrara54 min
Jun 8, 8:29 PM MDTSpecial Weather StatementCYSLaramie46 min
Jun 8, 8:35 PM MDTSevere Thunderstorm WarningCYSNiobrara55 min
Jun 8, 8:36 PM MDTSpecial Weather StatementCYSLaramie39 min
Jun 8, 9:03 PM MDTSevere Thunderstorm WarningCYSGoshen, Laramie42 min
Jun 8, 9:33 PM MDTSpecial Weather StatementCYSNiobrara57 min
Jun 8, 10:20 PM MDTAreal Flood AdvisoryCYSLaramie3 hr
Jun 8, 10:26 PM MDTSevere Thunderstorm WarningCYSLaramie49 min
Jun 8, 11:15 PM MDTSevere Thunderstorm WarningCYSLaramie45 min
Jun 9, 2:11 PM MDTHigh Wind WatchCYSAlbany, Converse, Goshen, Laramie, Niobrara, Platte12 hr
Jun 9, 2:11 PM MDTHigh Wind WarningCYSAlbany, Carbon, Converse, Goshen, Laramie, Niobrara and 1 more39 hr

Nearby

Severe Thunderstorm Warnings in Wyoming, 2021Every 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.