Alert archive / Wyoming / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 111, NWS Cheyenne, WY

July 29, 2021Albany County, Carbon County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jul 29, 2021, 3:12 PM MDT for Albany County, Carbon County, Wyoming. It was in force for 48 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 29, 2021, 3:12 PM MDT (21:12 UTC)
Expired
Jul 29, 2021, 4:00 PM MDT
In force
48 min
Issued by
NWS Cheyenne, WY
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Albany County, WY, Carbon County, WY

The radar

The Cheyenne radar (KCYS), 112 km from the middle of the area, began a volume at 21:15 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.

The nearest sounding before it

Riverton, WY (KRIW), launched 12:00Z, 9.2 hours before the alert went out and 269 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, Riverton, WY at 12:00Z on 2021-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Riverton, WY at 12:00Z on 2021-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1746 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
90 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

702 
WUUS55 KCYS 292112
SVRCYS
WYC001-007-292200-
/O.NEW.KCYS.SV.W.0111.210729T2112Z-210729T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Cheyenne WY
312 PM MDT Thu Jul 29 2021

The National Weather Service in Cheyenne has issued a

* Severe Thunderstorm Warning for...
  East central Carbon County in south central Wyoming...
  Southwestern Albany County in southeastern Wyoming...

* Until 400 PM MDT.

* At 311 PM MDT, a severe thunderstorm was located over Libby Creek
  Campground, or 28 miles west of Laramie, 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.

* Locations impacted include...
  Centennial, Nash Fork Campground, Brooklyn Lake, Brooklyn Lake
  Campground, North Fork Campground and Libby Creek Campground.

This includes Interstate 80 in Wyoming between mile markers 277 and
293, and near mile marker 299.
 
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.

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

&&

LAT...LON 4124 10623 4133 10629 4158 10613 4132 10571
TIME...MOT...LOC 2111Z 250DEG 18KT 4134 10612 

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

Claycomb

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 2:01 PM MDTFlash Flood WatchCYSAlbany, Carbon, Converse, Goshen, Laramie, Platte34 hr
Jul 29, 2:23 PM MDTFlash Flood WarningCYSAlbany, Carbon101 min
Jul 29, 2:27 PM MDTSevere Thunderstorm WarningCYSAlbany, Carbon48 min
Jul 29, 3:19 PM MDTFlash Flood WarningCYSAlbany, Carbon104 min
Jul 29, 3:52 PM MDTSevere Thunderstorm WarningCYSAlbany38 min
Jul 29, 4:41 PM MDTAreal Flood AdvisoryCYSAlbany3 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.