Alert archive / Wyoming / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 108, NWS Cheyenne, WY

August 29, 1997Converse County, Platte County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Aug 29, 1997, 5:20 PM MDT for Converse County, Platte County, Wyoming. It was in force for 30 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Aug 29, 1997, 5:20 PM MDT (23:20 UTC)
Expired
Aug 29, 1997, 5:50 PM MDT
In force
30 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

Counties Converse County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 160 km from the middle of the area, began a volume at 23:22 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
Aug 29, 5:50 PM MDTHail 0.88Glendo, WYNickel size hail at Glendo marina.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Rapid City, SD (KUNR), launched 12:00Z, 11.3 hours before the alert went out and 255 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, Rapid City, SD at 12:00Z on 1997-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 275 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Rapid City, SD at 12:00Z on 1997-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 60 square meters per square second.19395878Sfc1 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
275 J/kg
Mixed-layer CIN
-280 J/kg
Mixed-layer LCL
2717 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
60 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KCYS 292320 RRA
SVRCYS
WYC009-031-292350-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
520 PM MDT FRI AUG 29 1997

* SEVERE THUNDERSTORM WARNING FOR
  SOUTHEASTERN CONVERSE COUNTY IN EAST CENTRAL WYOMING
  EXTREME NORTHWESTERN PLATTE COUNTY IN SOUTHEASTERN WYOMING

* UNTIL 550 PM MDT

  THIS STORM WILL REMAIN IN RURAL AREAS.

 
AT 515PM RADAR INDICATED A SEVERE THUNDERSTORM 10 MILES SOUTH OF
DOUGLAS.  THpE STORM WAS MOVING TO THE EAST AT 25 MPH.
 
LARGE HAIL IS LIKELY WITH THIS STORM.  SEEK SHELTER INSIDE A STURDY
BUILDING AWAY FROM ALL WINDOWS UNTIL THE STORM PASSES.

WCJIN-WYNE-WYSE

COX

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 5:36 PM MDTSevere Thunderstorm WarningCYSConverse, Platte44 min

Nearby

Severe Thunderstorm Warnings in Wyoming, 1997Every severe thunderstorm warning in 1997

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.