Alert archive / Wyoming / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 52, NWS Cheyenne, WY

June 20, 1997Platte County, Wyoming

NWS Cheyenne, WY issued this severe thunderstorm warning at Jun 20, 1997, 7:03 PM MDT for Platte County, Wyoming. It was in force for 47 min. 2 reports 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
Jun 20, 1997, 7:03 PM MDT (01:03 UTC)
Expired
Jun 20, 1997, 7:50 PM MDT
In force
47 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Platte County, WY

The radar

The Cheyenne radar (KCYS), 110 km from the middle of the area, began a volume at 01:04 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 20, 7:30 PM MDTHail 0.75Guernsey, WY
Jun 20, 7:35 PM MDTHail 0.88Guernsey, WY

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 00:00Z, 1.1 hours before the alert went out and 274 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 00:00Z on 1997-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 63 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 00:00Z on 1997-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 204 square meters per square second.1939587897117Sfc1 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
63 J/kg
Mixed-layer CIN
-31 J/kg
Mixed-layer LCL
785 m above ground
0-6 km bulk shear
85 kt
0-1 km storm-relative helicity
204 m²/s²
0-3 km storm-relative helicity
211 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

692 
WUUS1 KCYS 210106
SVRCYS
WYC031-210150-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING...CORRECTED TO LOCATION OF STORM
NATIONAL WEATHER SERVICE CHEYENNE WY
703 PM MDT FRI JUN 20 1997

* SEVERE THUNDERSTORM WARNING FOR
  EASTERN PLATTE COUNTY IN SOUTHEASTERN WYOMING

* UNTIL 750 PM MDT

* SOME AFFECTED LOCATIONS INCLUDE
  GUERSNEY  715 PM
  GUERSNEY STATE PARK  715 PM

* AT 701 PM MDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 5
  MILES NORTHEAST OF WHEATLAND.  MOVEMENT WAS NORTHEAST AT 25 MPH.

 
 
THIS IS A DANGEROUS STORM.  SEEK SHELTER IN A STURDY BUILDING.

WCJIN-WYSE
DMM

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Jun 20, 2:29 PM MDT, 4 hours 34 minutes before
WYZ060-068-NEZ001>003-019>021-054-055-210300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
230 PM MDT FRI JUN 20 1997

A TORNADO WATCH HAS BEEN ISSUED FOR THE NEBRASKA PANHANDLE AND PARTS
OF SOUTHEAST WYOMING AND IS VALID UNTIL 9 PM.

COUNTIES IN THE PANHANDLE INCLUDE SIOUX...DAWES...BOX BUTTE...MORRILL
...CHEYENNE...SCOTTS BLUFF...BANNER AND KIMBALL.  SOME CITIES INCLUDED
IN THE WATCH ARE HARRISON...CHADRON...ALLIANCE...BRIDGEPORT...SIDNEY
...KIMBALL...HARRISBURG...AND SCOTTSBLUFF/GERING.

COUNTIES IN WYOMING INCLUDED IN THE WATCH ARE GOSHEN...AND SOUTHERN
NIOBRARA.  SOME CITIES AND TOWNS IN THE WATCH ARE LUSK...AND
TORRINGTON.

A MOIST AND UNSTABLE AIRMASS IS IN PLACE OVER SOUTHEAST WYOMING AND THE
NEBRASKA PANHANDLE.  AN UPPER LEVEL DISTURBANCE MOVING THROUGH THE AREA
WILL RESULT IN SOME STRONG THUNDERSTORMS. SOME OF THESE STORMS COULD
COULD PRODUCE LARGE HAIL AND TORNADOES ALONG WITH HEAVY RAIN.

PEOPLE IN THE WATCH AREA SHOULD BE ALERT TO APPROACHING STORMS AND
BE PREPARED TO SEEK SHELTER.  LISTEN TO NOAA WEATHER RADIO OR YOUR
LOCAL TELEVISION AND RADIO STATIONS AS WELL AS YOUR CABLE TELEVISION
PROVIDER FOR LATER STATEMENTS AND WARNING.

WCJIN-WYNE-WYSE
LRE
Special weather statement, Jun 20, 2:30 PM MDT, 4 hours 33 minutes before
WYZ060-068-NEZ001>003-019>021-054-055-210300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
230 PM MDT FRI JUN 20 1997

A TORNADO WATCH HAS BEEN ISSUED FOR THE NEBRASKA PANHANDLE AND PARTS
OF SOUTHEAST WYOMING AND IS VALID UNTIL 9 PM.

COUNTIES IN THE PANHANDLE INCLUDE SIOUX...DAWES...BOX BUTTE...MORRILL
...CHEYENNE...SCOTTS BLUFF...BANNER AND KIMBALL.  SOME CITIES INCLUDED
IN THE WATCH ARE HARRISON...CHADRON...ALLIANCE...BRIDGEPORT...SIDNEY
...KIMBALL...HARRISBURG...AND SCOTTSBLUFF/GERING.

COUNTIES IN WYOMING INCLUDED IN THE WATCH ARE GOSHEN...AND SOUTHERN
NIOBRARA.  SOME CITIES AND TOWNS IN THE WATCH ARE LUSK...AND
TORRINGTON.

A MOIST AND UNSTABLE AIRMASS IS IN PLACE OVER SOUTHEAST WYOMING AND THE
NEBRASKA PANHANDLE.  AN UPPER LEVEL DISTURBANCE MOVING THROUGH THE AREA
WILL RESULT IN SOME STRONG THUNDERSTORMS. SOME OF THESE STORMS COULD
COULD PRODUCE LARGE HAIL AND TORNADOES ALONG WITH HEAVY RAIN.

PEOPLE IN THE WATCH AREA SHOULD BE ALERT TO APPROACHING STORMS AND
BE PREPARED TO SEEK SHELTER.  LISTEN TO NOAA WEATHER RADIO OR YOUR
LOCAL TELEVISION AND RADIO STATIONS AS WELL AS YOUR CABLE TELEVISION
PROVIDER FOR LATER STATEMENTS AND WARNING.

WCJIN-WYNE-WYSE
LRE

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 20, 7:17 PM MDTSevere Thunderstorm WarningCYSGoshen48 min
Jun 20, 8:03 PM MDTSevere Thunderstorm WarningCYSGoshen17 min
Jun 20, 8:13 PM MDTSevere Thunderstorm WarningCYSNiobrara47 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.