Alert archive / Wyoming / Tornado Warnings in 1987

Tornado Warning 9, NWS Cheyenne, WY

June 17, 1987Platte County, Wyoming

NWS Cheyenne, WY issued this tornado warning at Jun 17, 1987, 5:51 PM MDT for Platte County, Wyoming. It was in force for 29 min.

The area

The counties it named.

The facts

Issued
Jun 17, 1987, 5:51 PM MDT (23:51 UTC)
Expired
Jun 17, 1987, 6:20 PM MDT
In force
29 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Platte County, WY

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Rapid City, SD (KRAP), launched 12:00Z, 11.9 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 12:00Z on 1987-06-17Temperature 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°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 1987-06-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -10 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2503 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-10 m²/s²
0-3 km storm-relative helicity
99 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 180002 COR
TORCYS
WYC031-180020-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
558 PM MDT WED JUN 17 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING
EFFECTIVE UNTIL 620 PM MDT FOR PEOPLE IN THE FOLLOWING COUNTY OF

SOUTHEAST WYOMING...NORTHERN PLATTE COUNTY

INCLUDING THE TOWNS OF GLENDO...GUERNSEY AND WENDOVER

AT 538 PM MDT A TORNADO WAS SIGHTED A HALF MILE EAST OF GLENDO
BUT HAD GONE BACK IN TO THE CLOUDS...MARBLE SIZE HAIL WAS ALSO
WITH THIS STORM.  IN ADDITION A FUNNEL CLOUD WAS SIGHTED EAST OF
GUERNSEY.  RADAR CONTINUES TO INDICATE A SEVERE THUNDERSTORM
BETWEEN GUERNSEY AND GLENDO ABOUT 80 MILES NORTH OF CHEYENNE.
THE SEVERE THUNDERSTORM WARNING HAS BEEN SUPERCEDED.
SCOTT

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 17, 5:20 PM MDTSevere Thunderstorm WarningCYSPlatte55 min

Nearby

Tornado Warnings in Wyoming, 1987Every tornado warning in 1987Tornadoes in 1987

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.