Alert archive / South Dakota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 21, NWS Rapid City, SD

July 22, 1987Perkins County, South Dakota

NWS Rapid City, SD issued this severe thunderstorm warning at Jul 22, 1987, 8:31 PM MDT for Perkins County, South Dakota. It was in force for 29 min.

The area

The counties it named.

The facts

Issued
Jul 22, 1987, 8:31 PM MDT (02:31 UTC)
Expired
Jul 22, 1987, 9:00 PM MDT
In force
29 min
Issued by
NWS Rapid City, SD
Area
Whole counties

County Perkins County, SD

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 00:00Z, 2.5 hours before the alert went out and 161 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 1987-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 41 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 1987-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
41 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
3733 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
134 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 KRAP 230231
SVRRAP
SDC105-230300-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE RAPID CITY SD
831 PM MDT WED JUL 22 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL  900 PM MDT FOR PEOPLE IN THE FOLLOWING COUNTY...
 
IN NORTHWEST SOUTH DAKOTA
          ...SOUTHERN PERKINS
 
AT 830 PM MDT A DANGEROUS THUNDERSTORM WITH MULTIPLE FUNNEL CLOUD
SIGHTINGS WAS LOCATED ABOUT TEN MILES SOUTH OF BISON...PERKINS COUNTY
SOUTH DAKOTA...MOVING TO THE EAST AT 35 MPH.
 
THIS STORM WILL BE MOVING INTO NORTHERN ZIEBACH COUNTY BY 9 PM MDT IN
THE SAME GENERAL AREA AS AN EARLIER STORM...WHICH DROPPER HEAVY RAINS
AND 3/4 INCH HAIL BETWEEN GLAD VALLEY AND ISABEL.
 
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.
 
THIS IS A DANGEROUS STORM.  IF YOU ARE IN ITS PATH YOU SHOULD
PREPARE FOR DAMAGING WIND IN EXCESS OF 55 MPH...LARGE HAIL...AND
DEADLY LIGHTNING.  PEOP0LE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT STAY AWAY FROM WINDOWS.

The office that day

Everything else NWS Rapid City, SD issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 22, 7:24 PM MDTSevere Thunderstorm WarningUNRHarding51 min
Jul 22, 7:24 PM MDTSevere Thunderstorm WarningUNRZiebach51 min
Jul 23, 4:21 PM MDTSevere Thunderstorm WarningUNRHaakon, Jackson, Pennington69 min
Jul 23, 4:51 PM MDTSevere Thunderstorm WarningUNRCuster, Pennington29 min
Jul 23, 5:49 PM MDTSevere Thunderstorm WarningUNRBennett, Jackson56 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 1987Every severe thunderstorm warning 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.