Alert archive / South Dakota / Tornado Warnings in 1987

Tornado Warning 12, NWS Aberdeen, SD

July 10, 1987Stanley County, South Dakota

NWS Aberdeen, SD issued this tornado warning at Jul 10, 1987, 4:06 PM MDT for Stanley County, South Dakota. It was in force for 39 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: Jul 10, 1987, 4:06 PM MDT (22:06 UTC)
Expired: Jul 10, 1987, 4:45 PM MDT
In force: 39 min
Issued by: NWS Aberdeen, SD
Area: Whole counties

County Stanley County, SD

The radar

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

What was reported inside it

Time	Report	Where	Remark
Jul 10, 4:49 PM MDT	Hail 2.75	Stanley, SD

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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Rapid City, SD (KRAP), launched 12:00Z, 10.1 hours before the alert went out and 175 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 136 J/kg
Mixed-layer CIN: -314 J/kg
Mixed-layer LCL: 1547 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 187 m²/s²
0-3 km storm-relative helicity: 275 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.

000 
TTAA00 KHON 102207
TORHON
SDC117-102245-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE HURON SD
406 PM MDT FRI JUL 10 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING
EFFECTIVE UNTIL 445 PM MDT FOR PEOPLE IN THE FOLLOWING COUNTY OF

CENTRAL SOUTH DAKOTA...STANLEY

THIS WARNING INCLUDES THE ADJACENT WATERS OF THE MISSOURI RIVER.

SOME OF THE CITIES INCLUDED IN THIS WARNING ARE HAYES AND FORT
PIERRE.

AT 353 PM MDT  A TORNADO WAS REPORTED BY THE PUBLIC 25 MILES WEST
SOUTHWEST OF PIERRE. MOVEMENT WAS EAST AT 30 MILES AN HOUR.

 GOLF BALL SIZE HAIL WAS ALSO REPORTED AT THE SAME LOCATION.

IF YOU ARE IN THE PATH OF THIS TORNADO...YOU SHOULD GO TO A BASEMENT
SHELTER IF AVAILABLE. OTHERWISE GO TO A CENTRAL INTERIOR ROOM ON THE
LOWEST FLOOR POSSIBLE. CARS AND MOBILE HOMES SHOULD BE ABANDONED FOR
A REINFORCED BUILDING.

What forecasters said that day

The local office's own words before this tornado 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, Jul 10, 3:22 PM MDT, 44 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ABERDEEN SD
420 PM CDT FRI JUL 10 1987

AT 410 PM CDT RADAR INDICATED INTENSE THUNDERSTORMS ALONG THE
MISSOURI RIVER 5 MILES WEST OF AKASKA OR 15 MILES SOUTHEAST OF
MOBRIDGE SOUTH DAKOTA AND 30 MILES EAST NORTHEAST OF MOBRIDGE.

THE THUNDERSTORMS WERE MOVING NORTHEAST AT 30 MPH. PERSONS IN WESTERN
MCPHERSON AND ALL OF WALWORTH COUNTY SHOULD BE ALERT FOR RAPIDLY
CHANGING WEATHER CONDITIONS AND PREPKARE TO TAKE SHELTER IF WEATHER
THREATENS.
GILLESPIE

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 6:20 PM MDT	Tornado Warning	ABR	Brown	25 min
Jul 9, 7:13 PM MDT	Tornado Warning	ABR	Day	32 min
Jul 10, 3:26 PM MDT	Severe Thunderstorm Warning	ABR	Jones	64 min
Jul 10, 3:50 PM MDT	Severe Thunderstorm Warning	ABR	Stanley	55 min
Jul 10, 4:53 PM MDT	Tornado Warning	ABR	Sully	37 min
Jul 10, 5:05 PM MDT	Severe Thunderstorm Warning	ABR	Stanley	55 min
Jul 10, 5:13 PM MDT	Severe Thunderstorm Warning	ABR	Potter, Walworth	62 min
Jul 10, 5:55 PM MDT	Severe Thunderstorm Warning	ABR	Edmunds	65 min

Nearby

Tornado Warnings in South Dakota, 1987 Every tornado warning in 1987 Tornadoes 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.