Alert archive / South Dakota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 31, NWS Sioux Falls, SD

July 6, 19874 counties in South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 6, 1987, 6:32 PM CDT for 4 counties in South Dakota. It was in force for 118 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: Jul 6, 1987, 6:32 PM CDT (23:32 UTC)
Expired: Jul 6, 1987, 8:30 PM CDT
In force: 118 min
Issued by: NWS Sioux Falls, SD
Area: Whole counties

Counties Brule County, SD, Charles Mix County, SD, Gregory County, SD, Tripp 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 6, 7:15 PM CDT	Hail 1.75	Brule, SD
Jul 6, 7:30 PM CDT	Hail 1.75	Brule, 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

Aberdeen, SD (KHON), launched 12:00Z, 11.5 hours before the alert went out and 182 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: 190 J/kg
Mixed-layer CIN: -276 J/kg
Mixed-layer LCL: 1517 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -11 m²/s²
0-3 km storm-relative helicity: 69 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 KFSD 070032
SVRFSD
SDC015-023-053-123-070130-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
732 PM CDT MON JUL 6 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL  830 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES...
 
IN SOUTH CENTRAL SOUTH DAKOTA
          ...BRULE...WESTERN CHARLES-MIX...GREGORY
          ...EASTERN TRIPP
 
SOME CITIES INCLUDED IN THIS
WARNING...KIMBALL...ACADEMY...BURKE...COLOME.
 
AT 730 PM CDT RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS FROM
JUST NORTH OF CHAMBERLAIN TO 25 MILSE SOUTH OF WINNER MOVING EAST
NORTHEAST AT 15 MPH.
 
IN ADDITION THE TORNADO WARNING REMAINS IN EFFECT UNTIL 8 PM CDT FOR
WESTERN BRULE COUNTY.
 
THIS WARNING INCLUDES THE ADJACENT WATERS OF THE MISSOURI RIVER.
 
IF YOU ARE IN THE PATH OF THIS STORM...YOU SHOULD GET TO A
REINFORCED SHELTER. A SEVERE THUNDERSTORM PRODUCES WINDS IN EXCESS
OF 60 MPH...HAIL 3/4 INCH OR LARGER...DEADLY LIGHTNING...AND HEAVY
RAIN THAT CAN QUICKLY FLOOD A LOW LYING AREA.
JANSEN

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, Jul 6, 4:27 PM CDT, 2 hours 5 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HURON SD
425 PM CDT MON JUL 6 1987

AT 420 PM CDT...SCATTERED THUNDERSTORMS WERE DEVELOPING RAPIDLY
OVER CENTRAL SOUTH DAKOTA.  THE STORMS WERE MOSTLY IN EASTERN HUGHES
AND EASTERN SULLY COUNTIES...FROM 25 MILES SOUTHEAST OF PIERRE...
TO 25 MILES NORTHEAST OF PIERRE.

THESE STORMS WILL PRODUCE HAIL...GUSTY WIND...FREQUENT LIGHTNING...
AND VERY HEAVY RAINS.  THE STORMS MAY ALSO DEVELOP ALONG THE
MISSOURI RIVER.  IF YOU ARE IN SULLY...HUGHES...OR HYDE COUNTIES...
OR IF YOU ARE IN RECREATION AREAS ALONG THE MISSOURI...YOU SHOULD
BE PREPARED TO GET TO A PLACE OF SAFETY.   IF YOU ARE BOATING
ON THE MISSOURI RIVER...YOU SHOULD BE PREPARED TO GET OFF.

KRAUSE

Special weather statement, Jul 6, 6:08 PM CDT, 24 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
607 PM CDT MON JUL 6 1987

...SEVERE THUNDERSTORM WATCH FOR EASTERN SOUTH DAKOTA
   UNTIL 11 PM CDT...

AT 6 PM CDT NATIONAL WEATER SERVICE RADARS INDICATED AN INTENSE
THUNDERSTORM IN SOUTHEASTERN TODD COUNTY. THIS THUNDERSTORM WAS
MOVING EAST NORTHEAST AT 20 MPH AND WILL BE MOVING INTO WESTERN
TRIPP COUNTY BY 7 PM CDT. STRONG WINDS...SMALL HAIL...HEAVY RAINS
AND DANGEROUS CLOUD TO GROUND LIGHTNING CAN BE EXPECTED WITH THIS
STORM.

PERSONS ACROSS EASTERN TODD AND WESTERN TRIPP COUNTIES INCLUDING
THE COMMUNITIES OF KEYA PAHA AND CLEARFIELD SHOULD KEEP ABREAST
OF THIS WEATHER SITUATION AND BE PREPARED TO GO TO A SAFE PLAGCE
IN THREATENING WEATHER APPROACHES OR IF A WARNING IS ISSUED.
JANSEN

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 6, 6:35 PM CDT	Severe Thunderstorm Warning	FSD	Todd, Tripp	55 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 1987 Every 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.