Alert archive / South Dakota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 52, NWS Sioux Falls, SD

July 9, 1987Gregory County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 9, 1987, 7:36 PM CDT for Gregory County, South Dakota. It was in force for 54 min.

The area

The counties it named.

The facts

Issued
Jul 9, 1987, 7:36 PM CDT (00:36 UTC)
Expired
Jul 9, 1987, 8:30 PM CDT
In force
54 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Gregory 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

Aberdeen, SD (KHON), launched 00:00Z, 0.6 hours before the alert went out and 200 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, Aberdeen, SD at 00:00Z on 1987-07-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3310 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, Aberdeen, SD at 00:00Z on 1987-07-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 168 square meters per square second.193958Sfc1 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
3310 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
1122 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
168 m²/s²
0-3 km storm-relative helicity
328 m²/s²
Significant tornado parameter
4.0
Supercell composite
21.6

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFSD 100036
SVRFSD
SDC003-015-023-053-100130-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
736 PM CDT THU JUL 9 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
          ...WESTERN AURORA...BRULE...NORTHERN CHARLES-MIX
          ...NORTHERN GREGORY
 
AT 735 PM CDT RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS WHICH
EXTENDED FROM 30 MILES NORTHEAST OF CHAMBERLAIN SOUTH DAKOTA TO
30 MILES SOUTH OF CHAMBERLAIN. MOVEMENT WAS EAST AT 30 MPH.
 
SOME CITIES INCLUDED IN THIS WARNING ARE...ACADEMY...KIMBALL AND
WHITE RIVER.
 
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.
 
ANDERSON

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 9, 2:36 PM CDT, 5 hours before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HURON SD
235 PM CDT THU JUL 9 1987

...A TORNADO WATCH IS IN EFFECT FOR A LARGE PART OF CENTRAL AND
EASTERN SOUTH DAKOTA UNTIL 8 PM CDT THIS THURSDAY EVENING...

AT 225 PM CDT...SCATTERED THUNDERSTORMS...SOME INTENSE WITH
HAIL AND VERY HEAVY RAIN...CONTINUED DEVELOPING OVER NORTHWESTERN
SOUTH DAKOTA.

THE STORMS WERE MOSTLY IN ZIEBACH...WESTERN CORSON...AND NORTHWESTERN
DEWEY COUNTIES.  THEY EXTENDED FROM JUST SOUTHEAST OF LEMMON...
TO NEAR DUPREE...WHICH IS 75 MILES NORTHWEST OF PIERRE.

HAIL...STRONG WIND...VERY HEAVY RAIN...AND FREQUENT LIGHTNING ARE
WITH SOME OF THESE STORMS.  MOVEMENT WAS NORTHEAST AT 30 MILES AN HOUR.

IF YOU ARE ALONG THE MISSOURI RIVER TO THE NORTH OF PIERRE...
YOU SHOULD BE READY TO GET OFF QUICKLY.  IF YOU ARE IN THE PATH
OF THESE STORMS...YOU SHOULD BE READY TO GET TO A PLACE OF SAFETY.

KRAUSE
Special weather statement, Jul 9, 3:36 PM CDT, 4 hours before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HURON SD
335 PM CDT THU JUL 9 1987

...A TORNADO WATCH IS IN EFFECT FOR A LARGE PART OF CENTRAL AND
EASTERN SOUTH DAKOTA UNTIL 8 PM CDT THIS THURSDAY EVENING...

AT 325 PM CDT...SCATTERED INTENSE THUNDERSTORMS...SOME WITH HAIL
AND VERY HEAVY RAIN...WERE DEVELOPING OVER CENTRAL AND SOUTHWESTERN
SOUTH DAKOTA.  THERE ALSO WERE INTENSE STORMS ENTERING NORTH CENTRAL
SOUTH DAKOTA.

STRONG STORMS HAD DEVELOPED OVER SOUTHEASTERN HAAKON...EASTERN JACKSON...
AND WESTERN BENNETT COUNTIES.  THEY EXTENDED FROM 40 MILES SOUTHWEST
OF PIERRE...TO 85 MILES SOUTHEAST OF RAPID CITY.  HAIL...STRONG WIND...
VERY HEAVY RAIN...AND FREQUENT LIGHTNING ARE WITH SOME OF THESE STORMS.
MOVEMENT WAS NORTHEAST AT 30 MILES AN HOUR.

THESE STORMS ARE MOVING INTO STANLEY AND JONES COUNTIES.  IF YOU ARE
ALONG THE MISSOURI RIVER IN CENTRAL SOUTH DAKOTA...YOU SHOULD BE READY
TO GET OFF QUICKLY.  IF YOU ARE IN THE PATH OF THESE STORMS...
YOU SHOULD BE READY TO GET TO A PLACE OF SAFETY.

ALSO...INTENSE STORMS EXTENDED FROM 45 MILES NORTHWEST OF MOBRIDGE...
TO 40 MILES SOUTHWEST OF MOBRIDGE.  THESE STORMS ARE ALSO VERY STRONG...
AND IF YOU ARE IN THE PATH OF THESE...YOU SHOULD GET TO A PLACE OF
SAFETY...AND ALSO GET OFF THE RIVER.

KRAUSE

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 9, 7:36 PM CDTSevere Thunderstorm WarningFSDAurora, Brule, Charles Mix54 min
Jul 9, 8:07 PM CDTSevere Thunderstorm WarningFSDAurora, Davison, Douglas53 min
Jul 9, 9:39 PM CDTTornado WarningFSDHutchinson, Turner36 min
Jul 9, 9:47 PM CDTSevere Thunderstorm WarningFSDTurner43 min
Jul 9, 10:16 PM CDTSevere Thunderstorm WarningFSDBrookings59 min
Jul 9, 10:23 PM CDTSevere Thunderstorm WarningFSDTurner27 min
Jul 9, 10:23 PM CDTSevere Thunderstorm WarningFSDClay, Lincoln52 min
Jul 10, 12:00 AM CDTSevere Thunderstorm WarningFSDTodd, Tripp60 min
Jul 10, 2:06 AM CDTSevere Thunderstorm WarningFSDBon Homme, Charles Mix54 min
Jul 10, 6:51 AM CDTSevere Thunderstorm WarningFSDBon Homme, Charles Mix54 min
Jul 10, 3:56 PM CDTSevere Thunderstorm WarningFSDMellette64 min
Jul 10, 4:05 PM CDTTornado WarningFSDMellette25 min
Jul 10, 4:28 PM CDTTornado WarningFSDMellette32 min
Jul 10, 4:38 PM CDTSevere Thunderstorm WarningFSDTodd67 min
Jul 10, 4:59 PM CDTSevere Thunderstorm WarningFSDMellette61 min
Jul 10, 5:42 PM CDTSevere Thunderstorm WarningFSDTodd, Tripp63 min
Jul 10, 6:42 PM CDTSevere Thunderstorm WarningFSDTodd, Tripp63 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.