Alert archive / South Dakota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 85, NWS Sioux Falls, SD

July 11, 1987Mellette County, South Dakota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 11, 1987, 4:35 PM CDT for Mellette County, South Dakota. It was in force for 55 min.

The area

The counties it named.

The facts

Issued
Jul 11, 1987, 4:35 PM CDT (21:35 UTC)
Expired
Jul 11, 1987, 5:30 PM CDT
In force
55 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Mellette 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 12:00Z, 9.6 hours before the alert went out and 179 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 1987-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 12 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 12:00Z on 1987-07-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 156 square meters per square second.1939587897Sfc1 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
12 J/kg
Mixed-layer CIN
-208 J/kg
Mixed-layer LCL
719 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
156 m²/s²
0-3 km storm-relative helicity
205 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 112135
SVRFSD
SDC095-112230-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
435 PM CDT SAT JUL 11 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL  530 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY...
 
IN SOUTH CENTRAL SOUTH DAKOTA
          ...EASTERN MELLETTE
WHITE RIVER MAY BE EFFECTED BY THIS STORM. AT 430 PM CDT A TORNADO
WAS REPORTED A FEW MILES WEST OF WHITE RIVER BUT IT LIFTED IN A
COUPLE OF MINUTES.
 
 
 
THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE A TORNADO WITH LITTLE
OR NO ADVANCE WARNING SO BE ON THE LOOKOUT.
KOSCIELSKI

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 11, 3:14 PM CDT, 1 hour 21 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
315 PM CDT SAT JUL 11 1987

AT 305 PM CDT RADAR INDICATED 2 INTENSE THUNDERSTORMS WITH VERY HEAVY
RAIN OVER SIOUX COUNTY IOWA. THE STRONGEST WAS LOCATED 7 MILES EAST
OF SIOUX CENTER IOWA AND THE OTHER WAS LOCATED 12 MILES SOUTHWEST OF
SIOUX CENTER. THE STORMS WERE MOVING TO THE EAST AT 25 MPH.

PEOPLE IN THE PATH OF THESE STORMS SHOULD BE ON THE LOOKOUT FOR POSSIBLE
SEVERE WEATHER IN THE FORM OF LARGE HAIL AND STRONG GUSTY WINDS.
KOSCIELSKI
Special weather statement, Jul 11, 3:38 PM CDT, 57 minutes before
^DSMSPSSUX
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX CITY IA
335 PM CDT SAT JUL 11 1987

...SEVERE THUNDERSTORM WATCH UNTIL 9PM CDT THIS SATUDAY NIGHT...

AT 330 PM CDT SCATTERED SHOWERS AND THUNDERSTORMS CONTINUED IN A 30
MILE WIDE LINE FROM 90 MILES NORTHEAST OF SIOUX CITY IOWA TO COLUMBUS
NEBRASKA. THE STRONGEST STORMS WERE 5 MILES SOUTHEAST OF HAWARDEN IOWA
OR 45 MILES NORTH OF SIOUX CITY AND 5 MILES EAST OF SHELDON IOWA 60
MILES NORTHEAST OF SIOUX CITY. THESE THUNDERSTORMS WERE MOVING TO THE
NORTHEAST AT 30 MILES AN HOUR.

PEOPLE IN NORTHERN OBRIEN COUNTY AND SIOUX COUNTY IN IOWA SHOULD REMAIN
ALERT AND BE PREPARED TO TAKE COVER IF SEVERE WEATHER IS OBSERVED. THESE
THUNDERSTORMS ARE CAPABLE OF PRODUCING LARGE HAIL...STRONG GUSTY WIND...
DANGEROUS LIGHTNING AND VERY HEAVY RAIN.
ROSNER
Special weather statement, Jul 11, 4:01 PM CDT, 34 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
400 PM CDT SAT JUL 11 1987

...INTENSE THUNDERSORMS ACROSS THE EXTREME SOUTHEAST CORNER OF
SOUTH DAKOTA AND NORTHWEST IOWA...

AT 4 PM CDT INTENSE THUNDERSTORMS WITH VERY HEAVY RAIN CONTINUED
ACROSS THE EXTREME SOUTHEAST CORNER OF SOUTH DAKOTA AND NORTHWEST
IOWA.

THESE THUNDERSTORM WERE IN A BAND EXTENDING FROM 60 MILES SOUTH OF
SIOUX FALLS...NEAR ELK POINT SOUTH DAKOTA TO 75 MILES EAST OF SIOUX
FALLS...NEAR MILFORD IOWA.

THESE THUNDERSTORMS ARE CAPALBE OF PRODUCING VERY HEAVY RAIN...HAIL
...STRONG GUSTY WINDS AND DANGEROUS LIGHNING AS THEY MOVE NORTHEAST
AT 25 MILES AN HOUR.
BUSS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 10, 11:01 PM CDTSevere Thunderstorm WarningFSDTodd, Tripp59 min
Jul 11, 2:00 AM CDTSevere Thunderstorm WarningFSDCharles Mix, Gregory60 min
Jul 11, 2:00 AM CDTSevere Thunderstorm WarningFSDBon Homme60 min
Jul 11, 2:23 AM CDTSevere Thunderstorm WarningFSDDavison, Douglas, Hanson, Hutchinson67 min
Jul 11, 2:37 AM CDTSevere Thunderstorm WarningFSDBrookings, Lake68 min
Jul 11, 2:55 AM CDTSevere Thunderstorm WarningFSDTurner, Yankton65 min
Jul 11, 2:55 AM CDTSevere Thunderstorm WarningFSDBon Homme65 min
Jul 11, 3:16 AM CDTSevere Thunderstorm WarningFSDLake, McCook59 min
Jul 11, 3:46 AM CDTSevere Thunderstorm WarningFSDMinnehaha, Moody59 min
Jul 11, 3:46 AM CDTSevere Thunderstorm WarningFSDLincoln59 min
Jul 11, 5:00 PM CDTSevere Thunderstorm WarningFSDLincoln30 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.