Alert archive / Minnesota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 101, NWS Sioux Falls, SD

July 20, 1987Murray County, Minnesota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jul 20, 1987, 10:52 PM CDT for Murray County, Minnesota. It was in force for 68 min.

The area

The counties it named.

The facts

Issued
Jul 20, 1987, 10:52 PM CDT (03:52 UTC)
Expired
Jul 21, 1987, 12:00 AM CDT
In force
68 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

County Murray County, MN

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

Minneapolis, MN (KSTC), launched 00:00Z, 3.9 hours before the alert went out and 195 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, Minneapolis, MN at 00:00Z on 1987-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3871 joules per kilogram.LCLEL10008507005003002001001 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, Minneapolis, MN at 00:00Z on 1987-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 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
3871 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
860 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
73 m²/s²
Significant tornado parameter
0.9
Supercell composite
4.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFSD 210352
SVRFSD
SDC087-099-MNC101-133-210500-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1052 PM CDT MON JUL 20 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL MIDNIGHT CDT FOR PEOPLE IN THE FOLLOWING COUNTIES...
 
IN SOUTHEAST SOUTH DAKOTA
          ...SOUTHERN MCCOOK...MINNEHAHA
IN SOUTHWEST MINNESOTA
          ...MURRAY...NORTHERN ROCK
 
AT 1050 PM CDT RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS
EXTENDING FROM 40 MILES NORTHWEST OF SALEM TO 60 MILES NORTHEAST
OF SIOUX FALLS NEAR RUTHTON MINNESOTA. THIS LINE OF THUNDERSTORMS
WAS MOVING SOUTHEAST AT 15 MPH.
 
SOME CITIES INCLUDED IN THIS WARNING ARE...SALEM..SIOUX FALLS AND
HARDWICK AND SLAYTON.
 
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.
 
KAPELA/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 20, 5:44 PM CDT, 5 hours 8 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HURON SD
535 PM CDT MON JUL 20 1987

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHERN CLARK
   COUNTY UNTIL 615 PM CDT...

AT 530 PM CDT...AN ISOLATED SEVERE THUNDERSTORM CONTINUED OVER NORTHERN
CLARK COUNTY OF NORTHEAST SOUTH DAKOTA.

THE HEAVIEST PART OF THIS STORM WAS LOCATED JUST NORTH OF CLARK.
LARGE HAIL...DAMAGING THUNDERSTORM WINDS AND VERY HEAVY 1RAINS CAN BE
EXPECTED WITH THIS STORM.

MOVEMENT WAS NORTHEAST AT 5 MILES AN HOUR.
PFEIFFER
Special weather statement, Jul 20, 6:47 PM CDT, 4 hours 5 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HURON SD
635 PM CDT MON JUL 20 1987

AT 630 PM CDT...SCATTERED INTENSE THUNDERSTORMS CONTINUED OVER PARTS
OF NORTHEAST...EAST CENTRAL AND SOUTH CENTRAL SOUTH DAKOTA.

THESE STORMS WERE MOSTLY WITHIN A 50 MILE WIDE BAND BETWEEN WILMOT
AND THE NEBRASKA BORDER...SOUTHWEST OF MISSION.  THE HEAVIEST STORMS
WERE LOCATED 10 MILES NORTHWEST OF WATERTOWN...JUST NORTH OF BRISTOL
...5 MILES SOUTHEAST OF CONDE...JUST WEST OF DOLAND...10 MILES
NORTHEAST OF FORT THOMPSON AND 10 MILES SOUTHEAST OF PRESHO.

THESE STORMS ARE CAPABLE OF PRODUCING VERY HEAVY RAIN...HAIL AND
DANGEROUS LIGHTNING.  PERSONS IN THE NORTHEAST...EAST CENTRyAL AND SOUTH
CENTRAL PARTS OF SOUTH DAKOTA SHOULD BE ON THE ALERT FOR THREATENING
WEATHER.

MOVEMENT WAS NORTHEAST AT 15 MILES AN HOUR.
PFEIFFER
Special weather statement, Jul 20, 9:05 PM CDT, 1 hour 47 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
905 PM CDT MON JULY 20 1987

AT 9PM CDT...THUNDERSTORMS...SOME OF THEM INTENSE WITH HEAVY RAIN
WERE OCCURRING OVER PARTS OF SOUTHEAST SOUTH DAKOTA AND SOUTHWEST
MINNESOTA.  THE THUNDERSTORMS EXTENDED NORTH OF A LINE FROM ABOUT
90 MILES WEST/NORTHWEST OF SIOUX FALLS...NEAR WOONSOCKET SOUTH
DAKOTA...NORTHEAST TO ABOUT 100 MILES NORTHEAST OF SIOUX FALLS...
NEAR GRANITE FALLS MINNESOTA.

SOME OF THE MOST INTENSE THUNDERSTORMS WERE OCCURRING ABOUT 90
MILES WEST/NORTHWEST OF SIOUX FALLS...JUST NORTH OF WOONSOCKET AND
ABOUT 85 MILES NORTH OF SIOUX FALLS...NEAR BRANDT SOUTH DAKOTA.

THESE THUNDERSTORMS ARE CAPABLE OF PRODUC;ING VERY HEAVY RAIN...HAIL
AND DANGEROUS LIGHTNING.  THEY ARE MOVING NORTHEAST AT ABOUT 15 MILES
AN HOUR.
GOLDEN
Special weather statement, Jul 20, 9:27 PM CDT, 1 hour 25 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
925 PM CDT MON JULY 20 1987

AT 925 PM CDT A THUNDERSTORM WITH STRONG GUSTY WINDS AND VERY HEAVY
RAIN WAS LOCATED 10 MILES WEST OF BROOKINGS SOUTH DAKOTA. THIS THUNDER/
STORM WAS PRODUCING WIND GUSTS TO 45 MPH ACCORDING TO THE BROOKINGS
FIRE DEPARTMENT. SMALL HAIL WAS ALSO POSSIBLE WITH THIS THUNDERSTORM AS
IT MOVED EAST/SOUTHEAST AT 15 MPH.

THIS THUNDERSTORM WAS PART OF A LINE OF THUNDERSTORMS WHICH EXTENDED
FROM 35 MILE NORTH OF REDWOOD FALLS MINNESOTA TO JUST NORTH OF
CHAMBERLAIN SOUTH DAKOTA. THIS LINE OF THUNDERSTORMS WAS SAGGING SLOWLY
SOUTH AT 10 MPH. EVENTUALLY THE CITIES OF MITCHELL AND SIOUX FALLS
WILL EXPERIENCE BEFORE MIDNIGHT CDT IF THESE STORM HOLD TOGETHER.
ANY OF THE THUNDERSTORMS CAN PRODUCE GUSTY WINDS TO AROUND 45 MPH...
SMALL HAIL...AND VERY HEAVY RAINS. SMALL STREAM AND URBAN FLOODING IS
ALSO POSSIBLE DUE TO REPEAT THUNDERSTORMS PASSINhG THROUGH THE SAME
AREAS.
KAPELA
Special weather statement, Jul 20, 10:05 PM CDT, 47 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1005 PM CDT MON JULY 20 1987

AT 1000 PM CDT...THUNDERSTORMS...SOME OF THEM INTENSE WITH HEAVY RAIN
...CONTINUED OVER PARTS OF EASTERN SOUTH DAKOTA AND NORTHWEST MIN/
NESOTA.  THESE THUNDERSTORMS EXTENDED NORTH OF A LINE FROM ABOUT 90
MILES WEST OF SIOUX FALLS...NEAR PLANKINTON SOUTH DAKOTA...NORTHEAST
TO ABOUT 100 MILES NORTHEAST OF SIOUX FALLS...NEAR REDWOOD FALLS
MINNESOTA.

SOME OF THE MOST INTENSE THUNDERSTORMS WERE OCCURRING ABOUT 45 MILES
NORTHWEST AND NORTH OF SIOUX FALLS...NEAR HOWARD AND BROOKINGS SOUTH
DAKOTA.

THESE THUNDERSTORMS CAN PRODUCE HEAVY RAIN...HAIL AND DEADLY LIGHT/
NING AS THEY MOVE EAST AT ABOUT 10 MILES AN HOUR.
GOLDEN
Special weather statement, Jul 20, 10:48 PM CDT, 4 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HURON SD
1040 PM CDT MON JUL 20 1987

...A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 2 AM CDT FOR NORTHEAST
   AND EAST CENTRAL SOUTH DAKOTA...

AT 1030 PM CDT...NUMEROUS INTENSE THUNDERSTORMS CONTINUED OVER EASTERN
SOUTH DAKOTA...MAINLY IN THE AREA ALONG AND 60 MILES EITHER SIDE OF A
LINE FROM THE MINNESOTA LINE NORTHEAST OF BROOKINGS TO FORT THOMPSON...
OR 60 MILES SOUTHEAST OF PIERRE. THE STRONGEST THUNDERSTORMS WERE IN
SOUTHEAST SOUTH DAKOTA...EAST OF THE MISSOURI RIVER AND SOUTH OF A LINE
FROM PIERRE TO BROOKINGS.

VERY HEAVY RAIN AND STRONG WIND ARE LIKELY WITH THE STORMS. HAIL IS
POSSIBLE.

MOVEMENT WAS EAST AT 10 MILES AN HOUR.

SPRINGER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 10:06 PM CDTSevere Thunderstorm WarningFSDPipestone54 min
Jul 20, 10:52 PM CDTSevere Thunderstorm WarningFSDRock68 min
Jul 20, 11:33 PM CDTSevere Thunderstorm WarningFSDNobles, Rock57 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 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.