Alert archive / Iowa / Severe Thunderstorm Warnings in 1989

Severe Thunderstorm Warning 41, NWS Sioux Falls, SD

June 20, 1989Lyon County, Iowa; Rock County, Minnesota

NWS Sioux Falls, SD issued this severe thunderstorm warning at Jun 20, 1989, 11:38 PM CDT for Lyon County, Iowa; Rock County, Minnesota. It was in force for 52 min.

The area

The counties it named.

The facts

Issued
Jun 20, 1989, 11:38 PM CDT (04:38 UTC)
Expired
Jun 21, 1989, 12:30 AM CDT
In force
52 min
Issued by
NWS Sioux Falls, SD
Area
Whole counties

Counties Lyon County, IA, Rock 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

Aberdeen, SD (KHON), launched 00:00Z, 4.6 hours before the alert went out and 231 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 1989-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 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 1989-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 104 square meters per square second.193958Sfc1 km3 km6 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
NaN m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
104 m²/s²
0-3 km storm-relative helicity
180 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KFSD 210439
SVRFSD
IAC119-MNC117-133-210530-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1138 PM CDT TUE JUN 20 1989
 
THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1230 AM CDT
FOR PEOPLE IN THE FOLLOWING COUNTIES...
 
IN NORTHWEST IOWA
          ...LYON
IN SOUTHWEST MINNESOTA
          ...SOUTHERN PIPESTONE...ROCK
 
SOME CITIES INCLUDED IN THIS SEVERE THUNDERSTORM WARNING ARE
PIPESTONE AND LUVERNE IN SOUTHWEST MINNESOTA AND ROCK RAPIDS
IN NORTHWEST IOWA.
 
AT 1133 PM CDT RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS
EXTENDING FROM 30 MILES NORTHEAST OF SIOUX FALLS...OR 10 MILES
SOUTHWEST OF PIPESTONE...TO 25 MILES SOUTHEAST OF SIOUX FALLS
NEAR INWOOD IOWA.
 
THIS LINE OF SEVERE THUDNERSTORMS WAS MOVING EAST AT 30 MPH.
 
IF YOU ARE IN THE PATH OF THIS STORM...YOU SHOULD GET TO A
REINFORCED SHELTER. A SEVERE THU%NDERSTORM 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

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, Jun 20, 7:43 PM CDT, 3 hours 55 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
740 PM CDT TUE JUN 20 1989

    ...THUNDERSTORMS BOIL UP IN SOUTHCENTRAL SOUTH DAKOTA...

AT 740 PM CDT SCATTERED THUNDERSTORMS WERE QUICKLY DEVELOPING
OVER SOUTHCENTRAL SOUTH DAKOTA. THE THUNDERSTORMS WERE IN AN AREA
FROM AROUND BONESTEEL TO STICKNEY...OR ABOUT 60 TO 25 MILES SOUTHWEST
OF MITCHELL SOUTH DAKOTA. ANY OF THESE THUNDERSTORMS COULD PRODUCE
STRONG GUSTY WINDS...HAIL...AND BRIEF HEAVY RAINS AS THEY MOVE NORTHEAST
AT ABOUT 30 MPH ALONG A COLD FRONT. RESIDENTS IN THE AREA FROM AROUND
BONESTEEL TO MITCHELL SHOULD BE ON THE LOOKOUT FOR THESE STORMS THIS
EVENING THROUGH AT LEAST 10 PM CDT.

BOATERS ON LAKE FRA;NCIS CASE SHOULD SEEK SAFE HARBOR SINCE THUNDERSTORMS
ARE EXPECTED THROUGH THE REMAINDER OF TONIGHT.
KAPELA
Special weather statement, Jun 20, 7:46 PM CDT, 3 hours 52 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HURON SD
745 PM CDT TUE JUN 20 1989

AT 730 PM CDT...A THUNDERSTORM WITH VERY HEAVY RAIN AND HAIL HAD
BEGUN MOVING INTO SOUTHEAST SOUTH DAKOTA FROM NEBRASKA. THE STORM
WAS NEAR BONESTEEL...WHICH IS 75 MILES SOUTHWEST OF MITCHELL.

MOVEMENT WAS NORTH AT 15 MILES AN HOUR.

VERY HEAVY RAIN...HAIL...AND STRONG WIND IS LIKELY IN THE AREA
ALONG AND 15 MILES EITHER SIDE OF A ALINE FROM BONESTEEL TO PLATTE...
WHICH IS 50 MILES SOUTHWEST OF MITCHELL.

SPRINGER
Local storm report, Jun 20, 10:12 PM CDT, 1 hour 26 minutes before
STORM REPORT
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1010 PM CDT TUE JUN 20 1989

STORM DATA FOR SOUTH DAKOTA

 TIME            COUNTY..LOCATION           CHARACTER OF STORM..DAMAGE
.......................................................................

 651 PM CDT     GREGORY...BURKE            HEAVY RAINS AND PEA SIZE HAIL

 900 PM CDT     AURORA...WHITE LAKE        3/4 INCH SIZE HAIL OR LARGER
                                           ROOFS BLOWN OFF A FEW SMALL
                                           SHEDS

 940 PM CDT     CHARLES MIX...GEDDES       FARMER REPORTED 2.50 INCHES
                                           OF RAIN IN ONE HOUR

 943 PM CDT     DAVISON...MITCHELL         RADIO STATION HAD 66 MPH GUST
KAPELA
Special weather statement, Jun 20, 11:38 PM CDT, 0 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE HURON SD
1140 PM CDT TUE JUN 20 1989

...A SEVERE THUNDERSTORMS WATCH IS IN EFFECT UNTIL 2 AM CDT FOR MOST OF
EASTERN SOUTH DAKOTA...

AT 1130 PM CDT...NUMEROUS THUNDERSTORMS WITH VERY HEAVY RAIN CONTINUED
OVER EASTERN SOUTH DAKOTA...MAINLY IN THE AREA NORTH AND EAST OF A LINE
FROM CHAMBERLAIN...THROUGH HURON...TO ABERDEEN.

VERY HEAVY RAIN...HAIL...AND STRONG WIND  ARE LIKELY IN THE AREA EAST OF
THE JAMES RIVER AND NORTH OF A LINE FROM HURON TO SIOUX FALLS.

THE STORMS WERE MOVING NORTH AT 25 MILES AN HOUR.

SPRINGER

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 12:20 AM CDTSevere Thunderstorm WarningFSDSioux25 min
Jun 20, 11:38 PM CDTSevere Thunderstorm WarningFSDPipestone52 min

Nearby

Severe Thunderstorm Warnings in Iowa, 1989Severe Thunderstorm Warnings in Minnesota, 1989Every severe thunderstorm warning in 1989

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.