Alert archive / Minnesota / Severe Thunderstorm Warnings in 1989

Severe Thunderstorm Warning 70, NWS Twin Cities, MN

August 4, 1989Olmsted County, Winona County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Aug 4, 1989, 6:21 PM CDT for Olmsted County, Winona County, Minnesota. It was in force for 39 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
Aug 4, 1989, 6:21 PM CDT (23:21 UTC)
Expired
Aug 4, 1989, 7:00 PM CDT
In force
39 min
Issued by
NWS Twin Cities, MN
Area
Whole counties

Counties Olmsted County, MN, Winona County, MN

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

TimeReportWhereRemark
Aug 4, 6:29 PM CDTHail 1.5Olmsted, MN
Aug 4, 6:40 PM CDTHail 1.25Olmsted, MN

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

Minneapolis, MN (KSTC), launched 12:00Z, 11.4 hours before the alert went out and 153 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 12:00Z on 1989-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 679 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, Minneapolis, MN at 12:00Z on 1989-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 60 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
679 J/kg
Mixed-layer CIN
-162 J/kg
Mixed-layer LCL
1471 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
60 m²/s²
0-3 km storm-relative helicity
96 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KRST 042330
SVRRST
MNC109-169-050000-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ROCHESTER MN
621 PM CDT FRI AUG 4 1989
 
THE NATIONAL WEATHER SERVICE IN ROCHESTER HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  700 PM CDT
FOR PEOPLE IN THE FOLLOWING COUNTIES...
 
IN SOUTHEAST MINNESOTA
          ...OLMSTED...WINONA
 
THIS INCLUDES THE TOWNS OF EYOTA AND CHESTER MINNESOTA.
 
AT 615 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM AT
ROCHESTER.  THE STORM HAS PRODUCED NUMEROUS REPORTS OF
HAIL RANGING IN SIZE FROM 1/2 INCH TO 1 INCH IN DIAMETER
IN THE CITY OF ROCHESTER.  1/4 INCH HAIL OCCURRED AT
THE ROCHESTER AIRPORT.  13 MILES SOUTHWEST OF WINONA
IN THE TOWN OF LEWISTON A THUNDERSTORM PRODUCED WIND
GUSTS TO 60 MPH.
 
THIS IS A DANGEROUS STORM.  IF YOU ARE IN ITS PATH YOU SHOULD
PREPARE FOR DAMAGING WIND IN EXCESS OF 55 MPH...LARGE HAIL...AND
DEADLY LIGHTNING.  PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT STAY AWAY FROM WINDOWS.
 
A SEVERE THUNDERSTORM IS ALSO IN EFFECT UNTIL 11PM THIS EVENING.
 
DE/ST

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, Aug 4, 6:09 PM CDT, 12 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MINNEAPOLIS/ST PAUL MN
600 PM CDT FRI AUG 4 1989

   ...SEVERE THUNDERSTORM WATCH BEING CLEARED FOR DAKOTA COUNTY...

STRONG THUNDERSTORMS CONTINUE OVER PORTIONS OF SOUTH CENTRAL AND
SOUTHEAST MINNESOTA WHERE SEVERE THUNDERSTORM WATCH 656 WILL REMAIN
IN EFFECT. THIS AREA OF SEVERE WEATHER HAS SLOWLY SAGGED SOUTHWARD
DURING THER PAST SEVERAL HOURS AND IS PROJECTED TO CONTINUE THIS TREND.
THESE IMPROVING CONDITIONS HAVE PROMPTED THE TWIN CITIES FORECAST
OFFICE TO CLEAR THOSE PORTIONS OF THE SOUTHERN METROPOLITIAN AREA
FROM SEVERE THUNDERSTORM WATCH 656.
RND

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 4, 1:51 AM CDTSevere Thunderstorm WarningMPXMille Lacs39 min
Aug 4, 4:26 PM CDTSevere Thunderstorm WarningMPXSteele, Waseca49 min
Aug 4, 5:10 PM CDTSevere Thunderstorm WarningMPXDodge, Goodhue, Rice, Steele50 min
Aug 4, 5:10 PM CDTSevere Thunderstorm WarningMPXWabasha50 min
Aug 4, 5:24 PM CDTSevere Thunderstorm WarningMPXFillmore, Houston66 min
Aug 4, 5:34 PM CDTSevere Thunderstorm WarningMPXDodge, Olmsted56 min

Nearby

Severe 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.