Alert archive / Minnesota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 50, NWS Twin Cities, MN

July 11, 1987Olmsted County, Winona County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 11, 1987, 7:07 PM CDT for Olmsted County, Winona County, Minnesota. It was in force for 53 min. 1 report 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
Jul 11, 1987, 7:07 PM CDT (00:07 UTC)
Expired
Jul 11, 1987, 8:00 PM CDT
In force
53 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
Jul 11, 7:10 PM CDTTornado F0Winona, 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 00:00Z, 0.1 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 00:00Z on 1987-07-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2069 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 00:00Z on 1987-07-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 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
2069 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
1014 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KRST 120007
SVRRST
MNC109-169-120100-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ROCHESTER MN
707 PM CDT SAT JUL 11 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 800 PM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTIES OF

SOUTHEAST MINNESOTA...OLMSTED AND WINONA

AT 703 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM 5 MILES WEST
OF ROCHESTER MN MOVING EAST AT 30 MPH.

SOME CITIES INCLUDED IN THE WARNING ARE ROCHESTER AND WINONA.

REMEMBER SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60
MPH..DESTRUCTIVE HAIL..DEADLY LIGHTNING AND VERY HEAVY RAIN. ALSO
SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DOV PRODUCE A TORNADO WITH
LITTLE OR NO ADVANCE WARNING..SO BE ON THE LOOKOUT AND BE PREPARED
TO MOVE TO A PLACE OF SAFETY IF ONE IS SPOTTED.

BUSS

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, 4:48 PM CDT, 2 hours 19 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE MINNEAPOLIS/ST PAUL MN
445 PM CDT SAT JUL 11 1987

...SEVERE THUNDERSTORM WATCH IN EFFECT FOR PARTS OF SOUTHERN AND EASTERN
MINNESOTA AND PARTS WESTERN WISCONSIN...UNTIL 10 PM CDT THIS EVENING...
...SEVERE THUNDERSTORM WARNING FOR MARTIN.. FARIBAULT.. AND WESTERN
FREEBORN COUNTIES OF EXTREME SOUTH CENTRAL MINNESOTA UNTIL 530 PM CDT...

AT 430 PM CDT...AN AREA OF SEVERE THUNDERSTORMS WERE LOCATED ALONG AND
AND JUST NORTH OF THE IOWA BORDER..NEAR THE TOWNS OF SHERBURN..FAIRMONT
BLUE EARTH AND BRICELYN.

THESE THUNDERSTORM WERE MOVING NORTHEAST AT 35 MILES AN HOUR. THESE ARE
DANGEROUS THUNDERSTORMS AND IF THREATENING WEATHER APPROACHES YOU TAKE
SHELTER IMMEDIATELY.. PROPERTY CAN BE REPLACED.
 CARLYON
Special weather statement, Jul 11, 5:54 PM CDT, 1 hour 13 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE MINNEAPOLIS/ST PAUL MN
552 PM CDT SAT JUL 11 1987

...SEVERE THUNDERSTORM WATCH IN EFFECT FOR PARTS OF SOUTHERN AND EASTERN
MINNESOTA AND PARTS WESTERN WISCONSIN...UNTIL 10 PM CDT THIS EVENING...
...SEVERE THUNDERSTORM WARNING IN EFFECT FOR NORTHEAST FREEBORN.. STEELE
AND DODGE COUNTIES OF SOUTH CENTRAL MINNESOTA  UNTIL 615 PM CDT...
...SEVERE THUNDERSTORM WARNING FOR NORTHERN WINNOA AND EASTERN WABASHA
   COUNTIES OF SOUTHEAST MINNESOTA UNTIL 630 PM CDT...
AT 535 PM CDT...AN AREA OF SEVERE THUNDERSTORMS WAS LOCATED NEAR THE
INTERSECTION OF I-35W AND 1-90..FROM BLUE EARTH THRU ALBERT LEA OVER TO
AUSTIN.. MOVING NORTHEAST AT 30 MPH.
SOME OF THE TOWNS IN THE PATH OF THESE STORMS WASECA..OWATONNA AND DODGE
CENTER OF SOUTH CENTRAL MINNESOTA.
MORE SEVERE THUNDERSTORMS WERE LOCATED ALONG THE WINNONA/WABASHA COUNTY
LINE JUST SOUTH OF WABASHA.. MOVING EAST AT 25 MPH..

THESE ARE DANGEROUS THUNDERSTORMS AND IF THREATENING WEATHER APPROACHES
YOU TAKE SHELTER IMMEDIATELY PROTECT YOUR LIVE PROPERTY CAN BE REPLACED.
Special weather statement, Jul 11, 6:55 PM CDT, 12 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE MINNEAPOLIS/ST PAUL MN
655 PM CDT SAT JUL 11 1987

...SEVERE THUNDERSTORM WATCH IN EFFECT FOR PARTS OF SOUTHERN AND EASTERN
MINNESOTA AND PARTS WESTERN WISCONSIN...UNTIL 10 PM CDT THIS EVENING...

AT 635 PM CDT...AN AREA OF POWERFUL THUNDERSTORMS WERE BETWEEN ROCHESTER
AND LA CROSSE JUST SOUTH OF I-90 AND ST. CHARLES..OTHER POWEREFUL STORMS
WERE LOCATED ACROSS EXTREME SOUTH CENTRAL MUCH OF SOUTHEAST MINNESOTA.
FOR THE MOST PART THE STORMS WERE SOUTH OF A LINE FROM FAIRMONT TO
OWATONNA TO THE MISSISSIPI RIVER JUST NORTH OF WABASHA NEAR LAKE CITY.

SOME OF THE TOWNS IN THE PATH OF THESE POWERFUL STORMS ARE..LEWISTONE..
WINONA.. AND ELBA MINNESOTA..FOUNTAIN CITY AND DODGE WISCONSIN.

MOVEMENT WAS TO THE NORTHEAST 25 TO 30 MILES AN HOUR.
 CARLYON

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 11, 10:31 PM CDTSevere Thunderstorm WarningMPXRedwood, Renville44 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.