Alert archive / Minnesota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 62, NWS Twin Cities, MN

July 20, 1987Lac qui Parle County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 20, 1987, 8:00 PM CDT for Lac qui Parle County, Minnesota. It was in force for 60 min.

The area

The counties it named.

The facts

Issued
Jul 20, 1987, 8:00 PM CDT (01:00 UTC)
Expired
Jul 20, 1987, 9:00 PM CDT
In force
60 min
Issued by
NWS Twin Cities, MN
Area
Whole counties

County Lac qui Parle 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, 1.0 hours before the alert went out and 176 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 1987-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2744 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 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 1987-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 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
2744 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
1591 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
125 m²/s²
Significant tornado parameter
0.4
Supercell composite
5.6

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KSTC 210200 RRA
SVRSTC
MNC073-210200-

BULLETIN-IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST CLOUD MN
800 PM CDT MON JUL 20 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL 900 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTY OF

CENTRAL  MINNESOTA...LAC QUI PARLE INCLUDING THE CITIES OF MARIETTA
AND MADISON.

AT 755 PM CDT RADAR INDICATED A SEVERE THUNDERSTORM IN EXTREME
WESTERN LAC QUI PARLE COUNTY OF WEST CENTRAL MINNESOTA. THIS STORM
WAS MOVING EAST AT 35 MPH.

LARGE HAIL...DANGEROUS LIGHTNING...HEAVY RAINFALL...AND DAMAGING
WINDS CAN BE EXPECTED FROM SEVERE THUNDERSTORMS.

IF THREATENING WEATHER APPROACHES...YOU SHOULD GO TO A SvAFE PLACE
IMMEDIATELY...AND YOU SHOULD ASK THE NEAREST LAW ENFORCEMENT AGENCY
TO RELAY YOUR SEVERE WEATHER REPORT TO THE LOCAL NATIONAL WEATHER
SERVICE OFFICE.

YOUNG

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, 2:16 PM CDT, 5 hours 44 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MINNEAPOLIS/ST PAUL MN
215 PM CDT MON JUL 20 1987

...SEVERE THUNDERSTORM WATCH NUMBER 404 CANCELED FOR EAST CENTRAL
   MINNESOTA...

THE NATIONAL WEATHER SERVICE HAS CANCELED THE SEVERE THUNDERSTORM WATCH
ISSUED EARLIER FOR EAST CENTRAL MINNESOTA WHICH INCLUDED THE TWIN CITIES
METRO AREA.

THE LINE OF THUNDERSTORMS HAD MOVED OUT OF MINNESOTA AND INTO WEST
WISCONSIN.

WITH A FRONTAL BOUNDARY STILL PRESENT OVER SOUTHERN MINNESOTA JUST
SOUTH OF THE TWIN CITIES...THUNDERSTORMS COULD REDEVELOP LATER THIS
AFTERNOON.

PERSONS SHOULD REMAIN ALERT TO LATER FORECASTS AND STATEMENTS FROM
THE NATIONAL WEATHER SERVICE DURING THE AFTERNOON.
JHM
Special weather statement, Jul 20, 2:53 PM CDT, 5 hours 7 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE MINNEAPOLIS/ST PAUL MN
250 PM CDT MON JUL 20 1987

AT 235 PM CDT...INTENSE THUNDERSTORMS CONTINUED OVER WEST CENTRAL
WISCONSIN FROM 35 MILES SOUTHEAST OF EAU CLAIRE NEAR FAIRCHILD TO 40
MILES SOUTHWEST OF EAU CLAIRE NEAR MONDOVI.

VERY HEAVY RAINS..STRONG GUSTY WINDS AND DANGEROUS LIGHTNING CAN BE
 EXPECTED WITH THESE STORMS AS THEY MOVE SOUTH AT 45 MILES AN HOUR.

THE STORMS SHOULD BE LOCATED ALONG A LINE FROM NEAR BLACK RIVER FALLS TO
25 MILES NORTH OF LA CROSSE BY 315 PM CDT.

THESE STORMS WERE PART OF AN AREA OF SHOWERS AND THUNDERSTORMS THAT
EXTENDED FROM 25 MILES EAST OF HAYWARD TO 25 MILES WEST OF WAUSAU TO#
SOUTH OF EAU CLAIRE.
STANDFIELD
JHM
Special weather statement, Jul 20, 3:47 PM CDT, 4 hours 13 minutes before
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE MINNEAPOLIS/ST PAUL MN
345 PM CDT MON JUL 20 1987

....SEVERE THUNDERSTORM WATCH UNTIL 9 PM CDT FOR PARTS OF WEST CENTRAL
WISCONSIN....

AT 330 PM CDT...STRONG THUNDERSTORMS CONTINUED OVER WEST CENTRAL WISCONSIN
35 MILES NORTHEAST OF LA CROSSE JUST NORTH AND WEST OF BLACK RIVER FALLS.

THE STORMS WERE MOVING SOUTH AT 40 MILES AN HOUR AND SHOULD BE LOCATED
JUST NORTHEAST OF LA CROSSE TO NORTH OF TOMAH BY 415 PM CDT.

VERY HEAVY RAINS...STRONG GUSTY WINDS AND DANGEROUS LIGHTNING CAN BE
 EXPECTED WITH THE STORMS.

ELSEWHERE..SHOWERS AND THUNDERSTORMS HAD DEVELOPED OVER WEST CENTRAL
MINNESOTA FROM THE MINNESOTA/SOUTHI DAKOTA BORDER NEAR BIG STONE LAKE
TO WEST OF ALEXANDRIA TO 35 MILES SOUTH OF DETROIT LAKES.
MOVEMENT WAS NORTHEAST AT 45 MILES AN HOUR. STANDFIELD
Special weather statement, Jul 20, 6:21 PM CDT, 1 hour 39 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MINNEAPOLIS/ST PAUL MN
615 PM CDT MON JUL 20 1987

    ..THUNDERSTORMS TO AFFECT THE LAKE MINNETONKA AREA..

A STRONG THUNDERSTORM HAS BEEN DEVELOPING RAPIDLY OVER WESTERN HENNEPIN
COUNTY IN THE MOUND AND INDEPENDENCE AREA. THIS THUNDERSTORM WAS SLOWLY
MOVING TO THE EAST SOUTHEAST AND IT WILL MOVE ACROSS PARTS OF LAKE
MINNETONKA THROUGH 700 PM.

SOME LIGHTNING..GUSTY WINDS AND HEAVY RAINS ARE POSSIBLE WITH THIS STORM.

PERSONS BOATING OR FISHING ON LAKE MINNETONKA SHOULD MAKE PLANS NOW TO
HEAD FOR SAFE HARBOR UNTIL THE THUNDERSTORMS PASS BY THE LAKE.

AT 615 PM CDT..OTHER THUNDERSTORMS WERE FORMING OVER SCOTT..WESTERN ANOKA
AND WRIGHT COUNTIES OF THE WESTERN METROPOLITAN AREA.

THEY WERE MOVING EAST AT ABOUT 20 MILES AN HOUR.
SWANBERG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 7:06 PM CDTTornado WarningMPXDakota24 min
Jul 20, 7:13 PM CDTTornado WarningMPXAnoka, Hennepin, Ramsey27 min
Jul 20, 7:14 PM CDTSevere Thunderstorm WarningMPXMeeker61 min
Jul 20, 8:09 PM CDTSevere Thunderstorm WarningMPXRamsey, Washington51 min
Jul 20, 9:34 PM CDTSevere Thunderstorm WarningMPXHennepin, Scott56 min
Jul 20, 9:45 PM CDTSevere Thunderstorm WarningMPXKandiyohi, Meeker60 min
Jul 20, 10:36 PM CDTSevere Thunderstorm WarningMPXCarver, Hennepin54 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.