Alert archive / Minnesota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 117, NWS Twin Cities, MN

August 21, 1987Dodge County, Mower County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Aug 21, 1987, 2:39 AM CDT for Dodge County, Mower County, Minnesota. It was in force for 36 min.

The area

The counties it named.

The facts

Issued
Aug 21, 1987, 2:39 AM CDT (07:39 UTC)
Expired
Aug 21, 1987, 3:15 AM CDT
In force
36 min
Issued by
NWS Twin Cities, MN
Area
Whole counties

Counties Dodge County, MN, Mower 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, 7.7 hours before the alert went out and 128 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 1987-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1057 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 1987-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 34 square meters per square second.1939587897Sfc1 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
1057 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
1129 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
89 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.7

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KRST 210739
SVRRST
MNC039-099-210815-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ROCHESTER MN
239 AM CDT FRI AUG 21 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 315 AM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTIES OF

SOUTHEAST MINNESOTA...SOUTHERN DODGE AND MOWER

THIS WARNING INCLUDES THE CITIES OF AUSTIN AND HAYFIELD.

AT 230 AM RADAR INDICATED A SEVERE THUNDERSTORM 20 MILES NORTHWEST
OF AUSTIN...MOVING TO THE SOUTHEAST AT 45 MILES AN HOUR.

AT 2 25 AM GOLF BALL SIZE HAIL WAS REPORTED BY STATE PATROL SOUTH
OF OWATONNA...BETWEEN HOPE AND ELLENDALE IN STEELE COUNTY.

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 DO PRODUCE A TORNADO WITH
LITTLE OR NO ADVANCE WARNING..SO BE ON THE LOOKOUT AND BE PREPARED
TO MOVE T;O A PLACE OF SAFETY IF ONE IS SPOTTED.

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 2:12 AM CDTSevere Thunderstorm WarningMPXWaseca18 min
Aug 21, 2:23 AM CDTSevere Thunderstorm WarningMPXFreeborn, Steele22 min
Aug 21, 1:55 PM CDTSevere Thunderstorm WarningMPXTodd65 min
Aug 21, 2:25 PM CDTSevere Thunderstorm WarningMPXMorrison65 min
Aug 21, 3:25 PM CDTSevere Thunderstorm WarningMPXChippewa, Lac qui Parle60 min
Aug 21, 3:55 PM CDTSevere Thunderstorm WarningMPXYellow Medicine50 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.