Alert archive / Minnesota / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 40, NWS Twin Cities, MN

July 11, 1987Watonwan County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 11, 1987, 7:11 AM CDT for Watonwan County, Minnesota. It was in force for 49 min.

The area

The counties it named.

The facts

Issued
Jul 11, 1987, 7:11 AM CDT (12:11 UTC)
Expired
Jul 11, 1987, 8:00 AM CDT
In force
49 min
Issued by
NWS Twin Cities, MN
Area
Whole counties

County Watonwan 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 12:00Z, 0.2 hours before the alert went out and 126 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 1987-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2637 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 1987-07-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 25 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
2637 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
638 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
43 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KRST 111211
SVRRST
MNC165-111300-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ROCHESTER MN
711 AM CDT SAT JUL 11 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL  800 AM CDT FOR PEOPLE IN THE FOLLOWING COUNTY...
 
IN SOUTH CENTRAL MINNESOTA
          ...WATONWAN
 
AT 705 AM CDT RADAR INDICATED A SEVERE THUNDERSTORM IN THE SOUTHWEST
CORNER OF WATONWON COUNTY...25 MILES NORTHWEST OF FAIRMONT...MOVING
TO THE NORTHEAST 40 MPH. PERSONS IN THE CITY OF ST. JAMES SHOULD SEEK
SHELTER IMMEDIATELY.
SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS IN EXCESS OF 55
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY
SO DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 10, 10:00 PM CDTSevere Thunderstorm WarningMPXTodd60 min
Jul 10, 10:20 PM CDTTornado WarningMPXTodd25 min
Jul 11, 12:16 AM CDTSevere Thunderstorm WarningMPXCarver, Scott, Sibley44 min
Jul 11, 3:20 AM CDTSevere Thunderstorm WarningMPXLac qui Parle, Yellow Medicine60 min
Jul 11, 4:20 AM CDTSevere Thunderstorm WarningMPXYellow Medicine60 min
Jul 11, 5:50 AM CDTSevere Thunderstorm WarningMPXKandiyohi60 min
Jul 11, 6:15 AM CDTSevere Thunderstorm WarningMPXMeeker60 min
Jul 11, 6:45 AM CDTSevere Thunderstorm WarningMPXWright45 min
Jul 11, 7:19 AM CDTSevere Thunderstorm WarningMPXHennepin, Sherburne21 min
Jul 11, 7:19 AM CDTSevere Thunderstorm WarningMPXAnoka, Isanti56 min
Jul 11, 7:42 AM CDTSevere Thunderstorm WarningMPXBlue Earth48 min
Jul 11, 7:52 AM CDTSevere Thunderstorm WarningMPXWashington28 min
Jul 11, 7:52 AM CDTSevere Thunderstorm WarningMPXChisago38 min
Jul 11, 4:47 PM CDTSevere Thunderstorm WarningMPXFaribault, Freeborn53 min
Jul 11, 4:47 PM CDTSevere Thunderstorm WarningMPXMartin53 min
Jul 11, 5:31 PM CDTSevere Thunderstorm WarningMPXDodge, Freeborn, Steele44 min
Jul 11, 5:48 PM CDTSevere Thunderstorm WarningMPXWabasha, Winona42 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.