Alert archive / Minnesota / Tornado Warnings in 1987

Tornado Warning 18, NWS Twin Cities, MN

July 20, 1987Anoka County, Hennepin County, Ramsey County, Minnesota

NWS Twin Cities, MN issued this tornado warning at Jul 20, 1987, 7:13 PM CDT for Anoka County, Hennepin County, Ramsey County, Minnesota. It was in force for 27 min.

The area

The counties it named.

The facts

Issued: Jul 20, 1987, 7:13 PM CDT (00:13 UTC)
Expired: Jul 20, 1987, 7:40 PM CDT
In force: 27 min
Issued by: NWS Twin Cities, MN
Area: Whole counties

Counties Anoka County, MN, Hennepin County, MN, Ramsey 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, 0.2 hours before the alert went out and 38 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 3871 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 860 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 73 m²/s²
Significant tornado parameter: 0.9
Supercell composite: 4.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMSP 210013
TORMSP
MNC053-003-123-210040-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING
NATIONAL WEATHER SERVICE MINNEAPOLIS MN
713 PM CDT MON JUL 20 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 740 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF

EAST CENTRAL MINNESOTA...NORTHEAST HENNEPIN...SOUTHERN ANOKA AND 
 NORTHERN RAMSEY


AT..708 PM CDT..RADAR WAS INDICATING A POSSIBLE TORNADO IN THE
MAPLE GROVE AND CHAMPLAIN AREAS OF NORTHEAST HENNEPIN COUNTY
ABOUT 15 TO 20 MILES NORTHWEST OF DOWNTOWN MINNEAPOLIS.

THIS DANGEROUS STROM WAS MOVING EASTWARD AT 20 MILES AN HOUR AND
IT WILL AFFECT AREAS NEAR THE TOWNS OF BROOKLYN PARK..ANOKA..
FRIDLEY AND ROSEVILLE.

THIS IS A DANGEROUS STORM SITUATION.  ACT QUICKLY.  IF YOU ARE IN
THE PATH OF A TORNADO MOVE TO A SHELTER BELOW GROUND IF AVAILABLE.
OTHERWISE..GO TO A SMALL INTERIOR ROOM ON THE LOWEST FLOOR
POSSIBLE.  AVOID WINDO@WS.  ABANDON CARS AND MOBILE HOMES FOR A
REINFORCED BUILDING OR GET INTO A DITCH OR CULVERT.

BRANCH

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 7:06 PM CDT	Tornado Warning	MPX	Dakota	24 min
Jul 20, 7:14 PM CDT	Severe Thunderstorm Warning	MPX	Meeker	61 min
Jul 20, 8:00 PM CDT	Severe Thunderstorm Warning	MPX	Lac qui Parle	60 min
Jul 20, 8:09 PM CDT	Severe Thunderstorm Warning	MPX	Ramsey, Washington	51 min
Jul 20, 9:34 PM CDT	Severe Thunderstorm Warning	MPX	Hennepin, Scott	56 min
Jul 20, 9:45 PM CDT	Severe Thunderstorm Warning	MPX	Kandiyohi, Meeker	60 min
Jul 20, 10:36 PM CDT	Severe Thunderstorm Warning	MPX	Carver, Hennepin	54 min

Nearby

Tornado Warnings in Minnesota, 1987 Every tornado warning in 1987 Tornadoes 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.