Alert archive / Missouri / Tornado Warnings in 1987

Tornado Warning 1, NWS St. Louis, MO

August 20, 1987Marion County, Missouri

NWS St. Louis, MO issued this tornado warning at Aug 20, 1987, 8:11 PM CDT for Marion County, Missouri. It was in force for 19 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
Aug 20, 1987, 8:11 PM CDT (01:11 UTC)
Expired
Aug 20, 1987, 8:30 PM CDT
In force
19 min
Issued by
NWS St. Louis, MO
Area
Whole counties

County Marion County, MO

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
Aug 20, 8:20 PM CDTThunderstorm Wind 56Marion, MO

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

Peoria Regional, IL (KPIA), launched 00:00Z, 1.2 hours before the alert went out and 197 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, Peoria Regional, IL at 00:00Z on 1987-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1095 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Peoria Regional, IL at 00:00Z on 1987-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 92 square meters per square second.19395878Sfc1 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
1095 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
1543 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
92 m²/s²
0-3 km storm-relative helicity
231 m²/s²
Significant tornado parameter
0.4
Supercell composite
6.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KSTL 210109
TORSTL
MOC127-210130-
 
BULLETIN - EBS ACTIVATION AND IMMEDIATE BROADCAST REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
811 PM CDT THU AUG 20 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING
EFFECTIVE UNTIL 830 PM CDT FOR THE FOLLOWING COUNTY OF
 
NORTHEAST MISSOURI... MARION

ST LOUIS RADAR INDICATES A VERY INTENSE THUNDERSTORM 15 MILES NORTHWEST
OF HANNIBAL MISSOURI.  THIS STORM MAY CONTAIN A TORNADO  AND WAS MOVING
TO THE SOUTHEAST AT 30 MPH.
 
SEEK SHELTER IMMEDIATELY.  GO TO YOUR BASEMENT OR AN INTERIOR ROOM
SUCH AS A CLOSET OR BATHROOM ON THE LOWEST FLOOR.  GET UNDER
SOMETHING STURDY.  AVOID WINDOWS AND PROTECT YOURSELF FROM FLYING
GLASS AND DEB?RIS.
 
IF YOU ARE IN A CAR OR MOBILE HOME...LEAVE AT ONCE FOR A BUILDING
OR OTHER SHELTER.  GO TO A BASEMENT OR INTERIOR PART OF THE
LOWEST FLOOR.  IF NO STRUCTURE IS NEARBY...SEEK SHELTER IN A DITCH
OR LOW SPOT.
 
SLAUGHTER

The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 20, 7:26 PM CDTSevere Thunderstorm WarningLSXAdair, Knox, Lewis49 min
Aug 20, 7:52 PM CDTSevere Thunderstorm WarningLSXMarion, Shelby38 min
Aug 20, 9:47 PM CDTSevere Thunderstorm WarningLSXLincoln43 min
Aug 20, 9:47 PM CDTSevere Thunderstorm WarningLSXPike33 min
Aug 20, 10:25 PM CDTSevere Thunderstorm WarningLSXSaint Charles35 min

Nearby

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