Alert archive / Iowa / Tornado Warnings in 1987

Tornado Warning 2, NWS Quad Cities, IA

May 20, 1987Cedar County, Muscatine County, Iowa

NWS Quad Cities, IA issued this tornado warning at May 20, 1987, 3:24 PM CDT for Cedar County, Muscatine County, Iowa. It was in force for 21 min.

The area

The counties it named.

The facts

Issued
May 20, 1987, 3:24 PM CDT (20:24 UTC)
Expired
May 20, 1987, 3:45 PM CDT
In force
21 min
Issued by
NWS Quad Cities, IA
Area
Whole counties

Counties Cedar County, IA, Muscatine County, IA

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

Peoria Regional, IL (KPIA), launched 12:00Z, 8.4 hours before the alert went out and 166 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 12:00Z on 1987-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1840 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, Peoria Regional, IL at 12:00Z on 1987-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 56 square meters per square second.1939Sfc1 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
1840 J/kg
Mixed-layer CIN
-73 J/kg
Mixed-layer LCL
690 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.8

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMLI 202024
TORMLI
IAC031-139-202130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
TORNADO WARNING
NATIONAL WEATHER SERVICE MOLINE IL
324 PM CDT WED MAY 20 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO WARNING 
EFFECTIVE UNTIL 430 PM CDT FOR PEOPLE IN THE FOLLOWING COUNTIES OF

EXTREME EAST IOWA...SOUTHERN CEDAR AND NORTHERN MUSCATINE

AT 316 PM CDT A TORNADO TOUCHED DOWN NEAR NICHOLS IA AND IS MOVING
TOWARD WEST LIBERTY.  RADAR SHOWS STORM IN THE AREA MOVING NORTH AT
 30 MPH.

IF YOU ARE IN THE PATH OF THIS TORNADO...TAKE COVER IMMEDIATELY.
A BASEMENT...INTERIOR HALLWAY...OR A ROOM ON THE LOWEST FLOOR IS
THE SAFEST PLACE.  TAKE COVER IN A STORM SHELTER OR LIE IN A$
NEARBY DITCH OR DEPRESSION.

IF TIME PERMITS..ASK THE NEAREST LAW ENFORCEMENT DAGENCY TO RELAY
YOUR REPORT OF SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE.

LEWIS

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 20, 5:10 PM CDTSevere Thunderstorm WarningDVNScott50 min

Nearby

Tornado Warnings in Iowa, 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; the sounding from the Mesonet's radiosonde archive.