Alert archive / Illinois / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 7, NWS Lincoln, IL

May 20, 1987Stark County, Illinois

NWS Lincoln, IL issued this severe thunderstorm warning at May 20, 1987, 5:30 PM CDT for Stark County, Illinois. It was in force for 60 min.

The area

The counties it named.

The facts

Issued
May 20, 1987, 5:30 PM CDT (22:30 UTC)
Expired
May 20, 1987, 6:30 PM CDT
In force
60 min
Issued by
NWS Lincoln, IL
Area
Whole counties

County Stark County, IL

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, 10.5 hours before the alert went out and 50 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 KPIA 202230
SVRPIA
ILC175-202330-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PEORIA IL
530 PM CDT WED MAY 20 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 630 PM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTY OF

CENTRAL ILLINOIS...STARK

AT 508 PM CDT A SEVERE THUNDERSTORM WAS OVER NORTHERN PEORIA
COUNTY OVER PRINCEVILLE AND AT 525 PM CDT THIS STORM HAS MOVE
INTO THE SOUTHERN PORTION OF STARK COUNTY.  DAMAGING WINDS AND
LARGE HAIL HAS BEEN REPORTED WITH THIS STORM.

COMMUNITIES DIRECTELY IN THE PATH OF THIS STORM ARE DUNCAN AND
WYOMING IN STARK COUNTY.

IF YOU ARE IN AN AREA THREATENED BY THE STORM..GO TO A REINFORECED
SHELTER AND PREPARE FOR DAMAGING WIND...LARGE HAIL...VERY HEAVY
RAIN AND LIGHTNING.

INTENSE LIGHTNING IS REPORTED WITH THIS STORM.  IF OUTDOORS...
STAY AWAY FROM HIGH OBJECTS.  MOVE INDOOR IF POSSIBLE.  WHEN
INDOORS...STAY AWAY FGROM WINDOWS AND DOORS AND AVOID USING
TELEPHONES AND ELECTRICAL EQUIPMENT.

ATTN ISP  8

STUMETZ

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, May 20, 4:46 PM CDT, 44 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SPRINGFIELD IL
445 PM CDT WED MAY 20 1987

...STRONG THUNDERSTORMS DEVELOPING RAPIDLY ACROSS CENTRAL ILLINOIS...

AT 440PM STRONG THUNDERSTORMS WERE SCATTERED ACROSS MUCH OF CENTRAL
ILLINOIS AND WERE DEVELOPING RAPIDLY.

THE STRONGEST STORMS WERE LOCATED 40 MILES WEST OF SPRINGFIELD
ILLINOIS...NEAR MEREDOSIA AND BEARDSTOWN. THESE STORMS MAY BE
ACCOMPANIED BY STRONG GUSTY WINDS...HAIL...VERY HEAVY RAIN AND
DANGEROUS LIGHTNING.  OTHER STRONG THUNDERSTORMS WERE DEVELOPING WEST
AND NORTH OF PEORIA.

THE THUNDERSTORMS WERE MOVING NORTH AT 20 MPH.

A SEVERE THUNDERSTORM WATCH HAS JUST BEEN ISSUED FOR A LARGE PART
OF CENTRAL ILLINOIS UNTIL 1000 PM CDT.
HUGHES

The office that day

Everything else NWS Lincoln, IL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 20, 9:44 AM CDTSevere Thunderstorm WarningILXVermilion31 min
May 20, 6:20 PM CDTSevere Thunderstorm WarningILXPeoria35 min
May 20, 6:34 PM CDTTornado WarningILXWoodford51 min

Nearby

Severe Thunderstorm Warnings in Illinois, 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.