Alert archive / Illinois / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 78, NWS Lincoln, IL

September 16, 1987Knox County, Illinois

NWS Lincoln, IL issued this severe thunderstorm warning at Sep 16, 1987, 5:50 PM CDT for Knox County, Illinois. It was in force for 55 min.

The area

The counties it named.

The facts

Issued
Sep 16, 1987, 5:50 PM CDT (22:50 UTC)
Expired
Sep 16, 1987, 6:45 PM CDT
In force
55 min
Issued by
NWS Lincoln, IL
Area
Whole counties

County Knox 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, 10.8 hours before the alert went out and 59 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 1987-09-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 723 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 1987-09-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 83 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
723 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
595 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
83 m²/s²
0-3 km storm-relative helicity
69 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.8

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPIA 162250
SVRPIA
ILC095-162345-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PEORIA IL
550 PM CDT WED SEP 16 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 645 PM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTY OF

WEST CENTRAL ILLINOIS...CENTRAL AND EAST CENTRAL KNOX

AT 545 PM CDT RADAR INDICATED A POTENTIALLY SEVERE THUNDERSTORM
IN SOUTHWEST KNOX COUNTY SOUTHWEST OF MAQUON WHICH IS 30 MILES
NORTHWEST OF PEORIA.  THIS STORM HAS A HISTORY OF DROPPING
THREE QUARTER INCH HAIL AS IT PASSED THROUGH MCDONOUGH COUNTY.

THIS STORM WAS NORTHEAST AT 30 MILES AN HOUR AND SHOULD BE
AFFECTING THE TOWNS OF MAQUOUN AND GILSON IN KNOX COUNTY WITHIN
THE NEXT HOUR.

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

ATTN ISP  DIST 7

NADOLSKI

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 16, 4:50 PM CDTSevere Thunderstorm WarningILXFulton, Knox, McDonough, Warren55 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.