Alert archive / Illinois / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 4, NWS St. Louis, MO

April 7, 1986Bond County, Clinton County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 7, 1986, 4:03 PM CST for Bond County, Clinton County, Illinois. It was in force for 47 min. 2 reports 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
Apr 7, 1986, 4:03 PM CST (22:03 UTC)
Expired
Apr 7, 1986, 4:50 PM CST
In force
47 min
Issued by
NWS St. Louis, MO
Area
Whole counties

Counties Bond County, IL, Clinton County, IL

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
Apr 7, 4:15 PM CSTHail 0.75Clinton, IL
Apr 7, 4:30 PM CSTHail 0.75Clinton, IL

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

Salem-Leckrone, IL (KSLO), launched 12:00Z, 10.1 hours before the alert went out and 47 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, Salem-Leckrone, IL at 12:00Z on 1986-04-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Salem-Leckrone, IL at 12:00Z on 1986-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 50 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2086 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
50 m²/s²
0-3 km storm-relative helicity
154 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KSTL 072203
SVRSTL
ILC027-005-072250-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SAINT LOUIS MO
403 PM CST MON APR 7 1986

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 450 PM CST FOR PEOPLE IN THE FOLLOWING 
COUNTIES OF

SOUTH CENTRAL ILLINOIS...CLINTON AND BOND

AT 355 PM CST RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS
FROM NEAR CARLYLE ILLINOIS TO 20 MILES EAST OF ALTON ILLINOIS.
THE STRONGEST STORMS WERE LOCATED NEAR GERMANTOWN OR 15 MILES
SOUTHWEST OF CARLYLE AND 15 MILES EAST OF GREENVILLE ILLINOIS.
THE LINE OF STORMS WAS MOVING EAST AT 15 MPH.

BOATERS ON LAKES SHOULD MOVE TO SHELTER IMMEDIATELY.%

SEVERE THUNDERSTORMS WILL PRODUCE DAMAGING WINDS..LARGE HAIL AND
DEADLY LIGHTNING.

 HAMILTON

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, Apr 7, 2:53 PM CST, 1 hour 10 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
253 PM CST MON MAR 10 1986

...STRONG THUNDERSTORMS IN THE ST. LOUIS METROPOLITAN AREA...

AT 245 PM..RADAR SHOWED A LINE OF VERY STRONG THUNDERSTORMS FROM THE
ST. LOUIS METROPOLITAN AREA..EXTENDING NORTHEAST INTO CENTRAL
ILLINOIS.  ONE VERY STRONG STORM WAS NEAR ALTON ILLINOIS.  IT DROPPED
MARBLE SIZE HAIL NEAR BRIGHTON AND ALTON ILLINOIS..ABOUT 25 MILES
NORTH OF ST. LOUIS BETWEEN 230 AND 245 PM.  ANOTHER STORM DROPPED
SMALL HAIL AT THE WEATHER SERVICE FORECAST OFFICE AT ST. PETERS
MISSOURI..JUST WEST OF ST. LOUIS BETWEEN 230 AND 245 PM.

THE STORMS WERE MOVING TO THE EAST SOUTHEAST AT 25 MPH.

MCCARTHY

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 7, 4:26 PM CSTSevere Thunderstorm WarningLSXMadison34 min
Apr 7, 4:32 PM CSTSevere Thunderstorm WarningLSXJefferson, Washington58 min
Apr 7, 5:37 PM CSTSevere Thunderstorm WarningLSXEffingham23 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1986Every severe thunderstorm warning in 1986

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.