Alert archive / Illinois / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 6, NWS St. Louis, MO

April 7, 1986Jefferson County, Washington County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 7, 1986, 4:32 PM CST for Jefferson County, Washington County, Illinois. It was in force for 58 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
Apr 7, 1986, 4:32 PM CST (22:32 UTC)
Expired
Apr 7, 1986, 5:30 PM CST
In force
58 min
Issued by
NWS St. Louis, MO
Area
Whole counties

Counties Jefferson County, IL, Washington 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, 4:35 PM CSTHail 0.75Washington, 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, 10.5 hours before the alert went out and 43 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 072237 COR
SVRSTL
ILC081-189-072330-

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

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM
WARNING EFFECTIVE UNTIL 530 PM CST FOR PEOPLE IN THE FOLLOWING
COUNTIES OF

SOUTH CENTRAL ILLINOIS...JEFFERSON AND WASHINGTON

AT 425 PM CST RADAR INDICATED A SEVERE THUNDERSTORM 25 MILES WEST
OF MT VERNON ILLINOIS MOVING EAST SOUTHEAST AT 25 MPH.  MARBLE
SIZE HAIL WAS REPORTED IN NORTHERN WASHINGTON AROUND 520 PM.

BOATERS ON LAKES SHOULD MOVE TO SHELTER IMMEDIATELY.

SEVERE THUNDERSTORMS WILL PRODUCE DAMAGING WINDS..LARGE HAIL AND
DEADLY LIGHTNING.
V
HEAVY RAINS WILL QUICKLY FLOOD SMALL STREAMS AND LOW LYING AREAS.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY OR THE
NATIONAL WEATHER SERVICE AT /314/922-9120.

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 39 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
Special weather statement, Apr 7, 4:23 PM CST, 9 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA MO
420 PM CST MON APR 7 1986

...A TORNADO WATCH IS IN EFFECT FOR THE WEST HALF OF CENTRAL MISSOURI
UNTIL 1100PM CST....A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR THE EAST
HALF OF CENTRAL MISSOURI UNTIL 900PM CST...

AT 415PM CST COLUMBIAS RADAR SHOWED SCATTERED THUNDERSHOWERS...SOME WITH
HEAVY SHOWERS...IN A LINE ABOUT 15 MILES WIDE EXTENDING FROM KANSAS CITY
TO POMME DE TERRE RESERVOIR..OR ABOUT 30 MILES NORTH OF SPRINGFIELD.
THE STRONGEST THUNDERSTORM WAS ABOUT 10 MILES IN DIAMETER AND CENTERED
35 MILES NORTH OF SPRINGFIELD.

THE THUNDERSTORMS HAVE BEEN DEVELOPING RAPIDLY SINCE 4PM CST AND WERE
MOVING TO THE SOUTHEAST AROUND :40 MILES AN HOUR.

NO SEVERE WEATHER WAS REPORTED OR INDICATED BY RADAR IN CENTRAL MISSOURI
DURING THE LAST HOUR.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 7, 4:03 PM CSTSevere Thunderstorm WarningLSXBond, Clinton47 min
Apr 7, 4:26 PM CSTSevere Thunderstorm WarningLSXMadison34 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.