Alert archive / Illinois / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 8, NWS St. Louis, MO

May 21, 1987Monroe County, Randolph County, Saint Clair County, Illinois; Sainte Genevieve County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at May 21, 1987, 7:01 PM CDT for Monroe County, Randolph County, Saint Clair County, Illinois; Sainte Genevieve County, Missouri. It was in force for 59 min.

The area

The counties it named.

The facts

Issued: May 21, 1987, 7:01 PM CDT (00:01 UTC)
Expired: May 21, 1987, 8:00 PM CDT
In force: 59 min
Issued by: NWS St. Louis, MO
Area: Whole counties

Counties Monroe County, IL, Randolph County, IL, Saint Clair County, IL, Sainte Genevieve County, MO

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

Salem-Leckrone, IL (KSLO), launched 00:00Z, 0.0 hours before the alert went out and 112 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1585 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 1856 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 21 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KSTL 220001
SVRSTL
ILC133-163-157-MOC186-220100-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
701 PM CDT THU MAY 21 1987
 
THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WARNING
EFFECTIVE UNTIL 800 PM CDT FOR THE FOLLOWING COUNTIES OF
 
SOUTHWEST ILLINOIS... MONROE... ST. CLAIR... RANDOLPH
 
SOUTHEAST MISSOURI... STE. GENEVIEVE
 
WEATHER SERVICE RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS
EXTENDING FROM JUST SOUTH OF ST LOUIS TO FARMINGTON MISSOURI.  THESE
THUNDERSTORMS ARE MOVING TO THE EAST AT 30 MPH.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH
...DESTRUCTIVE HAIL...DEADLY LIGHTNING AND VERY HEAVY RAIN.  FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS.
 
DJ

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 21, 4:09 PM CDT, 2 hours 52 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA MO
405 PM CDT THU MAY 21 1987

   ...STRONG THUNDERSTORMS APPROACHING THE LAKE OF THE OZARKS...

AT 400 PM RADAR INDICATED STRONG THUNDERSTORMS MOVING THROUGH SOUTH
PORTIONS OF CENTRAL MISSOURI. ONE WAS 10 MILES SOUTHWEST OF CAMDENTON
AND ANOTHER WAS 10 TO 15 MILES NORTHWEST OF WAYNESVILLE. THEY WERE
MOVING NORTHEAST AT 30 MILES AN HOUR.

THESE THUNDERSTORMS WILL DROP VERY HEAVY RAIN. SM1ALL HAIL AND GUSTY
WIND IS ALSO LIKELY. THE THUNDERSTORMS WILL PASS OVER SOUTH AND EAST
PORTIONS OF THE LAKE OF THE OZARKS BY 430 PM. THE OTHER THUNDERSTORMS
WILL PASS JUST NORTHWEST OF VIENNA.
VOTAW

Special weather statement, May 21, 5:12 PM CDT, 1 hour 49 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
510 PM CDT THU MAY 21 1987

...THUNDERSTORMS MOVING THROUGH ROLLA SALEM AREAS IN EAST CENTRAL
   MISSOURI.

AT 505 PM A BAND OF THUNDERSTORMS CAPABLE OF STRONG GUSTY WINDS AND
HEAVY RAINS ARE MOVING THROUGH PHELPS AND DENT COUNTIES INCLUDING
THE TOWNS OF ROLLA EDGAR SPRINGS AND SALEM.  THE STORMS ARE MOVING
NORTHEAST AT 35 MPH AND WILL MOVE INTO CRAWFORD MARIES AND
GASCONADE COUNTIES pBETWEEN 5 AND 630 PM.  PERSONS SHOULD BE ALERT
FOR THE STORMS AND REPORT ANY HAIL DAMAGING WINDS AND FLASH FLOODING
TO THE LOCAL POLICE FOR RELAY TO THE NATIONAL WEATHER SERVICE.

HAMILTON

Special weather statement, May 21, 5:15 PM CDT, 1 hour 46 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA MO
515 PM CDT THU MAY 21 1987

   ...TORNADO WATCH FOR CENTRAL MISSOURI UNTIL 1000 PM...

AT 505 PM VERY STRONG THUNDERSTORMS CONTINUED OVER SOUTH PORTIONS
OF CENTRAL MISSOURI...ESPECIALLY SOUTH OF A LINE FROM POMME DE TERRE
RESERVIOR TO BAGNELL DAM AT THE LAKE OF THE OZARKS AND OWENSVILLE.
ANOTHER THUNDERSTORM WAS BUILDING OVER CENTRALIA. THESE THUNDERSTORMS
WERE MOVING NORTHEAST AT 30 MwILES AN HOUR.

SMALL HAIL AND GUSTY WIND IS POSSIBLE WITH ANY OF THESE THUNDERSTORMS
AS WELL AS VERY HEAVY RAIN.

THE LARGEST THUNDERSTORM COMPLEX WAS 10 MILES WIDE AND LOCATED FROM
ROLLA TO 20 MILES SOUTH OF WAYNESVILLE.
VOTAW

Special weather statement, May 21, 5:47 PM CDT, 1 hour 14 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
540 PM CDT THU MAY 21 1987

...THUNDERSTORMS WITH HAIL REPORTED AT CUBA MISSOURI IN EAST CENTRAL
   MISSOURI.
...TORNADO WATCH CONTINUES IN NORTHEAST AND EAST CENTRAL MISSOURI UNTIL
   11 PM TUESDAY NIGHT...

AT 530 PM RADAR INDICATED AN INTENSE THUNDERSTORM IN CRAWFORD COUNTY
MOVING NORTHEAST AT 35 MPH.  THIS STORM HAS A HISTORY OF HAIL WITH
MARBLE SIZE HAIL REPORTED AT CUBA AND STRONG GUSTY WINDS.  HAIL TO
1/2 INCH WAS REPORTED WITH THIS STORM EARLIER.  PERSONS IN CRAWFORD
COUNTY..GASCONADE AND FRANKLIN COUNTIES SHOULD REMAIN ALERT FOR STORMS
CAPABLE OF PRODUCING HAIL STRONG GUSTY WINDS AND HEAVY RAINS BETWEEN
540 AND 7 PM THIS THURSDAY EVENING.  TOWNS IN THE PATH OF THE STORM ARE
SULLIVAN..BOURBON..SPRING BLUFF AND THE MERAMEC STATE PARK AREA.

HAMILTON

The office that day

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

Issued	Product	Office	Counties	Lasted
May 21, 7:12 PM CDT	Severe Thunderstorm Warning	LSX	Adams, Brown	48 min
May 21, 7:25 PM CDT	Severe Thunderstorm Warning	LSX	Greene, Pike, Scott	50 min
May 21, 7:25 PM CDT	Severe Thunderstorm Warning	LSX	Calhoun	50 min
May 21, 8:10 PM CDT	Severe Thunderstorm Warning	LSX	Brown, Pike	50 min
May 21, 8:10 PM CDT	Severe Thunderstorm Warning	LSX	Scott	50 min
May 21, 8:57 PM CDT	Severe Thunderstorm Warning	LSX	Greene, Scott	53 min
May 21, 7:59 PM CDT	Severe Thunderstorm Warning	LSX	Marion, Ralls	61 min
May 21, 8:10 PM CDT	Severe Thunderstorm Warning	LSX	Pike	50 min
May 21, 10:08 PM CDT	Severe Thunderstorm Warning	LSX	Reynolds	52 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1987 Severe Thunderstorm Warnings in Missouri, 1987 Every 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.