Alert archive / Missouri / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 5, NWS St. Louis, MO

May 20, 1987Clark County, Knox County, Scotland County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at May 20, 1987, 3:45 PM CDT for Clark County, Knox County, Scotland County, Missouri. It was in force for 45 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
May 20, 1987, 3:45 PM CDT (20:45 UTC)
Expired
May 20, 1987, 4:30 PM CDT
In force
45 min
Issued by
NWS St. Louis, MO
Area
Whole counties

Counties Clark County, MO, Knox County, MO, Scotland County, MO

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
May 20, 3:55 PM CDTThunderstorm Wind 61Knox, MO
May 20, 4:05 PM CDTThunderstorm Wind 0Scotland, MO

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

Peoria Regional, IL (KPIA), launched 12:00Z, 8.8 hours before the alert went out and 207 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 KSTL 202045
SVRSTL
MOC045-199-103-202130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SAINT LOUIS MO
345 PM CDT WED MAY 20 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 430 PM CDT FOR PEOPLE IN THE FOLLOWING 
COUNTIES OF

NORTHEAST MISSOURI...CLARK...SOUTHERN SCOTLAND AND EASTERN KNOX

AT 330 PM CDT A SEVERE THUNDERSTORM WAS REPORTED AT EDINA
MISSOURI IN KNOX COUNTY.  WINDS ESTIMATED AT 70 MPH AND LARGE
HAIL WERE REPORTED WITH THE STORM.

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

HEAVY RAINS WILL QUICKLY FLOOD SMALL STREAMS AND LOW LYING AREAS.

 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, May 20, 1:12 PM CDT, 2 hours 33 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA MO
100 PM CDT WED MAY 20 1987

...STRONG THUNDERSTORMS DEVELOPING RAPIDLY OVER CENTRAL MISSOURI...

AT 100 PM CDT SEVERAL STRONG THUNDERSTORMS ALONG WITH NUMEROUS SHOWERS
WERE BUILDING RAPIDLY OVER PARTS OF CENTRAL MISSOURI.  THE STRONGEST
OF THESE STORMS WAS JUST EAST OF FULTON OR ABOUT 25 MILES EAST OF
COLUMBIA MOVING NORTH AT 35 MPH.  ANOTHER STRONG THUNDERSTORM WAS 20
MILES SOUTHWEST OF SEDALIA AND MOVING NORTH AT 35 MPH.  SEVERAL OTHER
SHOWERS WERE BUILDING RAPIDLY TO THUNDERSTORMS OVER CENTRAL MISSOURI
BETWEEN MARSHALL AND BOONVILLE AND OVER ELDON.

THUNDERSTORMS WILL CONTINUE TO BUILD QUICKLY OVER MOST AREAS OF CENTRAL
MISSOURI THIS AFTERNOON AND THIS EVENING.  THE THUNDERSTORMS WILL
PRODUCE BRIEF HEAVY RAIN AND DANGEROUS LIGHTNING AND SOME MAY HAVE
STRONG GUSTY WINDS AND SMALL HAIL.
LARM
Special weather statement, May 20, 1:56 PM CDT, 1 hour 49 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA MO
150 PM CDT WED MAY 20 1987

...STRONG THUNDERSTORMS CONTINUE TO DEVELOP OVER CENTRAL MISSOURI...

AT 145 PM CDT A VERY STRONG THUNDERSTORM WITH SMALL HAIL..STRONG GUSTY
WIND..VERY HEAVY RAIN AND DANGEROUS LIGHTNING WAS OVER MONTGOMERY CITY..
40 MILES EAST OF COLUMBIA..MOVING NORTH AT 35 MPH.  NUMEROUS OTHER VERY
STRONG THUNDERSTORMS WERE STILL BUILDING OVER MANY PARTS OF CENTRAL
MISSOURI AND MOVING NORTH.

THUNDERSTORMS WILL CONTINUE TO BUILD OVER MOST AREAS OF CENTRAL MISSOURI
THIS AFTERNOON AND THIS EVENING.  THE THUNDERSTORMS WILL PRODUCE HEAVY
RAIN AND DANGEROUS LIGHTNING AND SOME MAY HAVE STRONG GUSTY WINDS AND
SMALL 8HAIL.
LARM
Special weather statement, May 20, 3:30 PM CDT, 15 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA MO
325 PM CDT WED MAY 20 1987

...LINE OF STRONG THUNDERSTORMS MOVING THROUGH CENTRAL MISSOURI...

AT 323 PM A VERY STRONG THUNDERSTORM WAS LOCATED 10 MILES SOUTH OF
MARSHALL. THIS STORM DROPPED MARBLE SIZE HAIL IN SEDALIA ALONG WITH
VERY HEAVY RAIN AND WINDS TO 50 MPH. THIS STORM WILL BE MOVING THROUGH
THE MARSHALL AREA BY 345 AND IT IS PART OF A 20 MILE WIDE LINE OF
THUNDERSTORMS STRETCHING ACROSS CENTRAL MISSOURI FROM MARSHALL TO 10
MILES EAST OF SEDALIA TO 10 MILES NORTHEAST OF WAYNESVILLE.
THE LINE WAS MOVING NORTHEAST AT 20 MILES AN HOUR WHILE THE INDIVIDUAL
STORMS WERE MOVING NORTH AT 30 MPH. STRONG GUSTY WINDS...SMALL HAIL...
FREQUENT LIGHTNING AND HEAVY RAIN WILL ACCOMPANY THESE THUNDERSTORMS.
HAGEMEYER

Nearby

Severe Thunderstorm Warnings in Missouri, 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.