Alert archive / Illinois / Severe Thunderstorm Warnings in 1986

Severe Thunderstorm Warning 24, NWS St. Louis, MO

July 9, 1986Clinton County, Saint Clair County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jul 9, 1986, 5:22 PM CDT for Clinton County, Saint Clair County, Illinois. It was in force for 38 min. 3 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
Jul 9, 1986, 5:22 PM CDT (22:22 UTC)
Expired
Jul 9, 1986, 6:00 PM CDT
In force
38 min
Issued by
NWS St. Louis, MO
Area
Whole counties

Counties Clinton County, IL, Saint Clair 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
Jul 9, 5:45 PM CDTHail 0.75St. Clair, IL
Jul 9, 5:50 PM CDTThunderstorm Wind 0St. Clair, IL
Jul 9, 6:00 PM CDTThunderstorm Wind 0Clinton, 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, 10.4 hours before the alert went out and 68 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 1986-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1507 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, Salem-Leckrone, IL at 12:00Z on 1986-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 120 square meters per square second.193958Sfc1 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
1507 J/kg
Mixed-layer CIN
-90 J/kg
Mixed-layer LCL
1015 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
120 m²/s²
0-3 km storm-relative helicity
77 m²/s²
Significant tornado parameter
0.4
Supercell composite
1.3

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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, Jul 9, 3:04 PM CDT, 2 hours 18 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
304 PM CDT WED JUL 9 1986

THE HEAT INDEX HAS TOPPED 100 IN SOUTHERN MISSOURI..AND ACROSS THE
MID SECTION OF THE STATE.  EXTRA CAUTION IS ADVISED THIS AFTERNOON
TO GUARD AGAINST THE DANGERS OF HEAT STRESS.

MID AFTERNOON TEMPERATURES HAVE REACHED THE MID 90S TO AROUND 100
DEGREES IN SOUTHERN AND CENTRAL MISSOURI.  TEMPERATURE READINGS IN
NORTHERN MISSOURI RANGED FROM THE MID 80S TO AROUND 90 AT MID
AFTERNOON.

SOME RELIEF WILL APPEAR LATER IN THE AFTERNOON OVER PARTS OF EAST
CENTRAL AND SOUTHEAST MISSOURI AS THUNDERSTORMS CONTINUE TO DEVELOP.
IN ADDITION..THE FRONT WHICH HAS BROKEN THE EXCESSIVE HEAT IN
NORTHERN MISSOURI WILL DRIFT A LITTLE FARTHER SOUTH LATE THIS
AFTERNOON AND EARLY TONIGHT.  IT SHOULD STALL ACROSS THE MID SECTION
OF THE STATE BY EARLY THURSDAY.

IN THE MEANTIME..PERSONS IN SOUTHERN AND CENTRAL MISSOURI SHOULD
BE ALERT TO THE DANGER OF EXCESSIVE HEAT AND HUMIDITY.  DO NOT OVERDO
OUTDOOR ACTIVITIES..ESPECIALLY IN SUNNY AREAS.  TAKE FREQUENT BREAKS
IN THE SHADE.  TRY TO KEEP YOUR INDOOR SURROUNDINGS WELL VENTILATED
IF AIR CONDITIONING IS NOT AVAILABLE.  WEAR LIGHT CLOTHING AND DRINK
PLENTY OF NON ALCOHOLIC LIQUIDS.

MCCARTHY
Special weather statement, Jul 9, 5:11 PM CDT, 11 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
505 PM CDT WED JUL 9 1986

.....VERY HEAVY THUNDERSTORM IN METRO EAST....

AT 5 PM CDT..A VERY HEAVY THUNDERSTORM WAS IN ST. CLAIR COUNTY ILLINOIS.
THE STORM WAS MOVING EAST AT 25 MPH.  THE STORM HAS DROPPED HEAVY RAIN
AND HAIL TO MARBLE SIZE IN THE BELLEVILLE AREA.  IT ALSO HAS PRODUCED
SOME GUSTY WIND.

THE STORM WILL MOVE THROUGH EASTERN ST CLAIR AND INTO WASHINGTON COUNTYp
ILLINOIS BETWEEN 515 AND 630 PM AND WILL PRODUCE SOME VERY HEAVY RAIN
SMALL HAIL AND WINDS 40 TO 50 MPH.

TUCKER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 9, 5:58 PM CDTSevere Thunderstorm WarningLSXClinton, Saint Clair47 min
Jul 9, 6:05 PM CDTSevere Thunderstorm WarningLSXMarion55 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.