Alert archive / Illinois / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 111, NWS St. Louis, MO

June 21, 1997Madison County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jun 21, 1997, 4:39 PM CDT for Madison County, Illinois. It was in force for 51 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: Jun 21, 1997, 4:39 PM CDT (21:39 UTC)
Expired: Jun 21, 1997, 5:30 PM CDT
In force: 51 min
Issued by: NWS St. Louis, MO
Area: Whole counties

County Madison County, IL

The radar

The St Louis radar (KLSX), 69 km from the middle of the area, began a volume at 21:40 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Jun 21, 4:50 PM CDT	Hail 1.75	Madison, IL	Skywarn spotters reported golfball size hail.

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.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 9.7 hours before the alert went out and 185 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: 3170 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 624 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 187 m²/s²
0-3 km storm-relative helicity: 146 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.

590 
WUUS1 KSTL 212148 RRB
SVRSTL
ILC119-212230-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING ...CORRECTED...
NATIONAL WEATHER SERVICE ST LOUIS MO
439 PM CDT SAT JUN 21 1997

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  530 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN SOUTHWEST ILLINOIS

   ...MADISON COUNTY

AT 438 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS DETECTING A LINE
OF SEVERE THUNDERSTORMS FROM 3 MILES NORTH OF GRANITE CITY TO 7 MILES
NORTH OF HIGHLAND. THE STORMS WERE MOVING TO THE EAST SOUTHEAST AT 10
MPH. THE STORMS WILL MOVE THROUGH THE TOWNS OF EDWARDSVILLLE...GLEN
CARBON AND HIGHLAND. THE STORMS WILL PRODUCE ONE INCH DIAMETER HAIL AND
STREET FLOODING.

THIS IS A DANGEROUS STORM BE PREPARED FOR DAMAGING WINDS...HAIL
AND DEADLY LIGHTNING. STAY INSIDE AND AWAY FROM WINDOWS.

GKS/RP

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, Jun 21, 11:30 AM CDT, 5 hours 9 minutes before

ILZ058>060-064-065-069-070-074-079-095>102-MOZ009-010-018-019-026-
027-034>036-041-042-047>052-059>065-072>075-084-085-099-211700-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
1130 AM CDT SAT JUN 21 1997

THIS OUTLOOK COVERS TH COUNTY WARNING AREA OF THE NATIONAL WEATHER
SERVICE FORECAST OFFICE IN ST LOUIS.  AREAS INCLUDED ARE PARTS OF
CENTRAL...NORTHEAST AND EAST CENTRAL MISSOURI...AND EXTREME SOUTHWEST
ILLINOIS.

THE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND TONIGHT OVER THE
COUNTY WARNING AREA HAS DECREASED. SOME STRONG THUNDERSTORMS MAY
DEVELOP OVER NORTHERN AND WESTERN MISSOURI BY LATE AFTERNOON...BUT
THE MAIN THREAT AT THIS TIME APPEARS TO BE LOCALLY HEAVY RAIN WHICH
MAY CAUSE FLASH FLOODING.

A FLASH FLOOD WATCH CONTINUES IN EFFECT FOR NORTHEAST MISSOURI AND
SOUTHWEST ILLINOIS FOR THIS AFTERNOON AND TONIGHT.

EMERGENCY MANAGERS AND STORM SPOTTER GROUPS SHOULD MONITOR THE LATEST
FORECASTS AND STATEMENTS FOR POSSIBLE UPDATES AND REVISIONS. AT THIS
TIME...SKYWARN OPERATIONS ARE NOT ANTICIPATED FOR THIS EVENING AND
TONIGHT.

BECHTOLD

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 21, 5:18 PM CDT	Severe Thunderstorm Warning	LSX	Saint Clair	57 min
Jun 21, 5:32 PM CDT	Severe Thunderstorm Warning	LSX	Clinton	43 min
Jun 21, 5:44 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Marion	46 min
Jun 21, 6:08 PM CDT	Severe Thunderstorm Warning	LSX	Saint Clair	52 min
Jun 21, 6:31 PM CDT	Severe Thunderstorm Warning	LSX	Monroe	44 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1997 Every severe thunderstorm warning in 1997

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; radar from the NEXRAD Level II archive.