Alert archive / Illinois / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 118, NWS St. Louis, MO

June 21, 1997Monroe County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Jun 21, 1997, 6:31 PM CDT for Monroe County, Illinois. It was in force for 44 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jun 21, 1997, 6:31 PM CDT (23:31 UTC)
Expired
Jun 21, 1997, 7:15 PM CDT
In force
44 min
Issued by
NWS St. Louis, MO
Area
Whole counties

County Monroe County, IL

The radar

The St Louis radar (KLSX), 64 km from the middle of the area, began a volume at 23:33 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.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 11.5 hours before the alert went out and 248 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, Lincoln, IL at 12:00Z on 1997-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3170 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, Lincoln, IL at 12:00Z on 1997-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 187 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
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.

343 
WUUS1 KSTL 212333 RRA
SVRSTL
ILC133-220015-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
631 PM CDT SAT JUN 21 1997
 
THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  715 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHWEST ILLINOIS
 
   ...MONROE COUNTY
 
AT 631 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS DETECTING A
SEVERE THUNDERSTORM NEAR WATERLOO. THE STORM WAS MOVING TO THE SOUTHEAST
AT 10 MPH. THE STORM WILL MOVE THROUGH THE TOWNS OF WATERLOO AND HECKER.
 
THIS IS A DANGEROUS STORM BE PREPARED FOR DAMAGING WINDS...HAIL
AND DEADLY LIGHTNING. STAY INSIDE AND AWAY FROM WINDOWS.
 
GKS/RP

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 4:39 PM CDTSevere Thunderstorm WarningLSXMadison51 min
Jun 21, 5:18 PM CDTSevere Thunderstorm WarningLSXSaint Clair57 min
Jun 21, 5:32 PM CDTSevere Thunderstorm WarningLSXClinton43 min
Jun 21, 5:44 PM CDTSevere Thunderstorm WarningLSXClinton, Marion46 min
Jun 21, 6:08 PM CDTSevere Thunderstorm WarningLSXSaint Clair52 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1997Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.