Alert archive / Illinois / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 28, NWS St. Louis, MO

April 18, 1997Madison County, Saint Clair County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 18, 1997, 10:20 PM CDT for Madison County, Saint Clair County, Illinois. It was in force for 40 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
Apr 18, 1997, 10:20 PM CDT (03:20 UTC)
Expired
Apr 18, 1997, 11:00 PM CDT
In force
40 min
Issued by
NWS St. Louis, MO
Area
Whole counties

Counties Madison County, IL, Saint Clair County, IL

The radar

The St Louis radar (KLSX), 67 km from the middle of the area, began a volume at 03:21 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 18, 9:15 PM CDTSevere Thunderstorm WatchSPC4 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 3.3 hours before the alert went out and 202 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 00:00Z on 1997-04-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 1997-04-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 96 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2539 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
96 m²/s²
0-3 km storm-relative helicity
257 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.

000 
TTAA00 KSTL 190321 RRA
SVRSTL
ILC119-163-190400-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
1020 PM CDT FRI APR 18 1997
 
THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1100 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN SOUTHWEST ILLINOIS
 
   ...SOUTHWESTERN MADISON COUNTY...ST. CLAIR COUNTY
 
A SEVERE THUNDERSTORM WAS OVER ST. LOUIS CITY MOVING SOUTHEfAST AT
30 MPH.
 
BELLEVILLE AND GRANITE CITY ARE IN THE PATH.
 
THIS STORM HAS A HISTORY OF DAMAGING HAIL AND WIND.
 
JPK

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 18, 8:51 PM CDTSevere Thunderstorm WarningLSXCalhoun39 min
Apr 18, 8:58 PM CDTSevere Thunderstorm WarningLSXPike47 min
Apr 18, 9:45 PM CDTSevere Thunderstorm WarningLSXCalhoun45 min
Apr 18, 11:17 PM CDTSevere Thunderstorm WarningLSXGreene, Jersey, Macoupin, Madison43 min
Apr 18, 11:56 PM CDTSevere Thunderstorm WarningLSXJersey, Madison49 min
Apr 19, 12:34 AM CDTSevere Thunderstorm WarningLSXClinton, Saint Clair, Washington41 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.