Alert archive / Illinois / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 39, NWS St. Louis, MO

April 30, 1997Randolph County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 30, 1997, 2:47 PM CDT for Randolph County, Illinois. It was in force for 43 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
Apr 30, 1997, 2:47 PM CDT (19:47 UTC)
Expired
Apr 30, 1997, 3:30 PM CDT
In force
43 min
Issued by
NWS St. Louis, MO
Area
Whole counties

County Randolph County, IL

The radar

The St Louis radar (KLSX), 104 km from the middle of the area, began a volume at 19:46 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

TimeReportWhereRemark
Apr 30, 3:00 PM CDTHail 0.75Sparta, 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.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 7.8 hours before the alert went out and 256 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 1997-04-30Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 1997-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 115 square meters per square second.19395878Sfc1 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
1130 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
115 m²/s²
0-3 km storm-relative helicity
166 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 301947 RRA
SVRSTL
ILC157-302030-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
247 PM CDT WED APR 30 1997
 
THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  330 PM CDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHWEST ILLINOIS
 
   ...NORTHERN RANDOLPH COUNTY
 
AT 245 PM...DOPPLER RADAR SHOWED A SEVERE THUNDERSTORM OVER NORTHWESTERN
RANDOLPH COUNTY NEAR THE TOWN OF RUMA. THE SEVERE THUNDERSTORM WAS
MOVING NORTHEAST AT 35 MPH AND WILL AFFECT THE COMMUNITIES OF PRAIRIE
...BALLWIN AND HOUSTON.
 
 
REMEMBER...A TORNADO WATCH IS ALSO IN EFFECT FOR THE WARNED AREA.
IF OUTDOORS...SEEK INSIDE SHtELTER IMMEDIATELY. STAY AWAY FROM
WINDOWS.
 
LEWIS/RP

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 30, 1:31 PM CDTSevere Thunderstorm WarningLSXAdams29 min
Apr 30, 1:42 PM CDTTornado WarningLSXAdams48 min
Apr 30, 2:23 PM CDTSevere Thunderstorm WarningLSXSaint Clair52 min
Apr 30, 2:28 PM CDTSevere Thunderstorm WarningLSXMacoupin47 min
Apr 30, 2:33 PM CDTTornado WarningLSXMacoupin42 min
Apr 30, 2:51 PM CDTSevere Thunderstorm WarningLSXBond, Fayette54 min
Apr 30, 2:58 PM CDTSevere Thunderstorm WarningLSXMontgomery47 min
Apr 30, 3:29 PM CDTSevere Thunderstorm WarningLSXWashington46 min
Apr 30, 3:43 PM CDTSevere Thunderstorm WarningLSXFayette32 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.