Alert archive / Illinois / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 77, NWS St. Louis, MO

May 2, 1998Randolph County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at May 2, 1998, 3:44 PM CDT for Randolph County, Illinois. It was in force for 61 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
May 2, 1998, 3:44 PM CDT (20:44 UTC)
Expired
May 2, 1998, 4:45 PM CDT
In force
61 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 20:46 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
May 2, 3:50 PM CDTHail 0.75Sparta, ILSpotters reported 3/4 inch hail south of Sparta.

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 watch it was issued in

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

IssuedProductOfficeLasted
May 2, 2:00 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 8.7 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 1998-05-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 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 1998-05-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 113 square meters per square second.1939Sfc1 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
4 J/kg
Mixed-layer CIN
-189 J/kg
Mixed-layer LCL
1009 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
113 m²/s²
0-3 km storm-relative helicity
150 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.

499 
WUUS1 KSTL 022046 RRA
SVRSTL
ILC157-022145-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
344 PM CDT SAT MAY 2 1998

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL AND SOUTHERN RANDOLPH COUNTY IN SOUTHWESTERN ILLINOIS

* UNTIL 445 PM CDT

* AT 344 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS 3 MILES NORTH OF CHESTER TO 10 MILES
  WEST OF STE GENEVIEVE... MOVING EAST AT 20 MPH.

* LOCATIONS THAT WILL BE AFFECTED...
  CHESTER
  BREMAN
  WELGE

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND GUSTS IN EXCESS OF 60
MPH...DAMAGING HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. MOVE
TO AN INTERIOR ROOM ON THE LOWEST FLOOR OR YOUR HOME OR BUSINESS.
HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO AREAS WHERE
WATER COVERS THE ROAD.

AMS/TRUETT

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, May 2, 11:23 AM CDT, 4 hours 21 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>075-084-085-099-022230-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
1123 AM CDT SAT MAY 2 1998

THIS OUTLOOK COVERS THE COUNTY WARNING AREA OF THE NWS OFFICE
IN ST LOUIS.  AREAS INCLUDED ARE PARTS OF CENTRAL...NORTHEAST
AND EAST CENTRAL MISSOURI...AND SOUTHWEST ILLINOIS.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EARLY TONIGHT OVER PARTS OF SOUTHERN ILLINOIS AND NORTHEAST THROUGH
SOUTHEAST MISSOURI IN THE AREAS COVERED BY ST LOUIS WARNING AREA.
THIS INCLUDES ALL THE AREA COVERED BY THE ST LOUIS AREA OF
RESPONSIBILITY.

EXTREMELY COLD AIR IN MIDDLE AND UPPER LEVELS OF THE ATMOSPHERE IS
MOVING SOUTHEAST FROM THE DAKOTAS OVER SOUTHERN ILLINOIS AND EASTERN
MISSOURI. THIS...COMBINED WITH SURFACE HEATING WILL PRODUCE A VERY
UNSTABLE AIR MASS...AND CAUSE THUNDERSTORMS TO DEVELOP ACROSS THE
STATE THIS AFTERNOON.

THE MOST SIGNIFICANT THREAT FOR SEVERE WEATHER FROM THESE STORMS WILL
BE LARGE HAIL. THE HEIGHT OF THE FREEZING LEVEL IS RELATIVELY
LOW...WHICH WILL REDUCE MELTING BEFORE STRIKING THE GROUND.

EMERGENCY MANAGERS AND STORM SPOTTERS GROUPS SHOULD MONITOR WEATHER
INFORMATION THROUGHOUT TODAY AND TONIGHT FOR POSSIBLE SKYWARN
ACTIVATION.

BECHTOLD
Special weather statement, May 2, 11:23 AM CDT, 4 hours 21 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>075-084-085-099-022230-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
1123 AM CDT SAT MAY 2 1998

THIS OUTLOOK COVERS THE COUNTY WARNING AREA OF THE NWS OFFICE
IN ST LOUIS.  AREAS INCLUDED ARE PARTS OF CENTRAL...NORTHEAST
AND EAST CENTRAL MISSOURI...AND SOUTHWEST ILLINOIS.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EARLY TONIGHT OVER PARTS OF SOUTHERN ILLINOIS AND NORTHEAST THROUGH
SOUTHEAST MISSOURI IN THE AREAS COVERED BY ST LOUIS WARNING AREA.
THIS INCLUDES ALL THE AREA COVERED BY THE ST LOUIS AREA OF
RESPONSIBILITY.

EXTREMELY COLD AIR IN MIDDLE AND UPPER LEVELS OF THE ATMOSPHERE IS
MOVING SOUTHEAST FROM THE DAKOTAS OVER SOUTHERN ILLINOIS AND EASTERN
MISSOURI. THIS...COMBINED WITH SURFACE HEATING WILL PRODUCE A VERY
UNSTABLE AIR MASS...AND CAUSE THUNDERSTORMS TO DEVELOP ACROSS THE
STATE THIS AFTERNOON.

THE MOST SIGNIFICANT THREAT FOR SEVERE WEATHER FROM THESE STORMS WILL
BE LARGE HAIL. THE HEIGHT OF THE FREEZING LEVEL IS RELATIVELY
LOW...WHICH WILL REDUCE MELTING BEFORE STRIKING THE GROUND.

EMERGENCY MANAGERS AND STORM SPOTTERS GROUPS SHOULD MONITOR WEATHER
INFORMATION THROUGHOUT TODAY AND TONIGHT FOR POSSIBLE SKYWARN
ACTIVATION.

BECHTOLD

Nearby

Severe Thunderstorm Warnings in Illinois, 1998Every severe thunderstorm warning in 1998

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.