Alert archive / Illinois / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 31, NWS St. Louis, MO

April 7, 1998Adams County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 7, 1998, 4:05 PM CDT for Adams County, Illinois. It was in force for 25 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 7, 1998, 4:05 PM CDT (21:05 UTC)
Expired
Apr 7, 1998, 4:30 PM CDT
In force
25 min
Issued by
NWS St. Louis, MO
Area
Whole counties

County Adams County, IL

The radar

The St Louis radar (KLSX), 150 km from the middle of the area, began a volume at 21:05 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 7, 2:00 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.1 hours before the alert went out and 190 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, Davenport, at 12:00Z on 1998-04-07Temperature 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, Davenport, at 12:00Z on 1998-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 101 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1589 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
101 m²/s²
0-3 km storm-relative helicity
31 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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, Apr 7, 11:30 AM CDT, 4 hours 35 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>075-084-085-099-080600-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
1130 AM CDT TUE APR 7 1998

THIS OUTLOOK COVERS THE COUNTY WARNING AREA OF THE NATIONAL WEATHER
SERVICE FORECAST OFFICE IN ST LOUIS.  AREAS INCLUDED ARE PORTIONS OF
NORTHEAST...CENTRAL...EAST CENTRAL AND SOUTHEAST MISSOURI AS WELL AS
WEST CENTRAL AND SOUTHWEST ILLINOIS.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE EASTERN PART
OF THE COUNTY WARNING AREA.  THE SLIGHT RISK AREA IS EAST A LINE FROM
MEMPHIS IN SCOTLAND COUNTY TO MEXICO IN AUDRAIN COUNTY TO CENTERVILLE
IN REYNOLDS COUNTY.

THE THREAT OF SEVERE THUNDERSTORMS WILL BE MAINLY DURING THE AFTERNOON
AND EVENING HOURS AS A FRONT MOVES INTO EASTERN MISSOURI.

STORM SPOTTER ACTIVATION MAY BE REQUIRED DURING THE AFTERNOON AND
EVENING HOURS.

TPS
Special weather statement, Apr 7, 11:30 AM CDT, 4 hours 35 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>075-084-085-099-080600-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
1130 AM CDT TUE APR 7 1998

THIS OUTLOOK COVERS THE COUNTY WARNING AREA OF THE NATIONAL WEATHER
SERVICE FORECAST OFFICE IN ST LOUIS.  AREAS INCLUDED ARE PORTIONS OF
NORTHEAST...CENTRAL...EAST CENTRAL AND SOUTHEAST MISSOURI AS WELL AS
WEST CENTRAL AND SOUTHWEST ILLINOIS.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE EASTERN PART
OF THE COUNTY WARNING AREA.  THE SLIGHT RISK AREA IS EAST A LINE FROM
MEMPHIS IN SCOTLAND COUNTY TO MEXICO IN AUDRAIN COUNTY TO CENTERVILLE
IN REYNOLDS COUNTY.

THE THREAT OF SEVERE THUNDERSTORMS WILL BE MAINLY DURING THE AFTERNOON
AND EVENING HOURS AS A FRONT MOVES INTO EASTERN MISSOURI.

STORM SPOTTER ACTIVATION MAY BE REQUIRED DURING THE AFTERNOON AND
EVENING HOURS.

TPS

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 7, 3:55 PM CDTSevere Thunderstorm WarningLSXAdams35 min
Apr 7, 4:34 PM CDTSevere Thunderstorm WarningLSXMacoupin41 min
Apr 7, 4:44 PM CDTTornado WarningLSXMacoupin46 min
Apr 7, 4:50 PM CDTSevere Thunderstorm WarningLSXBrown40 min
Apr 7, 5:08 PM CDTSevere Thunderstorm WarningLSXMontgomery37 min

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.