Alert archive / Illinois / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 67, NWS St. Louis, MO

April 29, 1998Macoupin County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 29, 1998, 7:09 PM CDT for Macoupin 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
Apr 29, 1998, 7:09 PM CDT (00:09 UTC)
Expired
Apr 29, 1998, 8:10 PM CDT
In force
61 min
Issued by
NWS St. Louis, MO
Area
Whole counties

County Macoupin County, IL

The radar

The St Louis radar (KLSX), 91 km from the middle of the area, began a volume at 00:09 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 29, 7:22 PM CDTHail 0.75Brighton, ILAmateur radio spotters reported 3/4 inch hail.

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

Davenport, (KDVN), launched 00:00Z, 0.2 hours before the alert went out and 267 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 00:00Z on 1998-04-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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, Davenport, at 00:00Z on 1998-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 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
2 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
537 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
28 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.

966 
WUUS1 KSTL 300010 RRA
SVRSTL
ILC117-300110-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
709 PM CDT WED APR 29 1998

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MACOUPIN COUNTY IN SOUTHWESTERN ILLINOIS

* UNTIL 810 PM CDT

* AT 705 PM CDT...SEVERE STORM SPOTTERS INDICATED A SEVERE
  THUNDERSTORM NEAR BRIGHTON IL... MOVING NORTHEAST AT 25 MILES AN
  HOUR.

* LOCATIONS THAT WILL BE AFFECTED...
  NEAR CARLINVILLE AT 730 PM CDT

3/4 INCH HAIL NEAR BRIGHTON AT 655 PM CDT

THE PRIMARY SEVERE WEATHER THREAT IS DAMAGING HAIL. LARGE HAIL CAN
CAUSE EXTENSIVE PROPERTY DAMAGE AN SERIOUS INJURY TO PEOPLE CAUGHT
OUTDOORS. MOVE INSIDE A STURDY BUILDING IMMEDIATELY.



TPS


&

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 29, 5:04 PM CDT, 2 hours 5 minutes before
ILZ058-059-292300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
504 PM CDT WED APR 29 1998

AT 5 PM...THE ST LOUIS WEATHER RADAR INDICATED A STORM NEAR GREENFIELD
IN GREEN COUNTY ILLINOIS...THIS STORM WAS MOVING TO THE NORTHEAST AT 30
MPH AND WILL HIT THE CITY OF PALMYRA BY 515 PM.  THIS STORM WILL
CONINUE TO PRODUCE HEAVY RAIN AND SMALL HAIL.
Special weather statement, Apr 29, 5:04 PM CDT, 2 hours 5 minutes before
ILZ058-059-292300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
504 PM CDT WED APR 29 1998

AT 5 PM...THE ST LOUIS WEATHER RADAR INDICATED A STORM NEAR GREENFIELD
IN GREEN COUNTY ILLINOIS...THIS STORM WAS MOVING TO THE NORTHEAST AT 30
MPH AND WILL HIT THE CITY OF PALMYRA BY 515 PM.  THIS STORM WILL
CONINUE TO PRODUCE HEAVY RAIN AND SMALL HAIL.
Special weather statement, Apr 29, 5:30 PM CDT, 1 hour 39 minutes before
ILZ099-100-MOZ061-063-300000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
530 PM CDT WED APR 29 1998

AT 530 PM...THE ST LOUIS WEATHER RADAR INDICATED A LINE OF STRONG
THUNDERSTOMRS FROM ST CHARLES TO PORTAGE DES SIOUX IN ST CHARLES
COUNTY.  VERY HEAVY RAIN AND SMALL HAIL WILL ACCOMPANY THE STORMS.
PERSONS IN ST CHARLES...PORTAGE DES SIOUX...BRIGHTON...AND MEDORA
MAY EXPERIENCE SMALL HAIL AND HEAVY RAIN BETWEEN 530 PM AND 615 PM.
THE STORMS WERE MOVING TO THE NORTHEAST AROUND 25 MILES AN HOUR.

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.