Alert archive / Illinois / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 92, NWS St. Louis, MO

May 17, 1999Marion County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at May 17, 1999, 3:39 PM CDT for Marion County, Illinois. It was in force for 46 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 17, 1999, 3:39 PM CDT (20:39 UTC)
Expired
May 17, 1999, 4:25 PM CDT
In force
46 min
Issued by
NWS St. Louis, MO
Area
Whole counties

County Marion County, IL

What was reported inside it

TimeReportWhereRemark
May 17, 3:45 PM CDTThunderstorm Wind 55Centralia, 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, 8.7 hours before the alert went out and 169 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 1999-05-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 8 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 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 1999-05-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -19 square meters per square second.193958Sfc1 km3 km6 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
8 J/kg
Mixed-layer CIN
-466 J/kg
Mixed-layer LCL
1464 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
-19 m²/s²
0-3 km storm-relative helicity
100 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.

999 
WUUS1 KSTL 172041 RRA
SVRSTL
ILC121-172125-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
339 PM CDT MON MAY 17 1999

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

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

* UNTIL 425 PM CDT

* AT 338 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 5 MILES WEST OF SANDOVAL... MOVING NORTHEAST
  35 MPH.

* LOCATIONS THAT WILL BE AFFECTED...
  SANDOVAL
  ODIN
  FAIRMAN
  SALEM

THIS STORM HAS HAD A HISTORY OF PRODUCING DAMAGING WINDS

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.

RP/MB

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 17, 11:00 AM CDT, 4 hours 39 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>075-084-085-099-181300-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
1100 AM CDT MON MAY 17 1999

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.

THE AREA DESIGNATED EARLIER AS A SLIGHT RISK FOR SEVERE THUNDERSTORMS
HAS BEEN SHIFTED SOUTHEAST SOMEWHAT AND NOW INCLUDES AN AREA EAST OF
A LINE FROM SPRINGFIELD ILLINOIS TO ST LOUIS TO BRANSON MISSOURI.
AREAS OF NORTHEASTERN MISSOURI HAVE BEEN EXCLUDED IN THIS OUTLOOK
AREA.

THOUGH THE CHANCE FOR SEVERE THUNDERSTORMS IS LIMITED...THE
PROBABILITY OF HEAVY AND REPEATED THUNDERSTORMS TREKING ACROSS THE
SAME AREA REMAINS A POSSIBILITY AND THEREFORE A FLASH FLOOD WATCH
REMAINS IN EFFECT FOR TODAY FOR THE ENTIRE WARNING AREA.

STORM SPOTTER GROUPS AND EMERGENCY MANAGERS SHOULD MONITOR WEATHER
DEVELOPMENTS THROUGHOUT THE DAY FOR POSSIBLE SKYWARN ACTION...FOR
FLOODING PROBLEMS NORTHWEST AND FOR SEVERE STORMS IN THE SOUTHEAST
PORTION OF THE FORECAST AREA.

PEDIGO
Special weather statement, May 17, 11:00 AM CDT, 4 hours 39 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>075-084-085-099-181300-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
1100 AM CDT MON MAY 17 1999

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.

THE AREA DESIGNATED EARLIER AS A SLIGHT RISK FOR SEVERE THUNDERSTORMS
HAS BEEN SHIFTED SOUTHEAST SOMEWHAT AND NOW INCLUDES AN AREA EAST OF
A LINE FROM SPRINGFIELD ILLINOIS TO ST LOUIS TO BRANSON MISSOURI.
AREAS OF NORTHEASTERN MISSOURI HAVE BEEN EXCLUDED IN THIS OUTLOOK
AREA.

THOUGH THE CHANCE FOR SEVERE THUNDERSTORMS IS LIMITED...THE
PROBABILITY OF HEAVY AND REPEATED THUNDERSTORMS TREKING ACROSS THE
SAME AREA REMAINS A POSSIBILITY AND THEREFORE A FLASH FLOOD WATCH
REMAINS IN EFFECT FOR TODAY FOR THE ENTIRE WARNING AREA.

STORM SPOTTER GROUPS AND EMERGENCY MANAGERS SHOULD MONITOR WEATHER
DEVELOPMENTS THROUGHOUT THE DAY FOR POSSIBLE SKYWARN ACTION...FOR
FLOODING PROBLEMS NORTHWEST AND FOR SEVERE STORMS IN THE SOUTHEAST
PORTION OF THE FORECAST AREA.

PEDIGO

The office that day

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

IssuedProductOfficeCountiesLasted
May 17, 2:43 AM CDTSevere Thunderstorm WarningLSXPike47 min
May 17, 2:25 PM CDTSevere Thunderstorm WarningLSXSaint Clair35 min
May 17, 3:02 PM CDTSevere Thunderstorm WarningLSXClinton, Washington48 min
May 17, 3:52 PM CDTSevere Thunderstorm WarningLSXFayette48 min

Nearby

Severe Thunderstorm Warnings in Illinois, 1999Every severe thunderstorm warning in 1999

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.