Alert archive / Illinois / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 77, NWS St. Louis, MO

May 12, 1999Fayette County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at May 12, 1999, 6:04 PM CDT for Fayette County, Illinois. It was in force for 31 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
May 12, 1999, 6:04 PM CDT (23:04 UTC)
Expired
May 12, 1999, 6:35 PM CDT
In force
31 min
Issued by
NWS St. Louis, MO
Area
Whole counties

County Fayette County, IL

The radar

The Lincoln radar (KILX), 131 km from the middle of the area, began a volume at 23:08 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 nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 11.1 hours before the alert went out and 133 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 1999-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 90 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 1999-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -66 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
90 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
1292 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-66 m²/s²
0-3 km storm-relative helicity
-46 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 122304 RRA
SVRSTL
ILC051-122335-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
604 PM CDT WED MAY 12 1999

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN FAYETTE COUNTY IN SOUTHWESTERN ILLINOIS

* UNTIL 635 PM CDT

* AT 600 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 3 MILES NORTH NORTHWEST OF VANDALIA... MOVING
  NORTH AT 20 MPH.

* LOCATIONS THAT WILL BE AFFECTED...
  RAMSEY
  BAYLE CITY

PUBLIC REPORTED TREE DAMAGE IN THE TOWN OF VANDALIA AROUND 555 PM.

THIS STORM HAS A HISTORY OF DAMAGING WINDS. MOVE QUICKLY TO A
STURDY BUILDING AND STAY AWAY~ FROM DOORS AND WINDOWS.



WDB/RP


&

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 12, 12:30 PM CDT, 5 hours 34 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>075-084-085-099-122330-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
1230 PM CDT WED MAY 12 1999

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 CHANCE OF THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON
AND TONIGHT.  HOWEVER...NONE OF THE STORMS ARE EXPECTED TO BECOME
SEVERE...THEREFORE SKYWARN ACTIVATION IS NOT ANTICIPATED.
Special weather statement, May 12, 12:30 PM CDT, 5 hours 34 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>075-084-085-099-122330-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
1230 PM CDT WED MAY 12 1999

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 CHANCE OF THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON
AND TONIGHT.  HOWEVER...NONE OF THE STORMS ARE EXPECTED TO BECOME
SEVERE...THEREFORE SKYWARN ACTIVATION IS NOT ANTICIPATED.

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