Alert archive / Illinois / Tornado Warnings in 1999

Tornado Warning 6, NWS St. Louis, MO

February 27, 1999Madison County, Saint Clair County, Illinois

NWS St. Louis, MO issued this tornado warning at Feb 27, 1999, 11:51 AM CST for Madison County, Saint Clair County, Illinois. It was in force for 49 min. 4 reports 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: Feb 27, 1999, 11:51 AM CST (17:51 UTC)
Expired: Feb 27, 1999, 12:40 PM CST
In force: 49 min
Issued by: NWS St. Louis, MO
Area: Whole counties

Counties Madison County, IL, Saint Clair County, IL

The radar

The St Louis radar (KLSX), 67 km from the middle of the area, began a volume at 17:50 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

Time	Report	Where
Feb 27, 11:52 AM CST	Hail 1	O Fallon, IL
Feb 27, 12:05 PM CST	Tornado F0	Troy, IL
Feb 27, 12:15 PM CST	Hail 1.75	Edwardsville, IL
Feb 27, 12:45 PM CST	Hail 1	Highland, 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, 5.9 hours before the alert went out and 202 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 107 J/kg
Mixed-layer CIN: -160 J/kg
Mixed-layer LCL: 635 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 275 m²/s²
0-3 km storm-relative helicity: 325 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 
WFUS1 KSTL 271753 RRA
TORSTL
ILC119-163-271840-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
1151 AM CST SAT FEB 27 1999

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHERN MADISON COUNTY ILLINOIS IN SOUTHWESTERN ILLINOIS
  NORTHERN ST CLAIR COUNTY IN SOUTHWESTERN ILLINOIS

* UNTIL 1240 PM CST

* AT 1150 AM CST... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A TORNADO JUST ENTERING FAR NORTHWEST ST CLAIR COUNTY AND FAR
  SOUTHWEST MADISON COUNTY... MOVING EAST NORTHEAST AT 30 MPH.

* LOCATIONS IN THE PATH...
  COLLINSVILLE
  GRANT CITY
  TROY
  OFALLON



DOPPLER RADAR IS SHOWING A STRONG TORNADO SIGNAL. IF YOU ARE IN
THE PATH MOVE TO A SHELTER NOW A BASEMENT IS BEST...BUT IF NOT
AVAILABLE...MOVE TO THE LOWEST LEVEL AND HIDE IN A SMALL INTERIOR
ROOM. GET OUT OF MOBILE HOMES AND CARS IN FAVOR OF A STRONG
BUILDING.

TES/RP

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 27, 11:34 AM CST	Severe Thunderstorm Warning	LSX	Madison, Saint Clair	66 min
Feb 27, 12:11 PM CST	Severe Thunderstorm Warning	LSX	Monroe	34 min
Feb 27, 12:13 PM CST	Tornado Warning	LSX	Monroe	47 min
Feb 27, 12:26 PM CST	Tornado Warning	LSX	Bond, Clinton	44 min
Feb 27, 12:45 PM CST	Severe Thunderstorm Warning	LSX	Fayette	50 min
Feb 27, 12:49 PM CST	Severe Thunderstorm Warning	LSX	Saint Clair	46 min
Feb 27, 1:05 PM CST	Severe Thunderstorm Warning	LSX	Monroe	50 min
Feb 27, 1:07 PM CST	Severe Thunderstorm Warning	LSX	Clinton	48 min
Feb 27, 1:26 PM CST	Severe Thunderstorm Warning	LSX	Randolph	49 min
Feb 27, 1:37 PM CST	Severe Thunderstorm Warning	LSX	Marion	48 min

Nearby

Tornado Warnings in Illinois, 1999 Every tornado warning in 1999 Tornadoes 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; radar from the NEXRAD Level II archive.