Alert archive / Illinois / Tornado Warnings in 2011

Tornado Warning 34, NWS St. Louis, MO

April 19, 2011Saint Clair County, Illinois

NWS St. Louis, MO issued this tornado warning at Apr 19, 2011, 7:51 PM CDT for Saint Clair County, Illinois. It was in force for 39 min. 7 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Apr 19, 2011, 7:51 PM CDT (00:51 UTC)
Expired
Apr 19, 2011, 8:30 PM CDT
In force
39 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon

County Saint Clair County, IL

The radar

The St Louis radar (KLSX), 61 km from the middle of the area, began a volume at 00:53 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 19, 8:07 PM CDTHAIL 0.7Belleville, IL
Apr 19, 8:10 PM CDTTSTM WND DMGBelleville, ILSMALL TREE BRANCHES DOWN
Apr 19, 8:13 PM CDTHAIL 0.25O'Fallon, IL
Apr 19, 8:15 PM CDTHAIL 0.5Fairview Heights, IL
Apr 19, 8:16 PM CDTFUNNEL CLOUD5 N Mascoutah, IL
Apr 19, 8:17 PM CDTTSTM WND GST 63Scott Afb, IL
Apr 19, 8:20 PM CDTTSTM WND GST 62Scott Afb, IL

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 19, 1:00 PM CDTTornado WatchSPC10 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 0.9 hours before the alert went out and 221 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 00:00Z on 2011-04-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2409 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, Lincoln, IL at 00:00Z on 2011-04-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 370 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
2409 J/kg
Mixed-layer CIN
-46 J/kg
Mixed-layer LCL
523 m above ground
0-6 km bulk shear
62 kt
0-1 km storm-relative helicity
370 m²/s²
0-3 km storm-relative helicity
547 m²/s²
Significant tornado parameter
0.0
Supercell composite
24.4

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

247 
WFUS53 KLSX 200051
TORLSX
ILC163-200130-
/O.NEW.KLSX.TO.W.0034.110420T0051Z-110420T0130Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
751 PM CDT TUE APR 19 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* TORNADO WARNING FOR...
  ST. CLAIR COUNTY IN SOUTHWEST ILLINOIS...

* UNTIL 830 PM CDT

* AT 749 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A TORNADO NEAR
  MEHLVILLE. DOPPLER RADAR SHOWED THIS TORNADO MOVING EAST AT 50 MPH.

* LOCATIONS IMPACTED INCLUDE...
  DUPO...CAHOKIA...MILLSTADT...CENTREVILLE...BELLEVILLE...SWANSEA...
  FAIRVIEW HEIGHTS...FREEBURG...SHILOH...O'FALLON...SCOTT AFB...
  MASCOUTAH...LEBANON...EAST CARONDELET...SMITHTON...BARR...SAUGET...
  FLORAVILLE AND SUMMERFIELD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TO REPEAT...A TORNADO IS ON THE GROUND. TAKE COVER NOW. MOVE TO AN
INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID
WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE
CLOSEST SUBSTANTIAL SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 3836 9008 3841 9014 3842 9014 3853 9027
      3858 9023 3859 9021 3866 8978 3865 8971
      3841 8971
TIME...MOT...LOC 0051Z 248DEG 45KT 3850 9027

$$

GLASS
2 follow-up statements
084 
WWUS53 KLSX 200107
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
807 PM CDT TUE APR 19 2011

ILC163-200130-
/O.CON.KLSX.TO.W.0034.000000T0000Z-110420T0130Z/
ST. CLAIR IL-
807 PM CDT TUE APR 19 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHERN ST. CLAIR COUNTY
UNTIL 830 PM CDT...

AT 806 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED NEAR SWANSEA...MOVING EAST AT 50 MPH.

LOCATIONS IMPACTED INCLUDE...
  SHILOH...O'FALLON...SCOTT AFB...MASCOUTAH...LEBANON AND
  SUMMERFIELD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 3841 8971 3836 9008 3846 9019 3855 9014
      3860 9012 3866 8978 3865 8971
TIME...MOT...LOC 0108Z 248DEG 45KT 3855 8994

$$

GLASS
153 
WWUS53 KLSX 200120
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
820 PM CDT TUE APR 19 2011

ILC163-200130-
/O.CON.KLSX.TO.W.0034.000000T0000Z-110420T0130Z/
ST. CLAIR IL-
820 PM CDT TUE APR 19 2011

...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHERN ST. CLAIR COUNTY
UNTIL 830 PM CDT...

AT 819 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED NEAR SHILOH...MOVING EAST AT 65 MPH.

DAMAGING WINDS TO 70 MPH AND HAIL TO THE SIZE OF QUARTERS WILL ALSO 
OCCUR WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
  SCOTT AFB...MASCOUTAH...LEBANON AND SUMMERFIELD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 3841 8971 3836 9008 3846 9019 3855 9014
      3860 9012 3866 8978 3865 8971
TIME...MOT...LOC 0120Z 254DEG 55KT 3853 8990

$$

GLASS

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 19, 7:30 PM CDTTornado WarningLSXMadison, Saint Clair45 min
Apr 19, 7:34 PM CDTTornado WarningLSXRandolph41 min
Apr 19, 7:35 PM CDTSevere Thunderstorm WarningLSXFayette, Montgomery40 min
Apr 19, 7:37 PM CDTTornado WarningLSXMonroe36 min
Apr 19, 7:54 PM CDTTornado WarningLSXRandolph36 min
Apr 19, 7:56 PM CDTSevere Thunderstorm WarningLSXBond, Montgomery34 min
Apr 19, 8:00 PM CDTTornado WarningLSXBond, Clinton, Madison45 min
Apr 19, 8:02 PM CDTAreal Flood AdvisoryLSXBond, Macoupin, Montgomery4 hr
Apr 19, 8:18 PM CDTTornado WarningLSXRandolph, Saint Clair, Washington42 min
Apr 19, 8:25 PM CDTSevere Thunderstorm WarningLSXBond, Clinton, Madison, Saint Clair22 min
Apr 19, 8:33 PM CDTTornado WarningLSXFayette42 min
Apr 19, 8:33 PM CDTTornado WarningLSXBond, Clinton, Fayette, Marion, Washington57 min
Apr 19, 9:37 PM CDTSevere Thunderstorm WarningLSXMadison21 min
Apr 19, 9:41 PM CDTRiver Flood WarningLSXFayette13 days

Nearby

Tornado Warnings in Illinois, 2011Every tornado warning in 2011Tornadoes in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.