Alert archive / Illinois / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 340, NWS St. Louis, MO

October 22, 2012Madison County, Saint Clair County, Illinois; Saint Louis County, City of Saint Louis, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Oct 22, 2012, 2:04 PM CDT for Madison County, Saint Clair County, Illinois; Saint Louis County, City of Saint Louis, Missouri. It was in force for 24 min. 1 report 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
Oct 22, 2012, 2:04 PM CDT (19:04 UTC)
Expired
Oct 22, 2012, 2:28 PM CDT
In force
24 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

Counties Madison County, IL, Saint Clair County, IL, City of Saint Louis, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 40 km from the middle of the area, began a volume at 19:04 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
Oct 22, 2:12 PM CDTHAIL 1St. Louis, MOSOUTH SIDE OF CITY AT INTERSECTION OF GUSTINE AND HARTFORD

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

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 7.1 hours before the alert went out and 224 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 2012-10-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 620 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2012-10-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 103 square meters per square second.193958Sfc1 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
620 J/kg
Mixed-layer CIN
-91 J/kg
Mixed-layer LCL
653 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
103 m²/s²
0-3 km storm-relative helicity
276 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.

740 
WUUS53 KLSX 221904
SVRLSX
ILC119-163-MOC189-510-221945-
/O.NEW.KLSX.SV.W.0340.121022T1904Z-121022T1945Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
204 PM CDT MON OCT 22 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHWESTERN MADISON COUNTY IN SOUTHWEST ILLINOIS...
  NORTHWESTERN ST. CLAIR COUNTY IN SOUTHWEST ILLINOIS...
  SOUTHEASTERN ST. LOUIS COUNTY IN EAST CENTRAL MISSOURI...
  ST. LOUIS CITY IN EAST CENTRAL MISSOURI...

* UNTIL 245 PM CDT

* AT 200 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR
  SHREWSBURY...AND MOVING EAST AT 30 MPH.

  HAZARD...QUARTER SIZE HAIL.

  SOURCE...RADAR INDICATED.

  IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS.

* LOCATIONS IMPACTED INCLUDE...
  NORMANDY...DUPO...HILLSDALE...NORTHWOODS...ST. LOUIS...JENNINGS...
  CAHOKIA...BELLEFONTAINE NEIGHBORS...RIVERVIEW...VENICE...EAST ST.
  LOUIS...MADISON...CENTREVILLE...WASHINGTON PARK...GRANITE CITY...
  BELLEVILLE...CASEYVILLE...SWANSEA...FAIRVIEW HEIGHTS AND PONTOON
  BEACH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

&&

LAT...LON 3856 8983 3849 9022 3852 9026 3848 9028
      3845 9040 3849 9041 3850 9040 3850 9042
      3862 9048 3881 9012 3880 9012 3882 9012
      3887 9001
TIME...MOT...LOC 1904Z 250DEG 26KT 3858 9030

HAIL...1.00IN
WIND...<50 MPH

$$

BRITT
2 follow-up statements
716 
WWUS53 KLSX 221920
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
220 PM CDT MON OCT 22 2012

MOC189-221928-
/O.CAN.KLSX.SV.W.0340.000000T0000Z-121022T1945Z/
ST. LOUIS MO-
220 PM CDT MON OCT 22 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ST. LOUIS COUNTY
IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED 
AREA.

LAT...LON 3849 9022 3852 9026 3855 9027 3857 9031
      3864 9028 3879 9014 3880 9012 3882 9011
      3887 9001 3856 8983
TIME...MOT...LOC 1918Z 250DEG 26KT 3861 9018

$$

ILC119-163-MOC510-221945-
/O.CON.KLSX.SV.W.0340.000000T0000Z-121022T1945Z/
MADISON IL-ST. CLAIR IL-ST. LOUIS CITY MO-
220 PM CDT MON OCT 22 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR ST. LOUIS
CITY...NORTHWESTERN ST. CLAIR AND SOUTHWESTERN MADISON COUNTIES UNTIL
245 PM CDT...

AT 217 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR EAST ST.
LOUIS...AND MOVING EAST AT 30 MPH.

HAZARD...QUARTER SIZE HAIL.

SOURCE...TRAINED WEATHER SPOTTERS.  QUARTER SIZE HAIL WAS REPORTED 
         ON THE SOUTH SIDE OF THE CITY OF ST. LOUIS WITH THIS STORM.

IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS.

LOCATIONS IMPACTED INCLUDE...
VENICE...EAST ST. LOUIS...MADISON...CENTREVILLE...WASHINGTON PARK...
GRANITE CITY...BELLEVILLE...CASEYVILLE...SWANSEA...FAIRVIEW
HEIGHTS...PONTOON BEACH...COLLINSVILLE...SHILOH...O'FALLON...
MARYVILLE...GLEN CARBON...BROOKLYN...FAIRMONT CITY...HARTFORD AND
ROXANA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM IS PRODUCING LARGE HAIL. SEEK SHELTER NOW INSIDE A STURDY
STRUCTURE AND STAY AWAY FROM WINDOWS.

&&

LAT...LON 3849 9022 3852 9026 3855 9027 3857 9031
      3864 9028 3879 9014 3880 9012 3882 9011
      3887 9001 3856 8983
TIME...MOT...LOC 1918Z 250DEG 26KT 3861 9018

HAIL...1.00IN
WIND...<50 MPH

$$

BRITT
424 
WWUS53 KLSX 221928
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
228 PM CDT MON OCT 22 2012

ILC119-163-MOC510-221938-
/O.CAN.KLSX.SV.W.0340.000000T0000Z-121022T1945Z/
MADISON IL-ST. CLAIR IL-ST. LOUIS CITY MO-
228 PM CDT MON OCT 22 2012

...THE SEVERE THUNDERSTORM WARNING FOR ST. LOUIS CITY...NORTHWESTERN
ST. CLAIR AND SOUTHWESTERN MADISON COUNTIES IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.

LAT...LON 3849 9022 3852 9026 3855 9027 3857 9031
      3864 9028 3879 9014 3880 9012 3882 9011
      3887 9001 3856 8983
TIME...MOT...LOC 1928Z 250DEG 26KT 3863 9009

$$

BRITT

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 22, 6:20 AM CDTSevere Thunderstorm WarningLSXAdams55 min
Oct 22, 6:56 AM CDTSevere Thunderstorm WarningLSXAdams, Pike49 min
Oct 22, 7:43 AM CDTSevere Thunderstorm WarningLSXPike47 min
Oct 22, 9:30 AM CDTSevere Thunderstorm WarningLSXGreene, Jersey, Macoupin45 min
Oct 22, 10:34 AM CDTSevere Thunderstorm WarningLSXMadison41 min
Oct 22, 11:38 AM CDTSevere Thunderstorm WarningLSXClinton, Madison, Saint Clair37 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2012Severe Thunderstorm Warnings in Missouri, 2012Every severe thunderstorm warning in 2012

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.