Alert archive / Illinois / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 328, NWS St. Louis, MO

September 25, 2012Madison County, Saint Clair County, Illinois; Saint Louis County, City of Saint Louis, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Sep 25, 2012, 8:13 PM CDT for Madison County, Saint Clair County, Illinois; Saint Louis County, City of Saint Louis, Missouri. It was in force for 47 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 25, 2012, 8:13 PM CDT (01:13 UTC)
Expired
Sep 25, 2012, 9:00 PM CDT
In force
47 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 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), 43 km from the middle of the area, began a volume at 01:13 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 watch it was issued in

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

IssuedProductOfficeLasted
Sep 25, 5:05 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 1.2 hours before the alert went out and 210 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 2012-09-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1015 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 00:00Z on 2012-09-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 145 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
1015 J/kg
Mixed-layer CIN
-72 J/kg
Mixed-layer LCL
957 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
145 m²/s²
0-3 km storm-relative helicity
222 m²/s²
Significant tornado parameter
0.9
Supercell composite
5.3

Open this sounding in Storm Lab

The text

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

941 
WUUS53 KLSX 260113
SVRLSX
ILC119-163-MOC189-510-260200-
/O.NEW.KLSX.SV.W.0328.120926T0113Z-120926T0200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
813 PM CDT TUE SEP 25 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...
  EASTERN ST. LOUIS COUNTY IN EAST CENTRAL MISSOURI...
  ST. LOUIS CITY IN EAST CENTRAL MISSOURI...

* UNTIL 900 PM CDT

* AT 808 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR OLIVETTE...
  AND MOVING EAST AT 30 MPH.

  HAZARD...QUARTER SIZE HAIL AND 60 MPH WIND GUSTS.

  SOURCE...TRAINED WEATHER SPOTTERS.  DIME SIZE HAIL HAS BEEN  
           REPORTED IN OLIVETTE WITH THIS STORM.

  IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS. MINOR TREE
           DAMAGE...WITH LIMBS UP TO ONE INCH IN DIAMETER BROKEN.

* LOCATIONS IMPACTED INCLUDE...
  UNIVERSITY CITY...BERKELEY...CLAYTON...MAPLEWOOD...BEL-RIDGE...
  KINLOCH...COOL VALLEY...NORMANDY...LEMAY...FERGUSON...HILLSDALE...
  NORTHWOODS...DELLWOOD...JENNINGS...BLACK JACK...ST. LOUIS...
  BELLEFONTAINE NEIGHBORS...RIVERVIEW...SPANISH LAKE AND CAHOKIA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3852 9047 3877 9046 3883 9014 3880 9012
      3884 9011 3889 8985 3853 8985
TIME...MOT...LOC 0113Z 267DEG 28KT 3867 9034

HAIL...1.00IN
WIND...60 MPH

$$

BRITT
2 follow-up statements
262 
WWUS53 KLSX 260136
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
836 PM CDT TUE SEP 25 2012

MOC189-510-260145-
/O.CAN.KLSX.SV.W.0328.000000T0000Z-120926T0200Z/
ST. LOUIS MO-ST. LOUIS CITY MO-
836 PM CDT TUE SEP 25 2012

...THE SEVERE THUNDERSTORM WARNING FOR ST. LOUIS CITY AND EASTERN ST.
LOUIS COUNTIES IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED 
AREA.  ADDITIONAL STRONG THUNDERSTORMS ARE POSSIBLE AND A SEVERE 
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 11 PM CDT.

LAT...LON 3860 8985 3871 9015 3884 9011 3889 8985
TIME...MOT...LOC 0135Z 261DEG 35KT 3878 9002

$$

ILC119-163-260200-
/O.CON.KLSX.SV.W.0328.000000T0000Z-120926T0200Z/
MADISON IL-ST. CLAIR IL-
836 PM CDT TUE SEP 25 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTH CENTRAL
ST. CLAIR AND CENTRAL MADISON COUNTIES UNTIL 900 PM CDT...

AT 831 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR PONTOON
BEACH...AND MOVING EAST AT 40 MPH.

HAZARD...QUARTER SIZE HAIL AND 60 MPH WIND GUSTS.

SOURCE...RADAR INDICATED.

IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS. MINOR TREE
         DAMAGE...WITH LIMBS UP TO ONE INCH IN DIAMETER BROKEN.

LOCATIONS IMPACTED INCLUDE...
GLEN CARBON...MARYVILLE...EDWARDSVILLE...TROY...KUHN AND FRUIT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3860 8985 3871 9015 3884 9011 3889 8985
TIME...MOT...LOC 0135Z 261DEG 35KT 3878 9002

HAIL...1.00IN
WIND...60 MPH

$$

BRITT
243 
WWUS53 KLSX 260154
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
854 PM CDT TUE SEP 25 2012

ILC119-163-260203-
/O.EXP.KLSX.SV.W.0328.000000T0000Z-120926T0200Z/
MADISON IL-ST. CLAIR IL-
854 PM CDT TUE SEP 25 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL ST. CLAIR AND
CENTRAL MADISON COUNTIES WILL EXPIRE AT 900 PM CDT...

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

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A SEVERE 
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 11 PM CDT.

LAT...LON 3860 8985 3871 9015 3884 9011 3889 8985
TIME...MOT...LOC 0153Z 261DEG 35KT 3881 8980

$$

BRITT

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 25, 7:05 PM CDTSevere Thunderstorm WarningLSXCalhoun40 min
Sep 25, 7:29 PM CDTSevere Thunderstorm WarningLSXMarion, Washington46 min
Sep 25, 8:11 PM CDTSevere Thunderstorm WarningLSXBond, Clinton, Madison, Saint Clair34 min
Sep 25, 8:38 PM CDTSevere Thunderstorm WarningLSXBond, Clinton, Fayette, Marion52 min
Sep 25, 8:59 PM CDTFlash Flood WarningLSXClinton, Washington6 hr
Sep 26, 3:01 AM CDTFlash Flood WarningLSXClinton, Marion, Washington6 hr
Sep 26, 9:08 AM CDTAreal Flood WarningLSXClinton, Marion, Washington12 hr
Sep 25, 7:41 PM CDTSevere Thunderstorm WarningLSXFranklin, Jefferson, Saint Louis49 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.