Alert archive / Illinois / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 232, NWS St. Louis, MO

August 4, 2012Jefferson County, Sainte Genevieve County, Missouri; Monroe County, Randolph County, Saint Clair County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Aug 4, 2012, 10:59 PM CDT for Jefferson County, Sainte Genevieve County, Missouri; Monroe County, Randolph County, Saint Clair County, Illinois. It was in force for 46 min. 2 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
Aug 4, 2012, 10:59 PM CDT (03:59 UTC)
Expired
Aug 4, 2012, 11:45 PM CDT
In force
46 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Monroe County, IL, Randolph County, IL, Saint Clair County, IL, Jefferson County, MO, Sainte Genevieve County, MO

The radar

The St Louis radar (KLSX), 69 km from the middle of the area, began a volume at 04:01 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
Aug 4, 11:26 PM CDTTSTM WND DMG4 Nw Ellis Grove, ILSEVERAL LIMBS AND POWER LINES BLOWN DOWN.
Aug 4, 11:35 PM CDTTSTM WND DMGRuma, ILHIGH WINDS SNAPPED POWER POLE... AND BLEW LARGE LIMB OFF AN OAK TREE. DELAYED REPORT

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
Aug 4, 6:12 PM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 4.0 hours before the alert went out and 252 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 2012-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 857 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 2012-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 93 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
857 J/kg
Mixed-layer CIN
-59 J/kg
Mixed-layer LCL
1700 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
93 m²/s²
0-3 km storm-relative helicity
210 m²/s²
Significant tornado parameter
0.2
Supercell composite
3.0

Open this sounding in Storm Lab

The text

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

019 
WUUS53 KLSX 050359
SVRLSX
ILC133-157-163-MOC099-186-050445-
/O.NEW.KLSX.SV.W.0232.120805T0359Z-120805T0445Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
1059 PM CDT SAT AUG 4 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MONROE COUNTY IN SOUTHWEST ILLINOIS...
  NORTHWESTERN RANDOLPH COUNTY IN SOUTHWEST ILLINOIS...
  SOUTH CENTRAL ST. CLAIR COUNTY IN SOUTHWEST ILLINOIS...
  SOUTHEASTERN JEFFERSON COUNTY IN EAST CENTRAL MISSOURI...
  NORTHWESTERN STE. GENEVIEVE COUNTY IN SOUTHEAST MISSOURI...

* UNTIL 1145 PM CDT

* AT 1056 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR FESTUS...
  AND MOVING EAST AT 25 MPH.

  HAZARD...60 MPH WIND GUSTS.

  SOURCE...TRAINED WEATHER SPOTTERS REPORTING 55 MPH WINDS. 

  IMPACT...MINOR TREE DAMAGE...WITH LIMBS UP TO ONE INCH IN DIAMETER
           BROKEN.

* LOCATIONS IMPACTED INCLUDE...
  HERCULANEUM...CRYSTAL CITY...WATERLOO...RED BUD...VALMEYER...NEW
  DESIGN...EVANSVILLE...HARRISONVILLE...CHALFIN BRIDGE...MONROE
  CITY...MADONNAVILLE...FOSTER POND...MAEYSTOWN...FULTS...WARTBURG...
  KIDD...BURKSVILLE...RENAULT...PRAIRIE DU ROCHER AND AMES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3837 8991 3803 8993 3806 9051 3834 9051
TIME...MOT...LOC 0359Z 272DEG 21KT 3820 9040

HAIL...<.75IN
WIND...60 MPH

$$

TRUETT
3 follow-up statements
997 
WWUS53 KLSX 050420
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1120 PM CDT SAT AUG 4 2012

MOC099-050430-
/O.CAN.KLSX.SV.W.0232.000000T0000Z-120805T0445Z/
JEFFERSON MO-
1120 PM CDT SAT AUG 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN JEFFERSON COUNTY
IS CANCELLED...

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

LAT...LON 3803 8993 3805 9040 3810 9033 3809 9029
      3812 9025 3816 9027 3819 9033 3821 9036
      3826 9037 3835 9037 3837 8991
TIME...MOT...LOC 0420Z 272DEG 21KT 3819 9023

$$

ILC133-157-163-MOC186-050445-
/O.CON.KLSX.SV.W.0232.000000T0000Z-120805T0445Z/
MONROE IL-RANDOLPH IL-ST. CLAIR IL-STE. GENEVIEVE MO-
1120 PM CDT SAT AUG 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHWESTERN
STE. GENEVIEVE...SOUTH CENTRAL ST. CLAIR...NORTHWESTERN RANDOLPH AND
MONROE COUNTIES UNTIL 1145 PM CDT...

AT 1118 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED 8 MILES EAST OF
CRYSTAL CITY...AND MOVING EAST AT 25 MPH.

HAZARD...60 MPH WIND GUSTS.

SOURCE...RADAR INDICATED.

IMPACT...MINOR TREE DAMAGE...WITH LIMBS UP TO ONE INCH IN DIAMETER
         BROKEN.

LOCATIONS IMPACTED INCLUDE...
WATERLOO...RED BUD...NEW DESIGN...EVANSVILLE...FULTS...WARTBURG...
KIDD...BURKSVILLE...RENAULT...PRAIRIE DU ROCHER...AMES...PADERBORN...
RUMA...PRAIRIE...MODOC AND HECKER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3803 8993 3805 9040 3810 9033 3809 9029
      3812 9025 3816 9027 3819 9033 3821 9036
      3826 9037 3835 9037 3837 8991
TIME...MOT...LOC 0420Z 272DEG 21KT 3819 9023

HAIL...<.75IN
WIND...60 MPH

$$

TRUETT
487 
WWUS53 KLSX 050435
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1135 PM CDT SAT AUG 4 2012

ILC133-163-MOC186-050444-
/O.CAN.KLSX.SV.W.0232.000000T0000Z-120805T0445Z/
MONROE IL-ST. CLAIR IL-STE. GENEVIEVE MO-
1135 PM CDT SAT AUG 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN STE. GENEVIEVE...
SOUTH CENTRAL ST. CLAIR AND MONROE COUNTIES IS CANCELLED...

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

LAT...LON 3803 8993 3804 9013 3806 9013 3807 9014
      3807 9017 3809 9020 3814 9003 3822 9004
      3822 8992
TIME...MOT...LOC 0434Z 279DEG 43KT 3811 8995

$$

ILC157-050445-
/O.CON.KLSX.SV.W.0232.000000T0000Z-120805T0445Z/
RANDOLPH IL-
1135 PM CDT SAT AUG 4 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHWESTERN
RANDOLPH COUNTY UNTIL 1145 PM CDT...

AT 1131 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR EVANSVILLE...
AND MOVING EAST AT 30 MPH.

HAZARD...60 MPH WIND GUSTS.

SOURCE...RADAR INDICATED....WITH A WEAKENING TREND NOTED.

IMPACT...MINOR TREE DAMAGE...WITH LIMBS UP TO ONE INCH IN DIAMETER
         BROKEN.

LOCATIONS IMPACTED INCLUDE...
EVANSVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3803 8993 3804 9013 3806 9013 3807 9014
      3807 9017 3809 9020 3814 9003 3822 9004
      3822 8992
TIME...MOT...LOC 0434Z 279DEG 28KT 3811 8995

HAIL...<.75IN
WIND...60 MPH

$$

TRUETT
387 
WWUS53 KLSX 050443
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1143 PM CDT SAT AUG 4 2012

ILC157-050452-
/O.EXP.KLSX.SV.W.0232.000000T0000Z-120805T0445Z/
RANDOLPH IL-
1143 PM CDT SAT AUG 4 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN RANDOLPH COUNTY
WILL EXPIRE AT 1145 PM CDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED AND MOVED OUT OF
THE WARNED AREA.  HOWEVER GUSTY WINDS AND HEAVY RAIN ARE STILL 
POSSIBLE WITH THIS THUNDERSTORM AS IT MOVES EAST SOUTHEAST THROUGH 
CENTRAL AND EASTERN RANDOLPH COUNTY THROUGH 1215 AM.

LAT...LON 3803 8993 3804 9013 3806 9013 3807 9014
      3807 9017 3809 9020 3814 9003 3822 9004
      3822 8992
TIME...MOT...LOC 0442Z 279DEG 28KT 3810 8987

$$

TRUETT

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 8:30 PM CDTSevere Thunderstorm WarningLSXCallaway, Gasconade, Montgomery, Osage45 min
Aug 4, 8:47 PM CDTSevere Thunderstorm WarningLSXGasconade, Osage43 min
Aug 4, 9:07 PM CDTSevere Thunderstorm WarningLSXGasconade, Montgomery, Osage, Warren23 min
Aug 4, 9:20 PM CDTSevere Thunderstorm WarningLSXCrawford, Franklin, Gasconade, Warren, Washington40 min
Aug 4, 9:38 PM CDTSevere Thunderstorm WarningLSXFranklin, Jefferson, Saint Charles, Saint Louis, Warren, Washington67 min
Aug 4, 10:22 PM CDTSevere Thunderstorm WarningLSXJefferson, Saint Charles, Saint Louis, City of Saint Louis38 min
Aug 4, 11:46 PM CDTSevere Thunderstorm WarningLSXLincoln, Saint Charles, Warren33 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.