Alert archive / Missouri / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 273, NWS St. Louis, MO

September 6, 2012Jefferson County, Sainte Genevieve County, Saint Louis County, Missouri; Monroe County, Randolph County, Saint Clair County, Illinois

NWS St. Louis, MO issued this severe thunderstorm warning at Sep 6, 2012, 4:38 PM CDT for Jefferson County, Sainte Genevieve County, Saint Louis County, Missouri; Monroe County, Randolph County, Saint Clair County, Illinois. It was in force for 37 min. 4 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
Sep 6, 2012, 4:38 PM CDT (21:38 UTC)
Expired
Sep 6, 2012, 5:15 PM CDT
In force
37 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

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

The radar

The St Louis radar (KLSX), 62 km from the middle of the area, began a volume at 21:37 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
Sep 6, 4:40 PM CDTTSTM WND DMGOakville, MO6 INCH DIAMETER TREE SPLIT...RELAYED THROUGH THE ST. LOUIS COUNTY EOC
Sep 6, 4:40 PM CDTTSTM WND GST 45Olympian Village, MO
Sep 6, 4:40 PM CDTTSTM WND GST 60Oakville, MO
Sep 6, 4:48 PM CDTTSTM WND GST 45Waterloo, IL40-45 MPH WINDS WITH OUTFLOW BOUNDARY.

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
Sep 6, 12:28 PM CDTSevere Thunderstorm WatchSPC9 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 9.6 hours before the alert went out and 270 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 2012-09-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2016 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 2012-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 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
2016 J/kg
Mixed-layer CIN
-64 J/kg
Mixed-layer LCL
681 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
92 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.5

Open this sounding in Storm Lab

The text

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

362 
WUUS53 KLSX 062138
SVRLSX
ILC133-157-163-MOC099-186-189-062215-
/O.NEW.KLSX.SV.W.0273.120906T2138Z-120906T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
438 PM CDT THU SEP 6 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...
  WEST CENTRAL ST. CLAIR COUNTY IN SOUTHWEST ILLINOIS...
  JEFFERSON COUNTY IN EAST CENTRAL MISSOURI...
  NORTHERN STE. GENEVIEVE COUNTY IN SOUTHEAST MISSOURI...
  SOUTHERN ST. LOUIS COUNTY IN EAST CENTRAL MISSOURI...

* UNTIL 515 PM CDT

* AT 437 PM CDT...A LINE OF SEVERE THUNDERSTORMS WAS LOCATED ALONG A
  LINE EXTENDING FROM BYRNES MILL TO PEVELY TO 5 MILES SOUTHEAST OF
  OLYMPIAN VILLAGE...AND MOVING EAST AT 55 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...
  BARNHART...HIGH RIDGE...MURPHY...FENTON...SUNSET HILLS...ARNOLD...
  MEHLVILLE...OAKVILLE...LEMAY...WATERLOO...COLUMBIA...DUPO...RED
  BUD...MILLSTADT...VALMEYER...BLOOMSDALE...FOUNTAIN...NEW DESIGN...
  HARRISONVILLE AND PARKDALE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3801 9037 3804 9041 3802 9053 3802 9061
      3807 9061 3808 9063 3830 9061 3848 9074
      3855 9073 3852 9008 3822 8991 3799 8996
TIME...MOT...LOC 2138Z 279DEG 49KT 3846 9059 3829 9037
          3810 9035

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

$$

KANOFSKY
2 follow-up statements
477 
WWUS53 KLSX 062203
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
503 PM CDT THU SEP 6 2012

ILC133-157-163-MOC099-186-189-062215-
/O.CON.KLSX.SV.W.0273.000000T0000Z-120906T2215Z/
MONROE IL-RANDOLPH IL-ST. CLAIR IL-JEFFERSON MO-STE. GENEVIEVE MO-
ST. LOUIS MO-
503 PM CDT THU SEP 6 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL
ST. LOUIS...NORTHERN STE. GENEVIEVE...EASTERN JEFFERSON...WEST
CENTRAL ST. CLAIR...NORTHWESTERN RANDOLPH AND MONROE COUNTIES UNTIL
515 PM CDT...

AT 501 PM CDT...A LINE OF SEVERE THUNDERSTORMS WAS LOCATED ALONG A
LINE EXTENDING FROM COLUMBIA TO RED BUD TO EVANSVILLE...AND MOVING
EAST AT 55 MPH.

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

SOURCE...TRAINED WEATHER SPOTTERS REPORTED 60 MPH WIND GUSTS IN      
         OAKVILLE WITH THESE STORMS.

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

LOCATIONS IMPACTED INCLUDE...
MILLSTADT...BARR...HECKER...PADERBORN AND FLORAVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3801 9037 3804 9041 3803 9049 3840 9048
      3854 9051 3852 9008 3822 8991 3799 8996
TIME...MOT...LOC 2203Z 279DEG 49KT 3839 9016 3822 8995
          3803 8993

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

$$

KANOFSKY
467 
WWUS53 KLSX 062210
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
510 PM CDT THU SEP 6 2012

ILC133-157-163-MOC099-186-189-062220-
/O.EXP.KLSX.SV.W.0273.000000T0000Z-120906T2215Z/
MONROE IL-RANDOLPH IL-ST. CLAIR IL-JEFFERSON MO-STE. GENEVIEVE MO-
ST. LOUIS MO-
510 PM CDT THU SEP 6 2012

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL ST. LOUIS...
NORTHERN STE. GENEVIEVE...EASTERN JEFFERSON...WEST CENTRAL ST.
CLAIR...NORTHWESTERN RANDOLPH AND MONROE COUNTIES WILL EXPIRE AT 515
PM CDT...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAS WEAKENED BELOW
SEVERE LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR
PROPERTY.  HOWEVER GUSTY WINDS ARE STILL POSSIBLE WITH THESE
THUNDERSTORMS.

IN ADDITION...STRONG THUNDERSTORMS MAY REDEVELOP...AND A SEVERE 
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 8 PM CDT.

LAT...LON 3801 9037 3804 9041 3803 9049 3840 9048
      3854 9051 3852 9008 3822 8991 3799 8996
TIME...MOT...LOC 2210Z 279DEG 49KT 3836 9004 3819 8983
          3800 8982

$$

KANOFSKY

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 6, 1:44 PM CDTSevere Thunderstorm WarningLSXCole, Moniteau46 min
Sep 6, 2:28 PM CDTSevere Thunderstorm WarningLSXCallaway, Cole, Osage47 min
Sep 6, 2:31 PM CDTSevere Thunderstorm WarningLSXCrawford44 min
Sep 6, 3:00 PM CDTFlash Flood WarningLSXCrawford5 hr
Sep 6, 3:13 PM CDTSevere Thunderstorm WarningLSXSaint Francois, Washington27 min
Sep 6, 3:15 PM CDTSevere Thunderstorm WarningLSXCrawford, Franklin, Gasconade45 min
Sep 6, 3:31 PM CDTSevere Thunderstorm WarningLSXIron, Washington44 min
Sep 6, 3:39 PM CDTSevere Thunderstorm WarningLSXFranklin54 min
Sep 6, 3:58 PM CDTSevere Thunderstorm WarningLSXIron, Reynolds47 min
Sep 6, 4:02 PM CDTSevere Thunderstorm WarningLSXFranklin, Jefferson, Saint Charles, Saint Louis, Warren, Washington43 min
Sep 6, 4:20 PM CDTSevere Thunderstorm WarningLSXMadison40 min
Sep 6, 5:18 PM CDTAreal Flood AdvisoryLSXMadison, Saint Francois3 hr

Nearby

Severe Thunderstorm Warnings in Missouri, 2012Severe Thunderstorm Warnings in Illinois, 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.