Alert archive / Missouri / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 237, NWS St. Louis, MO

August 8, 2012Saint Charles County, Warren County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Aug 8, 2012, 9:31 PM CDT for Saint Charles County, Warren County, Missouri. It was in force for 44 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
Aug 8, 2012, 9:31 PM CDT (02:31 UTC)
Expired
Aug 8, 2012, 10:15 PM CDT
In force
44 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Saint Charles County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 9 km from the middle of the area, began a volume at 02:30 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 8, 9:36 PM CDTTSTM WND GST 591 N New Melle, MOHAIL RANGED IN SIZE FROM NICKELS TO QUARTERS
Aug 8, 9:36 PM CDTHAIL 11 N New Melle, MOHAIL RANGED IN SIZE FROM NICKELS TO QUARTERS
Aug 8, 9:45 PM CDTHAIL 0.5Wentzville, MO
Aug 8, 10:00 PM CDTTSTM WND DMGSt. Peters, MOTREE LIMB SIX INCHES IN DIAMETER AND 24 FEET IN LENGTH BLOWN DOWN. REPORT APPROX 1M WEST OF MID RIVERS MALL DRIVE AND I-70

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 00:00Z, 2.5 hours before the alert went out and 232 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 2012-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 296 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 2012-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 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
296 J/kg
Mixed-layer CIN
-254 J/kg
Mixed-layer LCL
1804 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
80 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.

826 
WUUS53 KLSX 090231
SVRLSX
MOC183-219-090315-
/O.NEW.KLSX.SV.W.0237.120809T0231Z-120809T0315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
931 PM CDT WED AUG 8 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL ST. CHARLES COUNTY IN EAST CENTRAL MISSOURI...
  EAST CENTRAL WARREN COUNTY IN EAST CENTRAL MISSOURI...

* UNTIL 1015 PM CDT

* AT 930 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR NEW MELLE...
  AND MOVING EAST AT 25 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...
  WENTZVILLE...LAKE ST. LOUIS...DARDENNE PRAIRIE...O'FALLON...
  COTTLEVILLE...WELDON SPRING...ST. PETERS...ST. CHARLES...NEW
  MELLE...HARVESTER AND KAMPVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3883 9044 3881 9046 3876 9049 3873 9054
      3870 9053 3868 9055 3868 9063 3869 9065
      3863 9074 3865 9106 3883 9106 3886 9041
      3883 9041
TIME...MOT...LOC 0232Z 270DEG 23KT 3874 9094

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

$$

CARNEY
2 follow-up statements
228 
WWUS53 KLSX 090256
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
956 PM CDT WED AUG 8 2012

MOC183-219-090315-
/O.CON.KLSX.SV.W.0237.000000T0000Z-120809T0315Z/
ST. CHARLES MO-WARREN MO-
956 PM CDT WED AUG 8 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR EAST CENTRAL
WARREN AND CENTRAL ST. CHARLES COUNTIES UNTIL 1015 PM CDT...

AT 950 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR LAKE ST.
LOUIS...AND MOVING EAST AT 30 MPH.

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

SOURCE...PUBLIC. AT 936 PM THE PUBLIC REPORTED OF 1 INCH HAIL AND
         59 MPH WINDS NEAR NEW MELLE.  ADDITIONALLY THERE HAVE BEEN
         SEVERAL REPORTS OF PEA SIZED HAIL COVERING THE GROUND 
         IN THE WENTZVILLE AREA.

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

LOCATIONS IMPACTED INCLUDE...
COTTLEVILLE...WELDON SPRING...ST. PETERS...ST. CHARLES...HARVESTER
AND KAMPVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3883 9044 3881 9046 3876 9049 3873 9054
      3870 9053 3868 9055 3868 9063 3869 9065
      3863 9074 3865 9106 3883 9106 3886 9041
      3883 9041
TIME...MOT...LOC 0255Z 268DEG 27KT 3879 9070

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

$$

CARNEY
650 
WWUS53 KLSX 090310
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1010 PM CDT WED AUG 8 2012

MOC183-219-090320-
/O.EXP.KLSX.SV.W.0237.000000T0000Z-120809T0315Z/
ST. CHARLES MO-WARREN MO-
1010 PM CDT WED AUG 8 2012

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL WARREN AND
CENTRAL ST. CHARLES COUNTIES WILL EXPIRE AT 1015 PM CDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.
 HOWEVER SMALL HAIL...GUSTY WINDS AND HEAVY RAIN ARE STILL POSSIBLE
WITH THIS THUNDERSTORM.

LAT...LON 3883 9044 3881 9046 3876 9049 3873 9054
      3870 9053 3868 9055 3868 9063 3869 9065
      3863 9074 3865 9106 3883 9106 3886 9041
      3883 9041
TIME...MOT...LOC 0310Z 268DEG 27KT 3879 9056

$$

CARNEY

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 7:26 PM CDTSevere Thunderstorm WarningLSXCole34 min
Aug 8, 7:47 PM CDTSevere Thunderstorm WarningLSXCallaway, Cole, Osage33 min
Aug 8, 10:51 PM CDTAreal Flood AdvisoryLSXSaint Charles4 hr

Nearby

Severe 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.