Alert archive / Missouri / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 29, NWS St. Louis, MO

April 4, 20114 counties in Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 4, 2011, 3:55 AM CDT for 4 counties in Missouri. It was in force for 35 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
Apr 4, 2011, 3:55 AM CDT (08:55 UTC)
Expired
Apr 4, 2011, 4:30 AM CDT
In force
35 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Franklin County, MO, Jefferson County, MO, Saint Charles County, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 17 km from the middle of the area, began a volume at 08:55 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
Apr 4, 4:06 AM CDTTSTM WND GST 65Gray Summit, MO
Apr 4, 4:06 AM CDTHAIL 1.5Gray Summit, MO

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, 8.9 hours before the alert went out and 257 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 2011-04-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 191 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 2011-04-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 363 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
191 J/kg
Mixed-layer CIN
-426 J/kg
Mixed-layer LCL
2183 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
363 m²/s²
0-3 km storm-relative helicity
578 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.

787 
WUUS53 KLSX 040855
SVRLSX
MOC071-099-183-189-040930-
/O.NEW.KLSX.SV.W.0029.110404T0855Z-110404T0930Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
355 AM CDT MON APR 4 2011

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN FRANKLIN COUNTY IN EAST CENTRAL MISSOURI...
  NORTHWESTERN JEFFERSON COUNTY IN EAST CENTRAL MISSOURI...
  WESTERN ST. CHARLES COUNTY IN EAST CENTRAL MISSOURI...
  ST. LOUIS COUNTY IN EAST CENTRAL MISSOURI...

* UNTIL 430 AM CDT

* AT 351 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  UNION...AND MOVING NORTHEAST AT 75 MPH.

  AT 353 AM...QUARTER SIZE HAIL WAS REPORTED IN UNION WITH THIS 
  STORM.

* LOCATIONS IMPACTED INCLUDE...
  VILLA RIDGE...GRAY SUMMIT...PACIFIC...EUREKA...BYRNES MILL...
  WILDWOOD...HIGH RIDGE...ELLISVILLE...CLARKSON VALLEY...WELDON
  SPRING...MURPHY...BALLWIN...COTTLEVILLE...CHESTERFIELD...
  MANCHESTER...VALLEY PARK...FENTON...ST. PETERS...SUNSET HILLS AND
  TOWN AND COUNTRY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 3851 9027 3830 9091 3853 9107 3856 9102
      3855 9097 3860 9097 3887 9056
TIME...MOT...LOC 0855Z 241DEG 64KT 3847 9092
WIND...HAIL 60MPH 1.00IN

$$

GLASS
2 follow-up statements
075 
WWUS53 KLSX 040916
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
416 AM CDT MON APR 4 2011

MOC071-040926-
/O.CAN.KLSX.SV.W.0029.000000T0000Z-110404T0930Z/
FRANKLIN MO-
416 AM CDT MON APR 4 2011

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN FRANKLIN COUNTY IS
CANCELLED...

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

LAT...LON 3851 9027 3842 9072 3863 9074 3864 9075
      3878 9049
TIME...MOT...LOC 0916Z 241DEG 64KT 3863 9045

$$

MOC099-183-189-040930-
/O.CON.KLSX.SV.W.0029.000000T0000Z-110404T0930Z/
JEFFERSON MO-ST. LOUIS MO-ST. CHARLES MO-
416 AM CDT MON APR 4 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR CENTRAL ST.
CHARLES...ST. LOUIS AND NORTH CENTRAL JEFFERSON COUNTIES UNTIL 430 AM
CDT...

AT 412 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
MANCHESTER...MOVING NORTHEAST AT 75 MPH.

LOCATIONS IMPACTED INCLUDE...
  FRONTENAC...CREVE COEUR...MARYLAND HEIGHTS...WARSON WOODS...
  GLENDALE...MEHLVILLE...LAKESHIRE...AFFTON...WEBSTER GROVES AND
  LADUE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MILES PER
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR
YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

&&

LAT...LON 3851 9027 3842 9072 3863 9074 3864 9075
      3878 9049
TIME...MOT...LOC 0916Z 241DEG 64KT 3863 9045
WIND...HAIL 60MPH 1.00IN

$$

GLASS
100 
WWUS53 KLSX 040929
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
429 AM CDT MON APR 4 2011

MOC099-183-189-040940-
/O.EXP.KLSX.SV.W.0029.000000T0000Z-110404T0930Z/
JEFFERSON MO-ST. LOUIS MO-ST. CHARLES MO-
429 AM CDT MON APR 4 2011

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL ST. CHARLES...
SOUTHWESTERN ST. LOUIS AND NORTH CENTRAL JEFFERSON COUNTIES HAS
EXPIRED...

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

LAT...LON 3851 9027 3842 9072 3863 9074 3864 9075
      3878 9049
TIME...MOT...LOC 0930Z 241DEG 64KT 3875 9017

$$

GLASS

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 3, 8:34 PM CDTSevere Thunderstorm WarningLSXKnox40 min
Apr 3, 9:30 PM CDTSevere Thunderstorm WarningLSXLewis30 min
Apr 3, 9:33 PM CDTSevere Thunderstorm WarningLSXLewis24 min
Apr 3, 11:14 PM CDTSevere Thunderstorm WarningLSXAudrain, Boone, Lewis, Marion, Monroe, Pike and 2 more46 min
Apr 3, 11:21 PM CDTSevere Thunderstorm WarningLSXBoone, Cole, Moniteau39 min
Apr 3, 11:54 PM CDTSevere Thunderstorm WarningLSXAudrain, Boone, Callaway, Cole, Montgomery, Osage35 min
Apr 4, 12:25 AM CDTSevere Thunderstorm WarningLSXBoone, Cole, Moniteau30 min
Apr 4, 3:28 AM CDTSevere Thunderstorm WarningLSXCrawford, Franklin, Gasconade32 min
Apr 4, 3:58 PM CDTFreeze WarningLSXBoone, Callaway, Cole, Crawford, Franklin, Gasconade and 12 more16 hr

Nearby

Severe Thunderstorm Warnings in Missouri, 2011Every severe thunderstorm warning in 2011

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.