Alert archive / Missouri / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 31, NWS St. Louis, MO

April 9, 2001Saint Louis County, City of Saint Louis, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 9, 2001, 9:43 PM CDT for Saint Louis County, City of Saint Louis, Missouri. It was in force for 47 min. 5 reports came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued
Apr 9, 2001, 9:43 PM CDT (02:43 UTC)
Expired
Apr 9, 2001, 10:30 PM CDT
In force
47 min
Issued by
NWS St. Louis, MO
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties City of Saint Louis, MO, Saint Louis County, MO

The radar

The St Louis radar (KLSX), 21 km from the middle of the area, began a volume at 02:45 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 9, 9:49 PM CDTHail 0.75Bridgeton, MOThe Missouri Highway Patrol reported 3/4 inch hail.
Apr 9, 10:00 PM CDTHail 1Manchester, MO
Apr 9, 10:02 PM CDTHail 1Vly Park, MOAmateur radio spotters reported 1 inch hail.
Apr 9, 10:05 PM CDTHail 0.75Des Peres, MO
Apr 9, 10:15 PM CDTHail 0.75Sappington, MOStorm spotters reported 3/4 inch hail.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 2.7 hours before the alert went out and 233 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 2001-04-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1891 joules per kilogram.LCLEL10008507005003002001001 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 2001-04-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 38 square meters per square second.1939587897Sfc1 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
1891 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
2017 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
38 m²/s²
0-3 km storm-relative helicity
99 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.6

Open this sounding in Storm Lab

The text

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

000 
WUUS53 KLSX 100244
SVRSTL
MOC189-510-100330-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
943 PM CDT MON APR 9 2001

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  ST. LOUIS COUNTY IN EAST CENTRAL MISSOURI
  ST. LOUIS CITY IN EAST CENTRAL MISSOURI

* UNTIL 1030 PM CDT

* AT 943 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
  A SEVERE THUNDERSTORM OVER BALLWIN...MOVING NORTHEAST AT 30 MPH.
  ANOTHER SEVERE THUNDERSTORM OVER UNION WAS MOVING NORTHEAST AT 50
  MPH.

* LOCATIONS IN THE PATH...
  DES PERES
  TOWN AND COUNTRY
  FRONTENAC
  KIRKWOOD
  CREVE COEUR
  LADUE
  WARSON WOODS
  BRENTWOOD
  OLIVETTE
  CLAYTON

THIS STORM HAS A HISTORY OF DAMAGING HAIL. STAY INSIDE...AND AVOID
OUTSIDE WALLS AND WINDOWS.

THIS THUNDERSTORM IS CAPABLE OF PRODUCING LARGE HAIL THAT CAN CAUSE
SERIOUS INJURY AND EXTENSIVE PROPERTY DAMAGE. TAKE SHELTER INSIDE OF
A STURDY BUILDING NOW

LAT...LON 3859 9072 3848 9074 3845 9032 3858 9023
          3880 9016 3889 9032

GLASS

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 9, 8:26 PM CDTSevere Thunderstorm WarningLSXCallaway49 min
Apr 9, 8:35 PM CDTSevere Thunderstorm WarningLSXCole, Osage40 min
Apr 9, 8:44 PM CDTSevere Thunderstorm WarningLSXFranklin46 min
Apr 9, 8:56 PM CDTSevere Thunderstorm WarningLSXSaint Charles, Saint Louis49 min
Apr 9, 8:59 PM CDTSevere Thunderstorm WarningLSXCrawford, Franklin, Gasconade46 min
Apr 9, 9:19 PM CDTSevere Thunderstorm WarningLSXWarren41 min
Apr 9, 9:29 PM CDTSevere Thunderstorm WarningLSXPike, Ralls46 min
Apr 9, 9:34 PM CDTSevere Thunderstorm WarningLSXCrawford26 min
Apr 9, 9:35 PM CDTSevere Thunderstorm WarningLSXFranklin40 min
Apr 9, 10:06 PM CDTSevere Thunderstorm WarningLSXJefferson39 min
Apr 9, 10:18 PM CDTTornado WarningLSXWashington42 min
Apr 9, 10:46 PM CDTSevere Thunderstorm WarningLSXJefferson44 min
Apr 10, 1:18 AM CDTSevere Thunderstorm WarningLSXBoone42 min
Apr 10, 1:55 AM CDTSevere Thunderstorm WarningLSXAudrain50 min
Apr 10, 2:29 AM CDTSevere Thunderstorm WarningLSXPike46 min
Apr 10, 4:24 AM CDTSevere Thunderstorm WarningLSXPike36 min
Apr 10, 6:26 PM CDTTornado WarningLSXBoone, Moniteau64 min
Apr 10, 6:56 PM CDTTornado WarningLSXCallaway64 min

Nearby

Severe Thunderstorm Warnings in Missouri, 2001Every severe thunderstorm warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.