Alert archive / Missouri / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 142, NWS St. Louis, MO

April 29, 2012Knox County, Lewis County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Apr 29, 2012, 10:13 PM CDT for Knox County, Lewis County, Missouri. It was in force for 47 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 29, 2012, 10:13 PM CDT (03:13 UTC)
Expired
Apr 29, 2012, 11:00 PM CDT
In force
47 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

Counties Knox County, MO, Lewis County, MO

The radar

The Quad Cities radar (KDVN), 184 km from the middle of the area, began a volume at 03:14 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 29, 10:33 PM CDTHAIL 0.25La Belle, MO
Apr 29, 10:33 PM CDTHAIL 1La Belle, MO

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 3.2 hours before the alert went out and 189 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, Davenport, at 00:00Z on 2012-04-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 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, Davenport, at 00:00Z on 2012-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 353 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
437 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
353 m²/s²
0-3 km storm-relative helicity
432 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.

034 
WUUS53 KLSX 300313
SVRLSX
MOC103-111-300400-
/O.NEW.KLSX.SV.W.0142.120430T0313Z-120430T0400Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
1013 PM CDT SUN APR 29 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN KNOX COUNTY IN NORTHEAST MISSOURI...
  LEWIS COUNTY IN NORTHEAST MISSOURI...

* UNTIL 1100 PM CDT

* AT 1011 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR LA BELLE...
  AND MOVING NORTHEAST AT 45 MPH.

  HAZARD...QUARTER SIZE HAIL.

  SOURCE...RADAR INDICATED.

  IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS.

* LOCATIONS IMPACTED INCLUDE...
  CANTON...LEWISTOWN AND MONTICELLO.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE IMMEDIATELY FOR LARGE HAIL AND DEADLY CLOUD TO GROUND
LIGHTNING. SEEK SHELTER INSIDE A WELL-BUILT STRUCTURE. STAY AWAY FROM
WINDOWS.

&&

LAT...LON 4026 9177 4025 9150 4025 9149 4020 9150
      4019 9151 4011 9151 4005 9149 3996 9198
      4012 9210 4026 9179
TIME...MOT...LOC 0314Z 240DEG 39KT 4010 9190

HAIL...1.00IN
WIND...<50 MPH

$$

BRITT
2 follow-up statements
266 
WWUS53 KLSX 300325
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1025 PM CDT SUN APR 29 2012

MOC103-300334-
/O.CAN.KLSX.SV.W.0142.000000T0000Z-120430T0400Z/
KNOX MO-
1025 PM CDT SUN APR 29 2012

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

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

LAT...LON 4025 9149 4020 9150 4019 9151 4011 9151
      4005 9149 4003 9194 4016 9195 4026 9179
TIME...MOT...LOC 0324Z 240DEG 39KT 4015 9178

$$

MOC111-300400-
/O.CON.KLSX.SV.W.0142.000000T0000Z-120430T0400Z/
LEWIS MO-
1025 PM CDT SUN APR 29 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR NORTHERN LEWIS
COUNTY UNTIL 1100 PM CDT...

AT 1021 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR LEWISTOWN...
AND MOVING NORTHEAST AT 45 MPH.

HAZARD...QUARTER SIZE HAIL.

SOURCE...RADAR INDICATED.

IMPACT...MINOR DAMAGE TO VEHICLES...ROOFS AND WINDOWS.

LOCATIONS IMPACTED INCLUDE...
CANTON AND MONTICELLO.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE IMMEDIATELY FOR LARGE HAIL AND DEADLY CLOUD TO GROUND
LIGHTNING. SEEK SHELTER INSIDE A WELL-BUILT STRUCTURE. STAY AWAY FROM
WINDOWS.

&&

LAT...LON 4025 9149 4020 9150 4019 9151 4011 9151
      4005 9149 4003 9194 4016 9195 4026 9179
TIME...MOT...LOC 0324Z 240DEG 39KT 4015 9178

HAIL...1.00IN
WIND...<50 MPH

$$

BRITT
419 
WWUS53 KLSX 300352
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1052 PM CDT SUN APR 29 2012

MOC111-300402-
/O.EXP.KLSX.SV.W.0142.000000T0000Z-120430T0400Z/
LEWIS MO-
1052 PM CDT SUN APR 29 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN LEWIS COUNTY WILL
EXPIRE AT 1100 PM CDT...

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

LAT...LON 4025 9149 4020 9150 4019 9151 4011 9151
      4005 9149 4003 9194 4016 9195 4026 9179
TIME...MOT...LOC 0352Z 240DEG 39KT 4030 9144

$$

BRITT

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 29, 8:11 PM CDTRiver Flood WarningLSXCole45 hr
Apr 29, 10:10 PM CDTRiver Flood WarningLSXLincoln11 hr
Apr 29, 10:43 PM CDTFlash Flood WarningLSXAudrain, Boone8 hr
Apr 29, 10:45 PM CDTSevere Thunderstorm WarningLSXAudrain, Monroe, Ralls45 min
Apr 30, 12:02 AM CDTFlash Flood WarningLSXBoone7 hr
Apr 30, 2:40 AM CDTFlash Flood WarningLSXCallaway6 hr
Apr 30, 6:29 AM CDTFlash Flood WarningLSXAudrain, Boone5 hr
Apr 30, 8:31 AM CDTAreal Flood WarningLSXCallaway6 hr
Apr 30, 10:48 AM CDTAreal Flood WarningLSXBoone6 hr
Apr 30, 4:51 PM CDTAreal Flood WarningLSXBoone6 hr
Apr 30, 5:27 PM CDTRiver Flood WarningLSXLincoln17 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.