Alert archive / Missouri / Tornado Warnings in 2012

Tornado Warning 9, NWS St. Louis, MO

February 29, 2012Jefferson County, Saint Francois County, Washington County, Missouri

NWS St. Louis, MO issued this tornado warning at Feb 29, 2012, 2:13 AM CST for Jefferson County, Saint Francois County, Washington County, Missouri. It was in force for 20 min. 3 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
Feb 29, 2012, 2:13 AM CST (08:13 UTC)
Expired
Feb 29, 2012, 2:33 AM CST
In force
20 min
Issued by
NWS St. Louis, MO
Area
Storm-based polygon

Counties Jefferson County, MO, Saint Francois County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 71 km from the middle of the area, began a volume at 08:13 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
Feb 29, 2:15 AM CSTTSTM WND GST 40Potosi, MO
Feb 29, 2:15 AM CSTHAIL 0.25Potosi, MO
Feb 29, 2:22 AM CSTTSTM WND GST 50De Soto, MOSMALL TREE LIMBS DOWN.

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
Feb 29, 1:14 AM CSTTornado WatchSPC11 hr

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 8.2 hours before the alert went out and 290 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 2012-02-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2012-02-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 211 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1465 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
211 m²/s²
0-3 km storm-relative helicity
390 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.

218 
WFUS53 KLSX 290813
TORLSX
MOC099-187-221-290845-
/O.NEW.KLSX.TO.W.0009.120229T0813Z-120229T0845Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
213 AM CST WED FEB 29 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTH CENTRAL JEFFERSON COUNTY IN EAST CENTRAL MISSOURI...
  NORTHERN ST. FRANCOIS COUNTY IN SOUTHEAST MISSOURI...
  EAST CENTRAL WASHINGTON COUNTY IN EAST CENTRAL MISSOURI...

* UNTIL 245 AM CST

* AT 209 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED NEAR OLD MINES...OR NEAR POTOSI...AND MOVING EAST
  AT 55 MPH.

* LOCATIONS IMPACTED INCLUDE...
  DE SOTO...OLYMPIAN VILLAGE...CADET...BLACKWELL AND VALLES MILL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

TORNADOES ARE DIFFICULT TO SEE AND CONFIRM AT NIGHT. TAKE COVER NOW.

&&

LAT...LON 3818 9044 3800 9042 3790 9084 3804 9088
TIME...MOT...LOC 0813Z 254DEG 49KT 3801 9074

$$

TILLY
2 follow-up statements
520 
WWUS53 KLSX 290825
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
225 AM CST WED FEB 29 2012

MOC221-290835-
/O.CAN.KLSX.TO.W.0009.000000T0000Z-120229T0845Z/
WASHINGTON MO-
225 AM CST WED FEB 29 2012

...THE TORNADO WARNING FOR EAST CENTRAL WASHINGTON COUNTY IS
CANCELLED...

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

LAT...LON 3800 9063 3805 9064 3808 9064 3808 9066
      3809 9066 3809 9065 3810 9066 3818 9044
      3800 9042
TIME...MOT...LOC 0825Z 253DEG 48KT 3807 9052

$$

MOC099-187-290845-
/O.CON.KLSX.TO.W.0009.000000T0000Z-120229T0845Z/
JEFFERSON MO-ST. FRANCOIS MO-
225 AM CST WED FEB 29 2012

...A TORNADO WARNING REMAINS IN EFFECT FOR EXTREME NORTHERN ST.
FRANCOIS AND SOUTH CENTRAL JEFFERSON COUNTIES UNTIL 245 AM CST...

AT 223 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO.  THIS DANGEROUS
STORM WAS LOCATED 5 MILES SOUTH OF DE SOTO...MOVING EAST AT 55 MPH.

LOCATIONS IMPACTED INCLUDE...
  OLYMPIAN VILLAGE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.

TORNADOES ARE DIFFICULT TO SEE AND CONFIRM AT NIGHT. TAKE COVER NOW.

&&

LAT...LON 3800 9063 3805 9064 3808 9064 3808 9066
      3809 9066 3809 9065 3810 9066 3818 9044
      3800 9042
TIME...MOT...LOC 0825Z 253DEG 48KT 3807 9052

$$

TILLY
821 
WWUS53 KLSX 290833
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
233 AM CST WED FEB 29 2012

MOC099-187-290843-
/O.CAN.KLSX.TO.W.0009.000000T0000Z-120229T0845Z/
JEFFERSON MO-ST. FRANCOIS MO-
233 AM CST WED FEB 29 2012

...THE TORNADO WARNING FOR EXTREME NORTHERN ST. FRANCOIS AND SOUTH
CENTRAL JEFFERSON COUNTIES IS CANCELLED...

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

ADDITIONAL STRONG THUNDERSTORMS ARE STILL POSSIBLE...AND A TORNADO 
WATCH REMAINS IN EFFECT UNTIL 900 AM CST.

LAT...LON 3800 9063 3805 9064 3808 9064 3808 9066
      3809 9066 3809 9065 3810 9066 3818 9044
      3800 9042
TIME...MOT...LOC 0833Z 250DEG 56KT 3812 9036

$$

TILLY

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 29, 1:21 AM CSTTornado WarningLSXCrawford39 min
Feb 29, 1:52 AM CSTSevere Thunderstorm WarningLSXJefferson, Saint Francois, Washington53 min
Feb 29, 2:22 AM CSTSevere Thunderstorm WarningLSXIron, Reynolds38 min
Feb 29, 2:31 AM CSTSevere Thunderstorm WarningLSXJefferson, Sainte Genevieve31 min
Feb 29, 2:50 AM CSTSevere Thunderstorm WarningLSXMadison40 min
Feb 29, 3:05 AM CSTTornado WarningLSXMadison25 min

Nearby

Tornado Warnings in Missouri, 2012Every tornado warning in 2012Tornadoes 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.