Alert archive / Missouri / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 21, NWS St. Louis, MO

February 29, 2012Madison County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Feb 29, 2012, 2:50 AM CST for Madison County, Missouri. It was in force for 40 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: Feb 29, 2012, 2:50 AM CST (08:50 UTC)
Expired: Feb 29, 2012, 3:30 AM CST
In force: 40 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Madison County, MO

The radar

The St Louis radar (KLSX), 135 km from the middle of the area, began a volume at 08:51 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

Time	Report	Where	Remark
Feb 29, 3:11 AM CST	TSTM WND DMG	2 W Marquand, MO	* 1 INJ * 3 HOMES DAMAGED... AT LEAST ONE WITH A ROOF MISSING AND THE OTHERS WITH SIDING REMOVED. ANOTHER ROOF REMOVED FROM BARN. SEVERAL TREES DOWNED WITH DIAMETERS IN EXCESS OF 16 INCHES.
Feb 29, 3:11 AM CST	TORNADO	2 W Marquand, MO	* 1 INJ * 3 HOMES DAMAGED... AT LEAST ONE WITH A ROOF MISSING AND THE OTHERS WITH SIDING REMOVED. ANOTHER ROOF REMOVED FROM BARN. SEVERAL TREES DOWNED WITH DIAMETERS IN EXCESS OF 16 INCHES. DAMAGE RATED AT EF1.

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.

Issued	Product	Office	Lasted
Feb 29, 1:14 AM CST	Tornado Watch	SPC	11 hr

The nearest sounding before it

Little Rock, AR (KLZK), launched 00:00Z, 8.8 hours before the alert went out and 300 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 61 J/kg
Mixed-layer CIN: -316 J/kg
Mixed-layer LCL: 578 m above ground
0-6 km bulk shear: 70 kt
0-1 km storm-relative helicity: 335 m²/s²
0-3 km storm-relative helicity: 421 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.2

Open this sounding in Storm Lab

The text

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

855 
WUUS53 KLSX 290850
SVRLSX
MOC123-290930-
/O.NEW.KLSX.SV.W.0021.120229T0850Z-120229T0930Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
250 AM CST WED FEB 29 2012

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MADISON COUNTY IN SOUTHEAST MISSOURI...

* UNTIL 330 AM CST

* AT 246 AM CST...TRAINED WEATHER SPOTTERS REPORTED A SEVERE
  THUNDERSTORM PRODUCING QUARTER SIZE HAIL...AND DAMAGING WINDS IN
  EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR GLOVER...OR 10 MILES
  SOUTH OF IRONTON...AND MOVING EAST AT 65 MPH.

  AT 240 AM...QUARTER SIZE HAIL AND 50 MPH WIND GUSTS WERE REPORTED 
  AT LESTERVILLE WITH THIS STORM.

* LOCATIONS IMPACTED INCLUDE...
  FREDERICKTOWN...SACO...JUNCTION CITY...MARQUAND...CATHERINE PLACE
  AND MINE LA MOTTE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A TORNADO WATCH REMAINS IN EFFECT FOR THE WARNED AREA. TORNADOES CAN
DEVELOP QUICKLY FROM SEVERE THUNDERSTORMS. ALTHOUGH NOT IMMEDIATELY
LIKELY...IF A TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF
SAFETY INSIDE A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL
INTERIOR ROOM.

&&

LAT...LON 3734 9055 3759 9055 3760 9053 3764 9053
      3764 9014 3737 9014
TIME...MOT...LOC 0850Z 263DEG 59KT 3746 9056
WIND...HAIL 60MPH 1.00IN

$$

TILLY

1 follow-up statement

879 
WWUS53 KLSX 290929
SVSLSX

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

MOC123-290939-
/O.EXP.KLSX.SV.W.0021.000000T0000Z-120229T0930Z/
MADISON MO-
329 AM CST WED FEB 29 2012

...THE SEVERE THUNDERSTORM WARNING FOR MADISON COUNTY WILL EXPIRE AT
330 AM CST...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED
AREA.  HOWEVER GUSTY WINDS ARE STILL POSSIBLE WITH THIS THUNDERSTORM.

IN ADDITION...STRONG THUNDERSTORMS MAY REDEVELOP...AND A TORNADO 
WATCH REMAINS IN EFFECT UNTIL 900 AM CST. 

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
IN ST LOUIS.

LAT...LON 3734 9055 3759 9055 3760 9053 3764 9053
      3764 9014 3737 9014
TIME...MOT...LOC 0929Z 264DEG 46KT 3746 9000

$$

TILLY

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 29, 1:21 AM CST	Tornado Warning	LSX	Crawford	39 min
Feb 29, 1:52 AM CST	Severe Thunderstorm Warning	LSX	Jefferson, Saint Francois, Washington	53 min
Feb 29, 2:13 AM CST	Tornado Warning	LSX	Jefferson, Saint Francois, Washington	20 min
Feb 29, 2:22 AM CST	Severe Thunderstorm Warning	LSX	Iron, Reynolds	38 min
Feb 29, 2:31 AM CST	Severe Thunderstorm Warning	LSX	Jefferson, Sainte Genevieve	31 min
Feb 29, 3:05 AM CST	Tornado Warning	LSX	Madison	25 min

Nearby

Severe Thunderstorm Warnings in Missouri, 2012 Every 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.