Alert archive / Louisiana / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 39, NWS New Orleans, LA

March 21, 20125 parishes in Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Mar 21, 2012, 9:18 AM CDT for 5 parishes in Louisiana. It was in force for 57 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Mar 21, 2012, 9:18 AM CDT (14:18 UTC)
Expired
Mar 21, 2012, 10:15 AM CDT
In force
57 min
Issued by
NWS New Orleans, LA
Area
Storm-based polygon

Counties Ascension Parish, LA, Assumption Parish, LA, Lafourche Parish, LA, Saint James Parish, LA, Terrebonne Parish, LA

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Mar 21, 5:04 AM CDTTornado WatchSPC7 hr

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 2.3 hours before the alert went out and 119 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, Slidell Radar S, LA at 12:00Z on 2012-03-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 983 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, Slidell Radar S, LA at 12:00Z on 2012-03-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 363 square meters per square second.193958Sfc1 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
983 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
519 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
363 m²/s²
0-3 km storm-relative helicity
421 m²/s²
Significant tornado parameter
1.7
Supercell composite
10.7

Open this sounding in Storm Lab

The text

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

745 
WUUS54 KLIX 211418
SVRLIX
LAC005-007-057-093-109-211515-
/O.NEW.KLIX.SV.W.0039.120321T1418Z-120321T1515Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
918 AM CDT WED MAR 21 2012

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL ASCENSION PARISH IN SOUTHEAST LOUISIANA...
  EASTERN ASSUMPTION PARISH IN SOUTHEAST LOUISIANA...
  THIS INCLUDES THE CITY OF NAPOLEONVILLE...
  NORTHWESTERN LAFOURCHE PARISH IN SOUTHEAST LOUISIANA...
  THIS INCLUDES THE CITY OF THIBODAUX...
  ST. JAMES PARISH IN SOUTHEAST LOUISIANA...
  NORTHERN TERREBONNE PARISH IN SOUTHEAST LOUISIANA...
  THIS INCLUDES THE CITY OF HOUMA...

* UNTIL 1015 AM CDT

* AT 917 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS IN
  EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
  FROM 7 MILES WEST OF CONVENT TO 20 MILES SOUTHWEST OF BAYOU CANE...
  OR ALONG A LINE EXTENDING FROM DONALDSONVILLE TO 18 MILES SOUTHEAST
  OF MORGAN CITY...AND MOVING NORTHEAST AT 15 MPH.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL NOON CDT WEDNESDAY FOR
SOUTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI.

&&

LAT...LON 2934 9114 2960 9110 2960 9108 2962 9109
      3002 9102 3019 9072 3018 9069 3023 9066
      3005 9066 3003 9069 2998 9066 2995 9067
      2994 9066 2948 9066
TIME...MOT...LOC 1418Z 235DEG 12KT 3005 9095 2948 9104

$$

The office that day

Everything else NWS New Orleans, LA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 21, 7:34 AM CDTSevere Thunderstorm WarningLIXEast Baton Rouge, Iberville, Livingston, Pointe Coupee, West Baton Rouge, West Feliciana56 min
Mar 21, 8:30 AM CDTSevere Thunderstorm WarningLIXAscension, Assumption, East Baton Rouge, Iberville60 min
Mar 21, 8:32 AM CDTSevere Thunderstorm WarningLIXEast Baton Rouge, East Feliciana, Iberville, Pointe Coupee, West Baton Rouge, West Feliciana58 min
Mar 21, 8:45 AM CDTAreal Flood AdvisoryLIXAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Lafourche and 7 more2 hr
Mar 21, 8:49 AM CDTTornado WarningLIXAscension, Assumption, Iberville, Saint James38 min
Mar 21, 9:10 AM CDTSevere Thunderstorm WarningLIXEast Baton Rouge, East Feliciana, Saint Helena, West Feliciana65 min
Mar 21, 9:19 AM CDTTornado WarningLIXAscension, East Baton Rouge, Iberville, Livingston26 min
Mar 21, 9:29 AM CDTRiver Flood WarningLIXSaint Tammany, Washington19 days
Mar 21, 9:36 AM CDTSevere Thunderstorm WarningLIXAscension, Livingston, Saint Helena, Tangipahoa54 min
Mar 21, 9:49 AM CDTTornado WarningLIXEast Baton Rouge, East Feliciana, Livingston, Saint Helena56 min
Mar 21, 10:05 AM CDTRiver Flood WarningLIXTangipahoa4 days
Mar 21, 10:07 AM CDTSevere Thunderstorm WarningLIXJefferson, Lafourche, Saint Charles, Saint John the Baptist, Saint Tammany, Tangipahoa and 1 more53 min
Mar 21, 10:11 AM CDTSpecial Marine WarningLIX2 hr
Mar 21, 10:16 AM CDTTornado WarningLIXLivingston, Saint John the Baptist, Tangipahoa44 min
Mar 21, 10:24 AM CDTRiver Flood WarningLIXSaint Tammany49 hr
Mar 21, 10:24 AM CDTSevere Thunderstorm WarningLIXLivingston, Saint Helena, Tangipahoa, Washington51 min
Mar 21, 10:33 AM CDTSpecial Marine WarningLIX117 min
Mar 21, 11:01 AM CDTSevere Thunderstorm WarningLIXSaint Tammany, Tangipahoa, Washington59 min
Mar 21, 11:05 AM CDTSevere Thunderstorm WarningLIXJefferson, Lafourche, Saint Charles, Saint John the Baptist, Tangipahoa, Terrebonne55 min
Mar 21, 11:11 AM CDTSmall Craft AdvisoryLIX5 hr
Mar 21, 11:12 AM CDTAreal Flood AdvisoryLIXJefferson, Lafourche, Saint Charles, Saint John the Baptist, Saint Tammany, Tangipahoa and 2 more2 hr
Mar 21, 11:18 AM CDTSevere Thunderstorm WarningLIXTangipahoa, Washington57 min
Mar 21, 11:52 AM CDTSevere Thunderstorm WarningLIXJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles53 min
Mar 21, 12:03 PM CDTSevere Thunderstorm WarningLIXSaint Tammany, Washington57 min
Mar 21, 12:04 PM CDTSpecial Marine WarningLIX116 min
Mar 21, 12:12 PM CDTTornado WarningLIXSaint Tammany36 min
Mar 21, 12:38 PM CDTTornado WarningLIXJefferson, Orleans, Saint Bernard25 min
Mar 21, 12:55 PM CDTSevere Thunderstorm WarningLIXSaint Tammany, Washington65 min
Mar 21, 1:16 PM CDTSpecial Marine WarningLIX119 min
Mar 21, 1:46 PM CDTTornado WarningLIXSaint Tammany29 min
Mar 21, 1:57 PM CDTSpecial Marine WarningLIX33 min
Mar 21, 2:05 PM CDTSevere Thunderstorm WarningLIXWashington55 min
Mar 21, 3:13 PM CDTSpecial Marine WarningLIX2 hr
Mar 21, 4:57 PM CDTAreal Flood AdvisoryLIXOrleans, Plaquemines, Saint Bernard, Saint Tammany2 hr
Mar 21, 5:25 PM CDTFlash Flood WarningLIXOrleans, Saint Bernard, Saint Tammany2 hr
Mar 21, 5:44 PM CDTSpecial Marine WarningLIX2 hr

Nearby

Severe Thunderstorm Warnings in Louisiana, 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; the sounding from the Mesonet's radiosonde archive.