Alert archive / Louisiana / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 79, NWS New Orleans, LA

April 11, 1997Assumption Parish, Lafourche Parish, Saint James Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Apr 11, 1997, 9:29 AM CDT for Assumption Parish, Lafourche Parish, Saint James Parish, Louisiana. It was in force for 46 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Apr 11, 1997, 9:29 AM CDT (14:29 UTC)
Expired
Apr 11, 1997, 10:15 AM CDT
In force
46 min
Issued by
NWS New Orleans, LA
Area
Whole counties

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

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 2.5 hours before the alert went out and 238 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, Lake Charles Mun, LA at 12:00Z on 1997-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 723 joules per kilogram.LCLLFCEL10008507005003002001001 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, Lake Charles Mun, LA at 12:00Z on 1997-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 137 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
723 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
601 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
137 m²/s²
0-3 km storm-relative helicity
205 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.9

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KNEW 111430 RRA
SVRNEW
LAC007-057-093-111515-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
929 AM CDT FRI APR 11 1997
 
THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1015 AM CDT
FOR RESIDENTS IN THE FOLLOWING LOCATIONS...
 
IN SOUTHEAST LOUISIANA
 
   ...ASSUMPTION PARISH...NORTHERN LAFOURCHE PARISH
   ...ST. JAMES PARISH
 
AND THE ADJACENT COASTAL WATERS
 
 
AT 928 AM NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE
THUNDERSTORMS JUST SOUTHWEST OF LABADIEVILLE. THE THUNDERSTORM WAS
MOVING NORTHEAST AT 35 MILES AN HOUR. COMMUNITIES IN THE PATH OF THIS
THUNDERSTORM INCLUDE THIBODAUX...NAPOLEANVILLE...AND CONVENT.
 
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUS|INESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 11, 9:36 AM CDTSevere Thunderstorm WarningLIXTerrebonne69 min
Apr 11, 10:14 AM CDTSevere Thunderstorm WarningLIXLafourche, Saint James, Saint John the Baptist46 min
Apr 11, 10:27 AM CDTSevere Thunderstorm WarningLIXLafourche48 min
Apr 11, 10:45 AM CDTSevere Thunderstorm WarningLIXSaint Charles45 min
Apr 11, 11:00 AM CDTFlash Flood WarningLIXAssumption4 hr
Apr 11, 11:09 AM CDTSevere Thunderstorm WarningLIXJefferson, Orleans, Plaquemines66 min
Apr 11, 11:09 AM CDTSevere Thunderstorm WarningLIXSaint Bernard66 min
Apr 11, 11:26 AM CDTTornado WarningLIXJefferson, Lafourche34 min
Apr 11, 11:31 AM CDTSevere Thunderstorm WarningLIXTangipahoa44 min
Apr 11, 11:49 AM CDTTornado WarningLIXSaint Tammany, Tangipahoa26 min
Apr 11, 12:12 PM CDTTornado WarningLIXSaint Tammany, Tangipahoa33 min
Apr 11, 12:17 PM CDTSevere Thunderstorm WarningLIXOrleans, Plaquemines, Saint Bernard43 min
Apr 11, 12:32 PM CDTSevere Thunderstorm WarningLIXWashington43 min
Apr 11, 12:59 PM CDTSevere Thunderstorm WarningLIXPlaquemines, Saint Bernard46 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 1997Every severe thunderstorm warning in 1997

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.