Alert archive / Louisiana / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 86, NWS New Orleans, LA

April 11, 1997Tangipahoa Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Apr 11, 1997, 11:31 AM CDT for Tangipahoa Parish, Louisiana. It was in force for 44 min. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Apr 11, 1997, 11:31 AM CDT (16:31 UTC)
Expired
Apr 11, 1997, 12:15 PM CDT
In force
44 min
Issued by
NWS New Orleans, LA
Area
Whole counties

County Tangipahoa Parish, LA

What was reported inside it

TimeReportWhereRemark
Apr 11, 11:55 AM CDTTornado F0Ponchatoula, LA
Apr 11, 12:10 PM CDTThunderstorm WindPonchatoula, LA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

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

IssuedProductOfficeLasted
Apr 11, 10:15 AM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 4.5 hours before the alert went out and 191 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, Jackson, MS at 12:00Z on 1997-04-11Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jackson, MS at 12:00Z on 1997-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 210 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1830 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
210 m²/s²
0-3 km storm-relative helicity
354 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.

000 
TTAA00 KNEW 111631 RRA
SVRNEW
LAC105-111715-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1131 AM CDT FRI APR 11 1997
 
THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1215 PM CDT
FOR RESIDENTS IN THE FOLLOWING LOCATION...
 
IN SOUTHEAST LOUISIANA
 
   ...TANGIPAHOA PARISH
 
AT 1130 AM NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE
THUNDERSTORM FROM NEAR AMITE TO LAKE MAUREPAS. THE THUNDERSTORM WAS
MOVING NORTHEAST AROUND 35 MPH. COMMUNITIES IN THE PATH OF THIS
THUNDERSTORM INCLUDE HAMMOND AND PONTHCATOULA.
 
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 BUSINESS.  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, 9:29 AM CDTSevere Thunderstorm WarningLIXAssumption, Lafourche, Saint James46 min
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, 11:49 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.