Alert archive / Louisiana / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 99, NWS New Orleans, LA

March 7, 1998Saint Charles Parish, Saint John the Baptist Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Mar 7, 1998, 4:46 PM CST for Saint Charles Parish, Saint John the Baptist Parish, Louisiana. It was in force for 34 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
Mar 7, 1998, 4:46 PM CST (22:46 UTC)
Expired
Mar 7, 1998, 5:20 PM CST
In force
34 min
Issued by
NWS New Orleans, LA
Area
Whole counties

Counties Saint Charles Parish, LA, Saint John the Baptist Parish, LA

The watch it was issued in

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

IssuedProductOfficeLasted
Mar 7, 1:30 PM CSTTornado WatchSPC6 hr

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 10.8 hours before the alert went out and 73 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 1998-03-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 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 1998-03-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 325 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
520 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
325 m²/s²
0-3 km storm-relative helicity
480 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.8

Open this sounding in Storm Lab

The text

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

731 
WUUS1 KNEW 072244 RRA
SVRNEW
LAC089-095-072320-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
446 PM CST SAT MAR 7 1998

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS LA HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 520 PM CST
FOR PEOPLE IN THE FOLLOWING LOCATIONS...

IN SOUTHEASTERN LOUISIANA

   ...ST JOHN PARISH
   ...ST CHARLES PARISH

AT 444 PM CST...RADAR INDICATED A CLUSTER OF SEVERE THUNDERSTORMS
FROM AIRLINE HIGHWAY SOUTH OF SORRENTO...ACROSS GRAMERCY...TO NEAR
LAPLACE. LARGE HAIL IS EXPECTED WITH THESE STORMS. MOVEMENT WAS TO
THE NORTHWEST 60 MPH.

A TORNADO WATCH IS ALSO IN EFFECT FOR THE WARNED AREA.  REMEMBER
SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES
WITH LITTLE OR NO ADVANCE WARNING.  REMAIN CALM BUT BE ALERT TO
RAPIDLY CHANGING WEATHER CONDITIONS.

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 7, 3:51 AM CSTSevere Thunderstorm WarningLIXWashington59 min
Mar 7, 4:19 AM CSTSevere Thunderstorm WarningLIXLivingston36 min
Mar 7, 4:24 AM CSTTornado WarningLIXSaint Tammany31 min
Mar 7, 4:56 AM CSTTornado WarningLIXAscension, Iberville34 min
Mar 7, 5:07 AM CSTTornado WarningLIXSaint Tammany33 min
Mar 7, 5:51 AM CSTSevere Thunderstorm WarningLIXSaint James34 min
Mar 7, 6:41 AM CSTSevere Thunderstorm WarningLIXSaint Tammany44 min
Mar 7, 8:10 AM CSTSevere Thunderstorm WarningLIXPointe Coupee, West Feliciana35 min
Mar 7, 4:14 PM CSTSevere Thunderstorm WarningLIXAssumption61 min
Mar 7, 4:20 PM CSTSevere Thunderstorm WarningLIXWest Feliciana30 min
Mar 7, 4:41 PM CSTFlash Flood WarningLIXSaint Bernard4 hr
Mar 7, 5:00 PM CSTSevere Thunderstorm WarningLIXSaint Tammany, Tangipahoa, Washington35 min
Mar 7, 5:44 PM CSTSevere Thunderstorm WarningLIXTerrebonne61 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 1998Every severe thunderstorm warning in 1998

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.