Alert archive / Louisiana / Tornado Warnings in 1998

Tornado Warning 41, NWS New Orleans, LA

November 20, 1998Lafourche Parish, Louisiana

NWS New Orleans, LA issued this tornado warning at Nov 20, 1998, 11:59 AM CST for Lafourche Parish, Louisiana. It was in force for 31 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
Nov 20, 1998, 11:59 AM CST (17:59 UTC)
Expired
Nov 20, 1998, 12:30 PM CST
In force
31 min
Issued by
NWS New Orleans, LA
Area
Whole counties

County Lafourche Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 6.0 hours before the alert went out and 107 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 1998-11-20Temperature 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, Slidell Radar S, LA at 12:00Z on 1998-11-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 141 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
1119 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
141 m²/s²
0-3 km storm-relative helicity
170 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.

542 
WFUS1 KNEW 201756 RRA
TORNEW
GMZ550-LAC057-201830-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1159 AM CST FRI NOV 20 1998

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS LA HAS ISSUED A...

* TORNADO WARNING FOR
   - SOUTHERN LAFOURCHE PARISH IN SOUTHEASTERN LOUISIANA

* UNTIL 1230 PM CST

* AT 1154 AM CST... SHERIFFS DEPARTMENT REPORTED A TORNADO 16 MILES
  NORTHWEST OF GOLDEN MEADOW OR IN LOCKPORT MOVING SOUTHEAST
  AT 10 MPH. SOME POWERLINES WERE DOWNED WITH THIS TORNADO.

* SOME LOCATIONS IN AND NEAR THE PATH OF THIS TORNADO ARE...
  CUT OFF AT 1216 PM CST

IF YOU ARE IN THESE AREAS...SEEK SHELTER IN A SMALL INTERIOR ROOM
AWAY FROM WINDOWS

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A NEARBY REINFORCED
BUILDING.  AS A LAST RESORT...SEEK SHELTER IN A CULVERT...DITCH
OR LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

&

What forecasters said that day

The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Nov 20, 10:30 AM CST, 1 hour 29 minutes before
GMZ530-550-555-570-575-LAZ034>040-046>050-056>070-MSZ068>071-077-
080>082-202130-

THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1030 AM CST FRI NOV 20 1998

A COLD FRONT...EXTENDING FROM NATCHEZ MISSISSIPPI TO JUST NORTH OF
LAKE CHARLES...WILL MOVE SOUTH THROUGH THE REST OF LOUISIANA AND
COASTAL WATERS TODAY INTO THIS EVENING. A FEW THUNDERSTORMS ARE
EXPECTED AHEAD OF THE FRONT. HOWEVER...THUNDERSTORMS ARE NOT EXPECTED
TO REACH SEVERE LIMITS.

OUR WEB SITE PROVIDES MORE WEATHER INFORMATION AT:
HTTP://WWW.SRH.NOAA.GOV/LIX (ALL LOWER CASE)
Special weather statement, Nov 20, 10:30 AM CST, 1 hour 29 minutes before
GMZ530-550-555-570-575-LAZ034>040-046>050-056>070-MSZ068>071-077-
080>082-202130-

THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1030 AM CST FRI NOV 20 1998

A COLD FRONT...EXTENDING FROM NATCHEZ MISSISSIPPI TO JUST NORTH OF
LAKE CHARLES...WILL MOVE SOUTH THROUGH THE REST OF LOUISIANA AND
COASTAL WATERS TODAY INTO THIS EVENING. A FEW THUNDERSTORMS ARE
EXPECTED AHEAD OF THE FRONT. HOWEVER...THUNDERSTORMS ARE NOT EXPECTED
TO REACH SEVERE LIMITS.

OUR WEB SITE PROVIDES MORE WEATHER INFORMATION AT:
HTTP://WWW.SRH.NOAA.GOV/LIX (ALL LOWER CASE)
Special weather statement, Nov 20, 11:45 AM CST, 14 minutes before
GMZ530-550-555-570-575-LAZ034>040-046>050-056>070-MSZ068>071-077-
080>082-202130-

THUNDERSTORM OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1145 AM CST FRI NOV 20 1998

A COLD FRONT WILL MOVE SOUTH THROUGH THE REST OF LOUISIANA AND
COASTAL WATERS THIS AFTERNOON INTO THIS EVENING. SCATTERED
THUNDERSTORMS ARE EXPECTED AHEAD OF THE FRONT. WITH BREAKS IN THE
CLOUD COVER AND SURFACE TEMPERATURES RISING TO NEAR 80 DEGREES...THE
ATMOSPHERE WILL BECOME UNSTABLE AND A FEW THUNDERSTORMS MAY BECOME
SEVERE THIS AFTERNOON.

OUR WEB SITE PROVIDES MORE WEATHER INFORMATION AT:
HTTP://WWW.SRH.NOAA.GOV/LIX (ALL LOWER CASE)
Special weather statement, Nov 20, 11:45 AM CST, 14 minutes before
GMZ530-550-555-570-575-LAZ034>040-046>050-056>070-MSZ068>071-077-
080>082-202130-

THUNDERSTORM OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1145 AM CST FRI NOV 20 1998

A COLD FRONT WILL MOVE SOUTH THROUGH THE REST OF LOUISIANA AND
COASTAL WATERS THIS AFTERNOON INTO THIS EVENING. SCATTERED
THUNDERSTORMS ARE EXPECTED AHEAD OF THE FRONT. WITH BREAKS IN THE
CLOUD COVER AND SURFACE TEMPERATURES RISING TO NEAR 80 DEGREES...THE
ATMOSPHERE WILL BECOME UNSTABLE AND A FEW THUNDERSTORMS MAY BECOME
SEVERE THIS AFTERNOON.

OUR WEB SITE PROVIDES MORE WEATHER INFORMATION AT:
HTTP://WWW.SRH.NOAA.GOV/LIX (ALL LOWER CASE)

Nearby

Tornado Warnings in Louisiana, 1998Every tornado warning in 1998Tornadoes 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.