Alert archive / Louisiana / Severe Thunderstorm Warnings in 1992

Severe Thunderstorm Warning 49, NWS New Orleans, LA

April 20, 1992Lafourche Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Apr 20, 1992, 7:10 AM CDT for Lafourche Parish, Louisiana. It was in force for 65 min.

The area

The counties it named.

The facts

Issued
Apr 20, 1992, 7:10 AM CDT (12:10 UTC)
Expired
Apr 20, 1992, 8:15 AM CDT
In force
65 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, 0.2 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 1992-04-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1940 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, Slidell Radar S, LA at 12:00Z on 1992-04-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 200 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
1940 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
588 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
200 m²/s²
0-3 km storm-relative helicity
313 m²/s²
Significant tornado parameter
2.4
Supercell composite
14.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KNEW 201223 COR
SVRNEW
LAC057-201315-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM AND SPECIAL MARINE WARNING...CORRECTED
NATIONAL WEATHER SERVICE NEW ORLEANS LA
710 AM CDT MON APR 20 1992

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A
SEVERE THUNDERSTORM AND SPECIAL MARINE WARNING
EFFECTIVE UNTIL  815 AM CDT
FOR RESIDENTS IN THE FOLLOWING PARISHES

IN SOUTHEAST LOUISIANA

   ...SOUTHERN LAFOURCHE PARISH

AND THE ADJACENT COASTAL WATERS FROM TERREBONNE BAY TO BARATARIA PASS.


AT 707 AM CDT RADAR INDICATED SEVERAL STRONG THUNDERSTORMS OVER THE
COASTAL WATERS NEAR TERREBONNE BAY MOVING NORTHEAST AT 35 MPH. THESE
THUNDERSTORMS WILL LIKELY MOVE NORTHEAST INTO SOUTHERN LAFOURCHE
PARISH IN THE NEXT 30 MINUTES.

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.

MARINERS SHOULD AVOID THESE STORMS IF POSSIBLE AS WINDS IN EXCESS
OF 50 KNOTS ARE POSSIBLE.

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.

What forecasters said that day

The local office's own words before this severe thunderstorm 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, Apr 20, 4:37 AM CDT, 2 hours 33 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-201100-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
436 AM CDT MON APR 20 1992

...A TORNADO WATCH IS IN EFFECT UNTIL 7 AM CDT FOR THE FOLLOWING PARISHES
   IN SOUTHEAST LOUISIANA...ASSUMPTION...IBERIA...LOWER ST MARTIN...UPPER
   ST MARTIN...LAFOURCHE...ST MARY...ST JAMES...AND TANGIPAHOA...

AT 430 AM...WEATHER RADAR INDICATED NUMEROUS THUNDERSTORMS ACROSS PARTS OF
SOUTH CENTRAL AND SOUTHEAST LOUISIANA.  THE THUNDERSTORMS WITH THE HEAVIER
RAINFALL WERE LOCATED FROM JUST NORTH OF OPELOUSAS TO JUST NORTHWEST OF
BATON ROUGE TO NEAR AMITE.

THESE THUNDERSTORMS WILL LIKELY PRODUCE VERY HEAVY RAINFALL...DANGEROUS
LIGHTNING...STRONG GUSTY WINDS...AND LARGE HAIL.

RESIDENTS IN THE PATH OF THESE DANGEROUS THUNDERSTORMS SHOULD BE ALERT
AND TAKE SHELTER IF THREATENING WEATHER IS SIGHTED.
Special weather statement, Apr 20, 5:35 AM CDT, 1 hour 35 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-201200-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
534 AM CDT MON APR 20 1992

...A TORNADO WATCH IS IN EFFECT UNTIL 7 AM CDT FOR THE FOLLOWING PARISHES
   IN SOUTHEAST LOUISIANA...ASSUMPTION...IBERIA...LOWER ST MARTIN...UPPER
   ST MARTIN...LAFOURCHE...ST MARY...ST JAMES...AND TANGIPAHOA...

AT 530 AM...WEATHER RADAR INDICATED SEVERAL STRONG THUNDERSTORMS ACROSS
SOUTH CENTRAL LOUISIANA EXTENDING INTO THE SOUTHWEST CORNER OF MISSISSIPPI.

THE THUNDERSTORMS WITH THE HEAVIER RAINFALL WERE LOCATED IN AN AREA FROM
SIMMESPORT LOUISIANA TO NATCHEZ MISSISSIPPI TO MCCOMB MISSISSIPPI.

THE THUNDERSTORMS WERE MOVING NORTHEAST AT ABOUT 30 MILES AN HOUR.
Special weather statement, Apr 20, 5:37 AM CDT, 1 hour 33 minutes before
LAZ006-008-009-200900-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BATON ROUGE LA
535 AM CDT MON APR 20 1992

...A TORNADO WATCH IS IN EFFECT UNTIL 7 AM CDT FOR ALL OF EAST CENTRAL
LOUISIANA...

RADAR AT 535 AM SHOWED STRONG THUNDERSTORMS EXTENDING FROM CROWLEY TO
OPELOUSAS...SIMMESPORT AND LIBERTY MISSISSIPPI.  THIS WAS PART OF A
LARGE AREA OF THUNDERSTORMS COVERING MUCH OF EAST CENTRAL LOUISIANA
AND SOUTHWESTERN MISSISSIPPI.  MOVEMENT WAS NORTHEAST AT 30 MILES PER
HOUR.

PEOPLE THROUGHOUT EAST CENTRAL LOUISIANA SHOULD BE ALERT TO POSSIBLE
SEVERE WEATHER AND BE READY TO MOVE QUICKLY TO A SAFE PLACE IF NEEDED.
HEAVY RAIN WITH STREET FLOODING LIKELY AS THUNDERSTORMS MOVE THROUGH
DURING THE EARLY HOURS THIS MORNING...WITH GUSTY WINDS AND HAIL.
Special weather statement, Apr 20, 5:38 AM CDT, 1 hour 32 minutes before
LAZ006-008-009-201200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BATON ROUGE LA
535 AM CDT MON APR 20 1992

...A TORNADO WATCH IS IN EFFECT UNTIL 7 AM CDT FOR ALL OF EAST CENTRAL
LOUISIANA...

RADAR AT 535 AM SHOWED STRONG THUNDERSTORMS EXTENDING FROM CROWLEY TO
OPELOUSAS...SIMMESPORT AND LIBERTY MISSISSIPPI.  THIS WAS PART OF A
LARGE AREA OF THUNDERSTORMS COVERING MUCH OF EAST CENTRAL LOUISIANA
AND SOUTHWESTERN MISSISSIPPI.  MOVEMENT WAS NORTHEAST AT 30 MILES PER
HOUR.

PEOPLE THROUGHOUT EAST CENTRAL LOUISIANA SHOULD BE ALERT TO POSSIBLE
SEVERE WEATHER AND BE READY TO MOVE QUICKLY TO A SAFE PLACE IF NEEDED.
HEAVY RAIN WITH STREET FLOODING LIKELY AS THUNDERSTORMS MOVE THROUGH
DURING THE EARLY HOURS THIS MORNING...WITH GUSTY WINDS AND HAIL.
Special weather statement, Apr 20, 6:34 AM CDT, 36 minutes before
LAZ006-008-009-201300-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BATON ROUGE LA
635 AM CDT MON APR 20 1992

...A TORNADO WATCH IS IN EFFECT UNTIL 1 PM FOR ALL OF EAST CENTRAL
LOUISIANA...

RADAR AT 635 AM SHOWED STRONG THUNDERSTORMS EXTENDING FROM ABBEVILLE
TO LAFAYETTE...ST FRANCISVILLE AND WOODHAVEN MISSISSIPPI.  OTHER
SCATTERED THUNDERSTORMS FROM BATON ROUGE SOUTH TO DONALDSONVILLE...
HOUMA AND TERREBONNE BAY.  MOVEMENT WAS NORTHEAST AT 30 MILES PER
HOUR.

PEOPLE THROUGHOUT EAST CENTRAL LOUISIANA SHOULD BE ALERT TO POSSIBLE
SEVERE WEATHER AND BE READY TO MOVE QUICKLY TO A SAFE PLACE IF NEEDED.
HEAVY RAIN WITH STREET FLOODING LIKELY AS THUNDERSTORMS MOVE THROUGH
THIS MORNING..W.WITH GUSTY WINDS AND HAIL.
Special weather statement, Apr 20, 6:36 AM CDT, 34 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-201300-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
635 AM CDT MON APR 20 1992

...A TORNADO WATCH IS IN EFFECT UNTIL 7 AM CDT FOR THE FOLLOWING PARISHES
   IN SOUTHEAST LOUISIANA...ASSUMPTION...IBERIA...LOWER ST MARTIN...UPPER
   ST MARTIN...LAFOURCHE...ST MARY...ST JAMES...AND TANGIPAHOA...

...AT 7 AM CDT THE TORNADO WATCH WILL BE EXTENDED EAST TO INCLUDE ALL
   OF THE PARISHES IN SOUTHEAST LOUISIANA UNTIL 1 PM CDT THIS AFTERNOON...

AT 630 AM...WEATHER RADAR INDICATED SEVERAL STRONG THUNDERSTORMS ACROSS
SOUTH CENTRAL AND SOUTHEAST LOUISIANA EXTENDING INTO SOUTHWEST MISSISSIPPI.

THE THUNDERSTORMS WITH THE HEAVIER RAINFALL WERE LOCATED OVER THIBODAUX...
JUST SOUTH OF BATON ROUGE...AND IN THE SOUTHWEST CORNER OF MISSISSIPPI
BETWEEN SIMMESPORT LOUISIANA AND MCCOMB MISSISSIPPI.

THE THUNDERSTORMS WERE MOVING NORTHEAST AT 35 MILES AN HOUR.

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 20, 3:03 AM CDTSevere Thunderstorm WarningLIXSaint Martin57 min
Apr 20, 3:36 AM CDTSevere Thunderstorm WarningLIXSaint Landry69 min
Apr 20, 4:15 AM CDTSevere Thunderstorm WarningLIXPointe Coupee45 min
Apr 20, 4:31 AM CDTSevere Thunderstorm WarningLIXEast Feliciana, West Feliciana59 min
Apr 20, 7:32 AM CDTSevere Thunderstorm WarningLIXSaint Tammany73 min
Apr 20, 7:52 AM CDTSevere Thunderstorm WarningLIXEast Feliciana, West Feliciana38 min
Apr 20, 8:19 AM CDTSevere Thunderstorm WarningLIXSaint Tammany, Washington41 min
Apr 20, 10:08 AM CDTSevere Thunderstorm WarningLIXTangipahoa67 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 1992Every severe thunderstorm warning in 1992

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.