Alert archive / Louisiana / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 9, NWS New Orleans, LA

March 29, 19904 parishes in Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Mar 29, 1990, 9:17 PM CST for 4 parishes in Louisiana. It was in force for 58 min. 3 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: Mar 29, 1990, 9:17 PM CST (03:17 UTC)
Expired: Mar 29, 1990, 10:15 PM CST
In force: 58 min
Issued by: NWS New Orleans, LA
Area: Whole counties

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

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

What was reported inside it

Time	Report	Where
Mar 29, 9:40 PM CST	Thunderstorm Wind 0	Assumption, LA
Mar 29, 10:00 PM CST	Tornado F1	Terrebonne, LA
Mar 29, 10:05 PM CST	Thunderstorm Wind 0	Lafourche, 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. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 3.3 hours before the alert went out and 121 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 16 J/kg
Mixed-layer CIN: -222 J/kg
Mixed-layer LCL: 1008 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 78 m²/s²
0-3 km storm-relative helicity: 158 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 300319
SVRNEW
LAC007-057-093-109-300415-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
917 PM CST THU MAR 29 1990
 
THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1015 PM CST
FOR RESIDENTS IN THE FOLLOWING PARISHES
 
IN SOUTHEAST LOUISIANA
 
   ...ASSUMPTION PARISH...NORTHERN LAFOURCHE PARISH...ST.JAMES PARISH
   ...TERREBONNE PARISH
 
AND THE ADJACENT COASTAL WATERS OF SOUTHEAST LOUISIANA.
 
 
SLIDELL RADAR AT 913 PM CST INDICATED A LINE OF SEVERE THUNDERSTORMS
ABOUT 10 MILES WIDE EXTENDING FROM 15 MILES SE OF IBERIA SOUTH TO NEAR
MORGAN CITY AND SOUTHWARD INTO THE GULF. THIS LINE OF THUNDERSTORMS IS
MOVING EAST ABOUT 35 MPH WHILE INDIVIDUAL
THUNDERSTORMS ARE MOVING NORTHEAST ABOUT 35 MPH.
 
 
THIS IS A DANGEROUS STORM.  IF YOU ARE IN ITS PATH YOU SHOULD
PREPARE FOR DAMAGING WIND IN EXCESS OF 55 MPH...LARGE HAIL...AND
DEADLY LIGHTNING.  PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT STAY AWAY FROM WINDOWS.

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 29, 8:06 PM CST	Severe Thunderstorm Warning	LIX	Iberia, Saint Martin, St. Mary	69 min
Mar 29, 8:24 PM CST	Severe Thunderstorm Warning	LIX	Saint Landry	51 min
Mar 29, 8:58 PM CST	Severe Thunderstorm Warning	LIX	Iberville, Pointe Coupee	62 min
Mar 29, 9:25 PM CST	Severe Thunderstorm Warning	LIX	West Baton Rouge, West Feliciana	65 min
Mar 29, 9:43 PM CST	Severe Thunderstorm Warning	LIX	Ascension, East Baton Rouge, East Feliciana	62 min
Mar 29, 10:11 PM CST	Severe Thunderstorm Warning	LIX	Livingston, Saint Helena	64 min
Mar 29, 10:17 PM CST	Severe Thunderstorm Warning	LIX	Lafourche, Saint Charles, Saint John the Baptist	58 min
Mar 29, 10:17 PM CST	Severe Thunderstorm Warning	LIX	Terrebonne	58 min
Mar 29, 10:34 PM CST	Tornado Warning	LIX	Lafourche	26 min
Mar 29, 10:44 PM CST	Tornado Warning	LIX	Jefferson, Saint Charles	61 min
Mar 29, 10:56 PM CST	Tornado Warning	LIX	Orleans	64 min
Mar 29, 11:24 PM CST	Tornado Warning	LIX	Saint Tammany	66 min
Mar 30, 12:22 AM CST	Tornado Warning	LIX	Saint Tammany	48 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 1990 Every severe thunderstorm warning in 1990

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.