Alert archive / Louisiana / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 63, NWS New Orleans, LA

August 30, 1990Assumption Parish, Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Aug 30, 1990, 9:29 PM CDT for Assumption Parish, Louisiana. It was in force for 61 min.

The area

The counties it named.

The facts

Issued: Aug 30, 1990, 9:29 PM CDT (02:29 UTC)
Expired: Aug 30, 1990, 10:30 PM CDT
In force: 61 min
Issued by: NWS New Orleans, LA
Area: Whole counties

County Assumption Parish, LA

The radar

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

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 2.5 hours before the alert went out and 137 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: NaN m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 82 m²/s²
0-3 km storm-relative helicity: 91 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KNEW 310230
SVRNEW
LAC007-310330-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
929 PM CDT THU AUG 30 1990
 
THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 1030 PM CDT
FOR RESIDENTS IN THE FOLLOWING PARISHES
 
IN SOUTHEAST LOUISIANA
 
   ...ASSUMPTION PARISH
 
AT 925 PM RADAR INDICATED A CLUSTER OF SEVERE THUNDERSTORMS IN
SOUTHERN IBERVILLE PARISH EXTENDING TOWARD DONALDSONVILLE. THE
THUNDERSTORMS ARE MOVING SOUTH AT 15 TO 20 MPH AND WILL MOVE INTO
ASSUMPTION PARISH DURING THE NEXT HOUR.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNIN2G...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.

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, Aug 30, 3:44 PM CDT, 5 hours 45 minutes before

LAZ008>010-012>014-MSZ010>014-ALZ016-302200-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
340 PM CDT THU AUG 30 1990

...SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 9 PM CDT FOR ALL OF
SOUTHEAST LOUISIANA...

SCATTERED THUNDERSTORMS CONTINUED TO DEVELOP ACROSS SOUTHEAST LOUISIANA
AND SOUTH MISSISSIPPI FROM BETWEEN HAMMOND AND MCCOMB EAST BETWEEN
POPLARVILLE AND LAUREL AND CONTINUED EAST INTO SOUTHWEST ALABAM#A.

THE STRONGEST THUNDERSTORMS WERE LOCATED BETWEEN BOGALUSA LOUISIANA AND
HATTIESBURG MISSISSIPPI AND EXTENDED EAST TO THE MOBILE AREA.

MOVEMENT WAS SOUTHEAST AT 20 MILES AN HOUR.

Local storm report, Aug 30, 8:18 PM CDT, 1 hour 11 minutes before

LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NEW ORLEANS LA
815 PM CDT THU AUG 30 1990

SEVERE WEATHER REPORTS FOR AUG 30 OVER SE LOUISIANA

530PM CDT   ST. TAMMANY PARISH    HALF INCH HAIL REPORTED IN SLIDELL
                                  BY CITY POLICE AND AT NWSFO

525PM CDT   ST TAMMANY PARISH     TREES DOWNED BY WIND GUSTS IN
                                  MANDEVILLE...POLICE DEPT.

555PM CDT                         15 S MANDEVILLE WIND GUSTS TO 62 KTS
                                  ...71 MPH ON CAUSEWAY BRIDGE...NWS.

610PM CDT                         15 S MANDEVILLE WIND GUSTS TO 50 KTS
                                  63 MPH ON CAUSEWAY BRIDGE...NWS.

630-730PM  TANGIPAHOA PARISH      REPORTS OF TREES DOWN IN S PORTION
                                  OF PARISH..SHERIFFS OFFICE

645PM CDT  ORLEANS PARISH     LAKEFRONT ARPT...NEW...WIND GUST 45 KT
                              52 MPH

658PM CDT  ORLEANS PARISH6     N.O. INTERNATIONAL AIRPORT...MSY...WIND
                              GUST 45 KT...52 MPH.

700-730 PM  ST. CHARLES PARISH   POWER LINES DOWN IN SEVERAL
                                 COMMUNITIES...EOC.

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 30, 7:28 PM CDT	Severe Thunderstorm Warning	LIX	Livingston	62 min
Aug 30, 8:28 PM CDT	Tornado Warning	LIX	Iberia, Saint Martin	62 min
Aug 30, 9:19 PM CDT	Severe Thunderstorm Warning	LIX	Ascension, Iberville	56 min
Aug 30, 9:47 PM CDT	Severe Thunderstorm Warning	LIX	St. Mary	58 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; the sounding from the Mesonet's radiosonde archive.