Alert archive / Louisiana / Flash Flood Warnings in 1990

Flash Flood Warning 9, NWS New Orleans, LA

May 13, 1990Orleans Parish, Plaquemines Parish, Saint Bernard Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at May 13, 1990, 2:16 PM CDT for Orleans Parish, Plaquemines Parish, Saint Bernard Parish, Louisiana. It was in force for 119 min.

The area

The counties it named.

The facts

Issued
May 13, 1990, 2:16 PM CDT (19:16 UTC)
Expired
May 13, 1990, 4:15 PM CDT
In force
119 min
Issued by
NWS New Orleans, LA
Area
Whole counties

Counties Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard 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 12:00Z, 7.3 hours before the alert went out and 49 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 1990-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 567 joules per kilogram.LCLLFCEL10008507005003002001001 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 1990-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 105 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
567 J/kg
Mixed-layer CIN
-61 J/kg
Mixed-layer LCL
579 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
105 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KNEW 131917
FFWNEW
LAC051-071-075-087-089-132115-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
216 PM CDT SUN MAY 13 1990
 
THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  415 PM CDT
FOR RESIDENTS IN THE FOLLOWING PARISHES
 
IN SOUTHEAST LOUISIANA
 
   ...JEFFERSON PARISH...ORLEANS PARISH...NORTHERN PLAQUEMINES PARISH
   ...ST.BERNARD PARISH...ST.CHARLES PARISH
 
STREET FLOODING CONTINUES OVER THE WARNED AREA. THE AREA OF RAIN HAS
DRIFTED SOUTH AND INTENSITIES HAVE DECREASED SOMEWHAT.
 
 
 
A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT.  MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES.7  DO NOT
ATTEMPT TO CROSS BRIDGES...DIPS...OR LOW SPOTS IF WATER COVERS
THE ROADWAY.  NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL
ONE...ON FOOT.  TO ESCAPE RISING WATER MOVE UP TO HIGHER GROUND.

What forecasters said that day

The local office's own words before this flash flood 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, May 13, 1:47 PM CDT, 29 minutes before
LAZ009-132000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BATON ROUGE LA
150 PM CDT SUN MAY 13 1990

...THUNDERSTORMS WITH VERY HEAVY RAIN OCCURRING OVER IBERVILLE AND
ASCENSION PARISHES OF EAST CENTRAL LOUISIANA...

RADAR SHOWED STRONG THUNDERSTORMS OVER THE SOUTHERN HALF OF IBERVILLE
AND ASCENSION PARISHES MOVING EAST AT 20 MPH.

PEOPLE IN THESE PARISHES CAN EXPECT GUSTY WINDS...HEAVY RAIN WITH
FLOODING OF STREETS AND OTHER LOW LYING AREAS...DANGEROUS LIGHTNING
AND POSSIBLY SOME HAIL DURING THE NEXT 2 HOURS.

The office that day

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

IssuedProductOfficeCountiesLasted
May 13, 10:07 AM CDTFlash Flood WarningLIXOrleans, Saint Bernard2 hr
May 13, 10:07 AM CDTFlash Flood WarningLIXJefferson2 hr
May 13, 12:05 PM CDTFlash Flood WarningLIXOrleans, Plaquemines, Saint Bernard115 min
May 13, 12:05 PM CDTFlash Flood WarningLIXJefferson, Saint Charles115 min
May 13, 2:16 PM CDTFlash Flood WarningLIXJefferson, Saint Charles119 min

Nearby

Flash Flood Warnings in Louisiana, 1990Every flash flood 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.