Alert archive / Louisiana / Flash Flood Warnings in 1990

Flash Flood Warning 3, NWS New Orleans, LA

March 9, 1990Saint James Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Mar 9, 1990, 6:40 PM CST for Saint James Parish, Louisiana. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued
Mar 9, 1990, 6:40 PM CST (00:40 UTC)
Expired
Mar 9, 1990, 10:45 PM CST
In force
4 hr
Issued by
NWS New Orleans, LA
Area
Whole counties

County Saint James 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, 0.7 hours before the alert went out and 108 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 00:00Z on 1990-03-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 667 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 00:00Z on 1990-03-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 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
667 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
599 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
61 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.2

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KNEW 100041
FFWNEW
LAC093-100445-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
640 PM CST FRI MAR 9 1990
 
THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL 1045 PM CST
FOR RESIDENTS IN THE FOLLOWING PARISHES
 
IN SOUTHEAST LOUISIANA
 
   ...ST.JAMES PARISH
 
SLIDELL RADAR AT 635 PM CST INDICATED THUNDERSTORMS WITH VERY HEAVY
RAIN ACROSS MUCH OF ST JAMES PARISH. EMERGENCY MANAGEMENT OFFICIALS
REPORTED AT 630 PM CST HEAVY RAIN WITH FLOODING IN SOME OF THE
CITY OF CONVENT LOUISIANA. WATER WAS REPORTED IN SOME OF THE HOUSES
IN CONVENT. FLOODING WAS ALSO REPORTED IN THE STREETS AND HIGHWAYS
IN THE ST JAMES PARISH AREA. THUNDERSTORMS ARE MOVING SLOWLY NORTH
ACROSS THE AREA WITH NEW DEVELOPMENT JUST TO THE SOUTH OF ST JAMES
PARISH.
 
 
 
A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT.  MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES.  DOZ 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, Mar 9, 3:42 PM CST, 2 hours 58 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-092300-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
340 PM CST FRI MAR 9 1990

A STRONG THUNDERSTORM WAS LOCATED OVER SOUTHEAST LOUISIANA JUST
SOUTHEAST OF PONTCHATOULA. IT WILL MOVE NORTH ACROSS PORTIONS OF
TANGIPAHOA PARISH AND INTO THE WEST PORTION OF ST. TAMMANY PARISH
DURING THE NEXT HOUR.

THIS STORM WILL PRODUCE PERIODS OF VERY HEAVY RAIN AND STRONG AND
GUSTY WINDS. SOME SMALL HAIL IS ALSO POSSIBLE.

ELSEWHERE...WIDELY SCATTERED SHOWERS AND THUNDERSTORMS CONTINUED
BETWEEN FRANKLINTON AND SLIDELL AND EXTENDED SOUTHWEST TO BETWEEN
NEW ORLEANS AND BATON ROUGE.

THE THUNDERSTORMS WERE MOVING NORTH AT 15 MILESq AN HOUR.
Special weather statement, Mar 9, 4:46 PM CST, 1 hour 54 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-092300-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
445 PM CST FRI MAR 9 1990

...STRONG THUNDERSTORMS WERE MOVING THROUGH PARISHES NORTH OF LAKE
   PONTCHARTRAIN...

AT 430 PM SEVERAL STRONG THUNDERSTORMS WITH VERY HEAVY RAINFALL WERE
LOCATED OVER SOUTHEAST LOUISIANA BETWEEN HAMMOND AND COVINGTON AND
15 MILES SOUTHWEST OF BOGALUSA.  THE THUNDERSTORMS WERE MOVING NORTH
AT 15 MILES AN HOUR AND WILL CONTINUE THROUGH NORTHERN ST TAMMANY
AND WASHINGTON PARISHES AT LEAST FOR ANOTHER HOUR OR SO BUT SHOULD
BE OUT OF TANGIPAHOA PARISH SHORTLY.

THESE THUNDERSTORMS WILL PRODUCE PERIODS OF VERY HEAVY RAIN AND STRONG
GUSTY WINDS AND SOME SMALL HAIL IS ALSO POSSIBLE.  ALSO...FLOODING OF
STREETS AND LOW LYING AREAS WILL OCCUR WITH THE HEAVY RAINFALL.
MOTORIST ARE URGED TO USE CAUTION WHILE DRIVING THROUGH THE HEAVY
RAINFALL.

ELSEWHERE...WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WERE OCCURRING
OVER SOUTHEAST LOUISIANA BETWEEN BATON ROUGE AND NEW ORLEANS AND
EXTENDED NORTHEAST INTO SOUTH MISSISSIPPI BETWEEN MCCOMB AND
HATTIESBURG.
Special weather statement, Mar 9, 5:27 PM CST, 1 hour 13 minutes before
LAZ009-100130-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BATON ROUGE LA
525 PM CST FRI MAR 9 1990

...STRONG THUNDERSTORMS WITH HEAVY RAIN WERE MOVING ACROSS PARTS OF
THE BATON ROUGE METRO AREA...

RADAR SHOWED A SOLID BAND OF STRONG THUNDERSTORMS WITH HEAVY RAIN
FROM THE WHITE CASTLE/DONALDSONVILLE AREA EAST ACROSS ASCENSION AND
SOUTHERN LIVINGSTON PARISHES.  MOVEMENT WAS SLOWLY NORTH.

THESE THUNDERSTORMS WILL PRODUCE PERIODS OF HEAVY RAIN AND STRONG
GUSTY WIND AND POSSIBLY SOME SMALL HAIL.  FLOODING OF STREETS AND LOW
LYING AREAS WILL ALSO OCCUR AS THESE THUNDERSTORMS MOVE ACROSS SOUTHERN
IBERVILLE...ASCENSION AND SOUTHERN LIVINGSTON PARISHES FOR THE NEXT TWO
HOURS.
Special weather statement, Mar 9, 6:34 PM CST, 6 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-092300-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
633 PM CST FRI MAR 9 1990

AT 630 PM SEVERAL STRONG THUNDERSTORMS WITH VERY HEAVY RAINFALL WERE
LOCATED OVER SOUTHEAST LOUISIANA...20 MILES WEST OF NEW ORLEANS AND
BETWEEN BOGALUSA AND COVINGTON.  THE THUNDERSTORMS WERE MOVING NORTH
AT 10 MILES AN HOUR.  PERSONS IN THE VICINITY OF THESE THUNDERSTORMS
CAN EXPECT TO RECEIVE GUSTY WINDS...VERY HEAVY RAINFALL...DANGEROUS
LIGHTNING AND POSSIBLY SOME SMALL HAIL.  ALSO...FLOODING OF STREETS
AND LOW LYING AREAS CAN BE EXPECTED WITH THESE THUNDERSTORMS.
MOTORIST ARE URGED TO USE CAUTION WHILE DRIVING THROUGH THE HEAVY
RAINFUALL.

ELSEWHERE...WIDELY SCATTERED SHOWERS WERE OCCURRING WITHIN AREAS OF
WIDESPREAD RAIN OVER SOUTHEAST LOUISIANA AND EXTENDED INTO A SMALL
PART OF SOUTH MISSISSIPPI.

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.