Alert archive / Louisiana / Flash Flood Warnings in 1990

Flash Flood Warning 2, NWS New Orleans, LA

February 21, 1990Jefferson Parish, Lafourche Parish, Saint Charles Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Feb 21, 1990, 10:20 PM CST for Jefferson Parish, Lafourche Parish, Saint Charles Parish, Louisiana. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued
Feb 21, 1990, 10:20 PM CST (04:20 UTC)
Expired
Feb 22, 1990, 2:15 AM CST
In force
4 hr
Issued by
NWS New Orleans, LA
Area
Whole counties

Counties Jefferson Parish, LA, Lafourche Parish, LA, Saint Charles 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, 4.3 hours before the alert went out and 84 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 1990-02-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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 1990-02-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 334 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
1 J/kg
Mixed-layer CIN
-27 J/kg
Mixed-layer LCL
571 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
334 m²/s²
0-3 km storm-relative helicity
493 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 220424
FFWNEW
LAC051-057-089-103-117-220815-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1020 PM CST WED FEB 21 1990
 
THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  215 AM CST
FOR PEOPLE IN THE FOLLOWING PARISHES...
 
IN SOUTHEAST LOUISIANA
          ...NORTHERN JEFFERSON...SOUTHERN LAFOURCHE...ST.CHARLES
          ...WESTERN ST.TAMMANY...WASHINGTON
 
WEATHER SERVICE RADAR SHOWS A LINE OF NUMEROUS THUNDERSTORMS...SOME
WITH HEAVY RAIN EXTENDING FROM SOUTH LAFOURCHE PARISH NORTH INTO THE
ST CHARLES...WEST JEFFERSON...WEST ST TAMMANY INTO WASHINGTON PARISH.
DUE TO THE SLOW EAST DRIFT OF THE LINE...PARISHES IN THE WARNED AREA
WILL RECEIVE VERY HEAVY RAINS DURING THE NEXT FEW HOURS. IT IS LIKELY
THAT THE FLASH FLOOD WARNING MAY HAVE TO BE EXTENDED TO COVER THE REST
OF THE NEW ORLEANS METROPOLITAN AREA LATER TONIGHT.
 
THE ST CHARLES OFFICE OF EMERGENCY PREPAREDNESS REPORTS NUMEROUS
STREETS ARE IMPASSABLE AND THAT FLOOD WATERS ARE ENTERING SOME HOMES.
IN LAFOURCHE PARISH SOME STREETS IN HOUMA ARE IMPASSBLE TO DUE FLOOD
WATERS. WHILE IN JEFFERSON PARISH THE KENNER POLICE HAVE CLOSED ONE
STRET SO FAR.
 
A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT.  MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES.  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, Feb 21, 4:48 PM CST, 5 hours 32 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-220000-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
445 PM CST WED FEB 21 1990

...A FLASH FLOOD WATCH IS IN EFFECT TONIGHT FOR LOUISIANA INCLUDING ALL
   OF SOUTHEAST LOUISIANA...

...A COASTAL FLOOD WATCH IS IN EFFECT TONIGHT AND THURSDAY FOR THE
   COASTAL AREAS FROM GULFPORT MISSISSIPPI WEST TO INTRACOASTAL CITY
   LOUISIANA...

WIDESPREAD LIGHT RAIN ALONG WITH A FEW SHOWERS CONTINUED BETWEEN BATON
ROUGE LOUISIANA AND MCCOMB MISSISSIPPI AND EXTENDED SOUTHEAST ACROSS
MUCH OF SOUTHEAST LOUISIANA AND COASTAL SOUTHEAST MISSISSIPPI INTO THE
ADJACENT COASTAL WATERS.

THE RAIN CONTINUED TO SPREAD NORTH.

A FLASH FLOOD WATCH MEANS THAT HEAVY RAIN COULD CAUSE FLOODING IN AND
CLOSE TO THE WATCH AREA. PEOPLE IN THE WATCH AREA ARE ADVISED TO
MONITOR THE LATEST FORECASTS. CHECK PREPAREDNESS REQUIREMENTS...STAY
AWAY FROM LOW LYING AREAS...AND BE READY TO TAKE QUICK ACTION IF IT
BECOMES NECESSARY.
Special weather statement, Feb 21, 5:40 PM CST, 4 hours 40 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-220100-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
545 PM CST WED FEB 21 1990

...A FLASH FLOOD WATCH IS IN EFFECT TONIGHT FOR LOUISIANA INCLUDING ALL
   OF SOUTHEAST LOUISIANA...

...A COASTAL FLOOD WATCH IS IN EFFECT TONIGHT AND THURSDAY FOR THE
   COASTAL AREAS FROM GULFPORT MISSISSIPPI WEST TO INTRACOASTAL CITY
   LOUISIANA...

SEVERAL BANDS OF SHOWERS ALONG WITH AND EXTENSIVE AREA OF LIGHT RAIN
CONTINUED ACROSS MUCH OF SOUTHEAST LOUISIANA...THE COASTAL SECTIONS OF
SOUTHEAST MISSISSIPPI AND SOUTHWEST ALABAMA...AND THE ADJACENT COASTAL
WATERS.

THE HEAVIER RAINFALL WAS OCCURRING WITH THE BANDS OF SHOWERS. ONE BAND
WAS LOCATED FROM FRANKLINTON SOUTHWEST ACROSS THE WEST HALF OF LAKE
PONTCHARTRAIN AND CONTINUED SOUTHWEST BETWEEN NEW ORLEANS AND HOUMA
INTO THE COASTAL WATERS. ANOTHER BAND OF SHOWERS WAS LOCATED ACROSS
THE MOUTH OF THE MISSSISSIPPI RIVER NORTH INTO BRETON SOUND.

THE RAIN AND SHOWERS CONTINUED TO MOVE NORTH AT 40 MILES AN HOUR.

A FLASH FLOOD WATCH MEANS THAT HEAVY RAIN COULD CAUSE FLOODING IN AND
CLOSE TO THE WATCH AREA. PEOPLE IN THE WATCH AREA ARE ADVISED TO
MONITOR THE LATEST #FORECASTS. CHECK PREPAREDNESS REQUIREMENTS...STAY
AWAY FROM LOW LYING AREAS...AND BE READY TO TAKE QUICK ACTION IF IT
BECOMES NECESSARY.
Special weather statement, Feb 21, 6:46 PM CST, 3 hours 34 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-220200-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
645 PM CST WED FEB 21 1990

...A FLASH FLOOD WATCH IS IN EFFECT TONIGHT FOR LOUISIANA INCLUDING ALL
   OF SOUTHEAST LOUISIANA...

...A COASTAL FLOOD WATCH IS IN EFFECT TONIGHT AND THURSDAY FOR THE
   COASTAL AREAS FROM GULFPORT MISSISSIPPI WEST TO INTRACOASTAL CITY
   LOUISIANA...

A BAND OF SHOWERS WAS INCREASING IN COVERAGE AND INTENSITY ACROSS
SOUEAST LOUISIANA FROM THE COAST SOUTH OF HOUMA NORTH ACROSS HOUMA TO
NEAR RESERVE. THE SHOWERS CONTINUED NORTH ACROSS LAKE MAUREPAS TO THE
HAMMOND AND KENTWOOD AREAS.

SOME OF THESE SHOWERS WERE PRODUCING PERIODS OF HEAVY RAIN. WITHIN THE
LAST HALF HOUR THE HOUMA POLICE DEPARTMENT REPORTED STREED FLOODING IN
THE CITY OF HOUMA.

THESE SHOWERS CONTINUED TO MOVE NORTH ACROSS THE SAME AREA AND FLOODING
OF STREETS AND LOW LYING AREAS IS POSSIBLE DURING THE NEXT HOUR OR TWO
ESPECIALLY ACROSS TERREBONNE...NORTHERN LAFOURCHE...ST. JOHN THE
BAPTIST...ST. CHARLES...AND TANGIPAHOA.

RESIDENTS OF SOUTHEAST LOUISIANA SHOULD REMAIN ALERT THROUGH THE NIGHT
FOR THE THREAT OF HEAVY RAIN AND FLASH FLOODING AND BE READY TO TAKE
QUICK ACTION IF IT BECOMES NECESSARY.

ELSEWHERE...ANOTHER BAND OF SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY
RAIN...WAS LOCATED OVER THE COASTAL WATERS SOUTH OF GRAND ISLE AND
EXTENDED NORTHEAST ACROSS BRETON SOUND TO THE COAST BETWEEN BILOXI
MISSISSIPPI AND MOBILE BAY.

AN EXTENSIVE AREA OF LIGHT RAIN CONTINUED ACROSS THE REMAINDER OF
SOUTHEAST LOUISIANA.
Special weather statement, Feb 21, 7:44 PM CST, 2 hours 36 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-220300-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
745 PM CST WED FEB 21 1990

...A FLASH FLOOD WATCH IS IN EFFECT TONIGHT FOR LOUISIANA INCLUDING ALL
   OF SOUTHEAST LOUISIANA...

...A COASTAL FLOOD WATCH IS IN EFFECT TONIGHT AND THURSDAY FOR THE
   COASTAL AREAS FROM GULFPORT MISSISSIPPI WEST TO INTRACOASTAL CITY
   LOUISIANA...

A BAND OF SHOWERS AND A FEW THUNDERSTORMS PRODUCING PERIODS OF HEAVY
RAIN CONTINUED OVER THE COASTAL WATERS SOUTH OF TERREBONNE BAY AND
EXTENDED NORTH ACROSS THE HOUMA AREA TO BETWEEN THIBODAUX AND RESERVE.

THESE SHOWERS AND THUNDERSTORMS CONTINUED TO MOVE NORTH ACROSS THE SAME
AREA AND FLOODING  OF STREETS AND LOW LYING AREAS IS POSSIBLE DURING THE
NEXT HOUR OR TWO ESPECIALLY ACROSS TERREBONNE...LAFOURCHE...ST JAMES...
ST JOHN THE BAPTIST...AND ST CHARLES PARISHES.

RESIDENTS OF SOUTHEAST LOUISIANA SHOULD REMAIN ALERT THROUGH THE NIGHT
FOR THE THREAT OF HEAVY RAIN AND FLASH FLOODING AND BE READY TO TAKE
QUICK ACTION IF IT BECOMES NECESSARY.

ELSEWHERE...AN EXTENSIVE AREA OF LIGHT RAIN ALONG WITH A FEW SHOWERS
AND THUNDERSTORMS CONINUED ACROSS MUCH OF SOUTHEAST LOUISIANA AND SOUTH
MISSISSIPPI AND EXTENDED SOUTH INTO THE COASTAL WATERS.
Special weather statement, Feb 21, 8:50 PM CST, 1 hour 30 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-220400-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
845 PM CST WED FEB 21 1990

...A FLASH FLOOD WATCH IS IN EFFECT TONIGHT FOR LOUISIANA INCLUDING ALL
   OF SOUTHEAST LOUISIANA...

...A COASTAL FLOOD WATCH IS IN EFFECT TONIGHT AND THURSDAY FOR THE
   COASTAL AREAS FROM GULFPORT MISSISSIPPI WEST TO INTRACOASTAL CITY
   LOUISIANA...

A LINE OF SHOWERS AND THUNDERSTORMS HAD DEVELOPED OVER SOUTHEAST
LOUISIANA FROM JUST WEST OF HAMMOND SOUTH ACROSS THE WEST PORTION OF
LAKE PONTCHARTRAIN TO JUST WEST OF NEW ORLEANS INTERNATIONAL AIRPORT.
THE LINE CONTINUED SOUTHWEST BETWEEN HOUMA AND GRAND ISLE AND ACROSS
TERREBONNE BAY INTO THE COASTAL WATERS SOUTH OF HOUMA.

THESE THUNDERSTORMS MAY PRODUCE STRONG AND GUSTY WINDS...PERIODS OF
VERY HEAVY RAIN...AND POSSIBLY SOME SMALL HAIL.

SOME FLOODING OF STREETS AND LOW LYING AREAS IS POSSIBLE AS THE HEAVIER
RAINS CONTINUE TO MOVE NORTH ACROSS AREAS THAT ARE ALREADY SATURATED BY
EARLIER RAINS.

ELSEWHERE...AND EXTENSIVE AREA OF RAIN AND A FEW THUNDERSTORMS
CONTINUED ACROSS MUCH OF SOUTHEAST LOUISIANA...SOUTH MISSISSIPPI AND
THE ADJACENT COASTAL WATERS.

RESIDENTbS OF SOUTHEAST LOUISIANA SHOULD REMAIN ALERT THROUGH THE NIGHT
FOR THE THREAT OF HEAVY RAIN AND FLASH FLOODING AND BE READY TO TAKE
QUICK ACTION IF IT BECOMES NECESSARY.
Special weather statement, Feb 21, 9:50 PM CST, 30 minutes before
LAZ008>010-012>014-MSZ010>014-ALZ016-220500-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE NEW ORLEANS LA
950 PM CST WED FEB 21 1990

...A FLASH FLOOD WATCH IS IN EFFECT TONIGHT FOR ALL OF SOUTHEAST
   LOUISIANA...

...A COASTAL FLOOD WATCH IS IN EFFECT TONIGHT AND THURSDAY FOR THE
   COASTAL AREAS FROM GULFPORT MISSISSIPPI WEST TO INTRACOASTAL CITY
   LOUISIANA...

A LINE OF THUNDERSTORMS CONTINUED OVER SOUTHEAST LOUISIANA FROM NEAR
FRANKLINTON SOUTH BETWEEN HAMMOND AND COVINGTON AND ACROSS THE WEST
PORTION OF LAKE PONTCHARTRAIN TO THE NEW ORLEANS INTERNATIONAL AIRPORT.
THE LINE CONTINUED SOUTH BETWEEN HOUMA AND LAKE SALVADOR INTO THE
COASTAL WATERS SOUTH OF TERREBONNE BAY.

THESE THUNDERSTORMS MAY PRODUCE STRONG AND GUSTY WINDS...PERIODS OF
VERY HEAVY RAIN...AND POSSIBLY SOME SMALL HAIL.

IN ADDITION THESE THUNDERSTORMS HAVE PERSISTED OVER BASICALLY THE SAME
AREA DURING THE PAST HOUR AND FLOODING OF STREETS AND LOW LYING AREAS
IS POSSIBLE ESPECIALLY ACROSS LAFOURCHE...ST. CHARLES...NORTHERN
JEFFERSON...AND WESTERN ST. TAMMANY PARISHES.

ELSEWHERE...AN EXTENSIVE AREA OF RAIN AND A FEW THUNDERSTORMS
CONTINUED ACROSS MUCH OF SOUTHEAST LOUISIANA...SOURTH MISSISSIPPI AND
THE ADJACENT COASTAL WATERS.

RESIDENTS OF SOUTHEAST LOUISIANA SHOULD REMAIN ALERT THROUGH THE NIGHT
FOR THE THREAT OF HEAVY RAIN AND FLASH FLOODING AND BE READY TO TAKE
QUICK ACTION IF IT BECOMES NECESSARY.

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 21, 10:20 PM CSTFlash Flood WarningLIXSaint Tammany, Washington4 hr

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.