Alert archive / Louisiana / Flash Flood Warnings in 1999

Flash Flood Warning 13, NWS New Orleans, LA

June 26, 1999Plaquemines Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Jun 26, 1999, 7:59 PM CDT for Plaquemines Parish, Louisiana. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jun 26, 1999, 7:59 PM CDT (00:59 UTC)
Expired
Jun 26, 1999, 10:00 PM CDT
In force
2 hr
Issued by
NWS New Orleans, LA
Area
Whole counties

County Plaquemines Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 1.0 hours before the alert went out and 79 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 1999-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 280 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 1999-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 109 square meters per square second.1939Sfc1 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
280 J/kg
Mixed-layer CIN
-86 J/kg
Mixed-layer LCL
856 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
109 m²/s²
0-3 km storm-relative helicity
154 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KNEW 270102
FFWNEW
LAC051-057-075-270300-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
759 PM CDT SAT JUN 26 1999

THE NATIONAL WEATHER SERVICE IN NEW ORLEANS LA HAS ISSUED A...

* FLASH FLOOD WARNING FOR
   - CENTRAL AND SOUTHERN JEFFERSON PARISH IN SOUTHEASTERN LOUISIANA
   - NORTHERN AND CENTRAL LAFOURCHE PARISH IN SOUTHEASTERN LOUISIANA
   - CENTRAL PLAQUEMINES PARISH IN SOUTHEASTERN LOUISIANA

* UNTIL 1000 PM CDT

* THE FLASH FLOOD WARNING FOR CENTRAL PLAQUEMINES...CENTRAL AND
  SOUTHERN JEFFERSON AND CENTRAL AND NORTHERN LAFOURCHE PARISHES
  HAS BEEN EXTENDED. AT 800 PM CDT...DOPLLER RADAR CONTINUED TO
  SHOW A PERSISTENT LINE OF THUNDERSTORMS PRODUCING VERY HEAVY
  RAIN EXTENDING FROM NEAR POINTE A LA HACHE WEST TO NEAR
  LAFITTE...LOCKPORT...RACELAND AND THIBODAUX. RAINFALL RATES OF TWO
  TO THREE INCHES PER HOUR CONTINUE OT BE ASSOCIATED WITH THE MORE
  INTENSE THUNDERSTORMS IN THIS LINE. FLOODING OF ROADWAYS...LOW
  LYING AREAS AND STREAMS IS LIKELY IN THESE AREAS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY.  THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO
CROSS SAFELY.  VEHICLES CAUGHT IN ,RISING WATER SHOULD BE
ABANDONED QUICKLY.  MOVE TO HIGHER GROUND.

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 26, 7:59 PM CDTFlash Flood WarningLIXJefferson, Lafourche2 hr
Jun 26, 10:09 PM CDTFlash Flood WarningLIXLafourche, Terrebonne111 min
Jun 26, 10:09 PM CDTFlash Flood WarningLIXJefferson, Plaquemines111 min
Jun 26, 11:50 PM CDTFlash Flood WarningLIXJefferson, Lafourche, Plaquemines110 min

Nearby

Flash Flood Warnings in Louisiana, 1999Every flash flood warning in 1999

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.