Alert archive / Louisiana / Flash Flood Warnings in 1999

Flash Flood Warning 4, NWS New Orleans, LA

June 26, 1999Saint Charles Parish, Saint John the Baptist Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Jun 26, 1999, 10:43 AM CDT for Saint Charles Parish, Saint John the Baptist Parish, Louisiana. It was in force for 117 min. 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, 10:43 AM CDT (15:43 UTC)
Expired
Jun 26, 1999, 12:40 PM CDT
In force
117 min
Issued by
NWS New Orleans, LA
Area
Whole counties

Counties Saint Charles Parish, LA, Saint John the Baptist Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 3.7 hours before the alert went out and 73 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 1999-06-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 762 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 12:00Z on 1999-06-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 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
762 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
871 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
58 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 261545
FFWNEW
LAC089-093-095-261740-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1043 AM CDT SAT JUN 26 1999

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

* FLASH FLOOD WARNING FOR
   - ST JAMES PARISH IN SOUTHEASTERN LOUISIANA
   - ST JOHN PARISH IN SOUTHEASTERN LOUISIANA
   - ST CHARLES PARISH IN SOUTHEASTERN LOUISIANA

* UNTIL 1240 PM CDT

* AT 1040 AM...TORRENTIAL RAINFALL WAS PRODUCING FLOODING OF
  NUMEROUS ROADS AND HIGHWAYS ACROSS ST JAMES...ST JOHN AND ST
  CHARLES PARISHES. HIGH WATER WAS ALSO THREATENING HOUSES IN A FEW
  SUBDIVISIONS. DOPPLER RADAR ESTIMATED 2 TO 4 INCHES OF RAIN HAS
  FALLEN ACROSS MUCH OF THE WARNING AREA. A BAND OF THUNDERSTORMS
  PRODUCING 1 TO 2 INCHES OF ADDITIONAL RAIN PER HOUR WILL CONTINUE
  TO MOVE OVER THE SAME GENERAL AREA WHICH WILL WORSEN THE FLOOD
  SITUATION.

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.

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, Jun 26, 10:15 AM CDT, 28 minutes before
LAZ034>040-046>050-056>070-MSZ068>071-077-080>082-270100-

THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1015 AM CDT SAT JUN 26 1999

RICH TROPICAL MOISTURE REMAINS ACROSS THE REGION TODAY. WIDESPREAD
RAIN AND EMBEDDED THUNDERSTORMS WILL CONTINUE DUE TO AN UPPER AIR
DISTURBANCE MOVING SLOWLY EAST FROM TEXAS.

LOCALLY HEAVY RAIN WITH RAINFALL RATES OF 1 TO 3 INCHES PER HOUR CAN
BE EXPECTED WITH THE MORE INTENSE THUNDERSTORMS. OCCASIONAL
LIGHTNING AND GUSTY WINDS TO 30 MPH WILL ACCOMPANY THE STRONGER
THUNDERSTORMS. HOWEVER...SEVERE THUNDERSTORMS ARE NOT EXPECTED
TODAY. WATERSPOUTS MAY ALSO FORM OVER LARGE BODIES OF WATER.

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 26, 10:43 AM CDTFlash Flood WarningLIXSaint James117 min
Jun 26, 1:08 PM CDTFlash Flood WarningLIXAscension, Saint James, Saint John the Baptist117 min
Jun 26, 2:58 PM CDTFlash Flood WarningLIXSaint Charles57 min
Jun 26, 4:08 PM CDTFlash Flood WarningLIXJefferson, Plaquemines, Saint Charles97 min
Jun 26, 4:08 PM CDTFlash Flood WarningLIXSaint Bernard97 min
Jun 26, 6:42 PM CDTFlash Flood WarningLIXJefferson, Lafourche88 min
Jun 26, 6:42 PM CDTFlash Flood WarningLIXPlaquemines88 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.