Alert archive / Louisiana / Flash Flood Warnings in 2021

Flash Flood Warning 87, NWS New Orleans, LA

August 29, 20216 parishes in Louisiana

NWS New Orleans, LA issued this flash flood warning at Aug 29, 2021, 4:08 PM CDT for 6 parishes in Louisiana. It was in force for 8 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 29, 2021, 4:08 PM CDT (21:08 UTC)
Expired
Aug 30, 2021, 12:00 AM CDT
In force
8 hr
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Emergency
Flash flood emergency
Flood severity
None

Counties Jefferson Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint John the Baptist Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 9.1 hours before the alert went out and 61 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 2021-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2021-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -55 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3256 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
-55 m²/s²
0-3 km storm-relative helicity
85 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.3

Open this sounding in Storm Lab

The text

As transmitted.

057 
WGUS54 KLIX 292108
FFWLIX
LAC051-071-075-087-089-095-300300-
/O.NEW.KLIX.FF.W.0087.210829T2108Z-210830T0300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
408 PM CDT Sun Aug 29 2021

The National Weather Service in New Orleans has issued a

* Flash Flood Warning for...
  Northwestern Jefferson Parish in southeastern Louisiana...
  Southwestern Orleans Parish in southeastern Louisiana...
  Northwestern Plaquemines Parish in southeastern Louisiana...
  West Central St. Bernard Parish in southeastern Louisiana...
  Northwestern St. Charles Parish in southeastern Louisiana...
  West Central St. John The Baptist Parish in southeastern Louisiana...

* Until 1000 PM CDT.

* At 408 PM CDT, Doppler radar and automated rain gauges indicated 
  heavy rain falling across the warned area. Between 1 and 3 inches 
  of rain have fallen. Additional rainfall amounts of 4 to 8 inches 
  are possible in the warned area through this evening. Flash 
  flooding is ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by heavy rain.

  SOURCE...Radar and automated gauges.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  New Orleans, Avondale, Metairie, Marrero, Harvey, Hahnville, 
  Timberlane, Belle Chasse, Chalmette, Laplace, East New Orleans, 
  Reserve, Jefferson, Gretna, Harahan, Westwego, River Ridge, 
  Waggaman, Elmwood and Bridge City.

This includes the following Interstates...
	Interstate 10 in Louisiana between mile markers 221 and 248.
	Interstate 510 between mile markers 1 and 3.
	Interstate 610 between mile markers 1 and 4.
	Interstate 310 between mile markers 1 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 3005 9067 3011 9064 3010 9051 3008 9043
      2998 9034 3004 9027 3002 9007 3008 8994
      3001 8988 2997 9001 2995 8991 2989 8983
      2986 8990 2990 8994 2975 9003 2992 9026
      2988 9037 2979 9045 2984 9047 2995 9043

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

TD
3 follow-up statements
269 
WGUS54 KLIX 300058
FFWLIX
LAC051-071-075-087-089-095-300500-
/O.EXT.KLIX.FF.W.0087.000000T0000Z-210830T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
758 PM CDT Sun Aug 29 2021

The National Weather Service in New Orleans has extended the

* Flash Flood Warning for...
  Northwestern Jefferson Parish in southeastern Louisiana...
  Southwestern Orleans Parish in southeastern Louisiana...
  Northwestern Plaquemines Parish in southeastern Louisiana...
  West Central St. Bernard Parish in southeastern Louisiana...
  Northwestern St. Charles Parish in southeastern Louisiana...
  West Central St. John The Baptist Parish in southeastern Louisiana...

* Until midnight CDT.

* At 758 PM CDT, the public reported flash flooding across the 
  warned area. Between 3 and 6 inches of rain have fallen. 
  Additional rainfall amounts of 3 to 6 inches are possible in the 
  warned area through midnight. Flash flooding is already occurring.

  HAZARD...Life threatening flash flooding. Heavy rain producing
           flash flooding.

  SOURCE...Public reported.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  New Orleans, Avondale, Metairie, Marrero, Harvey, Hahnville, 
  Timberlane, Belle Chasse, Chalmette, Laplace, East New Orleans, 
  Reserve, Jefferson, Gretna, Harahan, Westwego, River Ridge, 
  Waggaman, Elmwood and Bridge City.

This includes the following Interstates...
	Interstate 10 in Louisiana between mile markers 220 and 247.
	Interstate 510 between mile markers 1 and 3.
	Interstate 610 between mile markers 1 and 4.
	Interstate 310 between mile markers 1 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now. Act quickly to protect your life.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3005 9067 3011 9064 3010 9051 3008 9043
      2998 9034 3004 9027 3002 9007 3008 8994
      3001 8988 2997 9001 2995 8991 2989 8983
      2986 8990 2990 8994 2975 9003 2992 9026
      2988 9037 2979 9045 2984 9047 2995 9043

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

TD
625 
WGUS74 KLIX 300108
FFSLIX

Flash Flood Statement
National Weather Service New Orleans LA
808 PM CDT Sun Aug 29 2021

LAC051-071-075-087-089-095-300500-
/O.CON.KLIX.FF.W.0087.000000T0000Z-210830T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Jefferson LA-Orleans LA-Plaquemines LA-St. Bernard LA-St. Charles LA-
St. John The Baptist LA-
808 PM CDT Sun Aug 29 2021

...FLASH FLOOD EMERGENCY FOR SOUTH SHORE AREA OF METRO NEW ORLEANS...

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL MIDNIGHT CDT TONIGHT 
FOR NORTHWESTERN JEFFERSON, SOUTHWESTERN ORLEANS, NORTHWESTERN 
PLAQUEMINES, WEST CENTRAL ST. BERNARD, NORTHWESTERN ST. CHARLES AND 
WEST CENTRAL ST. JOHN THE BAPTIST PARISHES...

At 808 PM CDT, the public reported flash flooding across the warned 
area. Between 4 and 7 inches of rain have fallen. Additional 
rainfall amounts of 3 to 6 inches are possible in the warned area. 
Flash flooding is already occurring.

This is a FLASH FLOOD EMERGENCY for South shore area of metro New 
Orleans. This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER 
GROUND NOW!

HAZARD...Life threatening flash flooding. Heavy rain producing
         flash flooding.

SOURCE...Public reported.

IMPACT...This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER
         GROUND NOW! Life threatening flash flooding of low water
         crossings, small creeks and streams, urban areas,
         highways, streets and underpasses.

Some locations that will experience flash flooding include...
  New Orleans, Avondale, Metairie, Marrero, Harvey, Hahnville, 
  Timberlane, Belle Chasse, Chalmette, Laplace, East New Orleans, 
  Reserve, Jefferson, Gretna, Harahan, Westwego, River Ridge, 
  Waggaman, Elmwood and Bridge City.

This includes the following Interstates...
	Interstate 10 in Louisiana between mile markers 220 and 247.
	Interstate 510 between mile markers 1 and 3.
	Interstate 610 between mile markers 1 and 4.
	Interstate 310 between mile markers 1 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now! This is an extremely dangerous and 
life-threatening situation. Do not attempt to travel unless you are 
fleeing an area subject to flooding or under an evacuation order.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 3005 9067 3011 9064 3010 9051 3008 9043
      2998 9034 3004 9027 3002 9007 3008 8994
      3001 8988 2997 9001 2995 8991 2989 8983
      2986 8990 2990 8994 2975 9003 2992 9026
      2988 9037 2979 9045 2984 9047 2995 9043

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CATASTROPHIC

$$

TD
845 
WGUS74 KLIX 300242
FFSLIX

Flash Flood Statement
National Weather Service New Orleans LA
942 PM CDT Sun Aug 29 2021

LAC051-071-075-087-089-095-300500-
/O.CON.KLIX.FF.W.0087.000000T0000Z-210830T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Jefferson LA-Orleans LA-Plaquemines LA-St. Bernard LA-St. Charles LA-
St. John The Baptist LA-
942 PM CDT Sun Aug 29 2021

...FLASH FLOOD EMERGENCY FOR SOUTH SHORE AREA OF METRO NEW ORLEANS...

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL MIDNIGHT CDT TONIGHT 
FOR NORTHWESTERN JEFFERSON, SOUTHWESTERN ORLEANS, NORTHWESTERN 
PLAQUEMINES, WEST CENTRAL ST. BERNARD, NORTHWESTERN ST. CHARLES AND 
WEST CENTRAL ST. JOHN THE BAPTIST PARISHES...

At 942 PM CDT, the public reported flash flooding across the warned 
area. Between 5 and 9 inches of rain have fallen. Additional 
rainfall amounts of 3 to 6 inches are possible in the warned area. 
Flash flooding is already occurring.

This is a FLASH FLOOD EMERGENCY for South shore area of metro New 
Orleans. This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER 
GROUND NOW!

HAZARD...Life threatening flash flooding. Heavy rain producing
         flash flooding.

SOURCE...Public reported.

IMPACT...This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER
         GROUND NOW! Life threatening flash flooding of low water
         crossings, small creeks and streams, urban areas,
         highways, streets and underpasses.

Some locations that will experience flash flooding include...
  New Orleans, Avondale, Metairie, Marrero, Harvey, Hahnville, 
  Timberlane, Belle Chasse, Chalmette, Laplace, East New Orleans, 
  Reserve, Jefferson, Gretna, Harahan, Westwego, River Ridge, 
  Waggaman, Elmwood and Bridge City.

This includes the following Interstates...
	Interstate 10 in Louisiana between mile markers 220 and 247.
	Interstate 510 between mile markers 1 and 3.
	Interstate 610 between mile markers 1 and 4.
	Interstate 310 between mile markers 1 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now! This is an extremely dangerous and 
life-threatening situation. Do not attempt to travel unless you are 
fleeing an area subject to flooding or under an evacuation order.

Move to higher ground now. Act quickly to protect your life.

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

&&

LAT...LON 3005 9067 3011 9064 3010 9051 3008 9043
      2998 9034 3004 9027 3002 9007 3008 8994
      3001 8988 2997 9001 2995 8991 2989 8983
      2986 8990 2990 8994 2975 9003 2992 9026
      2988 9037 2979 9045 2984 9047 2995 9043

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CATASTROPHIC

$$

CAB

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 6:23 AM CDTSpecial Marine WarningLIX22 min
Aug 29, 7:49 AM CDTExtreme Wind WarningLIXJefferson, Lafourche, Plaquemines, Saint Bernard, Saint Charles, Terrebonne3 hr
Aug 29, 10:30 AM CDTExtreme Wind WarningLIXJefferson, Lafourche, Plaquemines, Saint Bernard, Saint Charles, Terrebonne3 hr
Aug 29, 1:26 PM CDTExtreme Wind WarningLIXAssumption, Jefferson, Lafourche, Plaquemines, Saint Charles, Saint James and 2 more3 hr
Aug 29, 2:42 PM CDTSpecial Marine WarningLIX18 min
Aug 29, 3:39 PM CDTFlash Flood WarningLIXLafourche, Terrebonne7 hr
Aug 29, 4:23 PM CDTExtreme Wind WarningLIXJefferson, Lafourche, Saint Charles, Saint James, Saint John the Baptist, Terrebonne2 hr
Aug 29, 5:01 PM CDTFlash Flood Warning EmergencyCatastrophic damage threatLIXPlaquemines6 hr
Aug 29, 5:04 PM CDTSpecial Marine WarningLIX26 min
Aug 29, 6:04 PM CDTSpecial Marine WarningLIX26 min
Aug 29, 6:09 PM CDTFlash Flood WarningLIXSaint Tammany8 hr
Aug 29, 6:21 PM CDTFlash Flood WarningLIXSaint Tammany16 hr
Aug 29, 6:25 PM CDTTornado WarningLIXOrleans, Saint Bernard, Saint Tammany35 min
Aug 29, 6:33 PM CDTSpecial Marine WarningLIX57 min
Aug 29, 6:54 PM CDTTornado WarningLIXSaint Tammany36 min

Nearby

Flash Flood Warnings in Louisiana, 2021Every flash flood warning in 2021

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.