Alert archive / Louisiana / Flash Flood Warnings in 2021

Flash Flood Warning 128, NWS New Orleans, LA

September 28, 2021Orleans Parish, Plaquemines Parish, Saint Bernard Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Sep 28, 2021, 5:19 PM CDT for Orleans Parish, Plaquemines Parish, Saint Bernard Parish, Louisiana. It was in force for 2 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Sep 28, 2021, 5:19 PM CDT (22:19 UTC)
Expired
Sep 28, 2021, 7:29 PM CDT
In force
2 hr
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Flood severity
None

Counties Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA

What was reported inside it

TimeReportWhereRemark
Sep 28, 6:00 PM CDTFLASH FLOOD1 E Chalmette, LASTREET FLOODING AT VERONICA DRIVE IN CHALMETTE AT AROUND 6 PM. THE STREET WAS IMPASSIBLE BUT HAD RECEDED BY 7 PM.
Sep 28, 6:00 PM CDTFLASH FLOOD1 Ene Chalmette, LASTREET FLOODING AT VERONICA DRIVE AROUND 6 PM. THE STREET WAS IMPASSIBLE BUT HAD RECEDED BY 7 PM.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 10.3 hours before the alert went out and 40 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 2021-09-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2461 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 2021-09-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 25 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
2461 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
624 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
27 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

934 
WGUS54 KLIX 282219
FFWLIX
LAC071-075-087-290130-
/O.NEW.KLIX.FF.W.0128.210928T2219Z-210929T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
519 PM CDT Tue Sep 28 2021

The National Weather Service in New Orleans has issued a

* Flash Flood Warning for...
  Western Orleans Parish in southeastern Louisiana...
  Northwestern Plaquemines Parish in southeastern Louisiana...
  West Central St. Bernard Parish in southeastern Louisiana...

* Until 830 PM CDT.

* At 519 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 4 inches of rain 
  have fallen. Additional rainfall amounts of 1 to 2 inches are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  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, Chalmette, East New Orleans, Belle Chasse, Arabi and 
  Meraux.

This includes the following Interstates...
	Interstate 10 in Louisiana between mile markers 241 and 252.
	Interstate 510 between mile markers 1 and 3.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2993 9004 3003 9002 3008 8993 3012 8990
      3011 8987 3003 8987 2993 8991 2986 8994
      2985 8998 2987 9002 2989 9000

FLASH FLOOD...RADAR INDICATED

$$

TD
1 follow-up statement
351 
WGUS74 KLIX 290029
FFSLIX

Flash Flood Statement
National Weather Service New Orleans LA
729 PM CDT Tue Sep 28 2021

LAC071-075-087-290039-
/O.CAN.KLIX.FF.W.0128.000000T0000Z-210929T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Orleans LA-Plaquemines LA-St. Bernard LA-
729 PM CDT Tue Sep 28 2021

...FLASH FLOOD WARNING FOR WESTERN ORLEANS, NORTHWESTERN PLAQUEMINES 
AND WEST CENTRAL ST. BERNARD PARISHES HAS BEEN CANCELLED...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

LAT...LON 2993 9004 3003 9002 3008 8993 3012 8990
      3011 8987 3003 8987 2993 8991 2986 8994
      2985 8998 2987 9002 2989 9000

$$

TD

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 28, 6:48 AM CDTDense Fog AdvisoryLIXWashington2 hr
Sep 28, 12:12 PM CDTSpecial Marine WarningLIX63 min
Sep 28, 12:21 PM CDTAreal Flood AdvisoryLIXWest Feliciana3 hr
Sep 28, 12:26 PM CDTSpecial Marine WarningLIX64 min
Sep 28, 12:44 PM CDTSpecial Marine WarningLIX61 min
Sep 28, 1:12 PM CDTSpecial Marine WarningLIX33 min
Sep 28, 1:51 PM CDTSpecial Marine WarningLIX54 min
Sep 28, 1:56 PM CDTSpecial Marine WarningLIX64 min
Sep 28, 2:28 PM CDTSpecial Marine WarningLIX62 min
Sep 28, 2:42 PM CDTSpecial Marine WarningLIX63 min
Sep 28, 2:56 PM CDTSpecial Marine WarningLIX64 min
Sep 28, 3:03 PM CDTSpecial Marine WarningLIX57 min
Sep 28, 3:04 PM CDTSpecial Marine WarningLIX38 min
Sep 28, 3:22 PM CDTSpecial Marine WarningLIX38 min
Sep 28, 3:57 PM CDTSpecial Marine WarningLIX48 min
Sep 28, 4:12 PM CDTAreal Flood AdvisoryLIXSaint Tammany3 hr
Sep 28, 4:18 PM CDTAreal Flood AdvisoryLIXSaint Tammany3 hr
Sep 28, 4:23 PM CDTSpecial Marine WarningLIX67 min
Sep 28, 4:43 PM CDTAreal Flood AdvisoryLIXOrleans, Saint Bernard2 hr
Sep 28, 4:46 PM CDTAreal Flood AdvisoryLIXSaint Tammany119 min
Sep 28, 5:02 PM CDTAreal Flood AdvisoryLIXOrleans, Saint Bernard118 min
Sep 28, 5:52 PM CDTSpecial Marine WarningLIX53 min
Sep 28, 5:59 PM CDTAreal Flood AdvisoryLIXJefferson, Orleans, Plaquemines, Saint Bernard3 hr
Sep 28, 6:36 PM CDTSpecial Weather StatementLIXPlaquemines39 min
Sep 28, 6:47 PM CDTSpecial Marine WarningLIX58 min
Sep 28, 6:57 PM CDTSpecial Marine WarningLIX63 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive.