Alert archive / Louisiana / Flash Flood Warnings in 2021

Flash Flood Warning 24, NWS New Orleans, LA

May 5, 20214 parishes in Louisiana

NWS New Orleans, LA issued this flash flood warning at May 5, 2021, 8:25 AM CDT for 4 parishes in Louisiana. It was in force for 2 hr. 1 report 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: May 5, 2021, 8:25 AM CDT (13:25 UTC)
Expired: May 5, 2021, 10:30 AM CDT
In force: 2 hr
Issued by: NWS New Orleans, LA
Area: Storm-based polygon
Flood severity: None

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

What was reported inside it

Time	Report	Where	Remark
May 5, 8:30 AM CDT	FLASH FLOOD	3 Nw New Orleans, LA	STREET FLOODING REPORTED IN THE LAKEVIEW NEIGHBORHOOD OF NEW ORLEANS.

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, 1.4 hours before the alert went out and 47 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 6 J/kg
Mixed-layer CIN: -305 J/kg
Mixed-layer LCL: 750 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 96 m²/s²
0-3 km storm-relative helicity: 260 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.2

Open this sounding in Storm Lab

The text

As transmitted.

592 
WGUS54 KLIX 051325
FFWLIX
LAC051-071-075-087-051530-
/O.NEW.KLIX.FF.W.0024.210505T1325Z-210505T1530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
825 AM CDT Wed May 5 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...

* Until 1030 AM CDT.

* At 825 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1 inch of rain 
  has fallen. Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Doppler radar.

  IMPACT...Flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other
           drainage and low lying areas.

* Some locations that will experience flash flooding include...
  New Orleans, Timberlane, Harvey, Chalmette, Belle Chasse, Marrero, 
  Metairie, East New Orleans, Avondale, Jefferson, Gretna, Harahan, 
  Westwego, Terrytown, Arabi, Woodmere, Meraux, Estelle, Bridge City 
  and Violet.

Additional rainfall amounts of 1 to 2 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, urban areas, highways, streets and underpasses 
as well as other drainage areas and low lying spots.

A Flash Flood Warning means that flooding is imminent or occurring. 
If you are in the warned area move to higher ground immediately. 
Residents living along streams and creeks should take immediate 
precautions to protect life and property.

&&

LAT...LON 2981 8995 2983 9006 2984 9013 2989 9021
      2996 9026 3004 9025 3002 9018 3002 9013
      3003 9009 3003 9008 3003 9006 3003 9003
      3005 9003 3004 9001 3008 8994 3005 8989
      2984 8982

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR 

$$

PG

The office that day

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

Issued	Product	Office	Counties	Lasted
May 4, 7:21 PM CDT	Special Marine Warning	LIX		54 min
May 4, 8:03 PM CDT	Special Weather Statement	LIX	Tangipahoa	27 min
May 4, 8:13 PM CDT	Special Weather Statement	LIX	Washington	17 min
May 4, 8:21 PM CDT	Special Marine Warning	LIX		54 min
May 4, 9:06 PM CDT	River Flood Warning	LIX	Saint Tammany	69 hr
May 4, 10:03 PM CDT	Severe Thunderstorm Warning	LIX	Livingston, Saint John the Baptist, Tangipahoa	27 min
May 4, 10:06 PM CDT	Special Marine Warning	LIX		24 min
May 4, 10:25 PM CDT	Special Marine Warning	LIX		65 min
May 4, 10:28 PM CDT	Severe Thunderstorm Warning	LIX	Saint John the Baptist, Tangipahoa	5 min
May 5, 12:47 AM CDT	Areal Flood Advisory	LIX	Jefferson, Orleans, Saint Bernard, Saint Charles, Saint James, Saint John the Baptist	103 min
May 5, 1:15 AM CDT	Special Weather Statement	LIX	Orleans	45 min
May 5, 4:24 AM CDT	Areal Flood Advisory	LIX	Saint Tammany	3 hr
May 5, 6:16 AM CDT	River Flood Warning	LIX	Saint Tammany	25 hr
May 5, 6:45 AM CDT	Areal Flood Advisory	LIX	Saint Charles, Saint James, Saint John the Baptist	2 hr
May 5, 7:01 AM CDT	Flash Flood Warning	LIX	Saint Tammany	89 min
May 5, 7:20 AM CDT	Flash Flood Warning	LIX	Saint Charles, Saint James, Saint John the Baptist	115 min
May 5, 7:39 AM CDT	Special Marine Warning	LIX		36 min
May 5, 7:48 AM CDT	Areal Flood Advisory	LIX	Orleans, Saint Tammany	117 min
May 5, 8:00 AM CDT	Areal Flood Advisory	LIX	Jefferson, Orleans, Plaquemines, Saint Bernard, Saint Charles	2 hr
May 5, 9:23 AM CDT	Special Marine Warning	LIX		67 min
May 5, 10:25 AM CDT	Special Marine Warning	LIX		50 min
May 5, 10:31 AM CDT	Special Marine Warning	LIX		59 min
May 5, 11:11 AM CDT	Special Marine Warning	LIX		49 min

Nearby

Flash Flood Warnings in Louisiana, 2021 Every 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.