Alert archive / Louisiana / Flash Flood Warnings in 2021

Flash Flood Warning 79, NWS New Orleans, LA

August 3, 2021Orleans Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Aug 3, 2021, 9:09 AM CDT for Orleans Parish, 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
Aug 3, 2021, 9:09 AM CDT (14:09 UTC)
Expired
Aug 3, 2021, 11:15 AM CDT
In force
2 hr
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Flood severity
None

County Orleans Parish, LA

What was reported inside it

TimeReportWhereRemark
Aug 3, 9:40 AM CDTFLASH FLOOD4 Sw East New Orleans, LAMULTIPLE REPORTS OF STREETS FLOODED IN NEW ORLEANS EAST WITH WATER OVER SIDEWALKS AND CURBS.

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, 2.2 hours before the alert went out and 32 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 2021-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 928 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 2021-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 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
928 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
708 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

583 
WGUS54 KLIX 031409
FFWLIX
LAC071-031615-
/O.NEW.KLIX.FF.W.0079.210803T1409Z-210803T1615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
909 AM CDT Tue Aug 3 2021

The National Weather Service in New Orleans has issued a

* Flash Flood Warning for...
  Central Orleans Parish in southeastern Louisiana...

* Until 1115 AM CDT.

* At 909 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 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 and East New Orleans.

This includes the following Interstates...
	Interstate 10 in Louisiana between mile markers 241 and 249.
	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 3008 8994 3008 8991 3005 8992 3008 8987
      3003 8984 3000 8989 3000 8991 2999 8992
      3000 9001 3003 9002 3004 9001 3006 8996

FLASH FLOOD...RADAR INDICATED

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 3, 4:23 AM CDTSpecial Marine WarningLIX67 min
Aug 3, 6:33 AM CDTSpecial Weather StatementLIXPlaquemines27 min
Aug 3, 6:44 AM CDTSpecial Weather StatementLIXAscension, Lafourche, Saint James61 min
Aug 3, 7:47 AM CDTSpecial Weather StatementLIXSaint Charles, Saint John the Baptist88 min
Aug 3, 8:42 AM CDTSpecial Marine WarningLIX63 min
Aug 3, 8:50 AM CDTAreal Flood AdvisoryLIXOrleans, Saint Bernard19 min
Aug 3, 10:04 AM CDTSpecial Marine WarningLIX86 min
Aug 3, 10:24 AM CDTSpecial Marine WarningLIX96 min
Aug 3, 10:40 AM CDTAreal Flood AdvisoryLIXAscension, East Baton Rouge, Livingston90 min
Aug 3, 10:53 AM CDTAreal Flood AdvisoryLIXAscension, East Baton Rouge, Livingston77 min
Aug 3, 11:04 AM CDTSpecial Marine WarningLIX116 min
Aug 3, 11:40 AM CDTSpecial Marine WarningLIX110 min
Aug 3, 11:49 AM CDTSpecial Marine WarningLIX86 min
Aug 3, 11:52 AM CDTSpecial Marine WarningLIX113 min
Aug 3, 2:45 PM CDTFlash Flood WarningLIXEast Baton Rouge, Livingston4 hr
Aug 3, 3:00 PM CDTAreal Flood AdvisoryLIXJefferson, Orleans, Saint Charles, Saint John the Baptist3 hr
Aug 3, 3:28 PM CDTFlash Flood WarningLIXSaint Charles, Saint John the Baptist2 hr
Aug 3, 3:39 PM CDTAreal Flood AdvisoryLIXJefferson, Orleans, Plaquemines, Saint Bernard119 min
Aug 3, 3:52 PM CDTAreal Flood AdvisoryLIXAscension, Saint Charles, Saint James, Saint John the Baptist103 min
Aug 3, 4:39 PM CDTAreal Flood AdvisoryLIXSaint Charles, Saint James, Saint John the Baptist50 min
Aug 3, 4:53 PM CDTFlash Flood WarningLIXSaint James, Saint John the Baptist39 min
Aug 3, 5:27 PM CDTAreal Flood AdvisoryLIXSaint Tammany, Tangipahoa, Washington3 hr
Aug 3, 5:33 PM CDTAreal Flood AdvisoryLIXSaint Tammany117 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.