Alert archive / Louisiana / Flash Flood Warnings in 2021

Flash Flood Warning 83, NWS New Orleans, LA

August 10, 2021Jefferson Parish, Louisiana

NWS New Orleans, LA issued this flash flood warning at Aug 10, 2021, 2:05 PM CDT for Jefferson Parish, Louisiana. It was in force for 81 min. 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 10, 2021, 2:05 PM CDT (19:05 UTC)
Expired
Aug 10, 2021, 3:26 PM CDT
In force
81 min
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Flood severity
None

County Jefferson Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 7.1 hours before the alert went out and 54 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 2021-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3054 joules per kilogram.LCLLFCEL10008507005003002001001 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 2021-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -16 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
3054 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
686 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-16 m²/s²
0-3 km storm-relative helicity
-5 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

402 
WGUS54 KLIX 101905
FFWLIX
LAC051-102130-
/O.NEW.KLIX.FF.W.0083.210810T1905Z-210810T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service New Orleans LA
205 PM CDT Tue Aug 10 2021

The National Weather Service in New Orleans has issued a

* Flash Flood Warning for...
  North Central Jefferson Parish in southeastern Louisiana...

* Until 430 PM CDT.

* At 205 PM 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...
  Metairie, Jefferson, Elmwood and Bridge City.

This includes the following Interstates...
	Interstate 10 in Louisiana near mile marker 228.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 2995 9014 2996 9019 2997 9020 2998 9020
      2999 9020 3000 9020 3000 9019 3000 9017
      2999 9014 2998 9013 2997 9013 2996 9014

FLASH FLOOD...RADAR INDICATED

$$

TD
1 follow-up statement
613 
WGUS74 KLIX 102026
FFSLIX

Flash Flood Statement
National Weather Service New Orleans LA
326 PM CDT Tue Aug 10 2021

LAC051-102036-
/O.CAN.KLIX.FF.W.0083.000000T0000Z-210810T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Jefferson LA-
326 PM CDT Tue Aug 10 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTH CENTRAL JEFFERSON 
PARISH...

Flooding is no longer expected to pose a threat. 

LAT...LON 2995 9014 2996 9019 2997 9020 2998 9020
      2999 9020 3000 9020 3000 9019 3000 9017
      2999 9014 2998 9013 2997 9013 2996 9014

$$

TD

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 1:41 PM CDTSpecial Weather StatementLIXSaint Charles49 min
Aug 10, 1:54 PM CDTSpecial Weather StatementLIXSaint Charles36 min
Aug 10, 2:13 PM CDTSpecial Weather StatementLIXTangipahoa32 min
Aug 10, 2:27 PM CDTSpecial Weather StatementLIXSaint Charles33 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.