Alert archive / Louisiana / Extreme Wind Warnings in 2021

Extreme Wind Warning 4, NWS New Orleans, LA

August 29, 20216 parishes in Louisiana

NWS New Orleans, LA issued this extreme wind warning at Aug 29, 2021, 4:23 PM CDT for 6 parishes in Louisiana. It was in force for 2 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, 4:23 PM CDT (21:23 UTC)
Expired
Aug 29, 2021, 6:30 PM CDT
In force
2 hr
Issued by
NWS New Orleans, LA
Area
Storm-based polygon

Counties Jefferson Parish, LA, Lafourche Parish, LA, Saint Charles Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Terrebonne Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 9.4 hours before the alert went out and 99 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°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 2021-08-29The 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.

229 
WFUS54 KLIX 292123
EWWLIX
LAC051-057-089-093-095-109-292330-
/O.NEW.KLIX.EW.W.0004.210829T2123Z-210829T2330Z/

BULLETIN - EAS ACTIVATION REQUESTED
Extreme Wind Warning
National Weather Service New Orleans LA
423 PM CDT Sun Aug 29 2021

The National Weather Service in New Orleans has issued a

* Extreme Wind Warning for...
  St. John The Baptist Parish in southeastern Louisiana...
  St. James Parish in southeastern Louisiana...
  St. Charles Parish in southeastern Louisiana...
  Eastern Terrebonne Parish in southeastern Louisiana...
  Lafourche Parish in southeastern Louisiana...
  Jefferson Parish in southeastern Louisiana...

* Until 630 PM CDT.

* At 422 PM CDT, National Weather Service Doppler radar and surface
  observations indicated extreme winds, associated with the eyewall 
  of Hurricane Ida, moving north at 10 mph. THIS IS AN EXTREMELY 
  DANGEROUS AND LIFE-THREATENING SITUATION!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Widespread destructive winds of 115 to 125 mph will spread across 
St. John The Baptist Parish,  St. James Parish,  St. Charles Parish, 
Terrebonne Parish,  Lafourche Parish,  Jefferson Parish, producing 
swaths of tornado-like damage.

&&

A Tornado Watch remains in effect until 700 PM CDT for southeastern
Louisiana.

LAT...LON 2918 9026 2934 9035 2931 9035 2931 9034
      2924 9039 2935 9044 2925 9059 2920 9055
      2936 9073 3012 9090 3023 9058 3023 9057
      3020 9060 3020 9042 3006 9038 3002 9015
      2945 8999
TIME...MOT...LOC 2122Z 177DEG 7KT 2952 9050 

$$

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, 4:08 PM CDTFlash Flood Warning EmergencyLIXJefferson, Orleans, Plaquemines, Saint Bernard, Saint Charles, Saint John the Baptist8 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

Extreme Wind Warnings in Louisiana, 2021Every extreme wind 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.