Alert archive / Louisiana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 101, NWS New Orleans, LA

May 11, 20214 parishes in Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at May 11, 2021, 9:17 AM CDT for 4 parishes in Louisiana. It was in force for 43 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
May 11, 2021, 9:17 AM CDT (14:17 UTC)
Expired
May 11, 2021, 10:00 AM CDT
In force
43 min
Issued by
NWS New Orleans, LA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties East Baton Rouge Parish, LA, East Feliciana Parish, LA, Livingston Parish, LA, Saint Helena Parish, LA

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 2.3 hours before the alert went out and 121 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 2021-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2600 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 2021-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 square meters per square second.19395878Sfc1 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
2600 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
469 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.6
Supercell composite
3.1

Open this sounding in Storm Lab

The text

As transmitted.

357 
WUUS54 KLIX 111417
SVRLIX
LAC033-037-063-091-111500-
/O.NEW.KLIX.SV.W.0101.210511T1417Z-210511T1500Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service New Orleans LA
917 AM CDT Tue May 11 2021

The National Weather Service in New Orleans has issued a

* Severe Thunderstorm Warning for...
  Western St. Helena Parish in southeastern Louisiana...
  Northwestern Livingston Parish in southeastern Louisiana...
  Southeastern East Feliciana Parish in southeastern Louisiana...
  Northeastern East Baton Rouge Parish in southeastern Louisiana...

* Until 1000 AM CDT.

* At 917 AM CDT, a severe thunderstorm was located near Watson, or 11
  miles northeast of Denham Springs, moving north at 20 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Clinton, Watson, Darlington and Pride. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3056 9073 3052 9093 3087 9109 3094 9078
TIME...MOT...LOC 1417Z 165DEG 16KT 3062 9086 

HAIL...<.75IN
WIND...60MPH
 
$$

MEFFER
2 follow-up statements
813 
WWUS54 KLIX 111433
SVSLIX

Severe Weather Statement
National Weather Service New Orleans LA
933 AM CDT Tue May 11 2021

LAC063-111442-
/O.CAN.KLIX.SV.W.0101.000000T0000Z-210511T1500Z/
Livingston LA-
933 AM CDT Tue May 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN LIVINGSTON PARISH
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3094 9078 3065 9074 3065 9092 3062 9094
      3060 9095 3060 9097 3087 9109
TIME...MOT...LOC 1432Z 165DEG 16KT 3069 9088 

$$

LAC033-037-091-111500-
/O.CON.KLIX.SV.W.0101.000000T0000Z-210511T1500Z/
St. Helena LA-East Feliciana LA-East Baton Rouge LA-
933 AM CDT Tue May 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 AM CDT
FOR WESTERN ST. HELENA...SOUTHEASTERN EAST FELICIANA AND NORTHEASTERN
EAST BATON ROUGE PARISHES...

At 932 AM CDT, a severe thunderstorm was located near Pride, or 14
miles southeast of Clinton, moving north at 20 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Clinton, Pride and Darlington. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3094 9078 3065 9074 3065 9092 3062 9094
      3060 9095 3060 9097 3087 9109
TIME...MOT...LOC 1432Z 165DEG 16KT 3069 9088 

HAIL...<.75IN
WIND...60MPH
 
$$

MEFFER
453 
WWUS54 KLIX 111454
SVSLIX

Severe Weather Statement
National Weather Service New Orleans LA
954 AM CDT Tue May 11 2021

LAC033-037-091-111504-
/O.EXP.KLIX.SV.W.0101.000000T0000Z-210511T1500Z/
St. Helena LA-East Feliciana LA-East Baton Rouge LA-
954 AM CDT Tue May 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN ST. HELENA...
SOUTHEASTERN EAST FELICIANA AND NORTHEASTERN EAST BATON ROUGE
PARISHES WILL EXPIRE AT 1000 AM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with this thunderstorm.

LAT...LON 3094 9078 3065 9074 3065 9092 3062 9094
      3060 9095 3060 9097 3087 9109
TIME...MOT...LOC 1454Z 165DEG 16KT 3078 9091 

$$

MEFFER

The office that day

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

IssuedProductOfficeCountiesLasted
May 10, 8:57 PM CDTRiver Flood WarningLIXTangipahoa5 days
May 10, 8:58 PM CDTRiver Flood WarningLIXSaint Tammany61 hr
May 10, 9:33 PM CDTAreal Flood AdvisoryLIXLafourche, Terrebonne48 min
May 11, 3:11 AM CDTFlash Flood WatchLIXAssumption, East Baton Rouge, East Feliciana, Iberville, Orleans, Pointe Coupee and 9 more39 hr
May 11, 7:11 AM CDTAreal Flood AdvisoryLIXJefferson, Orleans, Plaquemines32 min
May 11, 7:43 AM CDTFlash Flood WarningLIXJefferson, Orleans, Plaquemines77 min
May 11, 7:49 AM CDTAreal Flood AdvisoryLIXJefferson, Orleans116 min
May 11, 8:49 AM CDTAreal Flood AdvisoryLIXOrleans, Saint Tammany116 min
May 11, 9:14 AM CDTSevere Thunderstorm WarningLIXSaint Tammany, Washington29 min
May 11, 9:21 AM CDTSpecial Weather StatementLIXTangipahoa39 min
May 11, 9:25 AM CDTSpecial Marine WarningLIX65 min
May 11, 9:53 AM CDTSpecial Weather StatementLIXEast Baton Rouge, Iberville, West Baton Rouge67 min
May 11, 10:06 AM CDTRiver Flood WarningLIXSaint Tammany6 days
May 11, 10:20 AM CDTAreal Flood AdvisoryLIXAscension, Assumption, East Baton Rouge, Iberville, Livingston, Saint James and 1 more115 min
May 11, 10:25 AM CDTSpecial Marine WarningLIX65 min
May 11, 10:26 AM CDTRiver Flood WarningLIXSaint Tammany61 hr
May 11, 10:26 AM CDTRiver Flood WarningLIXSaint Helena24 hr
May 11, 10:34 AM CDTSpecial Weather StatementLIXWashington56 min
May 11, 11:25 AM CDTAreal Flood AdvisoryLIXSaint Tammany, Tangipahoa, Washington3 hr
May 11, 11:38 AM CDTSpecial Marine WarningLIX67 min
May 11, 11:50 AM CDTAreal Flood WarningLIXSaint Tammany, Tangipahoa115 min
May 11, 12:10 PM CDTSpecial Weather StatementLIXSaint Charles35 min
May 11, 12:28 PM CDTAreal Flood AdvisoryLIXJefferson, Orleans, Plaquemines, Saint Bernard, Saint Charles, Saint John the Baptist2 hr
May 11, 12:35 PM CDTSpecial Marine WarningLIX55 min
May 11, 1:04 PM CDTTornado WarningLIXOrleans14 min
May 11, 1:24 PM CDTAreal Flood AdvisoryLIXSaint Tammany66 min
May 11, 3:05 PM CDTSpecial Marine WarningLIX55 min
May 11, 3:52 PM CDTSpecial Marine WarningLIX53 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 2021Every severe thunderstorm 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.