Alert archive / Louisiana / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 4, NWS New Orleans, LA

March 17, 20216 parishes in Louisiana

NWS New Orleans, LA issued this severe thunderstorm warning at Mar 17, 2021, 4:44 PM CDT for 6 parishes in Louisiana. It was in force for 34 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: Mar 17, 2021, 4:44 PM CDT (21:44 UTC)
Expired: Mar 17, 2021, 5:18 PM CDT
In force: 34 min
Issued by: NWS New Orleans, LA
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Ascension Parish, LA, East Baton Rouge Parish, LA, Iberville Parish, LA, Livingston Parish, LA, Saint Helena Parish, LA, Tangipahoa Parish, LA

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Mar 17, 2:38 PM CDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 9.7 hours before the alert went out and 101 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: 1786 J/kg
Mixed-layer CIN: -40 J/kg
Mixed-layer LCL: 644 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 205 m²/s²
0-3 km storm-relative helicity: 396 m²/s²
Significant tornado parameter: 2.0
Supercell composite: 9.9

Open this sounding in Storm Lab

The text

As transmitted.

815 
WUUS54 KLIX 172144
SVRLIX
LAC005-033-047-063-091-105-172230-
/O.NEW.KLIX.SV.W.0004.210317T2144Z-210317T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service New Orleans LA
444 PM CDT Wed Mar 17 2021

The National Weather Service in New Orleans has issued a

* Severe Thunderstorm Warning for...
  Northern Ascension Parish in southeastern Louisiana...
  Southern St. Helena Parish in southeastern Louisiana...
  Livingston Parish in southeastern Louisiana...
  East central Iberville Parish in southeastern Louisiana...
  Southwestern Tangipahoa Parish in southeastern Louisiana...
  Central East Baton Rouge Parish in southeastern Louisiana...

* Until 530 PM CDT.

* At 443 PM CDT, severe thunderstorms were located along a line
  extending from near Pride to near Shenandoah, moving northeast at
  70 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Baton Rouge, Hammond, Zachary, Baker, Denham Springs, Gonzales,
  Amite, Oak Hills Place, St. Gabriel, Walker, Amite City, White
  Castle, Livingston, Independence, Sorrento, Roseland, French
  Settlement, Albany, Port Vincent and Springfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 900 PM CDT for southeastern
Louisiana.

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

&&

LAT...LON 3035 9112 3066 9114 3078 9047 3033 9046
      3034 9047 3034 9049 3030 9054 3030 9056
      3025 9059 3014 9115
TIME...MOT...LOC 2143Z 236DEG 62KT 3066 9098 3039 9095 

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

KLG

2 follow-up statements

314 
WWUS54 KLIX 172159
SVSLIX

Severe Weather Statement
National Weather Service New Orleans LA
459 PM CDT Wed Mar 17 2021

LAC005-033-047-063-091-105-172230-
/O.CON.KLIX.SV.W.0004.000000T0000Z-210317T2230Z/
Ascension LA-St. Helena LA-Livingston LA-Iberville LA-Tangipahoa LA-
East Baton Rouge LA-
459 PM CDT Wed Mar 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM CDT
FOR NORTHERN ASCENSION...SOUTHERN ST. HELENA...LIVINGSTON...EAST
CENTRAL IBERVILLE...SOUTHWESTERN TANGIPAHOA AND SOUTHEASTERN EAST
BATON ROUGE PARISHES...

At 459 PM CDT, severe thunderstorms were located along a line
extending from Greensburg to near Albany, moving northeast at 70 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Hammond, Gonzales, Amite, St. Gabriel, Walker, Amite City, White
Castle, Livingston, Independence, Sorrento, Roseland, French
Settlement, Albany, Port Vincent, Springfield, Montpelier, Geismar,
Prairieville, Natalbany and Carville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 900 PM CDT for southeastern
Louisiana.

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

&&

LAT...LON 3044 9088 3071 9087 3078 9047 3033 9046
      3034 9047 3034 9049 3030 9054 3030 9056
      3025 9059 3014 9115 3027 9113
TIME...MOT...LOC 2159Z 235DEG 60KT 3083 9067 3056 9064 

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

KLG

748 
WWUS54 KLIX 172218
SVSLIX

Severe Weather Statement
National Weather Service New Orleans LA
518 PM CDT Wed Mar 17 2021

LAC005-033-047-063-091-105-172228-
/O.CAN.KLIX.SV.W.0004.000000T0000Z-210317T2230Z/
Ascension LA-St. Helena LA-Livingston LA-Iberville LA-Tangipahoa LA-
East Baton Rouge LA-
518 PM CDT Wed Mar 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN ASCENSION...SOUTHERN
ST. HELENA...LIVINGSTON...EAST CENTRAL IBERVILLE...SOUTHWESTERN
TANGIPAHOA AND EASTERN EAST BATON ROUGE PARISHES IS CANCELLED...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning has been cancelled.  However gusty winds are
still possible with these thunderstorms.

A Tornado Watch remains in effect until 900 PM CDT for southeastern
Louisiana.

LAT...LON 3044 9088 3071 9087 3078 9047 3033 9046
      3034 9047 3034 9049 3030 9054 3030 9056
      3025 9059 3014 9115 3027 9113
TIME...MOT...LOC 2217Z 236DEG 62KT 3101 9036 3074 9033 

$$

KLG

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 17, 3:33 AM CDT	Wind Advisory	LIX	Assumption, East Baton Rouge, Iberville, Saint Bernard, Saint James, Saint John the Baptist and 1 more	18 hr
Mar 17, 3:18 PM CDT	Special Weather Statement	LIX	Pointe Coupee, West Feliciana	42 min
Mar 17, 3:30 PM CDT	Tornado Warning	LIX	Pointe Coupee, West Feliciana	45 min
Mar 17, 4:05 PM CDT	Severe Thunderstorm Warning	LIX	Ascension, Assumption, East Baton Rouge, Iberville, Livingston, Saint James and 1 more	40 min
Mar 17, 4:50 PM CDT	Special Weather Statement	LIX	East Feliciana, Saint Helena	55 min
Mar 17, 5:06 PM CDT	Special Weather Statement	LIX	Ascension, Iberville	39 min
Mar 17, 5:11 PM CDT	Special Weather Statement	LIX	Ascension, Livingston, Tangipahoa	49 min
Mar 17, 5:29 PM CDT	Special Weather Statement	LIX	Washington	46 min
Mar 17, 5:40 PM CDT	Severe Thunderstorm Warning	LIX	Washington	31 min
Mar 17, 5:59 PM CDT	Areal Flood Advisory	LIX	Ascension, Assumption, East Baton Rouge, Iberville, Livingston, Saint James and 2 more	3 hr
Mar 17, 6:05 PM CDT	Special Weather Statement	LIX	Livingston, Saint John the Baptist, Tangipahoa	55 min
Mar 17, 6:07 PM CDT	Special Marine Warning	LIX		53 min
Mar 17, 6:24 PM CDT	Areal Flood Advisory	LIX	Livingston, Saint John the Baptist, Saint Tammany, Tangipahoa	3 hr
Mar 17, 6:27 PM CDT	Severe Thunderstorm Warning	LIX	Ascension, Assumption, Iberville, Lafourche, Saint James, Terrebonne	63 min
Mar 17, 6:54 PM CDT	Special Weather Statement	LIX	Saint Tammany	66 min
Mar 17, 6:58 PM CDT	Special Marine Warning	LIX		62 min

Nearby

Severe Thunderstorm Warnings in Louisiana, 2021 Every 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.