Alert archive / Louisiana / Severe Thunderstorm Watches in 2006

Severe Thunderstorm Watch 232

April 21, 200636 parishes in Louisiana; 33 counties in Mississippi

The Storm Prediction Center issued this severe thunderstorm watch at Apr 21, 2006, 10:16 AM CDT for 36 parishes in Louisiana; 33 counties in Mississippi. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 21, 2006, 10:16 AM CDT (15:16 UTC)
Expired
Apr 21, 2006, 4:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 69 counties

Acadia Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Madison Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Pointe Coupee Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Tensas Parish, LA, Terrebonne Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Clarke County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, Hancock County, MS, Hinds County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Madison County, MS, Marion County, MS, Neshoba County, MS, Newton County, MS, Pearl River County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS, Warren County, MS, Wilkinson County, MS

Warnings issued inside it

9 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Apr 21, 12:40 PM CDTSevere Thunderstorm WarningLIXSaint Tammany, Tangipahoa50 min
Apr 21, 12:49 PM CDTSevere Thunderstorm WarningJANMadison41 min
Apr 21, 1:15 PM CDTTornado WarningLIXSaint Tammany18 min
Apr 21, 1:23 PM CDTSevere Thunderstorm WarningJANRankin67 min
Apr 21, 1:31 PM CDTSevere Thunderstorm WarningJANMadison44 min
Apr 21, 2:12 PM CDTSevere Thunderstorm WarningJANScott35 min
Apr 21, 2:13 PM CDTSevere Thunderstorm WarningJANLincoln33 min
Apr 21, 2:25 PM CDTSevere Thunderstorm WarningJANForrest, Lamar50 min
Apr 21, 3:53 PM CDTSevere Thunderstorm WarningJANJasper, Smith37 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 3.3 hours before the alert went out and 155 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 2006-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1172 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 2006-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 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
1172 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
699 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
55 m²/s²
Significant tornado parameter
0.3
Supercell composite
1.7

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 20, 10:00 PM CDTSevere Thunderstorm WatchSPCBossier, Caddo, Claiborne, De Soto, Union, Webster7 hr
Apr 20, 11:26 PM CDTMesoscale DiscussionSPCBeauregard, Bienville, Caldwell, De Soto, Franklin, Grant and 10 more94 min
Apr 21, 2:15 AM CDTMesoscale DiscussionSPCLincoln, Union2 hr
Apr 21, 9:51 AM CDTMesoscale DiscussionSPCAcadia, Ascension, Assumption, Avoyelles, Concordia, East Baton Rouge and 23 more84 min
Apr 21, 12:52 PM CDTMesoscale DiscussionSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 5 more83 min
Apr 20, 7:35 PM CDTMesoscale DiscussionSPCAttala, Bolivar, Calhoun, Carroll, Chickasaw, Choctaw and 26 more85 min
Apr 20, 9:31 PM CDTMesoscale DiscussionSPCAlcorn, Benton, Coahoma, DeSoto, Lafayette, Marshall and 5 more89 min
Apr 21, 12:04 AM CDTMesoscale DiscussionSPCAlcorn, Benton, Itawamba, Lafayette, Lee, Marshall and 8 more116 min
Apr 21, 5:00 AM CDTMesoscale DiscussionSPCAlcorn, Benton, Calhoun, Chickasaw, DeSoto, Itawamba and 12 more60 min
Apr 21, 1:24 PM CDTSevere Thunderstorm WatchSPCClay, George, Greene, Harrison, Jackson, Lowndes and 6 more8 hr

Nearby

Severe Thunderstorm Watches in Louisiana, 2006Severe Thunderstorm Watches in Mississippi, 2006Every severe thunderstorm watch in 2006

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.