Alert archive / Louisiana / Mesoscale Discussions in 2009

Mesoscale Discussion 282

March 26, 200922 parishes in Louisiana; 12 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 26, 2009, 6:56 PM CDT for 22 parishes in Louisiana; 12 counties in Texas. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
Mar 26, 2009, 6:56 PM CDT (23:56 UTC)
Expired
Mar 26, 2009, 8:30 PM CDT
In force
94 min
Issued by
the Storm Prediction Center
All 34 counties

Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Cameron Parish, LA, Evangeline Parish, LA, Grant Parish, LA, Iberia Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Rapides Parish, LA, Sabine Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, Winn Parish, LA, Angelina County, TX, Cherokee County, TX, Hardin County, TX, Jasper County, TX, Jefferson County, TX, Nacogdoches County, TX, Newton County, TX, Orange County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Tyler County, TX

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 11.9 hours before the alert went out and 84 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, Lake Charles Mun, LA at 12:00Z on 2009-03-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 605 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, Lake Charles Mun, LA at 12:00Z on 2009-03-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 136 square meters per square second.1939587897117Sfc1 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
605 J/kg
Mixed-layer CIN
-109 J/kg
Mixed-layer LCL
734 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
136 m²/s²
0-3 km storm-relative helicity
195 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 25, 8:32 PM CDTMesoscale DiscussionSPCAllen, Avoyelles, Beauregard, Caldwell, Catahoula, Concordia and 15 more88 min
Mar 25, 8:54 PM CDTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 32 more7 hr
Mar 25, 11:38 PM CDTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Lafayette and 15 more97 min
Mar 26, 1:25 AM CDTMesoscale DiscussionSPCJefferson, Lafourche, Orleans, Saint Bernard, Saint Charles35 min
Mar 26, 1:36 AM CDTTornado WatchSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 1 more9 hr
Mar 26, 3:40 AM CDTMesoscale DiscussionSPCOrleans, Saint Bernard95 min
Mar 26, 3:06 PM CDTMesoscale DiscussionSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 8 more54 min
Mar 26, 3:57 PM CDTTornado WatchSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 16 more7 hr
Mar 26, 5:36 PM CDTMesoscale DiscussionSPCAscension, Assumption, Avoyelles, Catahoula, Concordia, East Baton Rouge and 26 more54 min
Mar 26, 5:56 PM CDTTornado WatchSPCAscension, Assumption, Catahoula, Concordia, East Baton Rouge, East Feliciana and 20 more7 hr
Mar 25, 7:12 PM CDTTornado WatchSPCAustin, Brazoria, Chambers, Colorado, Fort Bend, Galveston and 9 more6 hr
Mar 25, 7:31 PM CDTMesoscale DiscussionSPCAustin, Brazos, Burleson, Fayette, Grimes, Harris and 9 more59 min
Mar 26, 9:14 AM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bexar, Blanco, Caldwell, Comal and 16 more31 min
Mar 26, 9:39 AM CDTSevere Thunderstorm WatchSPCAtascosa, Bandera, Bastrop, Bexar, Blanco, Burnet and 25 more5 hr
Mar 26, 12:43 PM CDTMesoscale DiscussionSPCAransas, Atascosa, Bee, Brazoria, Calhoun, DeWitt and 11 more62 min
Mar 26, 12:57 PM CDTSevere Thunderstorm WatchSPCAransas, Bee, Brazoria, Calhoun, Chambers, Duval and 17 more6 hr
Mar 26, 3:51 PM CDTMesoscale DiscussionSPCAransas, Brazoria, Calhoun, Chambers, Fort Bend, Galveston and 8 more54 min
Mar 26, 4:52 PM CDTMesoscale DiscussionSPCArcher, Clay, Comanche, Eastland, Erath, Hamilton and 9 more83 min
Mar 26, 6:32 PM CDTMesoscale DiscussionSPCDallam4 hr

Nearby

Mesoscale Discussions in Louisiana, 2009Mesoscale Discussions in Texas, 2009Every mesoscale discussion in 2009

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.