Alert archive / Louisiana / Mesoscale Discussions in 2008

Mesoscale Discussion 466

March 18, 200828 parishes in Louisiana; 22 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 18, 2008, 6:19 PM CDT for 28 parishes in Louisiana; 22 counties in Texas. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
Mar 18, 2008, 6:19 PM CDT (23:19 UTC)
Expired
Mar 18, 2008, 7:15 PM CDT
In force
56 min
Issued by
the Storm Prediction Center
All 50 counties

Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Evangeline Parish, LA, Grant Parish, LA, Jackson Parish, LA, Jefferson Davis Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Sabine Parish, LA, Saint Landry Parish, LA, Union Parish, LA, Vernon Parish, LA, Webster Parish, LA, Winn Parish, LA, Anderson County, TX, Angelina County, TX, Chambers County, TX, Cherokee County, TX, Hardin County, TX, Harrison County, TX, Houston County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Nacogdoches County, TX, Newton County, TX, Orange County, TX, Panola County, TX, Polk County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Trinity County, TX, Tyler County, TX

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 11.3 hours before the alert went out and 127 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 2008-03-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 650 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 2008-03-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 463 square meters per square second.1939587897Sfc1 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
650 J/kg
Mixed-layer CIN
-92 J/kg
Mixed-layer LCL
701 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
463 m²/s²
0-3 km storm-relative helicity
536 m²/s²
Significant tornado parameter
0.7
Supercell composite
7.8

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 18, 9:26 AM CDTMesoscale DiscussionSPCBossier, Caddo, Claiborne, Webster2 hr
Mar 18, 10:59 AM CDTTornado Watch PDSSPCBeauregard, Bienville, Bossier, Caddo, Caldwell, Claiborne and 14 more8 hr
Mar 18, 3:54 PM CDTMesoscale DiscussionSPCCaddo2 hr
Mar 18, 6:47 PM CDTTornado WatchSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 27 more9 hr
Mar 17, 7:09 PM CDTSevere Thunderstorm WatchSPCArcher, Baylor, Clay, Wichita, Wilbarger7 hr
Mar 17, 9:17 PM CDTMesoscale DiscussionSPCBandera, Blanco, Bosque, Brown, Burnet, Callahan and 53 more58 min
Mar 17, 10:21 PM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Wichita, Wilbarger54 min
Mar 17, 11:06 PM CDTMesoscale DiscussionSPCBandera, Blanco, Bosque, Brown, Burnet, Callahan and 53 more54 min
Mar 18, 1:13 AM CDTMesoscale DiscussionSPCArcher, Baylor, Clay, Foard, Haskell, Jack and 8 more62 min
Mar 18, 1:32 AM CDTMesoscale DiscussionSPCBrown, Callahan, Coke, Coleman, Concho, Crockett and 9 more58 min
Mar 18, 1:43 AM CDTMesoscale DiscussionSPCBrown, Callahan, Coke, Coleman, Concho, Crockett and 9 more32 min
Mar 18, 1:52 AM CDTTornado WatchSPCBandera, Blanco, Bosque, Brown, Burnet, Callahan and 34 more7 hr
Mar 18, 4:57 AM CDTMesoscale DiscussionSPCBandera, Blanco, Burnet, Coryell, Gillespie, Hamilton and 7 more93 min
Mar 18, 7:22 AM CDTMesoscale DiscussionSPCAnderson, Austin, Bastrop, Bell, Brazoria, Brazos and 40 more113 min
Mar 18, 7:50 AM CDTMesoscale DiscussionSPCBandera, Bosque, Brown, Burnet, Coleman, Comanche and 19 more55 min
Mar 18, 10:16 AM CDTTornado Watch PDSSPCBowie, Camp, Cass, Delta, Fannin, Franklin and 17 more7 hr
Mar 18, 12:10 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Delta, Fannin, Franklin and 13 more2 hr
Mar 18, 1:19 PM CDTMesoscale DiscussionSPCAnderson, Austin, Bastrop, Bell, Brazos, Burleson and 37 more116 min
Mar 18, 1:51 PM CDTMesoscale DiscussionSPCBowie, Camp, Collin, Dallas, Delta, Ellis and 15 more3 hr
Mar 18, 5:19 PM CDTTornado WatchSPCBowie, Camp, Cass, Franklin, Gregg, Harrison and 12 more11 hr

Nearby

Mesoscale Discussions in Louisiana, 2008Mesoscale Discussions in Texas, 2008Every mesoscale discussion in 2008

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.