Alert archive / Louisiana / Mesoscale Discussions in 2003

Mesoscale Discussion 559

April 24, 200316 parishes in Louisiana; Adams County, Mississippi; Sabine County, San Augustine County, Shelby County, Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2003, 11:40 AM CDT for 16 parishes in Louisiana; Adams County, Mississippi; Sabine County, San Augustine County, Shelby County, Texas. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Apr 24, 2003, 11:40 AM CDT (16:40 UTC)
Expired
Apr 24, 2003, 12:45 PM CDT
In force
65 min
Issued by
the Storm Prediction Center

Counties Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, De Soto Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Red River Parish, LA, Sabine Parish, LA, Webster Parish, LA, Winn Parish, LA, Adams County, MS, Sabine County, TX, San Augustine County, TX, Shelby 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

Shreveport, LA (KSHV), launched 12:00Z, 4.7 hours before the alert went out and 89 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, Shreveport, LA at 12:00Z on 2003-04-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1853 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, Shreveport, LA at 12:00Z on 2003-04-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 320 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
1853 J/kg
Mixed-layer CIN
-92 J/kg
Mixed-layer LCL
617 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
320 m²/s²
0-3 km storm-relative helicity
348 m²/s²
Significant tornado parameter
1.8
Supercell composite
10.4

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
Apr 23, 11:43 PM CDTMesoscale DiscussionSPCBossier, Caddo, De Soto2 hr
Apr 24, 2:41 AM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Claiborne, De Soto, Webster2 hr
Apr 24, 6:30 AM CDTSevere Thunderstorm WatchSPCAvoyelles, Beauregard, Bienville, Caldwell, Catahoula, Concordia and 17 more5 hr
Apr 24, 6:40 AM CDTSevere Thunderstorm WatchSPCAvoyelles, Beauregard, Bienville, Caldwell, Catahoula, Concordia and 17 more4 hr
Apr 24, 9:39 AM CDTMesoscale DiscussionSPCCaldwell, Catahoula, Concordia, Grant, LaSalle, Tensas and 1 more2 hr
Apr 24, 1:00 PM CDTTornado WatchSPCBossier, Caddo, Claiborne, Webster7 hr
Apr 24, 2:05 PM CDTTornado WatchSPCBienville, Caldwell, Catahoula, Concordia, East Carroll, Franklin and 14 more6 hr
Apr 24, 2:46 PM CDTMesoscale DiscussionSPCEast Carroll, Madison, Tensas, West Carroll119 min
Apr 24, 5:17 PM CDTMesoscale DiscussionSPCOrleans, Saint Tammany, Washington118 min
Apr 24, 6:49 PM CDTMesoscale DiscussionSPCCatahoula, Concordia, East Carroll, Franklin, Madison, Richland and 2 more56 min
Apr 24, 5:52 PM CDTMesoscale DiscussionSPCCoahoma, DeSoto, Quitman, Tate, Tunica113 min
Apr 24, 6:35 PM CDTTornado WatchSPCBolivar, Coahoma, DeSoto, Panola, Quitman, Tallahatchie and 1 more5 hr
Apr 23, 7:00 PM CDTMesoscale DiscussionSPCCrockett, Edwards, Kimble, Kinney, Mason, Menard and 5 more90 min
Apr 23, 7:03 PM CDTMesoscale DiscussionSPCBosque, Collin, Comanche, Cooke, Coryell, Dallas and 25 more117 min
Apr 23, 7:45 PM CDTTornado WatchSPCBandera, Bexar, Blanco, Burnet, Caldwell, Comal and 11 more4 hr
Apr 23, 8:43 PM CDTMesoscale DiscussionSPCArcher, Baylor, Brown, Callahan, Clay, Coleman and 15 more77 min
Apr 23, 9:35 PM CDTSevere Thunderstorm WatchSPCCollin, Cooke, Dallas, Delta, Denton, Ellis and 20 more5 hr
Apr 24, 7:14 AM CDTMesoscale DiscussionSPCAustin, Bastrop, Brazoria, Brazos, Burleson, Caldwell and 22 more2 hr
Apr 24, 7:30 AM CDTTornado WatchSPCAngelina, Austin, Brazoria, Brazos, Burleson, Chambers and 17 more6 hr
Apr 24, 9:11 AM CDTMesoscale DiscussionSPCFort Bend, Harris, Liberty, Montgomery, Polk, San Jacinto2 hr

Nearby

Mesoscale Discussions in Louisiana, 2003Mesoscale Discussions in Texas, 2003Mesoscale Discussions in Mississippi, 2003Every mesoscale discussion in 2003

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.