Alert archive / Texas / Mesoscale Discussions in 2005

Mesoscale Discussion 553

April 11, 20055 counties in Arkansas; 18 parishes in Louisiana; 32 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 11, 2005, 6:53 AM CDT for 5 counties in Arkansas; 18 parishes in Louisiana; 32 counties in Texas. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued
Apr 11, 2005, 6:53 AM CDT (11:53 UTC)
Expired
Apr 11, 2005, 8:00 AM CDT
In force
67 min
Issued by
the Storm Prediction Center
All 55 counties

Ashley County, AR, Columbia County, AR, Lafayette County, AR, Miller County, AR, Union County, AR, Beauregard Parish, LA, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Calcasieu Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Sabine Parish, LA, Union Parish, LA, Vernon Parish, LA, Webster Parish, LA, Winn Parish, LA, Angelina County, TX, Bowie County, TX, Cass County, TX, Chambers County, TX, Cherokee County, TX, Fort Bend County, TX, Gregg County, TX, Hardin County, TX, Harris County, TX, Harrison County, TX, Houston County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Marion County, TX, Montgomery County, TX, Morris 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, Upshur County, TX, Walker County, TX, Waller County, TX

The radar

The Shreveport radar (KSHV), 81 km from the middle of the area, began a volume at 11:54 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

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 00:00Z, 11.9 hours before the alert went out and 87 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 00:00Z on 2005-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 196 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 00:00Z on 2005-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 82 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
196 J/kg
Mixed-layer CIN
-151 J/kg
Mixed-layer LCL
1167 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
82 m²/s²
0-3 km storm-relative helicity
198 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

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
Apr 10, 8:53 PM CDTMesoscale DiscussionSPCBenton, Crawford, Sebastian, Washington2 hr
Apr 10, 9:15 PM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Clark, Crawford, Franklin, Howard and 10 more7 hr
Apr 11, 1:23 AM CDTMesoscale DiscussionSPCBenton, Carroll, Clark, Crawford, Franklin, Howard and 11 more67 min
Apr 11, 3:12 AM CDTMesoscale DiscussionSPCColumbia, Lafayette, Miller, Union63 min
Apr 11, 3:23 AM CDTMesoscale DiscussionSPCBenton, Carroll, Clark, Crawford, Franklin, Howard and 11 more67 min
Apr 11, 3:45 AM CDTSevere Thunderstorm WatchSPCAshley, Bradley, Columbia, Lafayette, Miller, Union7 hr
Apr 11, 6:17 AM CDTMesoscale DiscussionSPCArkansas, Clay, Cleburne, Conway, Craighead, Crittenden and 27 more118 min
Apr 11, 9:41 AM CDTMesoscale DiscussionSPCAshley, Bradley, Chicot, Columbia, Union2 hr
Apr 11, 10:15 AM CDTTornado WatchSPCAshley, Chicot, Desha, Drew9 hr
Apr 11, 12:12 PM CDTMesoscale DiscussionSPCAshley, Bradley, Chicot, Columbia, Union2 hr
Apr 11, 2:01 PM CDTMesoscale DiscussionSPCBenton, Carroll, Madison, Washington89 min
Apr 11, 3:56 AM CDTMesoscale DiscussionSPCFranklin, Madison, Tensas64 min
Apr 11, 1:41 PM CDTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Lafourche and 14 more2 hr
Apr 11, 2:05 PM CDTTornado WatchSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 14 more7 hr
Apr 11, 6:35 PM CDTTornado WatchSPCJefferson, Lafourche, Orleans, Saint Bernard, Saint Charles, Saint Tammany and 1 more4 hr
Apr 11, 6:52 PM CDTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Livingston and 9 more83 min
Apr 10, 7:39 PM CDTMesoscale DiscussionSPCBandera, Bastrop, Bell, Bexar, Blanco, Bosque and 45 more96 min
Apr 10, 10:45 PM CDTSevere Thunderstorm WatchSPCAnderson, Bastrop, Bell, Bexar, Blanco, Brazos and 39 more6 hr

Nearby

Mesoscale Discussions in Texas, 2005Mesoscale Discussions in Louisiana, 2005Mesoscale Discussions in Arkansas, 2005Every mesoscale discussion in 2005

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; radar from the NEXRAD Level II archive.