Alert archive / Louisiana / Mesoscale Discussions in 2005

Mesoscale Discussion 499

April 6, 200542 parishes in Louisiana; 42 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 6, 2005, 5:45 AM CDT for 42 parishes in Louisiana; 42 counties in Mississippi. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued
Apr 6, 2005, 5:45 AM CDT (10:45 UTC)
Expired
Apr 6, 2005, 7:15 AM CDT
In force
90 min
Issued by
the Storm Prediction Center
All 84 counties

Acadia Parish, LA, Allen Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Calcasieu Parish, LA, Cameron 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 Davis Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, LaSalle Parish, LA, Livingston Parish, LA, Madison Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Pointe Coupee Parish, LA, Rapides 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, Attala County, MS, Carroll County, MS, Choctaw County, MS, Claiborne County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, Hancock County, MS, Harrison County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Madison County, MS, Marion County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Stone County, MS, Walthall County, MS, Warren County, MS, Wilkinson County, MS, Yazoo County, MS

The watches that followed

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

The nearest sounding before it

Jackson, MS (KJAN), launched 00:00Z, 10.8 hours before the alert went out and 110 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, Jackson, MS at 00:00Z on 2005-04-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Jackson, MS at 00:00Z on 2005-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1739 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
82 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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 5, 8:25 PM CDTSevere Thunderstorm WatchSPCBossier, Caddo8 hr
Apr 5, 10:40 PM CDTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 50 more2 hr
Apr 6, 2:55 AM CDTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Calcasieu and 36 more7 hr
Apr 6, 7:00 AM CDTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Cameron and 27 more6 hr
Apr 6, 7:46 AM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Caldwell, Catahoula, Claiborne and 20 more119 min
Apr 6, 9:29 AM CDTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Cameron and 27 more2 hr
Apr 6, 10:40 AM CDTMesoscale DiscussionSPCCaldwell, Catahoula, East Carroll, Franklin, Grant, Jackson and 11 more65 min
Apr 6, 11:05 AM CDTTornado WatchSPCAscension, Assumption, Concordia, East Baton Rouge, East Carroll, East Feliciana and 22 more8 hr
Apr 6, 1:21 PM CDTMesoscale DiscussionSPCAscension, Assumption, Concordia, East Baton Rouge, East Carroll, East Feliciana and 22 more84 min
Apr 6, 3:43 PM CDTMesoscale DiscussionSPCAscension, Assumption, Concordia, East Baton Rouge, East Carroll, East Feliciana and 22 more92 min
Apr 6, 6:01 PM CDTMesoscale DiscussionSPCOrleans, Saint Bernard, Saint Tammany, Washington59 min
Apr 6, 6:45 PM CDTTornado WatchSPCWashington6 hr
Apr 6, 11:05 AM CDTTornado WatchSPCGeorge, Greene, Harrison, Jackson, Wayne8 hr
Apr 6, 1:55 PM CDTTornado WatchSPCBenton, Calhoun, Chickasaw, Coahoma, DeSoto, Lafayette and 12 more7 hr
Apr 6, 3:18 PM CDTMesoscale DiscussionSPCBenton, Calhoun, Chickasaw, Coahoma, DeSoto, Lafayette and 12 more87 min
Apr 6, 4:53 PM CDTMesoscale DiscussionSPCAlcorn, Tishomingo37 min
Apr 6, 5:44 PM CDTMesoscale DiscussionSPCBenton, Calhoun, Chickasaw, Coahoma, DeSoto, Lafayette and 12 more91 min

Nearby

Mesoscale Discussions in Louisiana, 2005Mesoscale Discussions in Mississippi, 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.