Alert archive / Mississippi / Mesoscale Discussions in 2005

Mesoscale Discussion 469

March 31, 200514 parishes in Louisiana; 24 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Mar 31, 2005, 8:59 PM CST for 14 parishes in Louisiana; 24 counties in Mississippi. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued
Mar 31, 2005, 8:59 PM CST (02:59 UTC)
Expired
Mar 31, 2005, 10:00 PM CST
In force
61 min
Issued by
the Storm Prediction Center
All 38 counties

Ascension Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberville Parish, LA, Livingston Parish, LA, Pointe Coupee Parish, LA, Saint Helena Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Stone County, MS, Walthall County, MS, Wayne County, MS, Wilkinson 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

Slidell Radar S, LA (KSIL), launched 00:00Z, 3.0 hours before the alert went out and 129 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, Slidell Radar S, LA at 00:00Z on 2005-04-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1854 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, Slidell Radar S, LA at 00:00Z on 2005-04-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 101 square meters per square second.193958Sfc1 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
1854 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
456 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
101 m²/s²
0-3 km storm-relative helicity
173 m²/s²
Significant tornado parameter
1.7
Supercell composite
7.1

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 31, 6:49 PM CSTMesoscale DiscussionSPCAcadia, Allen, Beauregard, Bienville, Bossier, Caddo and 16 more56 min
Mar 31, 7:05 PM CSTSevere Thunderstorm WatchSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 17 more5 hr
Mar 31, 8:25 PM CSTMesoscale DiscussionSPCAcadia, Calcasieu, Cameron, Jefferson Davis, Vermilion65 min
Mar 31, 8:45 PM CSTSevere Thunderstorm WatchSPCAcadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 4 more7 hr
Mar 31, 9:27 PM CSTMesoscale DiscussionSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 15 more63 min
Mar 31, 10:53 PM CSTMesoscale DiscussionSPCAvoyelles, Bienville, Bossier, Caddo, Caldwell, Catahoula and 29 more67 min
Mar 31, 11:15 PM CSTTornado WatchSPCAvoyelles, Bienville, Caldwell, Catahoula, Claiborne, Concordia and 27 more8 hr
Apr 1, 12:25 AM CSTMesoscale DiscussionSPCAcadia, Allen, Beauregard, Calcasieu, Cameron, Jefferson Davis and 3 more95 min
Apr 1, 1:29 AM CSTMesoscale DiscussionSPCJefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Tammany2 hr
Apr 1, 2:05 AM CSTTornado WatchSPCOrleans, Saint Bernard, Saint Tammany, Washington5 hr
Apr 1, 4:14 AM CSTMesoscale DiscussionSPCSaint Helena, Tangipahoa, Washington2 hr
Apr 1, 11:16 AM CSTMesoscale DiscussionSPCAlcorn, Benton, Itawamba, Lee, Pontotoc, Prentiss and 3 more2 hr
Apr 1, 11:20 AM CSTMesoscale DiscussionSPCClarke, Jasper, Jones, Kemper, Lauderdale, Lowndes and 9 more115 min
Apr 1, 11:45 AM CSTSevere Thunderstorm WatchSPCAlcorn, Chickasaw, Clay, Itawamba, Kemper, Lauderdale and 10 more6 hr
Apr 1, 3:19 PM CSTMesoscale DiscussionSPCGeorge, Greene, Perry, Stone, Wayne116 min

Nearby

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