Alert archive / Mississippi / Mesoscale Discussions in 2013

Mesoscale Discussion 356

March 31, 20137 parishes in Louisiana; 9 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Mar 31, 2013, 3:21 PM CDT for 7 parishes in Louisiana; 9 counties in Mississippi. It was in force for 54 min.

The area

The outline as issued.

The facts

Issued: Mar 31, 2013, 3:21 PM CDT (20:21 UTC)
Expired: Mar 31, 2013, 4:15 PM CDT
In force: 54 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

Counties Jefferson Parish, LA, Orleans Parish, LA, Saint Charles Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, Washington Parish, LA, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Lamar County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 8.4 hours before the alert went out and 26 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 321 J/kg
Mixed-layer CIN: -49 J/kg
Mixed-layer LCL: 513 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 74 m²/s²
0-3 km storm-relative helicity: 56 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

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.

Issued	Product	Office	Counties	Lasted
Mar 31, 7:36 AM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Lincoln and 3 more	114 min
Mar 31, 9:20 AM CDT	Severe Thunderstorm Watch	SPC	Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 11 more	5 hr
Mar 31, 10:33 AM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 5 more	57 min
Mar 31, 11:54 AM CDT	Mesoscale Discussion	SPC	Allen, Avoyelles, Beauregard, Caldwell, Catahoula, Concordia and 20 more	36 min
Mar 31, 12:17 PM CDT	Severe Thunderstorm Watch	SPC	Acadia, Allen, Ascension, Avoyelles, Beauregard, Calcasieu and 32 more	6 hr
Mar 31, 2:32 PM CDT	Mesoscale Discussion	SPC	Allen, Avoyelles, Beauregard, Calcasieu, Caldwell, Catahoula and 21 more	58 min
Mar 31, 2:48 PM CDT	Severe Thunderstorm Watch	SPC	Cameron, Iberia, Saint Martin, St. Mary, Vermilion	5 hr
Mar 31, 3:38 PM CDT	Severe Thunderstorm Watch	SPC	Assumption, Jefferson, Lafourche, Orleans, Plaquemines, Saint Bernard and 5 more	3 hr

Nearby

Mesoscale Discussions in Mississippi, 2013 Mesoscale Discussions in Louisiana, 2013 Every mesoscale discussion in 2013

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.