Alert archive / Louisiana / Mesoscale Discussions in 2004

Mesoscale Discussion 691

May 13, 200435 parishes in Louisiana; Adams County, Wilkinson County, Mississippi

The Storm Prediction Center issued this mesoscale discussion at May 13, 2004, 3:54 PM CDT for 35 parishes in Louisiana; Adams County, Wilkinson County, Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 13, 2004, 3:54 PM CDT (20:54 UTC)
Expired: May 13, 2004, 6:00 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 37 counties

Acadia Parish, LA, Allen Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Bienville Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jackson Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Union Parish, LA, Vermilion Parish, LA, Webster Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Winn Parish, LA, Adams County, MS, Wilkinson County, MS

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 8.9 hours before the alert went out and 123 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: 1515 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 727 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 70 m²/s²
0-3 km storm-relative helicity: 111 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.7

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
May 12, 8:03 PM CDT	Mesoscale Discussion	SPC	Jefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 1 more	57 min
May 13, 12:10 PM CDT	Tornado Watch	SPC	Allen, Beauregard, Calcasieu	6 hr
May 13, 1:38 PM CDT	Mesoscale Discussion	SPC	Beauregard, Calcasieu, Sabine	97 min
May 13, 2:55 PM CDT	Tornado Watch	SPC	Acadia, Allen, Assumption, Avoyelles, Bienville, Bossier and 31 more	6 hr
May 13, 5:22 PM CDT	Mesoscale Discussion	SPC	Calcasieu	53 min
May 13, 6:23 PM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Assumption, Avoyelles, Bienville, Caldwell and 30 more	97 min

Nearby

Mesoscale Discussions in Louisiana, 2004 Mesoscale Discussions in Mississippi, 2004 Every mesoscale discussion in 2004

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.