Alert archive / Louisiana / Mesoscale Discussions in 2004

Mesoscale Discussion 329

April 11, 200413 parishes in Louisiana; Hancock County, Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 11, 2004, 3:13 AM CDT for 13 parishes in Louisiana; Hancock County, Mississippi. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
Apr 11, 2004, 3:13 AM CDT (08:13 UTC)
Expired
Apr 11, 2004, 4:45 AM CDT
In force
92 min
Issued by
the Storm Prediction Center

Counties Ascension Parish, LA, Assumption Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Terrebonne Parish, LA, Hancock County, MS

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 8.2 hours before the alert went out and 62 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 2004-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 779 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 2004-04-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 83 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
779 J/kg
Mixed-layer CIN
-79 J/kg
Mixed-layer LCL
1044 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
83 m²/s²
0-3 km storm-relative helicity
165 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.0

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 10, 7:19 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caldwell, Claiborne, De Soto, Franklin and 12 more86 min
Apr 11, 10:14 AM CDTMesoscale DiscussionSPCAcadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 3 more4 hr
Apr 11, 1:45 PM CDTMesoscale DiscussionSPCAcadia, Calcasieu, Cameron, Iberia, Jefferson Davis, Lafayette and 2 more3 hr

Nearby

Mesoscale Discussions in Louisiana, 2004Mesoscale Discussions in Mississippi, 2004Every 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.