Alert archive / Louisiana / Mesoscale Discussions in 2003

Mesoscale Discussion 1555

June 30, 200316 parishes in Louisiana; 7 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jun 30, 2003, 4:46 AM CDT for 16 parishes in Louisiana; 7 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jun 30, 2003, 4:46 AM CDT (09:46 UTC)
Expired: Jun 30, 2003, 7:15 AM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 23 counties

Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, Jefferson Parish, LA, Lafourche Parish, LA, Livingston 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, Tangipahoa Parish, LA, Terrebonne Parish, LA, Washington Parish, LA, George County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS

The watches that followed

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

Tornado Watch 606Jun 30, 6:55 AM CDT

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 9.8 hours before the alert went out and 33 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: 122 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 700 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -90 m²/s²
0-3 km storm-relative helicity: -48 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.

Issued	Product	Office	Counties	Lasted
Jun 30, 6:55 AM CDT	Tornado Watch	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 17 more	9 hr
Jun 30, 11:23 AM CDT	Mesoscale Discussion	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 17 more	2 hr
Jun 30, 3:13 PM CDT	Mesoscale Discussion	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 17 more	92 min
Jun 30, 3:35 PM CDT	Tornado Watch	SPC	Jefferson, Lafourche, Orleans, Saint Bernard, Saint Charles, Saint John the Baptist and 3 more	6 hr

Nearby

Mesoscale Discussions in Louisiana, 2003 Mesoscale Discussions in Mississippi, 2003 Every mesoscale discussion in 2003

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.