Alert archive / Louisiana / Mesoscale Discussions in 2003

Mesoscale Discussion 2391

September 21, 200321 parishes in Louisiana; Adams County, Wilkinson County, Mississippi

The Storm Prediction Center issued this mesoscale discussion at Sep 21, 2003, 2:26 PM CDT for 21 parishes in Louisiana; Adams County, Wilkinson County, Mississippi. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: Sep 21, 2003, 2:26 PM CDT (19:26 UTC)
Expired: Sep 21, 2003, 4:00 PM CDT
In force: 94 min
Issued by: the Storm Prediction Center

All 23 counties

Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Vermilion Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Wilkinson County, MS

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 7.4 hours before the alert went out and 79 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: 275 J/kg
Mixed-layer CIN: -20 J/kg
Mixed-layer LCL: 803 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 120 m²/s²
0-3 km storm-relative helicity: 151 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.1

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.

Issued	Product	Office	Counties	Lasted
Sep 21, 5:57 PM CDT	Mesoscale Discussion	SPC	Clay, Lowndes, Monroe, Noxubee, Oktibbeha	2 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.