Alert archive / Louisiana / Mesoscale Discussions in 2007

Mesoscale Discussion 138

February 12, 200716 parishes in Louisiana; 4 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 12, 2007, 6:27 PM CST for 16 parishes in Louisiana; 4 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Feb 12, 2007, 6:27 PM CST (00:27 UTC)
Expired: Feb 12, 2007, 8:30 PM CST
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, Rapides Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, Galveston County, TX, Jefferson County, TX, Newton County, TX, Orange County, TX

The radar

The Lake Charles radar (KLCH), 44 km from the middle of the area, began a volume at 00:28 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 00:00Z, 0.5 hours before the alert went out and 42 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: 276 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 585 m above ground
0-6 km bulk shear: 61 kt
0-1 km storm-relative helicity: 258 m²/s²
0-3 km storm-relative helicity: 297 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 2.4

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
Feb 12, 9:38 PM CST	Mesoscale Discussion	SPC	Acadia, Allen, Assumption, Avoyelles, Beauregard, Calcasieu and 16 more	97 min
Feb 12, 10:39 PM CST	Tornado Watch	SPC	Acadia, Allen, Ascension, Assumption, Avoyelles, Calcasieu and 30 more	7 hr
Feb 13, 2:26 AM CST	Mesoscale Discussion	SPC	Ascension, Assumption, Lafourche, Livingston, Orleans, Saint Charles and 5 more	64 min
Feb 13, 5:26 AM CST	Mesoscale Discussion	SPC	Orleans, Saint Bernard	94 min

Nearby

Mesoscale Discussions in Louisiana, 2007 Mesoscale Discussions in Texas, 2007 Every mesoscale discussion in 2007

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; radar from the NEXRAD Level II archive.