Alert archive / Louisiana / Mesoscale Discussions in 2017

Mesoscale Discussion 400

April 2, 201711 parishes in Louisiana

The Storm Prediction Center issued this mesoscale discussion at Apr 2, 2017, 9:05 AM CDT for 11 parishes in Louisiana. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued: Apr 2, 2017, 9:05 AM CDT (14:05 UTC)
Expired: Apr 2, 2017, 10:30 AM CDT
In force: 85 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Acadia Parish, LA, Ascension Parish, LA, East Baton Rouge Parish, LA, Iberville Parish, LA, Lafayette Parish, LA, Livingston Parish, LA, Pointe Coupee Parish, LA, Saint James Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, West Baton Rouge Parish, LA

The nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 2.1 hours before the alert went out and 158 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: 2197 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 489 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 243 m²/s²
0-3 km storm-relative helicity: 317 m²/s²
Significant tornado parameter: 3.3
Supercell composite: 19.3

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 2, 9:04 AM CDT	Mesoscale Discussion	SPC	Beauregard, Sabine, Vernon	2 hr
Apr 2, 10:39 AM CDT	Tornado Watch	SPC	Bienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 13 more	5 hr
Apr 2, 12:22 PM CDT	Mesoscale Discussion	SPC	Sabine	83 min
Apr 2, 12:49 PM CDT	Mesoscale Discussion	SPC	Avoyelles, Concordia, East Baton Rouge, East Carroll, East Feliciana, Franklin and 7 more	116 min
Apr 2, 1:34 PM CDT	Tornado Watch PDS	SPC	Acadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 28 more	7 hr
Apr 2, 2:06 PM CDT	Mesoscale Discussion	SPC	Grant, LaSalle, Natchitoches, Rapides, Sabine, Vernon and 1 more	54 min
Apr 2, 3:08 PM CDT	Mesoscale Discussion	SPC	Ascension, East Baton Rouge, East Feliciana, Livingston, Saint Charles, Saint Helena and 6 more	3 hr
Apr 2, 3:13 PM CDT	Mesoscale Discussion	SPC	Allen, Avoyelles, Beauregard, Caldwell, Catahoula, Concordia and 13 more	92 min
Apr 2, 4:52 PM CDT	Tornado Watch	SPC	Ascension, Concordia, East Baton Rouge, East Feliciana, Iberville, Livingston and 8 more	9 hr
Apr 2, 5:54 PM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Catahoula and 7 more	96 min

Nearby

Mesoscale Discussions in Louisiana, 2017 Every mesoscale discussion in 2017

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.