Alert archive / Louisiana / Mesoscale Discussions in 2015

Mesoscale Discussion 610

May 11, 20159 parishes in Louisiana; 9 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at May 11, 2015, 1:44 PM CDT for 9 parishes in Louisiana; 9 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 11, 2015, 1:44 PM CDT (18:44 UTC)
Expired: May 11, 2015, 3:45 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Ascension Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberville Parish, LA, Livingston Parish, LA, Saint Helena Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, Amite County, MS, Covington County, MS, Jefferson Davis County, MS, Lamar County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Pike County, MS, Walthall County, MS

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 6.7 hours before the alert went out and 97 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: 1277 J/kg
Mixed-layer CIN: -50 J/kg
Mixed-layer LCL: 695 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: -2 m²/s²
0-3 km storm-relative helicity: 61 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.2

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
May 10, 7:08 PM CDT	Mesoscale Discussion	SPC	Bossier, Caddo	97 min
May 10, 9:57 PM CDT	Mesoscale Discussion	SPC	Bossier, Caddo	93 min
May 10, 11:31 PM CDT	Tornado Watch	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Lincoln and 3 more	5 hr
May 11, 2:55 AM CDT	Mesoscale Discussion	SPC	Sabine	95 min
May 11, 12:30 PM CDT	Mesoscale Discussion	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 18 more	2 hr

Nearby

Mesoscale Discussions in Louisiana, 2015 Mesoscale Discussions in Mississippi, 2015 Every mesoscale discussion in 2015

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.