Alert archive / Mississippi / Mesoscale Discussions in 2017

Mesoscale Discussion 412

April 2, 201714 parishes in Louisiana; 39 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 2, 2017, 9:09 PM CDT for 14 parishes in Louisiana; 39 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Apr 2, 2017, 9:09 PM CDT (02:09 UTC)
Expired: Apr 2, 2017, 11:15 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 53 counties

Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Livingston Parish, LA, Madison Parish, LA, Pointe Coupee Parish, LA, Saint Helena Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Tensas Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Attala County, MS, Claiborne County, MS, Clarke County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, Hinds County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Lincoln County, MS, Madison County, MS, Marion County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Stone County, MS, Walthall County, MS, Warren County, MS, Wayne County, MS, Wilkinson County, MS, Winston County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 72 km from the middle of the area, began a volume at 02:09 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

Slidell Radar S, LA (KSIL), launched 00:00Z, 2.2 hours before the alert went out and 160 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: 2436 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 480 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 298 m²/s²
0-3 km storm-relative helicity: 333 m²/s²
Significant tornado parameter: 4.6
Supercell composite: 19.5

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, 8:07 PM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 8 more	83 min
Apr 2, 8:24 PM CDT	Tornado Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 10 more	6 hr
Apr 2, 11:37 PM CDT	Mesoscale Discussion	SPC	Acadia, Ascension, Assumption, Avoyelles, East Baton Rouge, East Feliciana and 18 more	83 min
Apr 3, 1:48 AM CDT	Tornado Watch	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Jefferson, Lafourche and 12 more	10 hr
Apr 3, 3:59 AM CDT	Mesoscale Discussion	SPC	Jefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 6 more	2 hr
Apr 3, 6:43 AM CDT	Mesoscale Discussion	SPC	Plaquemines, Saint Bernard	2 hr

Nearby

Mesoscale Discussions in Mississippi, 2017 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; radar from the NEXRAD Level II archive.