Alert archive / Louisiana / Mesoscale Discussions in 2014

Mesoscale Discussion 298

April 6, 20144 states

The Storm Prediction Center issued this mesoscale discussion at Apr 6, 2014, 6:24 PM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Apr 6, 2014, 6:24 PM CDT (23:24 UTC)
Expired: Apr 6, 2014, 8:30 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 80%

All 47 counties

Baldwin County, AL, Escambia County, AL, Mobile County, AL, Washington County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Pointe Coupee Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Amite County, MS, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Lamar County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Stone County, MS, Walthall County, MS, Wilkinson County, MS

The radar

The Mobile radar (KMOB), 88 km from the middle of the area, began a volume at 23:28 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Tornado Watch 65Apr 6, 6:55 PM CDT

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 11.4 hours before the alert went out and 61 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: 553 J/kg
Mixed-layer CIN: -46 J/kg
Mixed-layer LCL: 450 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 231 m²/s²
0-3 km storm-relative helicity: 331 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 6.4

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
Apr 6, 6:56 PM CDT	Tornado Watch	SPC	Baldwin, Butler, Choctaw, Clarke, Conecuh, Covington and 6 more	8 hr
Apr 6, 6:26 AM CDT	Severe Thunderstorm Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 23 more	12 hr
Apr 6, 9:39 AM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 17 more	66 min
Apr 6, 1:31 PM CDT	Mesoscale Discussion	SPC	Acadia, Allen, Avoyelles, Beauregard, Bienville, Bossier and 15 more	59 min
Apr 6, 3:27 PM CDT	Tornado Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Cameron and 10 more	14 hr

Nearby

Mesoscale Discussions in Louisiana, 2014 Mesoscale Discussions in Mississippi, 2014 Mesoscale Discussions in Alabama, 2014 Every mesoscale discussion in 2014

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.