Alert archive / Mississippi / Mesoscale Discussions in 2013

Mesoscale Discussion 443

April 11, 2013Saint Bernard Parish, Louisiana; 10 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 11, 2013, 12:53 PM CDT for Saint Bernard Parish, Louisiana; 10 counties in Mississippi. It was in force for 82 min.

The area

The outline as issued.

The facts

Issued: Apr 11, 2013, 12:53 PM CDT (17:53 UTC)
Expired: Apr 11, 2013, 2:15 PM CDT
In force: 82 min
Issued by: the Storm Prediction Center

Counties Saint Bernard Parish, LA, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Jones County, MS, Perry County, MS, Stone County, MS, Wayne County, MS

The radar

The Mobile radar (KMOB), 87 km from the middle of the area, began a volume at 17:55 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 98Apr 11, 1:30 PM CDT

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 5.9 hours before the alert went out and 70 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: 1207 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 495 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 89 m²/s²
0-3 km storm-relative helicity: 205 m²/s²
Significant tornado parameter: 1.1
Supercell composite: 5.4

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 10, 9:14 PM CDT	Mesoscale Discussion	SPC	Allen, Avoyelles, Beauregard, Bienville, Calcasieu, Caldwell and 21 more	2 hr
Apr 11, 6:55 AM CDT	Mesoscale Discussion	SPC	Acadia, Ascension, Assumption, Avoyelles, Concordia, East Baton Rouge and 25 more	65 min
Apr 11, 8:00 AM CDT	Tornado Watch	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 19 more	8 hr
Apr 10, 8:28 PM CDT	Tornado Watch	SPC	Benton, Coahoma, DeSoto, Lafayette, Marshall, Panola and 5 more	7 hr
Apr 10, 11:08 PM CDT	Mesoscale Discussion	SPC	DeSoto, Marshall, Panola, Tate, Tunica	97 min
Apr 11, 10:41 AM CDT	Mesoscale Discussion	SPC	Kemper, Lauderdale, Lowndes, Noxubee	2 hr

Nearby

Mesoscale Discussions in Mississippi, 2013 Mesoscale Discussions in Louisiana, 2013 Every mesoscale discussion in 2013

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.