Alert archive / Louisiana / Mesoscale Discussions in 2015

Mesoscale Discussion 842

May 30, 201524 parishes in Louisiana; Panola County, Shelby County, Texas

The Storm Prediction Center issued this mesoscale discussion at May 30, 2015, 10:14 AM CDT for 24 parishes in Louisiana; Panola County, Shelby County, Texas. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued: May 30, 2015, 10:14 AM CDT (15:14 UTC)
Expired: May 30, 2015, 11:45 AM CDT
In force: 91 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 26 counties

Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Franklin Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Tensas Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Winn Parish, LA, Panola County, TX, Shelby County, TX

The radar

The Shreveport radar (KSHV), 81 km from the middle of the area, began a volume at 15:17 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

Shreveport, LA (KBAD), launched 12:00Z, 3.2 hours before the alert went out and 73 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: 1281 J/kg
Mixed-layer CIN: -33 J/kg
Mixed-layer LCL: 775 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 69 m²/s²
0-3 km storm-relative helicity: 59 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 30, 5:16 PM CDT	Mesoscale Discussion	SPC	East Feliciana, Saint Helena, Tangipahoa, Washington	59 min
May 29, 7:03 PM CDT	Mesoscale Discussion	SPC	Andrews, Bailey, Borden, Briscoe, Castro, Cochran and 35 more	117 min
May 29, 7:21 PM CDT	Severe Thunderstorm Watch	SPC	Andrews, Borden, Briscoe, Cochran, Coke, Crosby and 30 more	7 hr
May 30, 12:58 AM CDT	Mesoscale Discussion	SPC	Brown, Callahan, Coleman, Comanche, Eastland, Erath and 12 more	92 min
May 30, 1:35 AM CDT	Severe Thunderstorm Watch	SPC	Bell, Bosque, Brown, Callahan, Coke, Coleman and 37 more	6 hr
May 30, 6:20 AM CDT	Mesoscale Discussion	SPC	Anderson, Camp, Cherokee, Ellis, Freestone, Gregg and 14 more	85 min
May 30, 12:10 PM CDT	Mesoscale Discussion	SPC	Dimmit, Duval, Kinney, La Salle, Maverick, Webb and 2 more	65 min
May 30, 12:32 PM CDT	Severe Thunderstorm Watch	SPC	Dimmit, Frio, Kinney, La Salle, Maverick, Medina and 3 more	6 hr
May 30, 5:01 PM CDT	Mesoscale Discussion	SPC	Atascosa, Bee, DeWitt, Duval, Goliad, Jim Hogg and 7 more	59 min

Nearby

Mesoscale Discussions in Louisiana, 2015 Mesoscale Discussions in Texas, 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; radar from the NEXRAD Level II archive.