Alert archive / Mississippi / Mesoscale Discussions in 2012

Mesoscale Discussion 748

May 7, 20125 parishes in Louisiana; 27 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at May 7, 2012, 3:53 PM CDT for 5 parishes in Louisiana; 27 counties in Mississippi. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued: May 7, 2012, 3:53 PM CDT (20:53 UTC)
Expired: May 7, 2012, 5:30 PM CDT
In force: 97 min
Issued by: the Storm Prediction Center

All 32 counties

Catahoula Parish, LA, Concordia Parish, LA, Franklin Parish, LA, Madison Parish, LA, Tensas Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Clarke County, MS, Copiah County, MS, Covington County, MS, Franklin County, MS, Hinds County, MS, Jasper County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lauderdale County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Newton County, MS, Pike County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS, Warren County, MS, Wayne County, MS, Wilkinson County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 64 km from the middle of the area, began a volume at 20:54 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

Jackson, MS (KJAN), launched 12:00Z, 8.9 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: 2057 J/kg
Mixed-layer CIN: -12 J/kg
Mixed-layer LCL: 496 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: -24 m²/s²
0-3 km storm-relative helicity: -21 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 7, 1:07 PM CDT	Severe Thunderstorm Watch	SPC	Catahoula, Concordia, Franklin, Madison, Richland, Tensas	5 hr
May 7, 4:38 PM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Claiborne, Red River, Webster	67 min
May 7, 11:00 AM CDT	Mesoscale Discussion	SPC	Attala, Choctaw, Clay, Hinds, Kemper, Lauderdale and 14 more	90 min

Nearby

Mesoscale Discussions in Mississippi, 2012 Mesoscale Discussions in Louisiana, 2012 Every mesoscale discussion in 2012

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.