Alert archive / Mississippi / Mesoscale Discussions in 2007

Mesoscale Discussion 8

January 4, 20077 parishes in Louisiana; 12 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Jan 4, 2007, 8:33 PM CST for 7 parishes in Louisiana; 12 counties in Mississippi. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued: Jan 4, 2007, 8:33 PM CST (02:33 UTC)
Expired: Jan 4, 2007, 10:00 PM CST
In force: 87 min
Issued by: the Storm Prediction Center

Counties Jefferson Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Tammany Parish, LA, Washington Parish, LA, 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, Stone County, MS, Walthall County, MS

The watches that followed

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

Tornado Watch 2Jan 4, 8:45 PM CST

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 00:00Z, 2.6 hours before the alert went out and 42 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: 478 J/kg
Mixed-layer CIN: -17 J/kg
Mixed-layer LCL: 547 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 221 m²/s²
0-3 km storm-relative helicity: 236 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 4.9

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
Jan 4, 6:34 PM CST	Mesoscale Discussion	SPC	Ascension, Assumption, East Baton Rouge, Jefferson, Lafourche, Livingston and 7 more	86 min
Jan 4, 8:47 PM CST	Tornado Watch	SPC	Jefferson, Lafourche, Orleans, Plaquemines, Saint Bernard, Saint Charles and 6 more	7 hr
Jan 4, 10:56 PM CST	Mesoscale Discussion	SPC	Jefferson, Orleans, Plaquemines, Saint Bernard, Saint Tammany, Washington	94 min
Jan 5, 2:26 AM CST	Mesoscale Discussion	SPC	Jefferson, Lafourche, Orleans, Plaquemines, Saint Bernard	64 min
Jan 5, 12:47 AM CST	Mesoscale Discussion	SPC	Alcorn, Itawamba, Lowndes, Monroe, Prentiss, Tishomingo	28 min
Jan 5, 1:15 AM CST	Tornado Watch	SPC	Choctaw, Clay, Lowndes, Noxubee, Oktibbeha, Webster and 1 more	6 hr

Nearby

Mesoscale Discussions in Mississippi, 2007 Mesoscale Discussions in Louisiana, 2007 Every mesoscale discussion in 2007

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.