Alert archive / Louisiana / Mesoscale Discussions in 2005

Mesoscale Discussion 2491

November 28, 200526 parishes in Louisiana; 5 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Nov 28, 2005, 4:42 AM CST for 26 parishes in Louisiana; 5 counties in Mississippi. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued: Nov 28, 2005, 4:42 AM CST (10:42 UTC)
Expired: Nov 28, 2005, 6:15 AM CST
In force: 93 min
Issued by: the Storm Prediction Center

All 31 counties

Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Pointe Coupee Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Amite County, MS, Marion County, MS, Pike County, MS, Walthall County, MS, Wilkinson County, MS

The nearest sounding before it

Jackson, MS (KJAN), launched 00:00Z, 10.7 hours before the alert went out and 276 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: 197 J/kg
Mixed-layer CIN: -56 J/kg
Mixed-layer LCL: 843 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 257 m²/s²
0-3 km storm-relative helicity: 359 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.1

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
Nov 27, 11:44 PM CST	Tornado Watch	SPC	Catahoula, Concordia, East Carroll, Franklin, Madison, Morehouse and 3 more	6 hr
Nov 28, 2:40 AM CST	Mesoscale Discussion	SPC	Concordia, Madison, Tensas	95 min
Nov 27, 8:44 PM CST	Mesoscale Discussion	SPC	Benton, DeSoto, Lafayette, Marshall, Panola, Quitman and 1 more	91 min
Nov 27, 11:26 PM CST	Tornado Watch	SPC	Alcorn, Benton, Calhoun, Chickasaw, Coahoma, DeSoto and 16 more	7 hr
Nov 28, 12:43 AM CST	Mesoscale Discussion	SPC	Coahoma, DeSoto, Panola, Quitman, Tallahatchie, Tate and 1 more	62 min
Nov 28, 3:28 AM CST	Mesoscale Discussion	SPC	Alcorn, Benton, Calhoun, Chickasaw, Itawamba, Lafayette and 12 more	62 min
Nov 28, 9:29 AM CST	Mesoscale Discussion	SPC	Clarke, Forrest, George, Greene, Harrison, Jackson and 11 more	2 hr

Nearby

Mesoscale Discussions in Louisiana, 2005 Mesoscale Discussions in Mississippi, 2005 Every mesoscale discussion in 2005

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.