Alert archive / Mississippi / Mesoscale Discussions in 2003

Mesoscale Discussion 278

March 18, 200317 parishes in Louisiana; 19 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Mar 18, 2003, 6:08 PM CST for 17 parishes in Louisiana; 19 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Mar 18, 2003, 6:08 PM CST (00:08 UTC)
Expired: Mar 18, 2003, 8:15 PM CST
In force: 2 hr
Issued by: the Storm Prediction Center

All 36 counties

Ascension Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Carroll Parish, LA, East Feliciana Parish, LA, Franklin Parish, LA, Iberville Parish, LA, Livingston Parish, LA, Madison Parish, LA, Pointe Coupee Parish, LA, Saint Helena Parish, LA, Saint Martin Parish, LA, Tangipahoa Parish, LA, Tensas Parish, LA, West Baton Rouge Parish, LA, West Carroll Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Hinds County, MS, Issaquena County, MS, Jefferson County, MS, Lawrence County, MS, Lincoln County, MS, Madison County, MS, Pike County, MS, Rankin County, MS, Sharkey County, MS, Simpson County, MS, Walthall County, MS, Warren County, MS, Wilkinson County, MS, Yazoo County, MS

The nearest sounding before it

Jackson, MS (KJAN), launched 00:00Z, 0.1 hours before the alert went out and 134 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: 209 J/kg
Mixed-layer CIN: -77 J/kg
Mixed-layer LCL: 936 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 121 m²/s²
0-3 km storm-relative helicity: 166 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

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
Mar 18, 10:25 PM CST	Tornado Watch	SPC	Washington	7 hr
Mar 18, 6:39 PM CST	Mesoscale Discussion	SPC	Clarke, Lauderdale, Wayne	3 hr
Mar 18, 7:30 PM CST	Tornado Watch	SPC	Clarke, George, Greene, Jackson, Wayne	6 hr
Mar 18, 9:10 PM CST	Mesoscale Discussion	SPC	Clarke, George, Greene, Jackson, Kemper, Lauderdale and 2 more	3 hr
Mar 18, 11:50 PM CST	Mesoscale Discussion	SPC	Alcorn, Attala, Benton, Calhoun, Chickasaw, Choctaw and 27 more	115 min
Mar 19, 2:02 AM CST	Mesoscale Discussion	SPC	Alcorn, Clarke, Clay, Greene, Itawamba, Kemper and 10 more	118 min

Nearby

Mesoscale Discussions in Mississippi, 2003 Mesoscale Discussions in Louisiana, 2003 Every mesoscale discussion in 2003

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.