Alert archive / Mississippi / Mesoscale Discussions in 2008

Mesoscale Discussion 2433

December 9, 200812 parishes in Louisiana; 18 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Dec 9, 2008, 10:19 PM CST for 12 parishes in Louisiana; 18 counties in Mississippi. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued: Dec 9, 2008, 10:19 PM CST (04:19 UTC)
Expired: Dec 9, 2008, 11:15 PM CST
In force: 56 min
Issued by: the Storm Prediction Center

All 30 counties

Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberville Parish, LA, Livingston Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint Martin Parish, LA, Tangipahoa Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, Amite County, MS, Covington County, MS, Jasper County, MS, Jefferson Davis County, MS, Kemper County, MS, Lawrence County, MS, Lincoln County, MS, Lowndes County, MS, Marion County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Pike County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Walthall County, MS, Winston County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 51 km from the middle of the area, began a volume at 04:20 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 00:00Z, 4.3 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: 1039 J/kg
Mixed-layer CIN: -1 J/kg
Mixed-layer LCL: 630 m above ground
0-6 km bulk shear: 62 kt
0-1 km storm-relative helicity: 331 m²/s²
0-3 km storm-relative helicity: 385 m²/s²
Significant tornado parameter: 2.7
Supercell composite: 8.9

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
Dec 9, 6:15 PM CST	Mesoscale Discussion	SPC	Orleans, Saint Charles, Saint Tammany	90 min
Dec 9, 8:03 PM CST	Tornado Watch	SPC	Saint Tammany	6 hr
Dec 10, 1:25 AM CST	Mesoscale Discussion	SPC	Orleans, Saint Bernard, Saint Tammany	65 min
Dec 10, 1:41 AM CST	Tornado Watch	SPC	George, Greene, Hancock, Harrison, Jackson, Pearl River and 3 more	5 hr
Dec 10, 3:31 AM CST	Mesoscale Discussion	SPC	George, Greene, Hancock, Harrison, Jackson, Perry and 1 more	59 min

Nearby

Mesoscale Discussions in Mississippi, 2008 Mesoscale Discussions in Louisiana, 2008 Every mesoscale discussion in 2008

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.