Alert archive / Mississippi / Mesoscale Discussions in 2005

Mesoscale Discussion 943

May 20, 200512 parishes in Louisiana; 16 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at May 20, 2005, 8:40 PM CDT for 12 parishes in Louisiana; 16 counties in Mississippi. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued: May 20, 2005, 8:40 PM CDT (01:40 UTC)
Expired: May 20, 2005, 10:15 PM CDT
In force: 95 min
Issued by: the Storm Prediction Center

All 28 counties

Caldwell Parish, LA, Catahoula Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, LaSalle Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Richland Parish, LA, Tensas Parish, LA, Union Parish, LA, West Carroll Parish, LA, Claiborne County, MS, Copiah County, MS, Covington County, MS, Franklin County, MS, Hinds County, MS, Issaquena County, MS, Jefferson County, MS, Jefferson Davis County, MS, Lawrence County, MS, Lincoln County, MS, Madison County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Warren County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 71 km from the middle of the area, began a volume at 01:42 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, 1.7 hours before the alert went out and 65 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: 1048 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 1512 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 94 m²/s²
0-3 km storm-relative helicity: 229 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 3.1

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
May 20, 7:15 PM CDT	Severe Thunderstorm Watch	SPC	Forrest, George, Greene, Harrison, Jackson, Perry and 1 more	6 hr
May 20, 10:37 PM CDT	Mesoscale Discussion	SPC	Claiborne, Clarke, Copiah, Covington, Franklin, Greene and 11 more	83 min

Nearby

Mesoscale Discussions in Mississippi, 2005 Mesoscale Discussions in Louisiana, 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; radar from the NEXRAD Level II archive.