Alert archive / South Carolina / Mesoscale Discussions in 2011

Mesoscale Discussion 393

April 9, 201114 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Apr 9, 2011, 10:39 PM EDT for 14 counties in South Carolina. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued: Apr 9, 2011, 10:39 PM EDT (02:39 UTC)
Expired: Apr 9, 2011, 11:45 PM EDT
In force: 66 min
Issued by: the Storm Prediction Center

Counties Berkeley County, SC, Calhoun County, SC, Clarendon County, SC, Darlington County, SC, Dorchester County, SC, Florence County, SC, Georgetown County, SC, Horry County, SC, Kershaw County, SC, Lee County, SC, Marion County, SC, Richland County, SC, Sumter County, SC, Williamsburg County, SC

The radar

The Wilmington radar (KLTX), 114 km from the middle of the area, began a volume at 02:39 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

Charleston AFB, SC (KCHS), launched 00:00Z, 2.7 hours before the alert went out and 92 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: 307 J/kg
Mixed-layer CIN: -377 J/kg
Mixed-layer LCL: 482 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 350 m²/s²
0-3 km storm-relative helicity: 398 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 4.5

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
Apr 9, 8:21 PM EDT	Severe Thunderstorm Watch	SPC	Berkeley, Charleston, Dorchester, Georgetown, Horry, Marion and 1 more	5 hr

Nearby

Mesoscale Discussions in South Carolina, 2011 Every mesoscale discussion in 2011

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.