Alert archive / South Carolina / Mesoscale Discussions in 2017

Mesoscale Discussion 711

May 12, 201719 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at May 12, 2017, 6:33 PM EDT for 19 counties in South Carolina. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 12, 2017, 6:33 PM EDT (22:33 UTC)
Expired: May 12, 2017, 9:00 PM EDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

Counties Berkeley County, SC, Chester County, SC, Chesterfield County, SC, Clarendon County, SC, Darlington County, SC, Fairfield County, SC, Florence County, SC, Georgetown County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Lee County, SC, Marion County, SC, Newberry County, SC, Richland County, SC, Sumter County, SC, Union County, SC, Williamsburg County, SC, York County, SC

The radar

The Columbia radar (KCAE), 82 km from the middle of the area, began a volume at 22:37 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

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 10.6 hours before the alert went out and 248 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: 1 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 534 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 134 m²/s²
0-3 km storm-relative helicity: 197 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 12, 2:06 PM EDT	Mesoscale Discussion	SPC	Anderson, Greenville, Oconee, Pickens, Spartanburg	2 hr

Nearby

Mesoscale Discussions in South Carolina, 2017 Every mesoscale discussion in 2017

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.