Alert archive / South Carolina / Mesoscale Discussions in 2020

Mesoscale Discussion 460

April 23, 2020Chatham County, Effingham County, Screven County, Georgia; 12 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Apr 23, 2020, 2:22 PM EDT for Chatham County, Effingham County, Screven County, Georgia; 12 counties in South Carolina. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: Apr 23, 2020, 2:22 PM EDT (18:22 UTC)
Expired: Apr 23, 2020, 3:45 PM EDT
In force: 83 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

Counties Chatham County, GA, Effingham County, GA, Screven County, GA, Allendale County, SC, Bamberg County, SC, Beaufort County, SC, Berkeley County, SC, Charleston County, SC, Colleton County, SC, Dorchester County, SC, Georgetown County, SC, Hampton County, SC, Jasper County, SC, Orangeburg County, SC, Williamsburg County, SC

The radar

The Charleston,SC radar (KCLX), 77 km from the middle of the area, began a volume at 18:20 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

Jacksonville, FL (KJAX), launched 12:00Z, 6.4 hours before the alert went out and 301 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1362 m above ground
0-6 km bulk shear: 62 kt
0-1 km storm-relative helicity: 108 m²/s²
0-3 km storm-relative helicity: 225 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
Apr 23, 8:43 AM EDT	Mesoscale Discussion	SPC	Baker, Calhoun, Clay, Decatur, Early, Grady and 3 more	92 min
Apr 23, 10:29 AM EDT	Mesoscale Discussion	SPC	Appling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 39 more	61 min
Apr 23, 10:52 AM EDT	Tornado Watch	SPC	Appling, Atkinson, Bacon, Baker, Ben Hill, Berrien and 40 more	6 hr
Apr 23, 1:25 PM EDT	Mesoscale Discussion	SPC	Atkinson, Brantley, Clinch, Echols, Lanier, Lowndes and 3 more	95 min
Apr 23, 3:47 PM EDT	Tornado Watch	SPC	Brooks, Decatur, Grady, Lowndes, Seminole, Thomas	6 hr
Apr 23, 6:09 PM EDT	Mesoscale Discussion	SPC	Brooks, Decatur, Echols, Grady, Lowndes, Seminole and 1 more	96 min
Apr 23, 6:52 PM EDT	Tornado Watch	SPC	Camden, Charlton, Clinch, Echols, Ware	5 hr

Nearby

Mesoscale Discussions in South Carolina, 2020 Mesoscale Discussions in Georgia, 2020 Every mesoscale discussion in 2020

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.