Alert archive / South Carolina / Mesoscale Discussions in 2021

Mesoscale Discussion 1404

July 31, 202111 counties in North Carolina; 16 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Jul 31, 2021, 1:40 PM EDT for 11 counties in North Carolina; 16 counties in South Carolina. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 31, 2021, 1:40 PM EDT (17:40 UTC)
Expired
Jul 31, 2021, 3:45 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%
All 27 counties

Bladen County, NC, Brunswick County, NC, Carteret County, NC, Columbus County, NC, Craven County, NC, Duplin County, NC, Jones County, NC, New Hanover County, NC, Onslow County, NC, Pamlico County, NC, Pender County, NC, Allendale County, SC, Bamberg County, SC, Berkeley County, SC, Calhoun County, SC, Charleston County, SC, Clarendon County, SC, Colleton County, SC, Dorchester County, SC, Florence County, SC, Georgetown County, SC, Hampton County, SC, Horry County, SC, Marion County, SC, Orangeburg County, SC, Sumter County, SC, Williamsburg County, SC

The radar

The Wilmington radar (KLTX), 56 km from the middle of the area, began a volume at 17:43 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 12:00Z, 5.7 hours before the alert went out and 158 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-pSkew-T log-p diagram, Charleston AFB, SC at 12:00Z on 2021-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2518 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Charleston AFB, SC at 12:00Z on 2021-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
2518 J/kg
Mixed-layer CIN
-41 J/kg
Mixed-layer LCL
924 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
67 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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Nearby

Mesoscale Discussions in South Carolina, 2021Mesoscale Discussions in North Carolina, 2021Every mesoscale discussion in 2021

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.