Alert archive / South Carolina / Tornado Watches in 2018

Tornado Watch 408

October 10, 20186 counties in Georgia; 42 counties in South Carolina

The Storm Prediction Center issued this tornado watch at Oct 10, 2018, 11:38 PM EDT for 6 counties in Georgia; 42 counties in South Carolina. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Oct 10, 2018, 11:38 PM EDT (03:38 UTC)
Expired
Oct 11, 2018, 7:00 AM EDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 48 counties

Burke County, GA, Columbia County, GA, Elbert County, GA, Lincoln County, GA, McDuffie County, GA, Richmond County, GA, Abbeville County, SC, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Beaufort County, SC, Berkeley County, SC, Calhoun County, SC, Charleston County, SC, Cherokee County, SC, Chester County, SC, Chesterfield County, SC, Clarendon County, SC, Colleton County, SC, Darlington County, SC, Dillon County, SC, Dorchester County, SC, Edgefield County, SC, Fairfield County, SC, Florence County, SC, Georgetown County, SC, Greenwood County, SC, Hampton County, SC, Horry County, SC, Jasper County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Lee County, SC, Lexington County, SC, Marion County, SC, Marlboro County, SC, McCormick County, SC, Newberry County, SC, Orangeburg County, SC, Richland County, SC, Saluda County, SC, Spartanburg County, SC, Sumter County, SC, Union County, SC, Williamsburg County, SC, York County, SC

The radar

The Columbia radar (KCAE), 7 km from the middle of the area, began a volume at 03:37 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
50%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
5%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
20%

Warnings issued inside it

6 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Oct 10, 11:54 PM EDTTornado WarningCAECalhoun, Lexington, Orangeburg, Richland21 min
Oct 11, 2:37 AM EDTTornado WarningCAENewberry23 min
Oct 11, 2:45 AM EDTTornado WarningGSPLaurens, Union30 min
Oct 11, 3:12 AM EDTTornado WarningGSPSpartanburg, Union15 min
Oct 11, 4:15 AM EDTTornado WarningCAECalhoun, Richland30 min
Oct 11, 6:10 AM EDTFlash Flood WarningCAELexington, Richland4 hr

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 00:00Z, 3.6 hours before the alert went out and 156 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 00:00Z on 2018-10-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 846 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 00:00Z on 2018-10-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 87 square meters per square second.193958Sfc1 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
846 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
746 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
87 m²/s²
0-3 km storm-relative helicity
137 m²/s²
Significant tornado parameter
0.3
Supercell composite
3.6

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 10, 9:08 PM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Baldwin, Ben Hill, Berrien and 35 more2 hr
Oct 10, 11:08 PM EDTMesoscale DiscussionSPCAnson, Union97 min
Oct 11, 4:34 AM EDTMesoscale DiscussionSPCAnson, Bladen, Brunswick, Cabarrus, Chatham, Columbus and 22 more56 min
Oct 11, 8:31 AM EDTMesoscale DiscussionSPCAlamance, Bladen, Caswell, Chatham, Cumberland, Duplin and 25 more89 min
Oct 11, 9:58 AM EDTTornado WatchSPCAlamance, Beaufort, Bertie, Bladen, Brunswick, Camden and 49 more13 hr
Oct 11, 12:48 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Camden, Carteret, Chowan, Craven and 28 more117 min
Oct 11, 3:54 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Camden, Caswell, Chowan, Currituck and 18 more2 hr

Nearby

Tornado Watches in South Carolina, 2018Tornado Watches in Georgia, 2018Every tornado watch in 2018

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.