Alert archive / South Carolina / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 278

May 15, 201217 counties in Georgia; 6 counties in North Carolina; 34 counties in South Carolina

The Storm Prediction Center issued this severe thunderstorm watch at May 15, 2012, 2:27 PM EDT for 17 counties in Georgia; 6 counties in North Carolina; 34 counties in South Carolina. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
May 15, 2012, 2:27 PM EDT (18:27 UTC)
Expired
May 15, 2012, 9:00 PM EDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 57 counties

Bryan County, GA, Bulloch County, GA, Burke County, GA, Candler County, GA, Chatham County, GA, Columbia County, GA, Effingham County, GA, Evans County, GA, Jenkins County, GA, Liberty County, GA, Lincoln County, GA, Long County, GA, McDuffie County, GA, McIntosh County, GA, Richmond County, GA, Screven County, GA, Tattnall County, GA, Bladen County, NC, Brunswick County, NC, Columbus County, NC, New Hanover County, NC, Pender County, NC, Robeson County, NC, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Beaufort County, SC, Berkeley County, SC, Calhoun County, SC, Charleston 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, Hampton County, SC, Horry County, SC, Jasper County, SC, Kershaw County, SC, Lancaster 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, Sumter County, SC, Williamsburg County, SC

The radar

The Charleston,SC radar (KCLX), 45 km from the middle of the area, began a volume at 18:27 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
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 15, 3:28 PM EDTSevere Thunderstorm WarningCHSBryan, Liberty, Long, McIntosh62 min
May 15, 3:54 PM EDTSevere Thunderstorm WarningCHSScreven20 min
May 15, 4:03 PM EDTSevere Thunderstorm WarningILMBladen, Columbus, Robeson34 min
May 15, 4:19 PM EDTSevere Thunderstorm WarningCHSBryan, Chatham, Liberty56 min
May 15, 4:34 PM EDTSevere Thunderstorm WarningCAEFairfield, Newberry26 min
May 15, 4:42 PM EDTSevere Thunderstorm WarningCHSBryan, Chatham, Effingham, Liberty63 min
May 15, 4:59 PM EDTSevere Thunderstorm WarningCAELexington31 min
May 15, 5:25 PM EDTSevere Thunderstorm WarningCHSBeaufort, Colleton, Hampton, Jasper65 min
May 15, 5:32 PM EDTSevere Thunderstorm WarningCAENewberry, Saluda28 min
May 15, 5:33 PM EDTSevere Thunderstorm WarningCAEClarendon, Orangeburg42 min
May 15, 5:51 PM EDTSevere Thunderstorm WarningCAENewberry24 min
May 15, 6:07 PM EDTSevere Thunderstorm WarningCAEKershaw, Richland23 min
May 15, 6:39 PM EDTSevere Thunderstorm WarningCAEKershaw, Lee, Richland, Sumter36 min
May 15, 7:50 PM EDTSevere Thunderstorm WarningCAELexington25 min
May 15, 8:14 PM EDTSevere Thunderstorm WarningCAERichland, Sumter46 min
May 15, 8:17 PM EDTSevere Thunderstorm WarningILMDarlington, Dillon, Florence, Marlboro37 min
May 15, 8:37 PM EDTSevere Thunderstorm WarningCAECalhoun, Lexington23 min
May 15, 9:00 PM EDTSevere Thunderstorm WarningCAECalhoun, Richland45 min

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 12:00Z, 6.5 hours before the alert went out and 98 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 2012-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1682 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 2012-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 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
1682 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
555 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
74 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 15, 1:07 PM EDTMesoscale DiscussionSPCBurke, Columbia, Elbert, Glascock, Hart, Lincoln and 4 more113 min
May 15, 3:13 PM EDTSevere Thunderstorm WatchSPCElbert, Franklin, Habersham, Hart, Rabun, Stephens7 hr
May 15, 5:38 PM EDTMesoscale DiscussionSPCBrantley, Camden, Charlton97 min
May 15, 6:30 PM EDTMesoscale DiscussionSPCBryan, Bulloch, Burke, Candler, Chatham, Columbia and 16 more90 min
May 15, 2:08 PM EDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Burke, Caldwell, Caswell and 21 more67 min

Nearby

Severe Thunderstorm Watches in South Carolina, 2012Severe Thunderstorm Watches in Georgia, 2012Severe Thunderstorm Watches in North Carolina, 2012Every severe thunderstorm watch in 2012

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.