Alert archive / South Carolina / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 507

June 18, 201112 counties in Georgia; 6 counties in North Carolina; 14 counties in South Carolina

The Storm Prediction Center issued this severe thunderstorm watch at Jun 18, 2011, 7:20 PM EDT for 12 counties in Georgia; 6 counties in North Carolina; 14 counties in South Carolina. It took effect at Jun 18, 2011, 7:25 PM EDT. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jun 18, 2011, 7:20 PM EDT (23:20 UTC)
In effect from
Jun 18, 2011, 7:25 PM EDT
Expired
Jun 19, 2011, 12:48 AM EDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 32 counties

Bryan County, GA, Bulloch County, GA, Candler County, GA, Chatham County, GA, Effingham County, GA, Evans County, GA, Jenkins County, GA, Liberty County, GA, Long County, GA, McIntosh 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, Allendale County, SC, Beaufort County, SC, Berkeley County, SC, Charleston County, SC, Colleton County, SC, Dillon County, SC, Dorchester County, SC, Florence County, SC, Georgetown County, SC, Hampton County, SC, Horry County, SC, Jasper County, SC, Marion County, SC, Williamsburg County, SC

The radar

The Wilmington radar (KLTX), 95 km from the middle of the area, began a volume at 23:23 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
10%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
80%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
10%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 18, 8:52 PM EDTSevere Thunderstorm WarningCHSBulloch, Candler, Jenkins, Screven53 min
Jun 18, 9:12 PM EDTSevere Thunderstorm WarningCHSColleton, Dorchester63 min
Jun 18, 9:34 PM EDTSevere Thunderstorm WarningCHSEffingham, Screven56 min
Jun 18, 9:45 PM EDTSevere Thunderstorm WarningCHSBulloch, Candler, Evans, Jenkins, Tattnall60 min
Jun 18, 10:05 PM EDTSevere Thunderstorm WarningCHSEvans, Liberty, Long, Tattnall55 min
Jun 18, 10:11 PM EDTSevere Thunderstorm WarningCHSChatham, Effingham64 min
Jun 18, 10:17 PM EDTSevere Thunderstorm WarningCHSBerkeley, Charleston, Colleton, Dorchester58 min
Jun 18, 10:37 PM EDTSevere Thunderstorm WarningCHSBryan, Bulloch, Chatham, Effingham, Liberty53 min
Jun 18, 10:58 PM EDTSevere Thunderstorm WarningCHSLiberty, Long, McIntosh62 min
Jun 18, 11:15 PM EDTSevere Thunderstorm WarningCHSChatham, Effingham60 min
Jun 18, 11:27 PM EDTSevere Thunderstorm WarningCHSBryan, Chatham, Effingham, Liberty50 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, 11.3 hours before the alert went out and 122 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 2011-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 151 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 2011-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -76 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
151 J/kg
Mixed-layer CIN
-89 J/kg
Mixed-layer LCL
901 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
-76 m²/s²
0-3 km storm-relative helicity
-45 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 18, 9:38 AM EDTMesoscale DiscussionSPCBanks, Bartow, Catoosa, Chattooga, Cherokee, Cobb and 22 more97 min
Jun 18, 11:05 AM EDTSevere Thunderstorm WatchSPCBanks, Bartow, Catoosa, Chattooga, Cherokee, Dade and 20 more9 hr
Jun 18, 2:21 PM EDTMesoscale DiscussionSPCBanks, Bartow, Catoosa, Chattooga, Cherokee, Dawson and 20 more84 min
Jun 18, 3:55 PM EDTMesoscale DiscussionSPCBarrow, Carroll, Clarke, Clayton, Cobb, Columbia and 25 more35 min
Jun 18, 4:08 PM EDTSevere Thunderstorm WatchSPCBaldwin, Barrow, Burke, Butts, Carroll, Clarke and 51 more6 hr
Jun 18, 6:49 PM EDTMesoscale DiscussionSPCBaldwin, Barrow, Bibb, Bleckley, Bulloch, Burke and 55 more86 min
Jun 18, 3:38 PM EDTSevere Thunderstorm WatchSPCAlamance, Anson, Caswell, Chatham, Davidson, Durham and 17 more4 hr
Jun 18, 5:46 PM EDTMesoscale DiscussionSPCAlamance, Anson, Caswell, Chatham, Cumberland, Durham and 19 more59 min

Nearby

Severe Thunderstorm Watches in South Carolina, 2011Severe Thunderstorm Watches in Georgia, 2011Severe Thunderstorm Watches in North Carolina, 2011Every severe thunderstorm watch in 2011

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.