Alert archive / South Carolina / Severe Thunderstorm Watches in 2009

Severe Thunderstorm Watch 421

June 15, 200917 counties in North Carolina; 23 counties in South Carolina

The Storm Prediction Center issued this severe thunderstorm watch at Jun 15, 2009, 3:21 PM EDT for 17 counties in North Carolina; 23 counties in South Carolina. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Jun 15, 2009, 3:21 PM EDT (19:21 UTC)
Expired
Jun 15, 2009, 11:00 PM EDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 40 counties

Anson County, NC, Bladen County, NC, Chatham County, NC, Columbus County, NC, Cumberland County, NC, Harnett County, NC, Hoke County, NC, Johnston County, NC, Lee County, NC, Moore County, NC, Richmond County, NC, Robeson County, NC, Sampson County, NC, Scotland County, NC, Wake County, NC, Wayne County, NC, Wilson County, NC, 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, Fairfield County, SC, Florence County, SC, Georgetown County, SC, Horry County, SC, Kershaw County, SC, Lancaster County, SC, Lee County, SC, Lexington County, SC, Marion County, SC, Marlboro County, SC, Orangeburg County, SC, Richland County, SC, Sumter County, SC, Williamsburg County, SC

The radar

The Wilmington radar (KLTX), 118 km from the middle of the area, began a volume at 19:24 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
2%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 15, 5:05 PM EDTSevere Thunderstorm WarningRAHCumberland, Harnett, Sampson55 min
Jun 15, 5:44 PM EDTSevere Thunderstorm WarningRAHChatham, Randolph46 min
Jun 15, 6:30 PM EDTSevere Thunderstorm WarningILMBladen, Columbus, Robeson60 min
Jun 15, 7:04 PM EDTSevere Thunderstorm WarningCAEFairfield, Kershaw, Richland41 min
Jun 15, 7:06 PM EDTSevere Thunderstorm WarningILMRobeson30 min
Jun 15, 7:21 PM EDTTornado WarningILMBladen, Columbus39 min
Jun 15, 7:28 PM EDTSevere Thunderstorm WarningILMColumbus, Robeson62 min
Jun 15, 8:06 PM EDTSevere Thunderstorm WarningILMBrunswick, Columbus39 min
Jun 15, 8:16 PM EDTSevere Thunderstorm WarningILMRobeson44 min
Jun 15, 9:52 PM EDTSevere Thunderstorm WarningILMHorry25 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

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 7.4 hours before the alert went out and 185 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, Greensboro/Hi Pt, NC at 12:00Z on 2009-06-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 276 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, Greensboro/Hi Pt, NC at 12:00Z on 2009-06-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 69 square meters per square second.19395878Sfc1 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
276 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
940 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
69 m²/s²
0-3 km storm-relative helicity
83 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.9

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 15, 1:26 PM EDTMesoscale DiscussionSPCAnson, Bladen, Buncombe, Burke, Cabarrus, Catawba and 37 more64 min
Jun 15, 6:42 PM EDTMesoscale DiscussionSPCBladen, Brunswick, Columbus, Cumberland, Duplin, Hoke and 7 more63 min

Nearby

Severe Thunderstorm Watches in South Carolina, 2009Severe Thunderstorm Watches in North Carolina, 2009Every severe thunderstorm watch in 2009

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.