Alert archive / North Carolina / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 536

July 28, 201223 counties in North Carolina; 6 counties in South Carolina

The Storm Prediction Center issued this severe thunderstorm watch at Jul 28, 2012, 4:01 PM EDT for 23 counties in North Carolina; 6 counties in South Carolina. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jul 28, 2012, 4:01 PM EDT (20:01 UTC)
Expired
Jul 28, 2012, 10:00 PM EDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 29 counties

Beaufort County, NC, Bladen County, NC, Brunswick County, NC, Carteret County, NC, Columbus County, NC, Craven County, NC, Dare County, NC, Duplin County, NC, Greene County, NC, Hyde County, NC, Jones County, NC, Lenoir County, NC, Martin County, NC, New Hanover County, NC, Onslow County, NC, Pamlico County, NC, Pender County, NC, Pitt County, NC, Robeson County, NC, Sampson County, NC, Tyrrell County, NC, Washington County, NC, Wayne County, NC, Dillon County, SC, Florence County, SC, Georgetown County, SC, Horry County, SC, Marion County, SC, Williamsburg County, SC

The radar

The Wilmington radar (KLTX), 73 km from the middle of the area, began a volume at 20:01 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
5%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
10%
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
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 28, 4:10 PM EDTSevere Thunderstorm WarningILMBrunswick, Columbus65 min
Jul 28, 5:34 PM EDTSevere Thunderstorm WarningILMBladen, Pender56 min
Jul 28, 5:50 PM EDTSevere Thunderstorm WarningMHXJones, Onslow40 min
Jul 28, 6:46 PM EDTSevere Thunderstorm WarningMHXCarteret, Craven, Jones, Onslow44 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

Newport, NC (KMHX), launched 12:00Z, 8.0 hours before the alert went out and 117 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, Newport, NC at 12:00Z on 2012-07-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2134 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, Newport, NC at 12:00Z on 2012-07-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 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
2134 J/kg
Mixed-layer CIN
-49 J/kg
Mixed-layer LCL
866 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.5
Supercell composite
4.7

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 28, 1:57 PM EDTMesoscale DiscussionSPCAvery, Buncombe, Burke, Caldwell, Cherokee, Clay and 16 more3 hr
Jul 28, 2:18 PM EDTMesoscale DiscussionSPCAlamance, Anson, Beaufort, Bertie, Bladen, Brunswick and 61 more117 min
Jul 28, 7:28 PM EDTMesoscale DiscussionSPCBladen, Brunswick, Carteret, Columbus, Craven, Duplin and 6 more32 min

Nearby

Severe Thunderstorm Watches in North Carolina, 2012Severe Thunderstorm Watches in South 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.