Alert archive / North Carolina / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 513

July 24, 201230 counties in North Carolina; 4 counties in South Carolina; 26 counties in Virginia

The Storm Prediction Center issued this severe thunderstorm watch at Jul 24, 2012, 4:24 PM EDT for 30 counties in North Carolina; 4 counties in South Carolina; 26 counties in Virginia. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jul 24, 2012, 4:24 PM EDT (20:24 UTC)
Expired
Jul 24, 2012, 8:35 PM EDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 60 counties

Beaufort County, NC, Bertie County, NC, Bladen County, NC, Brunswick County, NC, Camden County, NC, Carteret County, NC, Chowan County, NC, Columbus County, NC, Craven County, NC, Currituck County, NC, Dare County, NC, Duplin County, NC, Gates County, NC, Greene County, NC, Hertford County, NC, Hyde County, NC, Jones County, NC, Lenoir County, NC, Martin County, NC, New Hanover County, NC, Northampton County, NC, Onslow County, NC, Pamlico County, NC, Pasquotank County, NC, Pender County, NC, Perquimans County, NC, Pitt County, NC, Robeson County, NC, Tyrrell County, NC, Washington County, NC, Dillon County, SC, Horry County, SC, Marion County, SC, Marlboro County, SC, Accomack County, VA, Brunswick County, VA, City of Chesapeake, VA, City of Emporia, VA, City of Franklin, VA, City of Hampton, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Dinwiddie County, VA, Gloucester County, VA, Greensville County, VA, Isle of Wight County, VA, James City County, VA, Mathews County, VA, Northampton County, VA, Prince George County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, York County, VA

The radar

The Raleigh/Durham radar (KRAX), 70 km from the middle of the area, began a volume at 20:26 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
60%
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

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

IssuedProductOfficeCountiesLasted
Jul 24, 4:30 PM EDTSevere Thunderstorm WarningMHXDuplin, Greene, Lenoir, Martin, Pitt60 min
Jul 24, 4:44 PM EDTSevere Thunderstorm WarningAKQGloucester, James City, Mathews, Surry, York, City of Hampton and 3 more46 min
Jul 24, 4:46 PM EDTSevere Thunderstorm WarningMHXBeaufort, Craven, Duplin, Greene, Jones, Lenoir and 4 more59 min
Jul 24, 5:14 PM EDTSevere Thunderstorm WarningAKQIsle of Wight, City of Hampton, City of Newport News, City of Norfolk31 min
Jul 24, 5:20 PM EDTSevere Thunderstorm WarningAKQBertie, Chowan40 min
Jul 24, 5:26 PM EDTSevere Thunderstorm WarningMHXDuplin, Onslow49 min
Jul 24, 5:47 PM EDTSevere Thunderstorm WarningMHXBeaufort, Craven, Dare, Hyde, Jones, Onslow and 3 more58 min
Jul 24, 5:53 PM EDTSevere Thunderstorm WarningAKQChowan, Pasquotank, Perquimans52 min
Jul 24, 6:04 PM EDTSevere Thunderstorm WarningMHXCarteret56 min
Jul 24, 6:28 PM EDTSevere Thunderstorm WarningMHXDare32 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, 8.4 hours before the alert went out and 108 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 2012-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1601 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 2012-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 199 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
1601 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
888 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
199 m²/s²
0-3 km storm-relative helicity
232 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
Jul 24, 1:08 PM EDTSevere Thunderstorm WatchSPCAlleghany, Ashe, Caswell, Rockingham, Stokes, Surry and 3 more6 hr
Jul 24, 1:12 PM EDTMesoscale DiscussionSPCAlamance, Alexander, Anson, Avery, Buncombe, Burke and 37 more93 min
Jul 24, 1:42 PM EDTMesoscale DiscussionSPCBertie, Camden, Chowan, Currituck, Gates, Halifax and 8 more2 hr
Jul 24, 2:36 PM EDTSevere Thunderstorm WatchSPCAlamance, Alexander, Anson, Avery, Buncombe, Burke and 53 more5 hr
Jul 24, 3:46 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 40 more89 min
Jul 24, 6:46 PM EDTMesoscale DiscussionSPCCalhoun, Clarendon, Lee, Lexington, Richland, Saluda and 1 more89 min
Jul 24, 11:43 AM EDTMesoscale DiscussionSPCBuchanan, Dickenson, Wise, City of Norton62 min
Jul 24, 11:48 AM EDTMesoscale DiscussionSPCArlington, Clarke, Culpeper, Fairfax, Fauquier, Frederick and 22 more87 min
Jul 24, 12:33 PM EDTSevere Thunderstorm WatchSPCBuchanan, Dickenson, Lee, Russell, Scott, Washington and 3 more6 hr
Jul 24, 1:52 PM EDTMesoscale DiscussionSPCBuchanan, Dickenson, Wise, City of Norton53 min
Jul 24, 3:25 PM EDTMesoscale DiscussionSPCBuchanan, Dickenson, Lee, Russell, Scott, Smyth and 5 more95 min

Nearby

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