Alert archive / North Carolina / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 512

July 24, 201259 counties in North Carolina; Cherokee County, Chester County, York County, South Carolina

The Storm Prediction Center issued this severe thunderstorm watch at Jul 24, 2012, 2:36 PM EDT for 59 counties in North Carolina; Cherokee County, Chester County, York County, South Carolina. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Jul 24, 2012, 2:36 PM EDT (18:36 UTC)
Expired
Jul 24, 2012, 8:00 PM EDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 62 counties

Alamance County, NC, Alexander County, NC, Anson County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Cabarrus County, NC, Caldwell County, NC, Catawba County, NC, Chatham County, NC, Cleveland County, NC, Cumberland County, NC, Davidson County, NC, Davie County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Gaston County, NC, Graham County, NC, Granville County, NC, Guilford County, NC, Halifax County, NC, Harnett County, NC, Haywood County, NC, Henderson County, NC, Hoke County, NC, Iredell County, NC, Jackson County, NC, Johnston County, NC, Lee County, NC, Lincoln County, NC, Macon County, NC, Madison County, NC, McDowell County, NC, Mecklenburg County, NC, Mitchell County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Orange County, NC, Person County, NC, Polk County, NC, Randolph County, NC, Richmond County, NC, Rowan County, NC, Rutherford County, NC, Sampson County, NC, Scotland County, NC, Stanly County, NC, Swain County, NC, Transylvania County, NC, Union County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Wayne County, NC, Wilson County, NC, Yancey County, NC, Cherokee County, SC, Chester County, SC, York County, SC

The radar

The Raleigh/Durham radar (KRAX), 98 km from the middle of the area, began a volume at 18:37 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
90%
One or more gusts of 65 knots or more
50%
Ten or more severe hail reports
70%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 24, 2:55 PM EDTSevere Thunderstorm WarningRAHAlamance, Chatham, Durham, Lee, Orange50 min
Jul 24, 3:11 PM EDTSevere Thunderstorm WarningRAHAnson, Montgomery, Richmond64 min
Jul 24, 3:16 PM EDTSevere Thunderstorm WarningRAHDurham, Harnett, Wake63 min
Jul 24, 3:27 PM EDTSevere Thunderstorm WarningRAHLee, Montgomery, Moore, Richmond63 min
Jul 24, 3:46 PM EDTSevere Thunderstorm WarningRAHFranklin, Johnston, Nash, Wake47 min
Jul 24, 3:57 PM EDTSevere Thunderstorm WarningRAHCumberland, Harnett, Moore63 min
Jul 24, 4:11 PM EDTSevere Thunderstorm WarningRAHJohnston, Nash, Sampson, Wayne, Wilson64 min
Jul 24, 4:16 PM EDTSevere Thunderstorm WarningRAHHoke, Scotland59 min
Jul 24, 4:24 PM EDTSevere Thunderstorm WarningRAHAnson, Montgomery, Moore, Richmond51 min
Jul 24, 4:33 PM EDTSevere Thunderstorm WarningRAHCumberland, Sampson57 min
Jul 24, 4:34 PM EDTSevere Thunderstorm WarningRAHEdgecombe, Halifax41 min
Jul 24, 5:02 PM EDTSevere Thunderstorm WarningGSPAvery, Madison, Mitchell, Yancey58 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, 6.6 hours before the alert went out and 39 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 2012-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1441 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 2012-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 205 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
1441 J/kg
Mixed-layer CIN
-106 J/kg
Mixed-layer LCL
1104 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
205 m²/s²
0-3 km storm-relative helicity
197 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.7

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, 3:46 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 40 more89 min
Jul 24, 4:24 PM EDTSevere Thunderstorm WatchSPCBeaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 24 more4 hr
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 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.