Alert archive / North Carolina / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 105

March 24, 201239 counties in North Carolina; 27 counties in Virginia

The Storm Prediction Center issued this severe thunderstorm watch at Mar 24, 2012, 12:46 PM EDT for 39 counties in North Carolina; 27 counties in Virginia. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Mar 24, 2012, 12:46 PM EDT (16:46 UTC)
Expired
Mar 24, 2012, 8:00 PM EDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 66 counties

Alamance County, NC, Alexander County, NC, Alleghany County, NC, Anson County, NC, Ashe County, NC, Avery County, NC, Burke County, NC, Cabarrus County, NC, Caldwell County, NC, Caswell County, NC, Catawba County, NC, Chatham County, NC, Cleveland County, NC, Davidson County, NC, Davie County, NC, Forsyth County, NC, Gaston County, NC, Guilford County, NC, Iredell County, NC, Lincoln County, NC, McDowell County, NC, Mecklenburg County, NC, Montgomery County, NC, Moore County, NC, Orange County, NC, Person County, NC, Polk County, NC, Randolph County, NC, Richmond County, NC, Rockingham County, NC, Rowan County, NC, Rutherford County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Union County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Bedford County, VA, Bland County, VA, Botetourt County, VA, Campbell County, VA, Carroll County, VA, Charlotte County, VA, City of Danville, VA, City of Galax, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, Craig County, VA, Floyd County, VA, Franklin County, VA, Giles County, VA, Grayson County, VA, Halifax County, VA, Henry County, VA, Montgomery County, VA, Patrick County, VA, Pittsylvania County, VA, Pulaski County, VA, Roanoke County, VA, Smyth County, VA, Wythe County, VA

The radar

The Roanoke radar (KFCX), 61 km from the middle of the area, began a volume at 16:47 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
40%
One or more gusts of 65 knots or more
20%
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
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 24, 1:30 PM EDTSevere Thunderstorm WarningRNKAshe60 min
Mar 24, 1:57 PM EDTSevere Thunderstorm WarningRNKBland, Smyth, Tazewell, Wythe63 min
Mar 24, 2:00 PM EDTSevere Thunderstorm WarningRNKAlleghany, Surry60 min
Mar 24, 2:22 PM EDTSevere Thunderstorm WarningRNKBland, Grayson, Pulaski, Smyth, Wythe53 min
Mar 24, 2:30 PM EDTSevere Thunderstorm WarningRNKBland, Tazewell60 min
Mar 24, 2:34 PM EDTSevere Thunderstorm WarningRNKAlleghany, Ashe56 min
Mar 24, 2:34 PM EDTSevere Thunderstorm WarningRNKAlleghany, Surry, Wilkes56 min
Mar 24, 2:44 PM EDTSevere Thunderstorm WarningRNKSurry61 min
Mar 24, 2:52 PM EDTFlash Flood WarningRNKSurry6 hr
Mar 24, 2:57 PM EDTSevere Thunderstorm WarningRNKBland, Giles, Pulaski, Wythe63 min
Mar 24, 3:26 PM EDTSevere Thunderstorm WarningRNKAlleghany, Surry64 min
Mar 24, 3:37 PM EDTSevere Thunderstorm WarningRNKAlleghany, Craig, Giles, Montgomery, Pulaski53 min
Mar 24, 3:39 PM EDTSevere Thunderstorm WarningRNKFloyd, Franklin, Henry, Patrick66 min
Mar 24, 3:46 PM EDTSevere Thunderstorm WarningGSPCatawba, Gaston, Iredell, Lincoln, Mecklenburg44 min
Mar 24, 3:46 PM EDTTornado WarningRNKFloyd, Patrick29 min
Mar 24, 3:52 PM EDTSevere Thunderstorm WarningGSPGaston, Mecklenburg36 min
Mar 24, 4:08 PM EDTSevere Thunderstorm WarningRNKStokes, Surry, Wilkes, Yadkin67 min
Mar 24, 4:15 PM EDTTornado WarningRNKFranklin, Patrick30 min
Mar 24, 4:20 PM EDTSevere Thunderstorm WarningGSPIredell, Rowan55 min
Mar 24, 4:30 PM EDTSevere Thunderstorm WarningGSPDavie45 min
Mar 24, 4:31 PM EDTSevere Thunderstorm WarningRNKStokes, Surry, Yadkin44 min
Mar 24, 4:36 PM EDTSevere Thunderstorm WarningRAHForsyth39 min
Mar 24, 4:40 PM EDTSevere Thunderstorm WarningRAHDavidson, Forsyth95 min
Mar 24, 4:41 PM EDTTornado WarningRNKFranklin34 min
Mar 24, 4:48 PM EDTTornado WarningRNKPatrick42 min
Mar 24, 5:07 PM EDTSevere Thunderstorm WarningGSPCabarrus, Mecklenburg53 min
Mar 24, 5:09 PM EDTTornado WarningRNKBedford, Franklin36 min
Mar 24, 5:16 PM EDTSevere Thunderstorm WarningRAHDavidson59 min
Mar 24, 5:17 PM EDTFlash Flood WarningRNKFloyd, Patrick5 hr
Mar 24, 5:21 PM EDTSevere Thunderstorm WarningGSPCabarrus, Rowan43 min
Mar 24, 5:24 PM EDTTornado WarningRNKHenry, Patrick36 min
Mar 24, 5:33 PM EDTSevere Thunderstorm WarningRAHGuilford87 min
Mar 24, 5:35 PM EDTSevere Thunderstorm WarningRNKSurry55 min
Mar 24, 5:38 PM EDTSevere Thunderstorm WarningRNKBedford, Campbell, Pittsylvania67 min
Mar 24, 5:51 PM EDTTornado WarningRNKFranklin, Henry, City of Martinsville39 min
Mar 24, 5:52 PM EDTSevere Thunderstorm WarningRAHGuilford, Randolph83 min
Mar 24, 5:58 PM EDTSevere Thunderstorm WarningRAHMontgomery, Stanly62 min
Mar 24, 6:01 PM EDTSevere Thunderstorm WarningRAHDavidson59 min
Mar 24, 6:05 PM EDTFlash Flood WarningRNKSurry4 hr
Mar 24, 6:05 PM EDTTornado WarningRNKCampbell25 min
Mar 24, 6:07 PM EDTSevere Thunderstorm WarningRNKStokes53 min
Mar 24, 6:18 PM EDTSevere Thunderstorm WarningGSPUnion27 min
Mar 24, 6:19 PM EDTTornado WarningRNKPittsylvania41 min
Mar 24, 6:23 PM EDTSevere Thunderstorm WarningRAHRandolph97 min
Mar 24, 6:24 PM EDTSevere Thunderstorm WarningRAHAnson51 min
Mar 24, 6:25 PM EDTFlash Flood WarningRNKFranklin, Henry, Patrick4 hr
Mar 24, 6:25 PM EDTTornado WarningRNKAmherst, Bedford, Campbell, City of Lynchburg35 min
Mar 24, 6:33 PM EDTSevere Thunderstorm WarningRNKHenry, City of Martinsville34 min
Mar 24, 6:45 PM EDTSevere Thunderstorm WarningRNKCaswell, Rockingham60 min
Mar 24, 6:51 PM EDTSevere Thunderstorm WarningRAHAlamance84 min
Mar 24, 6:52 PM EDTSevere Thunderstorm WarningRAHDurham, Orange38 min
Mar 24, 6:53 PM EDTSevere Thunderstorm WarningRNKAppomattox, Campbell37 min
Mar 24, 7:04 PM EDTSevere Thunderstorm WarningRNKPittsylvania56 min
Mar 24, 7:14 PM EDTSevere Thunderstorm WarningRAHGuilford, Randolph61 min
Mar 24, 7:25 PM EDTSevere Thunderstorm WarningRAHDurham, Orange, Person65 min
Mar 24, 7:39 PM EDTSevere Thunderstorm WarningRNKCaswell81 min
Mar 24, 7:42 PM EDTSevere Thunderstorm WarningRAHAlamance, Chatham, Randolph64 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, 4.8 hours before the alert went out and 68 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 2012-03-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 226 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 2012-03-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 167 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
226 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
526 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
167 m²/s²
0-3 km storm-relative helicity
153 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.5

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 24, 12:03 PM EDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Anson, Cabarrus, Caswell and 20 more117 min
Mar 24, 2:31 PM EDTMesoscale DiscussionSPCAlexander, Alleghany, Ashe, Avery, Burke, Caldwell and 4 more59 min
Mar 24, 2:54 PM EDTMesoscale DiscussionSPCCaswell, Forsyth, Guilford, Rockingham, Stokes, Surry and 1 more66 min
Mar 24, 3:38 PM EDTTornado WatchSPCAlamance, Anson, Caswell, Chatham, Cumberland, Davidson and 30 more7 hr
Mar 24, 4:16 PM EDTMesoscale DiscussionSPCCabarrus, Davidson, Davie, Forsyth, Iredell, Mecklenburg and 6 more59 min
Mar 24, 6:03 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 24 more2 hr
Mar 24, 6:43 PM EDTTornado WatchSPCCaswell, Rockingham4 hr
Mar 24, 6:58 PM EDTMesoscale DiscussionSPCAlexander, Alleghany, Burke, Cabarrus, Caldwell, Catawba and 9 more92 min
Mar 24, 7:34 PM EDTMesoscale DiscussionSPCAlamance, Anson, Caswell, Chatham, Cumberland, Durham and 23 more116 min
Mar 24, 3:02 PM EDTSevere Thunderstorm WatchSPCAlbemarle, Alleghany, Amherst, Appomattox, Augusta, Bath and 13 more5 hr

Nearby

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