Alert archive / North Carolina / Mesoscale Discussions in 2011

Mesoscale Discussion 1280

June 18, 201125 counties in North Carolina; 14 counties in South Carolina; 18 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jun 18, 2011, 5:46 PM EDT for 25 counties in North Carolina; 14 counties in South Carolina; 18 counties in Virginia. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued
Jun 18, 2011, 5:46 PM EDT (21:46 UTC)
Expired
Jun 18, 2011, 6:45 PM EDT
In force
59 min
Issued by
the Storm Prediction Center
All 57 counties

Alamance County, NC, Anson County, NC, Caswell County, NC, Chatham County, NC, Cumberland County, NC, Durham County, NC, Franklin County, NC, Granville County, NC, Guilford County, NC, Harnett County, NC, Hoke County, NC, Johnston County, NC, Lee County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Orange County, NC, Person County, NC, Randolph County, NC, Richmond County, NC, Robeson County, NC, Scotland County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Chesterfield County, SC, Darlington County, SC, Dillon County, SC, Fairfield County, SC, Greenwood County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Lee County, SC, Marlboro County, SC, Newberry County, SC, Richland County, SC, Saluda County, SC, Sumter County, SC, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Bedford County, VA, Brunswick County, VA, Buckingham County, VA, Campbell County, VA, Charlotte County, VA, City of Danville, VA, City of Lynchburg, VA, Cumberland County, VA, Halifax County, VA, Lunenburg County, VA, Mecklenburg County, VA, Nottoway County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA

The radar

The Raleigh/Durham radar (KRAX), 134 km from the middle of the area, began a volume at 21:48 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 9.8 hours before the alert went out and 48 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 2011-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 166 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 2011-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 square meters per square second.1939Sfc1 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
166 J/kg
Mixed-layer CIN
-76 J/kg
Mixed-layer LCL
1389 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
-56 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 18, 9:38 AM EDTMesoscale DiscussionSPCBuncombe, Cherokee, Clay, Graham, Haywood, Henderson and 5 more97 min
Jun 18, 11:05 AM EDTSevere Thunderstorm WatchSPCAlexander, Avery, Buncombe, Burke, Cabarrus, Caldwell and 24 more9 hr
Jun 18, 2:21 PM EDTMesoscale DiscussionSPCAlexander, Alleghany, Ashe, Burke, Caldwell, Catawba and 18 more84 min
Jun 18, 3:38 PM EDTSevere Thunderstorm WatchSPCAlamance, Anson, Caswell, Chatham, Davidson, Durham and 17 more4 hr
Jun 18, 7:20 PM EDTSevere Thunderstorm WatchSPCBladen, Brunswick, Columbus, New Hanover, Pender, Robeson5 hr
Jun 18, 3:55 PM EDTMesoscale DiscussionSPCAbbeville, Aiken, Calhoun, Edgefield, Fairfield, Greenwood and 6 more35 min
Jun 18, 4:08 PM EDTSevere Thunderstorm WatchSPCAbbeville, Aiken, Bamberg, Barnwell, Calhoun, Chesterfield and 14 more6 hr
Jun 18, 6:49 PM EDTMesoscale DiscussionSPCAbbeville, Aiken, Allendale, Anderson, Bamberg, Barnwell and 21 more86 min

Nearby

Mesoscale Discussions in North Carolina, 2011Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in South Carolina, 2011Every mesoscale discussion in 2011

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.