Alert archive / Virginia / Mesoscale Discussions in 2011
Mesoscale Discussion 622
The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2011, 12:51 PM EDT for 53 counties in North Carolina; 23 counties in South Carolina; 55 counties in Virginia. It was in force for 84 min.
The area
The outline as issued.
The facts
- Issued
- Apr 27, 2011, 12:51 PM EDT (16:51 UTC)
- Expired
- Apr 27, 2011, 2:15 PM EDT
- In force
- 84 min
- Issued by
- the Storm Prediction Center
All 131 counties
Alamance County, NC, Anson County, NC, Bertie County, NC, Bladen County, NC, Cabarrus County, NC, Caswell County, NC, Chatham County, NC, Columbus County, NC, Cumberland County, NC, Davidson County, NC, Davie County, NC, Duplin County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Gaston County, NC, Gates County, NC, Granville County, NC, Greene County, NC, Guilford County, NC, Halifax County, NC, Harnett County, NC, Hertford County, NC, Hoke County, NC, Iredell County, NC, Johnston County, NC, Lee County, NC, Lenoir County, NC, Martin County, NC, Mecklenburg County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Northampton County, NC, Orange County, NC, Person County, NC, Pitt County, NC, Randolph County, NC, Richmond County, NC, Robeson County, NC, Rockingham County, NC, Rowan County, NC, Sampson County, NC, Scotland County, NC, Stanly County, NC, Stokes County, NC, Union County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Wayne County, NC, Wilson County, NC, Bamberg County, SC, Berkeley County, SC, Calhoun County, SC, Chester County, SC, Chesterfield County, SC, Clarendon County, SC, Darlington County, SC, Dillon County, SC, Dorchester County, SC, Fairfield County, SC, Florence County, SC, Horry County, SC, Kershaw County, SC, Lancaster County, SC, Lee County, SC, Lexington County, SC, Marion County, SC, Marlboro County, SC, Orangeburg County, SC, Richland County, SC, Sumter County, SC, Williamsburg County, SC, York County, SC, Albemarle County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Bedford County, VA, Brunswick County, VA, Buckingham County, VA, Campbell County, VA, Caroline County, VA, Charles City County, VA, Charlotte County, VA, Chesterfield County, VA, City of Charlottesville, VA, City of Colonial Heights, VA, City of Danville, VA, City of Emporia, VA, City of Franklin, VA, City of Hopewell, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Petersburg, VA, City of Richmond, VA, City of Suffolk, VA, City of Waynesboro, VA, City of Williamsburg, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Fluvanna County, VA, Franklin County, VA, Goochland County, VA, Greensville County, VA, Halifax County, VA, Hanover County, VA, Henrico County, VA, Henry County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Louisa County, VA, Lunenburg County, VA, Mecklenburg County, VA, Nelson County, VA, New Kent County, VA, Nottoway County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Richmond County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA
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, 4.9 hours before the alert went out and 83 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.
- Mixed-layer CAPE
- 446 J/kg
- Mixed-layer CIN
- -17 J/kg
- Mixed-layer LCL
- 564 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 106 m²/s²
- 0-3 km storm-relative helicity
- 130 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.2
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 27, 8:34 AM EDT | Tornado Watch | SPC | Cherokee, Clay | 4 hr |
| Apr 27, 11:27 AM EDT | Tornado Watch | SPC | Cherokee, Clay | 6 hr |
| Apr 27, 12:39 PM EDT | Mesoscale Discussion | SPC | Cherokee | 66 min |
| Apr 27, 1:23 PM EDT | Tornado Watch | SPC | Alamance, Anson, Caswell, Chatham, Cumberland, Davidson and 28 more | 5 hr |
| Apr 27, 2:03 PM EDT | Mesoscale Discussion | SPC | Cherokee, Clay, Graham | 57 min |
| Apr 27, 3:22 PM EDT | Mesoscale Discussion | SPC | Alleghany, Ashe, Avery, Buncombe, Caldwell, Haywood and 6 more | 83 min |
| Apr 27, 4:36 PM EDT | Tornado Watch | SPC | Cherokee, Clay | 8 hr |
| Apr 27, 6:00 PM EDT | Mesoscale Discussion | SPC | Alamance, Caswell, Durham, Franklin, Granville, Guilford and 5 more | 60 min |
| Apr 27, 6:15 PM EDT | Tornado Watch | SPC | Alamance, Alleghany, Ashe, Caswell, Davidson, Durham and 15 more | 6 hr |
| Apr 27, 6:41 PM EDT | Mesoscale Discussion | SPC | Alexander, Avery, Buncombe, Burke, Caldwell, Catawba and 16 more | 34 min |
| Apr 27, 6:52 PM EDT | Tornado Watch | SPC | Alexander, Avery, Buncombe, Burke, Caldwell, Catawba and 19 more | 9 hr |
| Apr 27, 7:55 PM EDT | Mesoscale Discussion | SPC | Alamance, Caswell, Granville, Orange, Person, Rockingham | 65 min |
| Apr 27, 4:39 PM EDT | Mesoscale Discussion | SPC | Albemarle, Arlington, Augusta, Clarke, Culpeper, Fairfax and 31 more | 66 min |
| Apr 27, 5:38 PM EDT | Mesoscale Discussion | SPC | Buchanan, Dickenson, Lee, Russell, Scott, Wise and 1 more | 37 min |
| Apr 27, 5:44 PM EDT | Tornado Watch | SPC | Buchanan, Dickenson, Lee, Russell, Scott, Smyth and 5 more | 7 hr |
Nearby
Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in North Carolina, 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.