Alert archive / Virginia / Mesoscale Discussions in 2013

Mesoscale Discussion 634

May 11, 2013Calvert County, Charles County, Saint Mary's County, Maryland; 41 counties in North Carolina; 69 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at May 11, 2013, 7:11 PM EDT for Calvert County, Charles County, Saint Mary's County, Maryland; 41 counties in North Carolina; 69 counties in Virginia. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued: May 11, 2013, 7:11 PM EDT (23:11 UTC)
Expired: May 11, 2013, 8:15 PM EDT
In force: 64 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 113 counties

Calvert County, MD, Charles County, MD, Saint Mary's County, MD, Alamance County, NC, Anson County, NC, Cabarrus County, NC, Caswell County, NC, Chatham County, NC, Davidson County, NC, Davie County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Gaston County, NC, Gates County, NC, Granville 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, Lincoln County, NC, Mecklenburg County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Northampton County, NC, Orange County, NC, Person County, NC, Randolph County, NC, Richmond County, NC, Rockingham County, NC, Rowan County, NC, Stanly County, NC, Stokes County, NC, Union County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Wilson County, NC, Albemarle County, VA, Amelia County, VA, Appomattox 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 Fredericksburg, VA, City of Hampton, VA, City of Hopewell, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Richmond, VA, City of Suffolk, VA, City of Williamsburg, VA, Culpeper County, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Fluvanna County, VA, Gloucester 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 George County, VA, King William County, VA, Lancaster County, VA, Louisa County, VA, Lunenburg County, VA, Mathews County, VA, Mecklenburg County, VA, Middlesex County, VA, Nelson County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Nottoway County, VA, Orange County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Richmond County, VA, Southampton County, VA, Spotsylvania County, VA, Stafford County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA

The radar

The Raleigh/Durham radar (KRAX), 98 km from the middle of the area, began a volume at 23:13 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 nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 11.2 hours before the alert went out and 113 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 43 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 733 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 70 m²/s²
0-3 km storm-relative helicity: 116 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.

Issued	Product	Office	Counties	Lasted
May 11, 1:44 PM EDT	Mesoscale Discussion	SPC	Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 15 more	91 min
May 11, 2:14 PM EDT	Mesoscale Discussion	SPC	Beaufort, Brunswick, Carteret, Craven, Dare, Hyde and 5 more	91 min

Nearby

Mesoscale Discussions in Virginia, 2013 Mesoscale Discussions in North Carolina, 2013 Mesoscale Discussions in Maryland, 2013 Every mesoscale discussion in 2013

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.