Alert archive / Virginia / Mesoscale Discussions in 2011

Mesoscale Discussion 996

May 27, 20114 states

The Storm Prediction Center issued this mesoscale discussion at May 27, 2011, 3:29 PM EDT for 4 states. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued: May 27, 2011, 3:29 PM EDT (19:29 UTC)
Expired: May 27, 2011, 5:00 PM EDT
In force: 91 min
Issued by: the Storm Prediction Center

All 119 counties

Saint Mary's County, MD, Alamance County, NC, Anson County, NC, Bertie County, NC, Bladen County, NC, Caswell County, NC, Chatham County, NC, Chowan County, NC, Columbus County, NC, Cumberland County, NC, Duplin County, NC, Durham County, NC, Edgecombe County, NC, Franklin 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, Johnston County, NC, Lee County, NC, Lenoir County, NC, Martin County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Northampton County, NC, Orange County, NC, Pender County, NC, Person County, NC, Pitt County, NC, Randolph County, NC, Richmond County, NC, Robeson County, NC, Sampson County, NC, Scotland County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Wayne County, NC, Wilson County, NC, Chesterfield County, SC, Darlington County, SC, Dillon County, SC, Florence County, SC, Horry County, SC, Lee County, SC, Marion County, SC, Marlboro County, SC, 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 Chesapeake, 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 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, 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, 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), 23 km from the middle of the area, began a volume at 19:31 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

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 7.5 hours before the alert went out and 150 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: 31 J/kg
Mixed-layer CIN: -292 J/kg
Mixed-layer LCL: 831 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 93 m²/s²
0-3 km storm-relative helicity: 106 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 27, 12:24 PM EDT	Mesoscale Discussion	SPC	Baltimore, Carroll, Frederick, Howard, Montgomery, Prince George's and 2 more	96 min
May 27, 12:57 PM EDT	Severe Thunderstorm Watch	SPC	Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more	9 hr
May 27, 6:14 PM EDT	Mesoscale Discussion	SPC	Anne Arundel, Baltimore, Carroll, Cecil, Charles, Frederick and 7 more	2 hr
May 26, 11:22 PM EDT	Mesoscale Discussion	SPC	Caswell, Forsyth, Rockingham, Stokes, Yadkin	113 min
May 27, 11:26 AM EDT	Mesoscale Discussion	SPC	Alamance, Anson, Caswell, Chatham, Cumberland, Durham and 27 more	94 min
May 27, 12:06 PM EDT	Severe Thunderstorm Watch	SPC	Alamance, Anson, Cabarrus, Caswell, Chatham, Cumberland and 34 more	7 hr
May 27, 6:24 PM EDT	Mesoscale Discussion	SPC	Alamance, Anson, Bladen, Caswell, Chatham, Columbus and 29 more	66 min

Nearby

Mesoscale Discussions in Virginia, 2011 Mesoscale Discussions in North Carolina, 2011 Mesoscale Discussions in South Carolina, 2011 Every 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.