Alert archive / Virginia / Mesoscale Discussions in 2008

Mesoscale Discussion 831

May 8, 20084 counties in Maryland; 26 counties in North Carolina; 67 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at May 8, 2008, 9:47 PM EDT for 4 counties in Maryland; 26 counties in North Carolina; 67 counties in Virginia. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: May 8, 2008, 9:47 PM EDT (01:47 UTC)
Expired: May 8, 2008, 10:45 PM EDT
In force: 58 min
Issued by: the Storm Prediction Center

All 97 counties

Calvert County, MD, Charles County, MD, Prince George's County, MD, Saint Mary's County, MD, Alamance County, NC, Cabarrus County, NC, Caswell County, NC, Chatham County, NC, Davidson County, NC, Davie County, NC, Durham County, NC, Forsyth County, NC, Franklin County, NC, Granville County, NC, Guilford County, NC, Iredell County, NC, Lee County, NC, Montgomery County, NC, Moore County, NC, Orange County, NC, Person County, NC, Randolph County, NC, Rockingham County, NC, Rowan County, NC, Stanly County, NC, Stokes County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Yadkin County, NC, Albemarle County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Arlington 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 Alexandria, VA, City of Charlottesville, VA, City of Colonial Heights, VA, City of Danville, VA, City of Emporia, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Hopewell, VA, City of Lynchburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Martinsville, VA, City of Petersburg, VA, City of Richmond, VA, City of Waynesboro, VA, Culpeper County, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Franklin County, VA, Goochland County, VA, Greene County, VA, Greensville County, VA, Halifax County, VA, Hanover County, VA, Henrico County, VA, Henry County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Louisa County, VA, Lunenburg County, VA, Madison County, VA, Mecklenburg County, VA, Nelson County, VA, New Kent County, VA, Nottoway County, VA, Orange County, VA, Patrick County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Prince William County, VA, Rappahannock County, VA, Richmond County, VA, Spotsylvania County, VA, Stafford County, VA, Sussex County, VA, Westmoreland County, VA

The radar

The Norfolk radar (KAKQ), 134 km from the middle of the area, began a volume at 01:49 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 00:00Z, 1.8 hours before the alert went out and 88 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: 196 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1306 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 98 m²/s²
0-3 km storm-relative helicity: 288 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.6

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 8, 8:38 PM EDT	Tornado Watch	SPC	Calvert, Charles, Saint Mary's	6 hr
May 9, 2:32 AM EDT	Mesoscale Discussion	SPC	Calvert, Charles, Saint Mary's, Somerset	88 min
May 9, 3:00 AM EDT	Tornado Watch	SPC	Calvert, Saint Mary's	8 hr
May 9, 6:37 AM EDT	Mesoscale Discussion	SPC	Dorchester, Somerset, Wicomico, Worcester	53 min
May 9, 12:06 AM EDT	Mesoscale Discussion	SPC	Alamance, Caswell, Durham, Granville, Guilford, Orange and 2 more	54 min
May 9, 5:04 AM EDT	Mesoscale Discussion	SPC	Bertie, Camden, Chatham, Chowan, Currituck, Durham and 25 more	56 min
May 9, 5:56 AM EDT	Mesoscale Discussion	SPC	Brunswick, Columbus	2 hr
May 9, 8:29 AM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Camden, Carteret, Chowan, Craven and 18 more	61 min
May 9, 7:18 PM EDT	Mesoscale Discussion	SPC	Dickenson, Lee, Scott, Wise, City of Norton	57 min

Nearby

Mesoscale Discussions in Virginia, 2008 Mesoscale Discussions in North Carolina, 2008 Mesoscale Discussions in Maryland, 2008 Every mesoscale discussion in 2008

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.