Alert archive / North Carolina / Mesoscale Discussions in 2008

Mesoscale Discussion 668

April 19, 20084 states

The Storm Prediction Center issued this mesoscale discussion at Apr 19, 2008, 9:00 PM EDT for 4 states. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued: Apr 19, 2008, 9:00 PM EDT (01:00 UTC)
Expired: Apr 19, 2008, 10:00 PM EDT
In force: 60 min
Issued by: the Storm Prediction Center

All 71 counties

Alamance County, NC, Alexander County, NC, Anson County, NC, Cabarrus County, NC, Caswell County, NC, Catawba County, NC, Chatham County, NC, Davidson County, NC, Davie County, NC, Forsyth County, NC, Gaston County, NC, Guilford County, NC, Iredell County, NC, Lee County, NC, Lincoln County, NC, Mecklenburg County, NC, Montgomery County, NC, Moore County, NC, Orange County, NC, Person County, NC, Randolph County, NC, Richmond County, NC, Rockingham County, NC, Rowan County, NC, Scotland County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Union County, NC, Yadkin County, NC, Chester County, SC, Chesterfield County, SC, Darlington County, SC, Fairfield County, SC, Kershaw County, SC, Lancaster County, SC, Lee County, SC, Marlboro County, SC, Richland County, SC, York County, SC, Alleghany County, VA, Amherst County, VA, Bath County, VA, Bedford County, VA, Botetourt County, VA, Campbell County, VA, Carroll County, VA, City of Buena Vista, VA, City of Covington, VA, City of Danville, VA, City of Galax, VA, City of Lexington, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, Craig County, VA, Floyd County, VA, Franklin County, VA, Giles County, VA, Halifax County, VA, Henry County, VA, Montgomery County, VA, Patrick County, VA, Pittsylvania County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Greenbrier County, WV, Monroe County, WV

The radar

The Roanoke radar (KFCX), 109 km from the middle of the area, began a volume at 01:03 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 00:00Z, 1.0 hours before the alert went out and 53 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: 40 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 1047 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 122 m²/s²
0-3 km storm-relative helicity: 166 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
Apr 20, 1:14 PM EDT	Mesoscale Discussion	SPC	Alamance, Anson, Beaufort, Bertie, Cabarrus, Caswell and 44 more	2 hr
Apr 20, 1:47 PM EDT	Severe Thunderstorm Watch	SPC	Alamance, Beaufort, Bertie, Camden, Carteret, Caswell and 48 more	8 hr
Apr 20, 4:20 PM EDT	Mesoscale Discussion	SPC	Alamance, Beaufort, Bertie, Camden, Carteret, Caswell and 42 more	85 min
Apr 20, 7:14 PM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Camden, Carteret, Chowan, Craven and 28 more	61 min
Apr 20, 11:20 AM EDT	Mesoscale Discussion	SPC	Chesterfield, Dinwiddie, Greensville, Hanover, City of Colonial Heights, City of Emporia and 3 more	2 hr
Apr 20, 6:44 PM EDT	Mesoscale Discussion	SPC	Caroline, Charles City, Essex, Hanover, Henrico, James City and 15 more	61 min

Nearby

Mesoscale Discussions in North Carolina, 2008 Mesoscale Discussions in Virginia, 2008 Mesoscale Discussions in South Carolina, 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.