Alert archive / Virginia / Mesoscale Discussions in 2013

Mesoscale Discussion 104

January 30, 20139 counties in North Carolina; 31 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jan 30, 2013, 7:09 PM EST for 9 counties in North Carolina; 31 counties in Virginia. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued: Jan 30, 2013, 7:09 PM EST (00:09 UTC)
Expired: Jan 30, 2013, 8:15 PM EST
In force: 66 min
Issued by: the Storm Prediction Center

All 40 counties

Alleghany County, NC, Caswell County, NC, Forsyth County, NC, Guilford County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Wilkes County, NC, Yadkin County, NC, Alleghany County, VA, Amherst County, VA, Appomattox County, VA, Bedford County, VA, Botetourt County, VA, Buckingham County, VA, Campbell County, VA, Carroll County, VA, Charlotte 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, Halifax County, VA, Henry County, VA, Montgomery County, VA, Nelson County, VA, Patrick County, VA, Pittsylvania County, VA, Prince Edward County, VA, Roanoke County, VA, Rockbridge County, VA

The radar

The Roanoke radar (KFCX), 71 km from the middle of the area, began a volume at 00:11 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Tornado Watch 25Jan 30, 8:20 PM EST

The nearest sounding before it

Roanoke, VA (KRNK), launched 00:00Z, 0.2 hours before the alert went out and 23 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: 64 J/kg
Mixed-layer CIN: -118 J/kg
Mixed-layer LCL: 567 m above ground
0-6 km bulk shear: 82 kt
0-1 km storm-relative helicity: -186 m²/s²
0-3 km storm-relative helicity: -11 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

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
Jan 30, 7:56 PM EST	Mesoscale Discussion	SPC	Alamance, Anson, Cabarrus, Chatham, Cumberland, Davidson and 28 more	94 min
Jan 30, 8:21 PM EST	Tornado Watch	SPC	Alamance, Anson, Bladen, Brunswick, Caswell, Chatham and 35 more	6 hr
Jan 30, 10:42 PM EST	Mesoscale Discussion	SPC	Bertie, Bladen, Chatham, Chowan, Columbus, Cumberland and 29 more	93 min
Jan 30, 11:59 PM EST	Tornado Watch	SPC	Beaufort, Bertie, Camden, Carteret, Chowan, Craven and 17 more	5 hr
Jan 31, 12:52 AM EST	Mesoscale Discussion	SPC	Beaufort, Bertie, Bladen, Brunswick, Camden, Chowan and 29 more	83 min
Jan 31, 3:40 AM EST	Mesoscale Discussion	SPC	Dare, Hyde	65 min
Jan 30, 9:38 PM EST	Mesoscale Discussion	SPC	Albemarle, Arlington, Buckingham, Caroline, Clarke, Culpeper and 27 more	67 min

Nearby

Mesoscale Discussions in Virginia, 2013 Mesoscale Discussions in North Carolina, 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.