Alert archive / Virginia / Mesoscale Discussions in 2012

Mesoscale Discussion 1360

July 2, 20125 states

The Storm Prediction Center issued this mesoscale discussion at Jul 2, 2012, 12:39 AM EDT for 5 states. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued: Jul 2, 2012, 12:39 AM EDT (04:39 UTC)
Expired: Jul 2, 2012, 2:15 AM EDT
In force: 96 min
Issued by: the Storm Prediction Center

All 87 counties

Montgomery County, MD, Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Caldwell County, NC, Caswell County, NC, Catawba County, NC, Cleveland County, NC, Davidson County, NC, Davie County, NC, Forsyth County, NC, Gaston County, NC, Guilford County, NC, Iredell County, NC, Lincoln County, NC, McDowell County, NC, Mitchell County, NC, Polk County, NC, Rockingham County, NC, Rowan County, NC, Rutherford County, NC, Stokes County, NC, Surry County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Yancey County, NC, Carter County, TN, Johnson County, TN, Unicoi County, TN, Albemarle 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 Charlottesville, VA, City of Danville, VA, City of Galax, VA, City of Harrisonburg, VA, City of Lexington, VA, City of Lynchburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Martinsville, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Fauquier County, VA, Floyd County, VA, Fluvanna County, VA, Franklin County, VA, Frederick County, VA, Grayson County, VA, Greene County, VA, Halifax County, VA, Henry County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Montgomery County, VA, Nelson County, VA, Orange County, VA, Page County, VA, Patrick County, VA, Pittsylvania County, VA, Prince William County, VA, Pulaski County, VA, Rappahannock County, VA, Roanoke County, VA, Rockbridge County, VA, Rockingham County, VA, Shenandoah County, VA, Warren County, VA, Jefferson County, WV

The radar

The Roanoke radar (KFCX), 21 km from the middle of the area, began a volume at 04:42 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.

Severe Thunderstorm Watch 453Jul 2, 12:55 AM EDT

The nearest sounding before it

Roanoke, VA (KRNK), launched 00:00Z, 4.7 hours before the alert went out and 54 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: 102 J/kg
Mixed-layer CIN: -174 J/kg
Mixed-layer LCL: 2439 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 65 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
Jul 1, 8:32 PM EDT	Mesoscale Discussion	SPC	Allegany, Garrett	88 min
Jul 1, 9:06 PM EDT	Severe Thunderstorm Watch	SPC	Allegany, Garrett, Washington	5 hr
Jul 1, 10:26 PM EDT	Mesoscale Discussion	SPC	Garrett	94 min
Jul 1, 9:45 PM EDT	Mesoscale Discussion	SPC	Anson, Union	60 min
Jul 2, 12:57 AM EDT	Severe Thunderstorm Watch	SPC	Alamance, Alexander, Burke, Cabarrus, Caldwell, Catawba and 23 more	3 hr
Jul 2, 6:16 PM EDT	Mesoscale Discussion	SPC	Bedford, Benton, Bledsoe, Bradley, Cannon, Cheatham and 41 more	2 hr
Jul 1, 8:21 PM EDT	Mesoscale Discussion	SPC	Boone, Cabell, Calhoun, Jackson, Kanawha, Lincoln and 9 more	54 min

Nearby

Mesoscale Discussions in Virginia, 2012 Mesoscale Discussions in North Carolina, 2012 Mesoscale Discussions in Tennessee, 2012 Every mesoscale discussion in 2012

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.