Alert archive / Virginia / Mesoscale Discussions in 2015

Mesoscale Discussion 1393

July 13, 20154 states

The Storm Prediction Center issued this mesoscale discussion at Jul 13, 2015, 4:07 PM EDT for 4 states. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: Jul 13, 2015, 4:07 PM EDT (20:07 UTC)
Expired: Jul 13, 2015, 5:30 PM EDT
In force: 83 min
Issued by: the Storm Prediction Center
Chance of a watch: 60%

All 76 counties

Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Caldwell County, NC, Catawba County, NC, Iredell County, NC, Madison County, NC, McDowell County, NC, Mitchell County, NC, Stokes County, NC, Surry County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Yancey County, NC, Carter County, TN, Cocke County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Hancock County, TN, Hawkins County, TN, Jefferson County, TN, Johnson County, TN, Sullivan County, TN, Unicoi County, TN, Washington County, TN, Alleghany County, VA, Bath County, VA, Bland County, VA, Botetourt County, VA, Carroll County, VA, City of Bristol, VA, City of Covington, VA, City of Galax, VA, City of Lexington, VA, City of Norton, 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, Grayson County, VA, Highland County, VA, Lee County, VA, Montgomery County, VA, Patrick County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Russell County, VA, Scott County, VA, Smyth County, VA, Tazewell County, VA, Washington County, VA, Wise County, VA, Wythe County, VA, Braxton County, WV, Clay County, WV, Fayette County, WV, Greenbrier County, WV, Mercer County, WV, Monroe County, WV, Nicholas County, WV, Pocahontas County, WV, Raleigh County, WV, Randolph County, WV, Summers County, WV, Upshur County, WV, Webster County, WV, Wyoming County, WV

The radar

The Roanoke radar (KFCX), 112 km from the middle of the area, began a volume at 20:10 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.

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 8.1 hours before the alert went out and 180 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: 377 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 669 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 131 m²/s²
0-3 km storm-relative helicity: 119 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

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 13, 4:39 PM EDT	Severe Thunderstorm Watch	SPC	Alexander, Alleghany, Ashe, Avery, Buncombe, Burke and 13 more	5 hr
Jul 13, 5:45 PM EDT	Mesoscale Discussion	SPC	Alleghany, Ashe, Avery, Caldwell, Madison, Mitchell and 5 more	2 hr
Jul 13, 6:23 PM EDT	Severe Thunderstorm Watch	SPC	Alamance, Anson, Caswell, Chatham, Cumberland, Davidson and 21 more	6 hr
Jul 13, 6:55 PM EDT	Severe Thunderstorm Watch	SPC	Cabarrus, Cherokee, Clay, Cleveland, Gaston, Graham and 11 more	4 hr
Jul 13, 12:01 PM EDT	Mesoscale Discussion	SPC	Cheatham, Clay, Davidson, Fentress, Jackson, Macon and 10 more	89 min
Jul 13, 12:55 PM EDT	Severe Thunderstorm Watch	SPC	Buchanan, Dickenson	7 hr
Jul 13, 3:04 PM EDT	Mesoscale Discussion	SPC	Buchanan, Dickenson	86 min

Nearby

Mesoscale Discussions in Virginia, 2015 Mesoscale Discussions in North Carolina, 2015 Mesoscale Discussions in West Virginia, 2015 Every mesoscale discussion in 2015

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.