Alert archive / North Carolina / Mesoscale Discussions in 2014

Mesoscale Discussion 1487

July 27, 201419 counties in North Carolina; 13 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jul 27, 2014, 4:49 PM EDT for 19 counties in North Carolina; 13 counties in Virginia. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued: Jul 27, 2014, 4:49 PM EDT (20:49 UTC)
Expired: Jul 27, 2014, 6:45 PM EDT
In force: 116 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

All 32 counties

Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Burke County, NC, Caldwell County, NC, Davie County, NC, Forsyth County, NC, Guilford County, NC, Iredell County, NC, McDowell County, NC, Mitchell County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Yancey County, NC, Carroll County, VA, City of Danville, VA, City of Galax, VA, City of Martinsville, VA, City of Radford, VA, Floyd County, VA, Franklin County, VA, Grayson County, VA, Henry County, VA, Patrick County, VA, Pittsylvania County, VA, Pulaski County, VA, Wythe County, VA

The radar

The Roanoke radar (KFCX), 105 km from the middle of the area, began a volume at 20:50 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 448Jul 27, 6:35 PM EDT

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 8.8 hours before the alert went out and 113 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: 116 J/kg
Mixed-layer CIN: -224 J/kg
Mixed-layer LCL: 1295 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: -70 m²/s²
0-3 km storm-relative helicity: 70 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 27, 10:08 AM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Bladen, Camden, Chowan, Craven and 28 more	67 min
Jul 27, 6:32 PM EDT	Tornado Watch	SPC	Alexander, Alleghany, Ashe, Avery, Buncombe, Burke and 27 more	6 hr
Jul 27, 1:00 PM EDT	Tornado Watch	SPC	Buchanan, Dickenson, Lee, Russell, Scott, Washington and 3 more	11 hr
Jul 27, 3:14 PM EDT	Mesoscale Discussion	SPC	Dickenson, Lee, Russell, Scott, Wise, City of Bristol and 1 more	2 hr
Jul 27, 6:52 PM EDT	Severe Thunderstorm Watch	SPC	Clarke, Frederick, Shenandoah, Warren, City of Winchester	7 hr
Jul 27, 7:28 PM EDT	Mesoscale Discussion	SPC	Dickenson, Lee, Russell, Scott, Washington, Wise and 2 more	92 min

Nearby

Mesoscale Discussions in North Carolina, 2014 Mesoscale Discussions in Virginia, 2014 Every mesoscale discussion in 2014

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.