Alert archive / Virginia / Mesoscale Discussions in 2017

Mesoscale Discussion 1741

October 23, 201725 counties in North Carolina; 31 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Oct 23, 2017, 7:34 PM EDT for 25 counties in North Carolina; 31 counties in Virginia. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued: Oct 23, 2017, 7:34 PM EDT (23:34 UTC)
Expired: Oct 23, 2017, 9:30 PM EDT
In force: 116 min
Issued by: the Storm Prediction Center

All 56 counties

Alamance County, NC, Bladen County, NC, Caswell County, NC, Chatham County, NC, Cumberland County, NC, Durham County, NC, Franklin County, NC, Granville County, NC, Harnett County, NC, Hoke County, NC, Johnston County, NC, Lee County, NC, Moore County, NC, Nash County, NC, Orange County, NC, Person County, NC, Richmond County, NC, Robeson County, NC, Sampson County, NC, Scotland County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Wayne County, NC, Wilson County, NC, Albemarle County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Augusta County, VA, Bath County, VA, Bedford County, VA, Botetourt County, VA, Brunswick County, VA, Buckingham County, VA, Campbell County, VA, Charlotte County, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Danville, VA, City of Harrisonburg, VA, City of Lexington, VA, City of Lynchburg, VA, City of Staunton, VA, City of Waynesboro, VA, Cumberland County, VA, Fluvanna County, VA, Halifax County, VA, Lunenburg County, VA, Mecklenburg County, VA, Nelson County, VA, Nottoway County, VA, Pittsylvania County, VA, Prince Edward County, VA, Rockbridge County, VA, Rockingham County, VA

The radar

The Raleigh/Durham radar (KRAX), 84 km from the middle of the area, began a volume at 23:36 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 12:00Z, 11.6 hours before the alert went out and 88 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 597 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 202 m²/s²
0-3 km storm-relative helicity: 259 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 23, 1:07 PM EDT	Mesoscale Discussion	SPC	Alexander, Anson, Burke, Cabarrus, Caldwell, Catawba and 15 more	113 min
Oct 23, 2:00 PM EDT	Tornado Watch	SPC	Alexander, Alleghany, Anson, Ashe, Avery, Burke and 28 more	8 hr
Oct 23, 4:33 PM EDT	Mesoscale Discussion	SPC	Alexander, Alleghany, Anson, Ashe, Burke, Cabarrus and 22 more	57 min
Oct 23, 5:40 PM EDT	Tornado Watch	SPC	Alamance, Chatham, Cumberland, Durham, Edgecombe, Franklin and 18 more	8 hr
Oct 23, 6:59 PM EDT	Mesoscale Discussion	SPC	Anson, Bladen, Cabarrus, Columbus, Davidson, Davie and 12 more	91 min
Oct 23, 4:58 PM EDT	Mesoscale Discussion	SPC	Amherst, Appomattox, Bedford, Botetourt, Campbell, Carroll and 19 more	92 min

Nearby

Mesoscale Discussions in Virginia, 2017 Mesoscale Discussions in North Carolina, 2017 Every mesoscale discussion in 2017

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.