Alert archive / Virginia / Mesoscale Discussions in 2020

Mesoscale Discussion 323

April 9, 20204 counties in North Carolina; 46 counties in Virginia; Hardy County, Pendleton County, West Virginia

The Storm Prediction Center issued this mesoscale discussion at Apr 9, 2020, 3:36 AM EDT for 4 counties in North Carolina; 46 counties in Virginia; Hardy County, Pendleton County, West Virginia. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Apr 9, 2020, 3:36 AM EDT (07:36 UTC)
Expired: Apr 9, 2020, 5:00 AM EDT
In force: 84 min
Issued by: the Storm Prediction Center

All 52 counties

Alleghany County, NC, Ashe County, NC, Stokes County, NC, Surry County, NC, Albemarle County, VA, Alleghany County, VA, Amherst County, VA, Augusta County, VA, Bath County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Carroll County, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Covington, VA, City of Galax, VA, City of Harrisonburg, 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, City of Staunton, VA, City of Waynesboro, VA, Craig County, VA, Culpeper County, VA, Floyd County, VA, Franklin County, VA, Giles County, VA, Grayson County, VA, Greene County, VA, Henry County, VA, Highland County, VA, Madison County, VA, Montgomery County, VA, Nelson County, VA, Orange County, VA, Page County, VA, Patrick County, VA, Pulaski County, VA, Rappahannock County, VA, Roanoke County, VA, Rockbridge County, VA, Rockingham County, VA, Shenandoah County, VA, Smyth County, VA, Warren County, VA, Wythe County, VA, Hardy County, WV, Pendleton County, WV

The radar

The Roanoke radar (KFCX), 105 km from the middle of the area, began a volume at 07:38 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

Roanoke, VA (KRNK), launched 00:00Z, 7.6 hours before the alert went out and 66 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: 1382 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 145 m²/s²
0-3 km storm-relative helicity: 268 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
Apr 8, 10:52 PM EDT	Mesoscale Discussion	SPC	Cherokee, Clay, Graham	113 min
Apr 8, 11:16 PM EDT	Severe Thunderstorm Watch	SPC	Avery, Buncombe, Cherokee, Clay, Graham, Haywood and 8 more	6 hr
Apr 9, 2:03 AM EDT	Severe Thunderstorm Watch	SPC	Alleghany, Ashe, Watauga	3 hr
Apr 8, 10:14 PM EDT	Mesoscale Discussion	SPC	Buchanan, Dickenson, Wise, City of Norton	3 hr
Apr 8, 10:51 PM EDT	Tornado Watch	SPC	Buchanan, Dickenson	5 hr
Apr 9, 12:50 AM EDT	Mesoscale Discussion	SPC	Alleghany, Bath, Bland, Craig, Giles, Highland and 7 more	115 min
Apr 9, 12:01 PM EDT	Severe Thunderstorm Watch	SPC	Arlington, Fairfax, City of Alexandria, City of Fairfax, City of Falls Church	4 hr

Nearby

Mesoscale Discussions in Virginia, 2020 Mesoscale Discussions in North Carolina, 2020 Mesoscale Discussions in West Virginia, 2020 Every mesoscale discussion in 2020

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.