Alert archive / Virginia / Mesoscale Discussions in 2012
Mesoscale Discussion 1929
The Storm Prediction Center issued this mesoscale discussion at Sep 8, 2012, 12:20 PM EDT for 16 counties in North Carolina; 28 counties in Virginia. It was in force for 115 min.
The area
The outline as issued.
The facts
- Issued
- Sep 8, 2012, 12:20 PM EDT (16:20 UTC)
- Expired
- Sep 8, 2012, 2:15 PM EDT
- In force
- 115 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 80%
All 44 counties
Alamance County, NC, Alexander County, NC, Alleghany County, NC, Caswell County, NC, Davidson County, NC, Davie County, NC, Forsyth County, NC, Guilford County, NC, Iredell County, NC, Orange County, NC, Person County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Wilkes County, NC, Yadkin County, NC, 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 Danville, VA, City of Galax, VA, City of Lexington, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Roanoke, VA, City of Salem, VA, Cumberland County, VA, Floyd County, VA, Fluvanna County, VA, Franklin County, VA, Halifax County, VA, Henry County, VA, Nelson County, VA, Patrick County, VA, Pittsylvania County, VA, Prince Edward County, VA, Roanoke County, VA, Rockbridge County, VA
The radar
The Roanoke radar (KFCX), 54 km from the middle of the area, began a volume at 16:24 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
Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 4.3 hours before the alert went out and 82 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.
- Mixed-layer CAPE
- 305 J/kg
- Mixed-layer CIN
- -62 J/kg
- Mixed-layer LCL
- 814 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 68 m²/s²
- 0-3 km storm-relative helicity
- 44 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 8, 1:14 PM EDT | Mesoscale Discussion | SPC | Cabarrus, Catawba, Cleveland, Gaston, Iredell, Lincoln and 6 more | 2 hr |
| Sep 8, 1:48 PM EDT | Severe Thunderstorm Watch | SPC | Alamance, Alexander, Anson, Cabarrus, Caswell, Catawba and 44 more | 7 hr |
| Sep 8, 3:25 PM EDT | Mesoscale Discussion | SPC | Alamance, Alexander, Cabarrus, Caswell, Catawba, Chatham and 33 more | 65 min |
| Sep 8, 7:10 PM EDT | Mesoscale Discussion | SPC | Beaufort, Bertie, Bladen, Chowan, Craven, Cumberland and 23 more | 65 min |
| Sep 8, 11:38 AM EDT | Mesoscale Discussion | SPC | Arlington, Clarke, Culpeper, Fairfax, Fauquier, Frederick and 16 more | 97 min |
| Sep 8, 12:15 PM EDT | Severe Thunderstorm Watch | SPC | Albemarle, Arlington, Augusta, Clarke, Culpeper, Fairfax and 27 more | 9 hr |
| Sep 8, 2:12 PM EDT | Mesoscale Discussion | SPC | Arlington, Culpeper, Fairfax, Fauquier, Loudoun, Prince William and 8 more | 93 min |
Nearby
Mesoscale Discussions in Virginia, 2012Mesoscale Discussions in North Carolina, 2012Every 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.