Alert archive / Virginia / Mesoscale Discussions in 2012
Mesoscale Discussion 1620
The Storm Prediction Center issued this mesoscale discussion at Jul 27, 2012, 1:08 PM EDT for Rockingham County, Stokes County, Surry County, North Carolina; 42 counties in Virginia. It was in force for 67 min.
The area
The outline as issued.
The facts
- Issued
- Jul 27, 2012, 1:08 PM EDT (17:08 UTC)
- Expired
- Jul 27, 2012, 2:15 PM EDT
- In force
- 67 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 80%
All 45 counties
Rockingham County, NC, Stokes County, NC, Surry County, NC, Albemarle County, VA, Amelia County, VA, 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 Charlottesville, VA, City of Danville, VA, City of Fredericksburg, 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, City of Staunton, VA, City of Waynesboro, VA, Cumberland County, VA, Floyd County, VA, Fluvanna County, VA, Franklin County, VA, Goochland County, VA, Greene County, VA, Halifax County, VA, Hanover County, VA, Henry County, VA, Louisa County, VA, Montgomery County, VA, Nelson County, VA, Orange County, VA, Patrick County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Roanoke County, VA, Rockbridge County, VA, Spotsylvania County, VA
The radar
The Roanoke radar (KFCX), 126 km from the middle of the area, began a volume at 17:11 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, 5.1 hours before the alert went out and 55 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
- 408 J/kg
- Mixed-layer CIN
- -166 J/kg
- Mixed-layer LCL
- 912 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 20 m²/s²
- 0-3 km storm-relative helicity
- 46 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 |
|---|---|---|---|---|
| Jul 27, 1:54 PM EDT | Mesoscale Discussion | SPC | Avery, Buncombe, Burke, Caldwell, Cherokee, Clay and 11 more | 66 min |
| Jul 27, 1:54 PM EDT | Severe Thunderstorm Watch | SPC | Alamance, Alleghany, Anson, Ashe, Bertie, Camden and 41 more | 8 hr |
| Jul 27, 4:52 PM EDT | Mesoscale Discussion | SPC | Alamance, Alleghany, Caswell, Forsyth, Granville, Guilford and 7 more | 53 min |
| Jul 27, 7:50 PM EDT | Mesoscale Discussion | SPC | Bertie, Camden, Chatham, Chowan, Cumberland, Currituck and 27 more | 85 min |
| Jul 26, 9:06 PM EDT | Mesoscale Discussion | SPC | Arlington, Clarke, Culpeper, Fairfax, Fauquier, Frederick and 17 more | 84 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.