Alert archive / Virginia / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 510
The Storm Prediction Center issued this severe thunderstorm watch at Jul 24, 2012, 1:08 PM EDT for 5 states. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 24, 2012, 1:08 PM EDT (17:08 UTC)
- Expired
- Jul 24, 2012, 7:17 PM EDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 65 kt
All 156 counties
Allegany County, MD, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Washington County, MD, Wicomico County, MD, Worcester County, MD, Alleghany County, NC, Ashe County, NC, Caswell County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Adams County, PA, Bedford County, PA, Blair County, PA, Cambria County, PA, Chester County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lancaster County, PA, Lebanon County, PA, Mifflin County, PA, Perry County, PA, Somerset County, PA, York County, PA, Albemarle County, VA, Alleghany County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Arlington County, VA, Augusta County, VA, Bath County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Buckingham County, VA, Campbell County, VA, Caroline County, VA, Carroll County, VA, Charles City County, VA, Charlotte County, VA, Chesterfield County, VA, City of Alexandria, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Covington, VA, City of Danville, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Galax, VA, City of Harrisonburg, VA, City of Lexington, VA, City of Lynchburg, VA, City of Manassas, VA, City of Martinsville, VA, City of Radford, VA, City of Richmond, VA, City of Roanoke, VA, City of Salem, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Craig County, VA, Culpeper County, VA, Cumberland County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Floyd County, VA, Fluvanna County, VA, Franklin County, VA, Frederick County, VA, Giles County, VA, Goochland County, VA, Grayson County, VA, Greene County, VA, Halifax County, VA, Hanover County, VA, Henrico County, VA, Henry County, VA, Highland County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Loudoun County, VA, Louisa County, VA, Lunenburg County, VA, Madison County, VA, Mecklenburg County, VA, Middlesex County, VA, Montgomery County, VA, Nelson County, VA, New Kent County, VA, Northumberland County, VA, Nottoway County, VA, Orange County, VA, Page County, VA, Patrick County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince William County, VA, Pulaski County, VA, Rappahannock County, VA, Richmond County, VA, Roanoke County, VA, Rockbridge County, VA, Rockingham County, VA, Shenandoah County, VA, Smyth County, VA, Spotsylvania County, VA, Stafford County, VA, Tazewell County, VA, Warren County, VA, Westmoreland County, VA, Wythe County, VA, Berkeley County, WV, Grant County, WV, Greenbrier County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mercer County, WV, Mineral County, WV, Monroe County, WV, Morgan County, WV, Pendleton County, WV, Summers County, WV
The radar
The Roanoke radar (KFCX), 143 km from the middle of the area, began a volume at 17:09 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 95%
- One or more gusts of 65 knots or more
- 50%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 20%
- Six or more combined severe hail and wind reports
- 95%
Warnings issued inside it
8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 24, 1:08 PM EDT | Tornado Warning | LWX | Rockingham, Shenandoah | 37 min |
| Jul 24, 1:34 PM EDT | Severe Thunderstorm Warning | RNK | Alleghany, Ashe, Wilkes | 56 min |
| Jul 24, 2:27 PM EDT | Severe Thunderstorm Warning | LWX | Albemarle, Greene, Madison, Orange, Page, Rockingham and 2 more | 48 min |
| Jul 24, 2:39 PM EDT | Severe Thunderstorm Warning | CTP | Bedford, Somerset | 40 min |
| Jul 24, 4:04 PM EDT | Severe Thunderstorm Warning | CTP | York | 41 min |
| Jul 24, 4:23 PM EDT | Severe Thunderstorm Warning | LWX | Frederick | 37 min |
| Jul 24, 5:24 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, City of Baltimore | 26 min |
| Jul 24, 5:27 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 21 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Roanoke, VA (KRNK), launched 12:00Z, 5.1 hours before the alert went out and 95 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
- 1035 J/kg
- Mixed-layer CIN
- -74 J/kg
- Mixed-layer LCL
- 834 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 252 m²/s²
- 0-3 km storm-relative helicity
- 206 m²/s²
- Significant tornado parameter
- 0.7
- Supercell composite
- 8.2
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 24, 11:48 AM EDT | Mesoscale Discussion | SPC | Allegany, Anne Arundel, Baltimore, Calvert, Caroline, Carroll and 15 more | 87 min |
| Jul 24, 1:42 PM EDT | Mesoscale Discussion | SPC | Calvert, Dorchester, Saint Mary's, Somerset, Wicomico, Worcester | 2 hr |
| Jul 24, 1:12 PM EDT | Mesoscale Discussion | SPC | Alamance, Alexander, Anson, Avery, Buncombe, Burke and 37 more | 93 min |
| Jul 24, 2:36 PM EDT | Severe Thunderstorm Watch | SPC | Alamance, Alexander, Anson, Avery, Buncombe, Burke and 53 more | 5 hr |
| Jul 24, 3:46 PM EDT | Mesoscale Discussion | SPC | Beaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 40 more | 89 min |
| Jul 24, 4:24 PM EDT | Severe Thunderstorm Watch | SPC | Beaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 24 more | 4 hr |
| Jul 24, 11:43 AM EDT | Mesoscale Discussion | SPC | Buchanan, Dickenson, Wise, City of Norton | 62 min |
| Jul 24, 12:33 PM EDT | Severe Thunderstorm Watch | SPC | Buchanan, Dickenson, Lee, Russell, Scott, Washington and 3 more | 6 hr |
| Jul 24, 1:52 PM EDT | Mesoscale Discussion | SPC | Buchanan, Dickenson, Wise, City of Norton | 53 min |
| Jul 24, 3:25 PM EDT | Mesoscale Discussion | SPC | Buchanan, Dickenson, Lee, Russell, Scott, Smyth and 5 more | 95 min |
Nearby
Severe Thunderstorm Watches in Virginia, 2012Severe Thunderstorm Watches in Maryland, 2012Severe Thunderstorm Watches in Pennsylvania, 2012Every severe thunderstorm watch 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.