Alert archive / Virginia / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 467
The Storm Prediction Center issued this severe thunderstorm watch at Jun 12, 2011, 1:48 PM EDT for 5 states. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 12, 2011, 1:48 PM EDT (17:48 UTC)
- Expired
- Jun 12, 2011, 8:00 PM EDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 152 counties
Kent County, DE, New Castle County, DE, 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, Talbot County, MD, Washington County, MD, Adams County, PA, Chester County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Lancaster County, PA, Lebanon County, PA, Perry 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, Botetourt County, VA, Brunswick 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 Colonial Heights, VA, City of Covington, VA, City of Danville, VA, City of Emporia, VA, City of Fairfax, VA, City of Falls Church, VA, City of Franklin, VA, City of Fredericksburg, VA, City of Galax, VA, City of Hampton, VA, City of Harrisonburg, VA, City of Hopewell, VA, City of Lexington, VA, City of Lynchburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Martinsville, VA, City of Newport News, VA, City of Petersburg, 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 Williamsburg, VA, City of Winchester, VA, Clarke County, VA, Craig County, VA, Culpeper County, VA, Cumberland County, VA, Dinwiddie 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, Gloucester County, VA, Goochland County, VA, Grayson County, VA, Greene County, VA, Greensville County, VA, Halifax County, VA, Hanover County, VA, Henrico County, VA, Henry County, VA, Highland County, VA, Isle of Wight County, VA, James City 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, Mathews 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 George 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, Southampton County, VA, Spotsylvania County, VA, Stafford County, VA, Surry County, VA, Sussex County, VA, Warren County, VA, Westmoreland County, VA, Wythe County, VA, York County, VA, Berkeley County, WV, Grant County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV, Pendleton County, WV
The radar
The Sterling radar (KLWX), 54 km from the middle of the area, began a volume at 17:50 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
- 10%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 70%
- One or more gusts of 65 knots or more
- 30%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 90%
Warnings issued inside it
37 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 12, 2:02 PM EDT | Severe Thunderstorm Warning | CTP | Franklin, Fulton | 58 min |
| Jun 12, 2:06 PM EDT | Severe Thunderstorm Warning | CTP | Adams, Cumberland, Dauphin, Lancaster, Lebanon, Perry and 1 more | 54 min |
| Jun 12, 2:10 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Frederick, Washington | 50 min |
| Jun 12, 2:42 PM EDT | Severe Thunderstorm Warning | LWX | Albemarle, Nelson, City of Charlottesville | 48 min |
| Jun 12, 2:43 PM EDT | Severe Thunderstorm Warning | RNK | Henry, Patrick, City of Martinsville | 62 min |
| Jun 12, 2:49 PM EDT | Tornado Warning | CTP | Dauphin, Lancaster, York | 26 min |
| Jun 12, 2:56 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 34 min |
| Jun 12, 2:56 PM EDT | Severe Thunderstorm Warning | CTP | Adams, Dauphin, Lancaster, Lebanon, York | 79 min |
| Jun 12, 3:11 PM EDT | Severe Thunderstorm Warning | RNK | Amherst, Appomattox, Buckingham | 79 min |
| Jun 12, 3:12 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Saint Mary's | 48 min |
| Jun 12, 3:16 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery, Washington | 44 min |
| Jun 12, 3:16 PM EDT | Tornado Warning | CTP | Lancaster, York | 44 min |
| Jun 12, 3:26 PM EDT | Severe Thunderstorm Warning | AKQ | Cumberland, Fluvanna, Goochland | 39 min |
| Jun 12, 3:32 PM EDT | Severe Thunderstorm Warning | LWX | Clarke, Loudoun | 43 min |
| Jun 12, 3:45 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 45 min |
| Jun 12, 3:47 PM EDT | Tornado Warning | CTP | York | 13 min |
| Jun 12, 3:51 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 54 min |
| Jun 12, 3:52 PM EDT | Tornado Warning | LWX | Harford | 23 min |
| Jun 12, 4:03 PM EDT | Severe Thunderstorm Warning | AKQ | Amelia, Cumberland, Powhatan, Prince Edward | 42 min |
| Jun 12, 4:03 PM EDT | Severe Thunderstorm Warning | LWX | Fairfax, Fauquier, Loudoun, Prince William, City of Fairfax, City of Manassas and 1 more | 42 min |
| Jun 12, 4:13 PM EDT | Tornado Warning | LWX | Harford | 47 min |
| Jun 12, 4:26 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 49 min |
| Jun 12, 4:41 PM EDT | Tornado Warning | LWX | Harford | 35 min |
| Jun 12, 4:49 PM EDT | Severe Thunderstorm Warning | RNK | Appomattox, Bedford, Campbell, Charlotte, Halifax, Pittsylvania | 58 min |
| Jun 12, 4:51 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford, City of Baltimore | 39 min |
| Jun 12, 5:00 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 45 min |
| Jun 12, 5:08 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 52 min |
| Jun 12, 5:26 PM EDT | Severe Thunderstorm Warning | RNK | Charlotte, Halifax | 50 min |
| Jun 12, 5:35 PM EDT | Severe Thunderstorm Warning | RNK | Amherst, Appomattox, Bedford, Campbell, City of Lynchburg | 44 min |
| Jun 12, 5:40 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 37 min |
| Jun 12, 5:55 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's, Talbot | 65 min |
| Jun 12, 6:13 PM EDT | Severe Thunderstorm Warning | AKQ | Isle of Wight, City of Newport News | 23 min |
| Jun 12, 6:30 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 45 min |
| Jun 12, 6:34 PM EDT | Severe Thunderstorm Warning | AKQ | Caroline, Essex, Westmoreland | 23 min |
| Jun 12, 6:50 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Sussex | 55 min |
| Jun 12, 6:53 PM EDT | Severe Thunderstorm Warning | AKQ | Caroline, Essex, King and Queen, Richmond, Westmoreland | 40 min |
| Jun 12, 7:28 PM EDT | Severe Thunderstorm Warning | AKQ | Caroline, Essex, King and Queen, King William, Lancaster, Richmond | 31 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
Washington/Dulle, VA (KIAD), launched 12:00Z, 5.8 hours before the alert went out and 59 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
- 360 J/kg
- Mixed-layer CIN
- -50 J/kg
- Mixed-layer LCL
- 861 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- -27 m²/s²
- 0-3 km storm-relative helicity
- 2 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 12, 12:03 PM EDT | Mesoscale Discussion | SPC | Allegany, Anne Arundel, Baltimore, Carroll, Charles, Frederick and 8 more | 87 min |
| Jun 12, 3:39 PM EDT | Mesoscale Discussion | SPC | Anne Arundel, Baltimore, Charles, Howard, Montgomery, Prince George's and 1 more | 96 min |
Nearby
Severe Thunderstorm Watches in Virginia, 2011Severe Thunderstorm Watches in Maryland, 2011Severe Thunderstorm Watches in Pennsylvania, 2011Every severe thunderstorm watch in 2011
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.