Alert archive / Virginia / Severe Thunderstorm Watches in 2007
Severe Thunderstorm Watch 486
The Storm Prediction Center issued this severe thunderstorm watch at Jul 4, 2007, 5:01 PM EDT for 9 counties in North Carolina; 52 counties in Virginia; 4 counties in West Virginia. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 4, 2007, 5:01 PM EDT (21:01 UTC)
- Expired
- Jul 4, 2007, 8:33 PM EDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 65 counties
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, Albemarle County, VA, Alleghany County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Bath County, VA, Bedford County, VA, Bland 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 Covington, VA, City of Danville, VA, City of Galax, 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, Craig County, VA, Cumberland County, VA, Floyd County, VA, Fluvanna County, VA, Franklin County, VA, Giles County, VA, Goochland County, VA, Grayson County, VA, Halifax County, VA, Henry County, VA, Louisa County, VA, Lunenburg County, VA, Mecklenburg County, VA, Montgomery County, VA, Nelson County, VA, Nottoway County, VA, Orange County, VA, Patrick County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Smyth County, VA, Spotsylvania County, VA, Tazewell County, VA, Wythe County, VA, Greenbrier County, WV, Mercer County, WV, Monroe County, WV, Summers County, WV
The radar
The Roanoke radar (KFCX), 48 km from the middle of the area, began a volume at 21:03 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
- 5%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 80%
Warnings issued inside it
1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 4, 5:32 PM EDT | Severe Thunderstorm Warning | LWX | Culpeper, Orange | 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, 9.0 hours before the alert went out and 284 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
- 139 J/kg
- Mixed-layer CIN
- -185 J/kg
- Mixed-layer LCL
- 759 m above ground
- 0-6 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 150 m²/s²
- 0-3 km storm-relative helicity
- 128 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 4, 12:39 PM EDT | Mesoscale Discussion | SPC | Accomack, Arlington, Caroline, Clarke, Culpeper, Essex and 24 more | 66 min |
| Jul 4, 2:06 PM EDT | Tornado Watch | SPC | Arlington, Augusta, Clarke, Culpeper, Fairfax, Fauquier and 22 more | 8 hr |
| Jul 4, 4:13 PM EDT | Mesoscale Discussion | SPC | Arlington, Augusta, Caroline, Clarke, Culpeper, Fairfax and 27 more | 62 min |
| Jul 4, 4:27 PM EDT | Mesoscale Discussion | SPC | Albemarle, Alleghany, Amelia, Amherst, Appomattox, Bath and 82 more | 63 min |
| Jul 4, 1:27 PM EDT | Mesoscale Discussion | SPC | Braxton, Cabell, Calhoun, Clay, Doddridge, Gilmer and 18 more | 63 min |
| Jul 4, 1:41 PM EDT | Tornado Watch | SPC | Barbour, Braxton, Brooke, Cabell, Calhoun, Doddridge and 22 more | 7 hr |
Nearby
Severe Thunderstorm Watches in Virginia, 2007Severe Thunderstorm Watches in North Carolina, 2007Severe Thunderstorm Watches in West Virginia, 2007Every severe thunderstorm watch in 2007
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.