Alert archive / Virginia / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 354
The Storm Prediction Center issued this severe thunderstorm watch at May 24, 2011, 10:00 AM EDT for 9 counties in North Carolina; 37 counties in Virginia; 4 counties in West Virginia. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- May 24, 2011, 10:00 AM EDT (14:00 UTC)
- Expired
- May 24, 2011, 4:45 PM EDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 50 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, Alleghany 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 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, Floyd County, VA, Franklin County, VA, Giles County, VA, Grayson County, VA, Halifax County, VA, Henry County, VA, Montgomery County, VA, Patrick County, VA, Pittsylvania County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Smyth 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), 87 km from the middle of the area, began a volume at 14:03 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 30%
- 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
- 20%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
14 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 24, 10:25 AM EDT | Severe Thunderstorm Warning | RNK | Bland, Smyth, Tazewell | 50 min |
| May 24, 11:34 AM EDT | Severe Thunderstorm Warning | RNK | Floyd, Franklin, Henry, Montgomery, Patrick, City of Martinsville | 56 min |
| May 24, 12:02 PM EDT | Severe Thunderstorm Warning | RNK | Stokes | 58 min |
| May 24, 12:12 PM EDT | Severe Thunderstorm Warning | RNK | Bedford, Campbell, Franklin, Pittsylvania | 36 min |
| May 24, 12:28 PM EDT | Severe Thunderstorm Warning | RNK | Franklin, Halifax, Henry, Pittsylvania | 62 min |
| May 24, 12:47 PM EDT | Severe Thunderstorm Warning | RNK | Caswell, Rockingham, Stokes | 58 min |
| May 24, 1:11 PM EDT | Severe Thunderstorm Warning | RNK | Campbell, Charlotte, Halifax, Pittsylvania | 54 min |
| May 24, 3:04 PM EDT | Severe Thunderstorm Warning | RNK | Alleghany, Ashe, Surry, Watauga, Wilkes, Yadkin | 56 min |
| May 24, 3:21 PM EDT | Tornado Warning | RNK | Alleghany, Surry, Wilkes | 39 min |
| May 24, 3:51 PM EDT | Tornado Warning | RNK | Surry, Wilkes, Yadkin | 39 min |
| May 24, 3:56 PM EDT | Severe Thunderstorm Warning | RNK | Alleghany, Surry, Wilkes, Yadkin | 64 min |
| May 24, 4:27 PM EDT | Tornado Warning | RNK | Stokes, Surry, Yadkin | 40 min |
| May 24, 4:31 PM EDT | Severe Thunderstorm Warning | RNK | Bland, Smyth, Tazewell, Wythe | 59 min |
| May 24, 4:37 PM EDT | Severe Thunderstorm Warning | RNK | Rockingham, Stokes, Surry, Yadkin | 53 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, 2.0 hours before the alert went out and 144 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
- 354 J/kg
- Mixed-layer CIN
- -64 J/kg
- Mixed-layer LCL
- 922 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 148 m²/s²
- 0-3 km storm-relative helicity
- 210 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.9
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 24, 8:34 AM EDT | Mesoscale Discussion | SPC | Alamance, Alexander, Alleghany, Ashe, Avery, Caldwell and 13 more | 116 min |
| May 24, 12:15 PM EDT | Mesoscale Discussion | SPC | Alamance, Bertie, Camden, Caswell, Chowan, Durham and 24 more | 90 min |
| May 24, 12:42 PM EDT | Severe Thunderstorm Watch | SPC | Alamance, Bertie, Camden, Chowan, Currituck, Durham and 20 more | 5 hr |
| May 24, 3:33 PM EDT | Mesoscale Discussion | SPC | Alamance, Alexander, Alleghany, Ashe, Avery, Bertie and 30 more | 87 min |
| May 24, 4:43 PM EDT | Tornado Watch | SPC | Alamance, Alleghany, Ashe, Caswell, Forsyth, Guilford and 8 more | 5 hr |
| May 24, 7:33 PM EDT | Mesoscale Discussion | SPC | Alamance, Alleghany, Ashe, Caswell, Durham, Forsyth and 11 more | 57 min |
| May 23, 8:47 PM EDT | Mesoscale Discussion | SPC | Bedford, Benton, Cannon, Cheatham, Chester, Clay and 32 more | 58 min |
| May 24, 6:24 AM EDT | Mesoscale Discussion | SPC | Anderson, Bledsoe, Campbell, Cannon, Claiborne, Clay and 27 more | 96 min |
| May 24, 7:01 AM EDT | Severe Thunderstorm Watch | SPC | Anderson, Bledsoe, Blount, Campbell, Cannon, Carter and 40 more | 8 hr |
| May 24, 12:55 PM EDT | Mesoscale Discussion | SPC | Anderson, Campbell, Claiborne, Clay, Cumberland, Davidson and 25 more | 65 min |
| May 24, 1:57 PM EDT | Severe Thunderstorm Watch | SPC | Anderson, Bedford, Bledsoe, Blount, Campbell, Cannon and 44 more | 6 hr |
| May 24, 4:27 PM EDT | Mesoscale Discussion | SPC | Anderson, Campbell, Carter, Claiborne, Fentress, Grainger and 14 more | 63 min |
| May 24, 7:46 PM EDT | Mesoscale Discussion | SPC | Anderson, Bledsoe, Blount, Campbell, Carter, Claiborne and 26 more | 59 min |
| May 23, 8:07 PM EDT | Mesoscale Discussion | SPC | Brooke, Hancock | 83 min |
| May 23, 8:31 PM EDT | Severe Thunderstorm Watch | SPC | Brooke, Cabell, Calhoun, Doddridge, Gilmer, Hancock and 15 more | 3 hr |
Nearby
Severe Thunderstorm Watches in Virginia, 2011Severe Thunderstorm Watches in North Carolina, 2011Severe Thunderstorm Watches in West Virginia, 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.