Alert archive / Virginia / Tornado Watches in 2009
Tornado Watch 276
The Storm Prediction Center issued this tornado watch at May 8, 2009, 10:01 PM EDT for Caswell County, Rockingham County, Stokes County, North Carolina; 27 counties in Virginia. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- May 8, 2009, 10:01 PM EDT (02:01 UTC)
- Expired
- May 9, 2009, 2:02 AM EDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 50 kt
All 30 counties
Caswell County, NC, Rockingham County, NC, Stokes County, NC, Alleghany County, VA, Amherst County, VA, Appomattox County, VA, Bedford County, VA, Botetourt County, VA, Buckingham County, VA, Campbell County, VA, Charlotte County, VA, City of Buena Vista, VA, City of Covington, VA, City of Danville, 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, Halifax County, VA, Henry County, VA, Montgomery County, VA, Patrick County, VA, Pittsylvania County, VA, Roanoke County, VA, Rockbridge County, VA
The radar
The Roanoke radar (KFCX), 50 km from the middle of the area, began a volume at 02:04 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
- 30%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 50%
Warnings issued inside it
5 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 8, 11:41 PM EDT | Severe Thunderstorm Warning | RNK | Carroll, Grayson, Patrick, City of Galax | 64 min |
| May 8, 11:48 PM EDT | Severe Thunderstorm Warning | RNK | Franklin, Henry, Patrick, Pittsylvania | 42 min |
| May 9, 12:23 AM EDT | Severe Thunderstorm Warning | RNK | Appomattox, Campbell, Charlotte, Halifax, Pittsylvania | 63 min |
| May 9, 12:29 AM EDT | Severe Thunderstorm Warning | RNK | Rockingham, Stokes | 37 min |
| May 9, 12:29 AM EDT | Severe Thunderstorm Warning | RNK | Franklin, Halifax, Henry, Pittsylvania | 33 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 00:00Z, 2.0 hours before the alert went out and 21 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
- 113 J/kg
- Mixed-layer CIN
- -42 J/kg
- Mixed-layer LCL
- 1561 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 84 m²/s²
- 0-3 km storm-relative helicity
- 103 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.8
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 8, 8:30 PM EDT | Mesoscale Discussion | SPC | Alexander, Alleghany, Ashe, Avery, Buncombe, Burke and 19 more | 90 min |
| May 8, 11:37 PM EDT | Mesoscale Discussion | SPC | Alleghany, Ashe, Forsyth, Rockingham, Stokes, Surry and 3 more | 53 min |
| May 9, 12:51 AM EDT | Mesoscale Discussion | SPC | Caswell, Edgecombe, Franklin, Gates, Granville, Halifax and 7 more | 84 min |
| May 9, 12:47 PM EDT | Mesoscale Discussion | SPC | Alamance, Alexander, Burke, Cabarrus, Caldwell, Caswell and 32 more | 118 min |
| May 9, 1:17 PM EDT | Severe Thunderstorm Watch | SPC | Alamance, Alexander, Anson, Burke, Cabarrus, Caldwell and 36 more | 8 hr |
| May 9, 4:30 PM EDT | Mesoscale Discussion | SPC | Alamance, Cabarrus, Caswell, Catawba, Chatham, Davidson and 19 more | 90 min |
| May 9, 5:58 PM EDT | Mesoscale Discussion | SPC | Bertie, Camden, Chatham, Chowan, Durham, Edgecombe and 20 more | 62 min |
| May 9, 6:25 PM EDT | Severe Thunderstorm Watch | SPC | Beaufort, Bertie, Camden, Carteret, Chowan, Craven and 31 more | 4 hr |
| May 9, 1:07 AM EDT | Tornado Watch | SPC | Amelia, Brunswick, Charles City, Chesterfield, Cumberland, Dinwiddie and 39 more | 4 hr |
Nearby
Tornado Watches in Virginia, 2009Tornado Watches in North Carolina, 2009Every tornado watch in 2009
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.