Alert archive / North Carolina / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 299
The Storm Prediction Center issued this severe thunderstorm watch at May 13, 2011, 4:44 PM EDT for 4 states. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- May 13, 2011, 4:44 PM EDT (20:44 UTC)
- Expired
- May 14, 2011, 12:57 AM EDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 75 counties
Elbert County, GA, Franklin County, GA, Hart County, GA, Stephens County, GA, Alamance County, NC, Anson County, NC, Cabarrus County, NC, Caswell County, NC, Catawba County, NC, Chatham County, NC, Cleveland County, NC, Davidson County, NC, Davie County, NC, Durham County, NC, Forsyth County, NC, Gaston County, NC, Granville County, NC, Guilford County, NC, Henderson County, NC, Iredell County, NC, Lee County, NC, Lincoln County, NC, Mecklenburg County, NC, Montgomery County, NC, Moore County, NC, Orange County, NC, Person County, NC, Polk County, NC, Randolph County, NC, Richmond County, NC, Rockingham County, NC, Rowan County, NC, Rutherford County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Union County, NC, Vance County, NC, Wake County, NC, Yadkin County, NC, Abbeville County, SC, Anderson County, SC, Cherokee County, SC, Chester County, SC, Chesterfield County, SC, Greenville County, SC, Greenwood County, SC, Lancaster County, SC, Laurens County, SC, Oconee County, SC, Pickens County, SC, Spartanburg County, SC, Union County, SC, York County, SC, Bedford County, VA, Botetourt County, VA, Campbell County, VA, Carroll County, VA, Charlotte County, VA, City of Danville, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Roanoke, VA, City of Salem, VA, Craig County, VA, Floyd County, VA, Franklin County, VA, Giles County, VA, Halifax County, VA, Henry County, VA, Montgomery County, VA, Patrick County, VA, Pittsylvania County, VA, Pulaski County, VA, Roanoke County, VA
The radar
The Roanoke radar (KFCX), 109 km from the middle of the area, began a volume at 20:47 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
- 40%
- One or more gusts of 65 knots or more
- 30%
- 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
- 70%
Warnings issued inside it
22 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 13, 4:52 PM EDT | Severe Thunderstorm Warning | GSP | Franklin, Stephens | 53 min |
| May 13, 5:10 PM EDT | Flash Flood Warning | RNK | Giles | 4 hr |
| May 13, 5:15 PM EDT | Severe Thunderstorm Warning | RNK | Stokes, Surry, Yadkin | 60 min |
| May 13, 5:30 PM EDT | Severe Thunderstorm Warning | GSP | Burke, McDowell, Rutherford | 60 min |
| May 13, 5:37 PM EDT | Severe Thunderstorm Warning | GSP | Franklin, Stephens | 53 min |
| May 13, 5:47 PM EDT | Severe Thunderstorm Warning | RAH | Davidson, Forsyth | 58 min |
| May 13, 6:05 PM EDT | Severe Thunderstorm Warning | GSP | Burke, Catawba, Cleveland, Lincoln | 55 min |
| May 13, 6:23 PM EDT | Severe Thunderstorm Warning | RAH | Chatham | 52 min |
| May 13, 6:25 PM EDT | Severe Thunderstorm Warning | GSP | Greenville, Pickens | 65 min |
| May 13, 6:30 PM EDT | Severe Thunderstorm Warning | RNK | Stokes, Surry, Yadkin | 37 min |
| May 13, 6:31 PM EDT | Severe Thunderstorm Warning | RAH | Chatham, Lee | 44 min |
| May 13, 6:48 PM EDT | Severe Thunderstorm Warning | RAH | Forsyth | 42 min |
| May 13, 7:01 PM EDT | Severe Thunderstorm Warning | RAH | Durham, Orange, Person | 44 min |
| May 13, 7:38 PM EDT | Severe Thunderstorm Warning | RAH | Durham, Wake | 52 min |
| May 13, 7:55 PM EDT | Severe Thunderstorm Warning | GSP | Cherokee, Spartanburg, Union | 47 min |
| May 13, 8:07 PM EDT | Severe Thunderstorm Warning | GSP | Alexander, Catawba, Iredell | 53 min |
| May 13, 8:34 PM EDT | Severe Thunderstorm Warning | GSP | Davie, Iredell, Rowan | 56 min |
| May 13, 9:01 PM EDT | Severe Thunderstorm Warning | GSP | Gaston, Mecklenburg | 26 min |
| May 13, 9:13 PM EDT | Severe Thunderstorm Warning | GSP | Davie | 47 min |
| May 13, 9:56 PM EDT | Severe Thunderstorm Warning | RAH | Davidson, Forsyth | 34 min |
| May 13, 10:23 PM EDT | Severe Thunderstorm Warning | GSP | Union | 55 min |
| May 13, 10:25 PM EDT | Severe Thunderstorm Warning | RAH | Guilford, Randolph | 50 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
Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 8.7 hours before the alert went out and 41 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
- 185 J/kg
- Mixed-layer CIN
- -88 J/kg
- Mixed-layer LCL
- 606 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 73 m²/s²
- 0-3 km storm-relative helicity
- 64 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 |
|---|---|---|---|---|
| May 13, 12:22 PM EDT | Mesoscale Discussion | SPC | Catoosa, Chattooga, Fannin, Floyd, Gilmer, Gordon and 4 more | 113 min |
| May 13, 1:10 PM EDT | Severe Thunderstorm Watch | SPC | Bartow, Catoosa, Chattooga, Cherokee, Dade, Dawson and 18 more | 6 hr |
| May 13, 3:47 PM EDT | Mesoscale Discussion | SPC | Banks, Barrow, Bartow, Cherokee, Cobb, Dawson and 22 more | 58 min |
| May 13, 4:36 PM EDT | Mesoscale Discussion | SPC | Alamance, Alexander, Alleghany, Anson, Ashe, Avery and 28 more | 24 min |
| May 13, 7:21 PM EDT | Severe Thunderstorm Watch | SPC | Bladen, Cumberland, Duplin, Edgecombe, Franklin, Greene and 11 more | 6 hr |
Nearby
Severe Thunderstorm Watches in North Carolina, 2011Severe Thunderstorm Watches in Virginia, 2011Severe Thunderstorm Watches in South Carolina, 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.