Alert archive / North Carolina / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 816
The Storm Prediction Center issued this severe thunderstorm watch at Aug 29, 2011, 3:28 PM EDT for 45 counties in North Carolina. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 29, 2011, 3:28 PM EDT (19:28 UTC)
- Expired
- Aug 29, 2011, 11:00 PM EDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 45 counties
Beaufort County, NC, Bertie County, NC, Camden County, NC, Chatham County, NC, Chowan County, NC, Craven County, NC, Cumberland County, NC, Currituck County, NC, Dare County, NC, Duplin County, NC, Durham County, NC, Edgecombe County, NC, Franklin County, NC, Gates County, NC, Granville County, NC, Greene County, NC, Halifax County, NC, Harnett County, NC, Hertford County, NC, Hoke County, NC, Hyde County, NC, Johnston County, NC, Jones County, NC, Lee County, NC, Lenoir County, NC, Martin County, NC, Moore County, NC, Nash County, NC, Northampton County, NC, Onslow County, NC, Orange County, NC, Pamlico County, NC, Pasquotank County, NC, Perquimans County, NC, Pitt County, NC, Richmond County, NC, Sampson County, NC, Scotland County, NC, Tyrrell County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Washington County, NC, Wayne County, NC, Wilson County, NC
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
27 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 29, 3:55 PM EDT | Severe Thunderstorm Warning | AKQ | Gates, Hertford | 50 min |
| Aug 29, 4:00 PM EDT | Tornado Warning | AKQ | Bertie, Hertford | 30 min |
| Aug 29, 4:13 PM EDT | Severe Thunderstorm Warning | RAH | Durham, Franklin, Granville, Wake | 62 min |
| Aug 29, 4:29 PM EDT | Tornado Warning | AKQ | Bertie, Chowan, Gates, Hertford | 31 min |
| Aug 29, 4:40 PM EDT | Tornado Warning | MHX | Dare, Hyde, Tyrrell | 50 min |
| Aug 29, 4:42 PM EDT | Severe Thunderstorm Warning | RAH | Durham, Granville, Person | 63 min |
| Aug 29, 4:48 PM EDT | Severe Thunderstorm Warning | RAH | Montgomery, Richmond | 57 min |
| Aug 29, 4:49 PM EDT | Tornado Warning | AKQ | Bertie, Chowan | 26 min |
| Aug 29, 5:05 PM EDT | Severe Thunderstorm Warning | AKQ | Bertie | 25 min |
| Aug 29, 5:05 PM EDT | Severe Thunderstorm Warning | RAH | Franklin, Nash | 55 min |
| Aug 29, 5:14 PM EDT | Severe Thunderstorm Warning | RAH | Franklin, Johnston, Wake | 24 min |
| Aug 29, 5:21 PM EDT | Severe Thunderstorm Warning | RAH | Alamance, Orange | 39 min |
| Aug 29, 6:01 PM EDT | Severe Thunderstorm Warning | RAH | Edgecombe, Halifax, Nash | 44 min |
| Aug 29, 6:06 PM EDT | Severe Thunderstorm Warning | RAH | Chatham | 39 min |
| Aug 29, 6:13 PM EDT | Tornado Warning | RAH | Edgecombe, Nash, Wilson | 47 min |
| Aug 29, 6:41 PM EDT | Tornado Warning | RAH | Edgecombe | 34 min |
| Aug 29, 6:45 PM EDT | Severe Thunderstorm Warning | RAH | Chatham, Harnett, Wake | 45 min |
| Aug 29, 6:46 PM EDT | Severe Thunderstorm Warning | MHX | Martin, Pitt | 59 min |
| Aug 29, 7:04 PM EDT | Severe Thunderstorm Warning | RAH | Franklin, Wake | 41 min |
| Aug 29, 7:09 PM EDT | Severe Thunderstorm Warning | MHX | Beaufort | 51 min |
| Aug 29, 7:30 PM EDT | Flash Flood Warning | RAH | Edgecombe, Nash | 3 hr |
| Aug 29, 7:48 PM EDT | Severe Thunderstorm Warning | MHX | Pitt | 42 min |
| Aug 29, 8:10 PM EDT | Severe Thunderstorm Warning | MHX | Beaufort, Pamlico | 41 min |
| Aug 29, 8:12 PM EDT | Severe Thunderstorm Warning | MHX | Dare | 18 min |
| Aug 29, 8:38 PM EDT | Severe Thunderstorm Warning | RAH | Hoke, Scotland | 67 min |
| Aug 29, 8:54 PM EDT | Severe Thunderstorm Warning | RAH | Cumberland | 52 min |
| Aug 29, 9:34 PM EDT | Severe Thunderstorm Warning | RAH | Edgecombe, Wilson | 25 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
Newport, NC (KMHX), launched 12:00Z, 7.5 hours before the alert went out and 155 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
- 1590 J/kg
- Mixed-layer CIN
- -37 J/kg
- Mixed-layer LCL
- 913 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 22 m²/s²
- 0-3 km storm-relative helicity
- 29 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.1
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 29, 11:08 AM EDT | Mesoscale Discussion | SPC | Beaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 39 more | 97 min |
| Aug 29, 2:13 PM EDT | Mesoscale Discussion | SPC | Alamance, Anson, Beaufort, Bertie, Bladen, Brunswick and 49 more | 2 hr |
| Aug 29, 3:56 PM EDT | Severe Thunderstorm Watch | SPC | Bladen, Brunswick, Columbus, New Hanover, Pender, Robeson | 7 hr |
| Aug 29, 7:53 PM EDT | Mesoscale Discussion | SPC | Beaufort, Bertie, Bladen, Camden, Chowan, Columbus and 36 more | 67 min |
Nearby
Severe Thunderstorm Watches in North 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.