Alert archive / North Carolina / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 301
The Storm Prediction Center issued this severe thunderstorm watch at May 13, 2011, 7:21 PM EDT for 17 counties in North Carolina. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- May 13, 2011, 7:21 PM EDT (23:21 UTC)
- Expired
- May 14, 2011, 12:57 AM EDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
Counties Bladen County, NC, Cumberland County, NC, Duplin County, NC, Edgecombe County, NC, Franklin County, NC, Greene County, NC, Harnett County, NC, Hoke County, NC, Johnston County, NC, Lenoir County, NC, Nash County, NC, Pitt County, NC, Robeson County, NC, Sampson County, NC, Scotland County, NC, Wayne County, NC, Wilson County, NC
The radar
The Raleigh/Durham radar (KRAX), 12 km from the middle of the area, began a volume at 23:21 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
- 2%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 13, 7:46 PM EDT | Severe Thunderstorm Warning | RAH | Harnett | 59 min |
| May 13, 8:34 PM EDT | Severe Thunderstorm Warning | RAH | Cumberland, Harnett, Johnston, Sampson, Wayne | 56 min |
The nearest sounding before it
Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 11.4 hours before the alert went out and 147 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 | Cherokee, Graham, Swain | 113 min |
| May 13, 1:10 PM EDT | Severe Thunderstorm Watch | SPC | Alexander, Alleghany, Ashe, Avery, Buncombe, Burke and 15 more | 6 hr |
| May 13, 3:47 PM EDT | Mesoscale Discussion | SPC | Ashe, Avery, Buncombe, Cherokee, Clay, Graham and 11 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, 4:44 PM EDT | Severe Thunderstorm Watch | SPC | Alamance, Anson, Cabarrus, Caswell, Catawba, Chatham and 30 more | 8 hr |
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; radar from the NEXRAD Level II archive.