Alert archive / North Carolina / Tornado Watches in 2011
Tornado Watch 809
The Storm Prediction Center issued this tornado watch at Aug 26, 2011, 8:11 PM EDT for 12 counties in North Carolina. It was in force for 9 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 26, 2011, 8:11 PM EDT (00:11 UTC)
- Expired
- Aug 27, 2011, 5:00 AM EDT
- In force
- 9 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 60 kt
Counties Beaufort County, NC, Brunswick County, NC, Carteret County, NC, Craven County, NC, Dare County, NC, Hyde County, NC, Jones County, NC, New Hanover County, NC, Onslow County, NC, Pamlico County, NC, Pender County, NC, Tyrrell County, NC
The radar
The Morehead City radar (KMHX), 56 km from the middle of the area, began a volume at 00:11 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
- 70%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 10%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 30%
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 |
|---|---|---|---|---|
| Aug 26, 9:09 PM EDT | Tornado Warning | MHX | Beaufort, Hyde, Pamlico | 36 min |
| Aug 26, 10:39 PM EDT | Tornado Warning | MHX | Onslow | 36 min |
| Aug 26, 10:53 PM EDT | Tornado Warning | MHX | Tyrrell, Washington | 52 min |
| Aug 26, 10:54 PM EDT | Tornado Warning | MHX | Beaufort, Hyde, Tyrrell, Washington | 36 min |
| Aug 26, 11:43 PM EDT | Tornado Warning | MHX | Tyrrell | 32 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 00:00Z, 0.2 hours before the alert went out and 56 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
- 148 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 445 m above ground
- 0-6 km bulk shear
- 50 kt
- 0-1 km storm-relative helicity
- 361 m²/s²
- 0-3 km storm-relative helicity
- 415 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.9
The text
As transmitted, in the capitals the NWS used until 2016.
353
WWUS20 KWNS 270020
SEL9
SPC WW 270020
NCZ000-CWZ000-270900-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 809
NWS STORM PREDICTION CENTER NORMAN OK
815 PM EDT FRI AUG 26 2011
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
FAR EASTERN NORTH CAROLINA
COASTAL WATERS
EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 815 PM
UNTIL 500 AM EDT.
TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.
THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 30 STATUTE
MILES EITHER SIDE OF A LINE FROM 40 MILES NORTH NORTHEAST OF CAPE
HATTERAS NORTH CAROLINA TO 15 MILES SOUTHWEST OF WILMINGTON NORTH
CAROLINA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).
REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.
OTHER WATCH INFORMATION...CONTINUE...WW 808...
DISCUSSION...DISCRETE SHOWERS AND TSTMS WITH LOW LVL ROTATION
EXPECTED TO PERSIST ALONG ARC OF LOW LVL CONFLUENCE NOW LOCATED OVER
THE NC CSTL WATERS ON NRN FRINGE OF CIRCULATION OF HRCN IRENE. AS
IRENE CONTINUES SLOWLY NWD...THE CONFLUENCE BAND SHOULD GRADUALLY
LIFT NWD...WITH ADDITIONAL WARMING/MOISTENING OF THE BOUNDARY LAYER
OCCURRING IN ITS VICINITY. THIS MAY ALLOW THE LOW LVL
CIRCULATIONS...AND THEIR ATTENDANT TORNADO THREAT...TO SPREAD
FARTHER W WITH TIME...IMPACTING THE BARRIER ISLANDS FIRST
AND...LATER THIS EVE/EARLY SAT...FAR ERN PORTIONS OF THE NC CSTL
PLN. GIVEN EXISTING WIND PROFILES...AND THE LIKELIHOOD FOR SOME
STRENGTHENING OF THE LOW LVL WIND FIELD IN WW AREA LATER
TNGT...EXPECT THAT TORNADO RISK WILL INCREASE WITH TIME...ESPECIALLY
OVER FAR ERN AND NERN NC
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 12035.
...CORFIDISPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 26, 11:06 PM EDT | Mesoscale Discussion | SPC | Beaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 36 more | 84 min |
| Aug 27, 12:32 AM EDT | Tornado Watch | SPC | Beaufort, Bertie, Camden, Carteret, Chowan, Craven and 14 more | 10 hr |
| Aug 27, 3:06 AM EDT | Mesoscale Discussion | SPC | Beaufort, Bertie, Brunswick, Camden, Carteret, Chowan and 14 more | 114 min |
| Aug 27, 7:52 AM EDT | Mesoscale Discussion | SPC | Camden, Currituck, Gates, Pasquotank | 113 min |
Nearby
Tornado Watches in North Carolina, 2011Every tornado 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.