Tornado Watch 644

Issued

Sep 18, 2012, 1:00 PM EDT (17:00 UTC)

Expired

Sep 18, 2012, 6:10 PM EDT

In force

5 hr

Issued by

the Storm Prediction Center

Largest hail expected

0.5 in

Strongest gust expected

60 kt

Counties Beaufort County, NC, Carteret County, NC, Craven County, NC, Dare County, NC, Duplin County, NC, Greene County, NC, Hyde County, NC, Jones County, NC, Lenoir County, NC, Martin County, NC, Onslow County, NC, Pamlico County, NC, Pitt County, NC, Tyrrell County, NC, Washington County, NC

The Morehead City radar (KMHX), 114 km from the middle of the area, began a volume at 17:00 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.

Two or more tornadoes

40%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

60%

One or more gusts of 65 knots or more

30%

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

80%

• Mesoscale Discussion 1960Sep 18, 11:19 AM EDT
• Mesoscale Discussion 1969Sep 18, 4:11 PM EDT

594 
WWUS20 KWNS 181632
SEL4
SPC WW 181632
NCZ000-CWZ000-190000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 644
NWS STORM PREDICTION CENTER NORMAN OK
1230 PM EDT TUE SEP 18 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

       EASTERN NORTH CAROLINA
       COASTAL WATERS

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 1230 PM UNTIL
800 PM 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 55 STATUTE
MILES EAST AND WEST OF A LINE FROM 20 MILES NORTH NORTHWEST OF
ELIZABETH CITY NORTH CAROLINA TO 25 MILES EAST SOUTHEAST OF
JACKSONVILLE NORTH CAROLINA.  FOR A COMPLETE DEPICTION OF THE
WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).

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 641...WW 642...WW 643...

DISCUSSION...DAYTIME HEATING COUPLED WITH A VERY MOIST ENVIRONMENT
HAS RESULTED IN A MODERATELY UNSTABLE AIR MASS WITH MLCAPE OF
1000-1500 J/KG.  CURRENT MHX VAD SHOWS A VERTICALLY VEERING WIND
PROFILE WITH SUFFICIENT LOW AND DEEP-LAYER SHEAR FOR ORGANIZED STORM
MODES INCLUDING SUPERCELLS AND BOWING LINE SEGMENTS.  WHILE DAMAGING
WINDS WILL BE THE PRIMARY HAZARD...A FEW TORNADOES ARE ALSO
POSSIBLE.

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
450. MEAN STORM MOTION VECTOR 23035.


...MEAD

Tornado Watches in North Carolina, 2012Every tornado watch in 2012

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.