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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

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