MESOSCALE DISCUSSION 0668
   NWS STORM PREDICTION CENTER NORMAN OK
   0727 PM CDT THU APR 28 2011
   
   AREAS AFFECTED...SERN VA...SRN DELMARVA PENINSULA...AND ERN NC
   
   CONCERNING...TORNADO WATCH 255...
   
   VALID 290027Z - 290100Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 255 CONTINUES.
   
   SEVERE WEATHER THREAT WILL CONTINUE TO AFFECT THE ERN PARTS OF WW
   255 BEYOND THE EXPIRATION TIME OF 01Z.  LIMITED SPATIAL AND TEMPORAL
   THREAT SHOULD PRECLUDE THE NEED FOR A NEW WATCH.  HOWEVER...LOCAL
   WFO EXTENSION OF THIS WATCH IS POSSIBLE DUE TO A CONTINUED SEVERE
   WEATHER THREAT THROUGH 02-03Z.
   
   THE AIR MASS ACROSS WW 255 REMAINS SUPPORTIVE FOR SEVERE STORMS
   /MODERATE INSTABILITY AND EFFECTIVE BULK SHEAR 45-60 KT/...
   INCLUDING A TORNADO THREAT PER EFFECTIVE SRH OF 200-300 M2/S2. 
   EARLY EVENING RADAR TRENDS SUGGEST STORMS WILL CONTINUE TO AFFECT
   FAR ERN NC INCLUDING THE OUTER BANKS THROUGH 02Z.  FARTHER
   N...WEAKER LOW LEVEL SHEAR SUGGESTS A GREATER THREAT FOR ISOLATED
   DAMAGING WINDS AND HAIL WITH STORMS TRACKING NEWD FROM SERN VA
   TOWARD THE SRN CHESAPEAKE BAY TO SRN DELMARVA THROUGH 02-03Z.
   
   ..PETERS.. 04/29/2011
   
   
   ATTN...WFO...AKQ...MHX...LWX...
   
   LAT...LON   34387624 34607714 35417660 36267653 36657684 37047729
               37787678 38427648 38387468 36827558 35377508 34907531
               34387624