MESOSCALE DISCUSSION 0458
   NWS STORM PREDICTION CENTER NORMAN OK
   0128 PM CDT SAT APR 16 2011
   
   AREAS AFFECTED...PORTIONS S-CENTRAL/SERN VA...CENTRAL/ERN NC...ERN
   SC.
   
   CONCERNING...TORNADO WATCH 150...
   
   VALID 161828Z - 162000Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 150 CONTINUES.
   
   THREAT FOR SUPERCELLS AND TORNADOES...SOME WITH POTENTIAL FOR
   SIGNIFICANT DAMAGE...CONTINUES OVER WW.
   
   LATEST/18Z SFC MESOANALYSIS SHOWS RAPIDLY DEVELOPING MESOLOW NEAR
   ALAMANCE COUNTY ALONG PRIMARY CONVECTIVE BAND...PRECEDED BY SMALL
   BUT PRONOUNCED AREA OF BACKED FLOW AND PRESSURE FALLS AT RATE OF 5-8
   MB PER 2 HOURS.  RELATED ISALLOBARIC FORCING SHOULD HELP TO
   MAINTAIN...AND PERHAPS LOCALLY INCREASE...ALREADY EXPANSIVE
   HODOGRAPH SIZE FROM RDU AREA ENEWD AND NEWD ACROSS N-CENTRAL NC INTO
   S-CENTRAL VA.  RDU VWP SHOWS 500 J/KG OF 0-1 KM AGL SRH...AND 900
   J/KG IN 0-3 KM LAYER...WHICH ALREADY IS EXTREME AND LIKELY
   UNDER-REPRESENTS VALUES NEARER TO THE MESOLOW.  0-1 KM SRH NEAR 300
   J/KG IS EVIDENT AS FAR S AS ERN SC.  CONTINUED
   HEATING/DESTABILIZATION OF AIR MASS OVER THIS REGION...COMBINED WITH
   BOUNDARY-LAYER THETAE ADVECTION...WILL JUXTAPOSE CORRIDOR OF
   500-1500 J/KG MLCAPE OVER THESE FAVORABLE KINEMATIC PROFILES IN
   PRE-STORM SECTOR.
   
   ..EDWARDS.. 04/16/2011
   
   
   ATTN...WFO...AKQ...MHX...LWX...RAH...ILM...RNK...CHS...CAE...
   
   LAT...LON   33428097 35057987 37007935 37997786 37987648 37487610
               36967597 36307580 35717547 35357549 35157553 35207567
               35017608 34657650 34507650 34627661 34627709 34237775
               33677800 33897806 33727884 33177922 32807982 32438044
               32148100 32608114 33428097