MESOSCALE DISCUSSION 0540
   NWS STORM PREDICTION CENTER NORMAN OK
   0357 PM CDT MON APR 20 2009
   
   AREAS AFFECTED...CENTRAL AND EASTERN VA/NORTHERN NC/SOUTHEAST MD
   
   CONCERNING...TORNADO WATCH 178...
   
   VALID 202057Z - 202230Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 178 CONTINUES.
   
   TORNADO WATCH 178 CONTINUES UNTIL 02Z ACROSS PORTIONS OF
   CENTRAL/EASTERN VA AND NORTHERN NC/SOUTHEAST MD...WITH A RISK FOR
   TORNADOES ALONG WITH SEVERE HAIL/DAMAGING WINDS.
   
   LATEST SURFACE ANALYSIS/VISIBLE SATELLITE IMAGERY REFLECT A WARM
   FRONT CONTINUING TO DEVELOP NORTHWARD ACROSS EAST CENTRAL VA
   INCLUDING THE RICHMOND VICINITY THIS AFTERNOON...WITHIN A CORRIDOR
   OF SUSTAINED PRESSURE FALLS ACROSS VA AHEAD OF SUB-SYNOPTIC SURFACE
   LOW ACROSS WESTERN VA. AS TSTMS CONTINUE TO INCREASE ACROSS THE
   PIEDMONT/COASTAL PORTIONS OF VA INTO NC/SOUTHEAST MD OVER THE NEXT
   FEW HOURS...SUFFICIENT LOW LEVEL SRH AMIDST LOWER 60 F SURFACE
   DEWPOINTS WILL SUPPORT A SUPERCELL TORNADO THREAT. WITH SOME
   TENDENCY FOR BOUNDARY LAYER DRYING ACROSS NORTHERN NC...THE PRIMARY
   TORNADO RISK WILL LIKELY REMAIN ACROSS VA/FAR SOUTHERN MD. THE
   RELATIVELY GREATEST TORNADO POTENTIAL COULD EVOLVE OVER THE NEXT FEW
   HOURS ACROSS CENTRAL/EASTERN VA AND PERHAPS SOUTHEAST MD AS
   SUPERCELLS POTENTIALLY INTERACT WITH THE WAVY/ROUGHLY WEST-EAST WARM
   FRONT.
   
   ..GUYER.. 04/20/2009
   
   
   ATTN...WFO...AKQ...MHX...LWX...RAH...RNK...
   
   LAT...LON   38237834 38567700 38167581 36227598 35697934 37137960
               38237834