MESOSCALE DISCUSSION 1057
   NWS STORM PREDICTION CENTER NORMAN OK
   0527 PM CDT WED JUN 01 2011
   
   AREAS AFFECTED...ERN WV...NRN VA...MD...DE...SRN NJ...DC
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 412...
   
   VALID 012227Z - 020000Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 412
   CONTINUES.
   
   MULTICELLULAR CONVECTIVE CLUSTERS THAT FORMED EARLIER ON A
   PREFRONTAL CONFLUENCE AXIS DRAPED ACROSS THE DELMARVA REGION WILL
   CONTINUE TO BE SUSTAINED ACROSS PORTIONS OF ERN VA...ERN MD...SRN
   NJ...AND THE DC AREA. IN THIS REGION...A VERY UNSTABLE AIR MASS
   /MLCAPE VALUES OF 3000 TO 4000 J PER KG/ COINCIDES WITH EFFECTIVE
   BULK SHEAR MAGNITUDES OF 20 TO 30 KT. MEANWHILE...FOR AREAS FARTHER
   WEST ACROSS PORTIONS OF NRN VA...ERN WV...AND WRN MD...A MODERATELY
   UNSTABLE AIR MASS EXISTS TO THE WEST OF THE PREFRONTAL CONFLUENCE
   AXIS. AN ISOLATED STORM MAY STILL DEVELOP ALONG OR JUST AHEAD OF THE
   WEAK SFC COLD FRONT EXTENDING FROM CNTRL PA INTO NERN KY...WITH A
   CONDITIONAL THREAT FOR HAIL AND GUSTY WINDS GIVEN THE DEGREE OF
   INSTABILITY. HOWEVER...THE OVERALL FLAT APPEARANCE TO THE CUMULUS
   FIELD WEST OF THE ONGOING CONVECTION PER RECENT VISIBLE SATELLITE
   TRENDS...AND SUBSIDENT FLOW WORKING INTO THE REGION SOUTH OF THE
   SHORTWAVE TROUGH OVER ONTARIO/QUEBEC PER WATER VAPOR
   IMAGERY...SUGGEST THE OVERALL THREAT FOR SEVERE STORMS IN THE WAKE
   OF ONGOING DEEP CONVECTION MAY BE DECREASING.
   
   ..COHEN.. 06/01/2011
   
   
   ATTN...WFO...PHI...AKQ...LWX...
   
   LAT...LON   38577929 38787818 39087703 39637574 39567467 39137439
               38127488 37947675 37867908 38577929