MESOSCALE DISCUSSION 1221
   NWS STORM PREDICTION CENTER NORMAN OK
   0721 PM CDT THU JUN 18 2009
   
   AREAS AFFECTED...SERN VA
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 464...
   
   VALID 190021Z - 190045Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 464
   CONTINUES.
   
   ISOLD LARGE HAIL/DMGG WIND POTENTIAL WILL LIKELY CONTINUE THROUGH
   THE HOUR ACROSS PARTS OF SERN VA.  WW WILL BE ALLOWED TO EXPIRE BUT
   AN ISOLD SEVERE THREAT MAY CONTINUE BEYOND 01Z.
   
   LATEST RADAR/SURFACE COMPOSITE SHOWS STRONG/SEVERE STORMS ARE NOW
   CONFINED TO SERN VA NEAR DIFFUSE WARM FRONTAL SEGMENT ATTENDANT TO A
   WEAK SURFACE LOW OVER SERN PA.  THE ONLY 2 STORMS OF SIGNIFICANCE
   /SUPERCELLS LOCATED OVER ISLE OF WIGHT/KING AND QUEEN COUNTIES AS OF
   0015Z/ WILL LIKELY CONTINUE TO MOVE SEWD ALONG AFOREMENTIONED
   BOUNDARY.
   
   STRONGLY VEERING LOW LEVEL CLOCKWISE CURVED HODOGRAPHS WITH OBSERVED
   STORM MOTIONS ROUGHLY AT 335 DEG/17 KTS SHOWS 0-1 KM SRH 150-200
   MS/S2 ACCORDING TO AKQ VWP DATA...BENEATH 45 KTS 0-6 KM SHEAR.  THIS
   WILL CONTINUE TO SUPPORT UPDRAFT ROTATION WITHIN THETA-E AXIS
   EXTENDING NEWD INTO THE TIDEWATER AREA.  COMBINED WITH A VERY MOIST
   BOUNDARY LAYER FAVORING A LOW LCL ENVIRONMENT BELOW 1000 M...A
   NON-ZERO THREAT FOR AN ISOLD TORNADO MAY EXIST IN THE NEAR TERM. 
   WITH THAT SAID...THESE STORMS WILL PROBABLY POSE A LARGE HAIL AND
   ISOLD DMGG WIND THREAT BEFORE GRADUAL DIURNAL STABILIZATION AND A
   GENERAL OVERALL WEAKENING TREND IS EXPECTED.
   
   ..SMITH.. 06/19/2009
   
   
   ATTN...WFO...AKQ...
   
   LAT...LON   36437661 37237691 37827694 37957671 37777636 37247605
               36597587 36247586 36217637 36437661