MESOSCALE DISCUSSION 1839
   NWS STORM PREDICTION CENTER NORMAN OK
   0740 PM CDT TUE AUG 21 2007
   
   AREAS AFFECTED...ERN NC...SERN VA
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 630...633...
   
   VALID 220040Z - 220245Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   630...633...CONTINUES.
   
   SVR CONVECTIVE LINE WILL CONTINUE TO PROGRESS EWD AROUND 35 KTS
   ACROSS REMAINING PORTIONS OF WW 630 AND MOST OF WW 633 THROUGH 02Z.
   WW 630 WILL LIKELY BE CANCELLED PRIOR TO IT/S EXPIRATION TIME OF
   02Z. WW 633 WILL LIKELY BE CANCELLED PRIOR TO IT/S EXPIRATION TIME
   OF 05Z.
   
   RADAR IMAGERY SHOWS A WELL DEFINED CONVECTIVE LINE...WITH A LINE
   MOTION AROUND 35 KTS. DESPITE WEAKENING LOW LEVEL LAPSE RATES DUE TO
   PRESENCE OF COOLER AND MORE MOIST OCEAN BREEZE AIRMASS OVER THE
   AREA...NEW SVR CONVECTIVE DEVELOPMENT AND DMGG WIND THREAT SHOULD
   CONTINUE TO OCCUR ALONG THE LEADING EDGE OF THE GUST FRONT GIVEN THE
   PRESENCE OF A WELL DEVELOPED AND DEEP COLD POOL /SFC PRESSURE RISES
   FROM 3-4 MB/2 HRS...MODERATE INSTABILITY /MUCAPE AROUND 3000 J/KG/
   AND LITTLE INHIBITION /PER THE 00Z MHX SOUNDING/. PRESENT LINE
   MOTIONS WILL TAKE THE SVR THREAT EAST OF THE REMAINING PORTIONS OF
   WW 630 BY 02Z AND WW 633 SHORTLY AFTER 03Z.
   
   ..CROSBIE.. 08/22/2007
   
   
   ATTN...WFO...AKQ...MHX...RAH...ILM...
   
   36967608 36827657 35737742 35177814 34857820 34577790
   34277719 34307660 34787599 34967564 35537507 35887512
   36397555 36937594