MESOSCALE DISCUSSION 2030
   NWS STORM PREDICTION CENTER NORMAN OK
   0131 AM CST MON NOV 18 2013

   AREAS AFFECTED...PARTS OF MID-ATLANTIC STATES TO NEW ENGLAND

   CONCERNING...SEVERE THUNDERSTORM WATCH 571...573...

   VALID 180731Z - 180900Z

   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   571...573...CONTINUES.

   SUMMARY...A FAST-MOVING LOW-TOPPED CONVECTIVE LINE WILL MOVE
   EASTWARD FROM ITS CURRENT POSITION OVER CENTRAL NY TO ERN PA AND IN
   LEE OF THE APPALACHIANS IN CENTRAL MD/VA.  A THREAT FOR LOCALLY
   STRONG WIND GUSTS WILL ACCOMPANY THIS CONVECTIVE LINE...DESPITE THE
   LACK OF LIGHTNING...WITH SOME GUSTS POTENTIALLY REACHING OR
   EXCEEDING 50 KT.

   SVR WIND GUST THREAT WILL END FROM W-E WITH THE PASSAGE OF THE
   CONVECTIVE LINE IN WW/S 571 AND 573.  CONVECTIVE TRENDS AND SURFACE
   OBSERVATIONS INDICATING AN UPTICK IN GUSTS APPROACHING OR EXCEEDING
   SVR VALUES WOULD SUGGEST POTENTIAL WW ISSUANCE OVER PARTS OF THE
   MID-ATLANTIC TO NEW ENGLAND STATES.

   DISCUSSION...EARLY OVERNIGHT MESO-ANALYSIS AND RADAR IMAGERY
   INDICATED THE ONGOING FAST-MOVING LOW-TOPPED CONVECTIVE LINE WAS
   LOCATED ALONG A COLD FRONT...AND AT 07Z THIS ACTIVITY EXTENDED SWD
   FROM CENTRAL NY /E OF KBGM/ THROUGH ERN PA...INTO MD/VA NEAR THE
   BALTIMORE AND WASHINGTON D.C. CORRIDOR.  DESPITE THE LACK OF
   LIGHTNING ATTENDANT TO THIS CONVECTIVE LINE...GIVEN THE MEAGER
   AVAILABILITY OF INSTABILITY...FURTHER DEEPENING/NEGATIVE-TILT OF THE
   MID-UPPER LEVEL TROUGH AND ACCOMPANYING STRONG WIND FIELDS WILL
   SUPPORT AN ENHANCED THREAT FOR STRONG WIND GUSTS.

   A RELATIVELY MOIST AIR MASS DOWNSTREAM INTO DELMARVA TO NJ...ERN NY
   AND SRN NEW ENGLAND COULD SUPPORT STRONGER GUSTS TO REACH THE
   SURFACE...DESPITE THE LIKELY PRESENCE OF A SHALLOW NEAR-SURFACE
   STABLE LAYER PER FORECAST SOUNDINGS.

   ..PETERS/CORFIDI.. 11/18/2013


   ATTN...WFO...GYX...BOX...BTV...OKX...ALY...PHI...BGM...AKQ...
   CTP...LWX...

   LAT...LON   38837788 39727693 40717641 41877594 42917600 43267503
               43217206 42567156 41577169 41017192 40397323 39687385
               38747442 38017524 38327688 38837788