MESOSCALE DISCUSSION 1672
   NWS STORM PREDICTION CENTER NORMAN OK
   0809 PM CDT WED JUL 20 2011
   
   AREAS AFFECTED...NRN/CNTRL MAINE
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 210109Z - 210245Z
   
   WHILE THE THREAT FOR A DMGG WIND GUST OR TWO CANNOT BE ENTIRELY
   RULED OUT DURING THE NEXT HOUR OR TWO IN ASSOCIATION WITH ONGOING
   CONVECTION...THE OVERALL SVR THREAT ACROSS NRN/CNTRL MAINE IS
   DIMINISHING. WHILE CONVECTIVE TRENDS WILL CONTINUE TO BE
   MONITORED...THE ISSUANCE OF A WW IS UNLIKELY.
   
   CONVECTION THAT FORMED INVOF A BAROCLINIC ZONE DRAPED ACROSS SERN
   CANADA ATTENDANT TO AN EWD-MIGRATING...MID-LEVEL SHORTWAVE TROUGH
   EVOLVED INTO A LINE SEGMENT. THIS FEATURE CURRENTLY STRETCHES FROM
   PORTIONS OF SRN AROOSTOOK COUNTY INTO FAR ERN PISCATAQUIS
   COUNTY...AND IS MOVING ESEWD AROUND 45-50 KT. CARIBOU WSR-88D TRENDS
   SUGGEST THAT THIS LINE IS BECOMING INCREASINGLY DISORGANIZED...AS IT
   CROSSES A SHALLOW BAROCLINIC ZONE THAT MARKS THE GRADIENT BETWEEN
   STABLE MARINE-LAYER TRAJECTORIES FROM THE WRN ATLANTIC TO ITS EAST
   AND MARGINAL INSTABILITY TO ITS WEST. THIS WEAKENING TREND IS ALSO
   CONSISTENT WITH THE RECENT DOWNWARD TREND IN OBSERVED CG FLASH
   RATES. AS INFLOW TO ONGOING CONVECTION BECOMES INCREASINGLY
   STABLE...IT WILL LIKELY CONTINUE TO LOSE ITS VIGOR PRIOR TO EXITING
   THE UNITED STATES. FURTHERMORE...MID-LEVEL HEIGHT RISES IN THE WAKE
   OF THE AXIS OF THE SHORTWAVE TROUGH /PER MULTI-DETERMINISTIC MODEL
   GUIDANCE/ ALSO INDICATE A LESSENING THREAT FOR CONVECTIVE SUSTENANCE
   OR UPSTREAM DEVELOPMENT. REGARDLESS...WITH 48 KT OF 0-6-KM BULK
   SHEAR PER CARIBOU VWP...THE LINE MAY RETAIN SOME ORGANIZED
   CONVECTIVE CHARACTERISTICS AND YIELD A LOCALIZED THREAT FOR STRONG
   WIND GUSTS...AIDED BY MODEST DCAPE VALUES IN PLACE ALONG WITH
   STORM-SCALE EFFECTS. WHILE A DMGG WIND GUST OR TWO CANNOT BE RULED
   OUT...THE OVERALL THREAT WILL BE SUBSTANTIALLY TEMPERED BY THE
   AFOREMENTIONED INHIBITING FACTORS FOR CONVECTION.
   
   ..COHEN.. 07/21/2011
   
   
   ATTN...WFO...CAR...GYX...
   
   LAT...LON   46407028 46896956 46926871 46586782 46176749 45556736
               44946778 44756877 44847016 45547061 46407028