MESOSCALE DISCUSSION 1238, AREAS AFFECTED...PORTIONS MAINE OUTSIDE COASTAL/DOWN-EAST AREAS. CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

        MESOSCALE DISCUSSION 1238     NWS STORM PREDICTION CENTER NORMAN OK     1053 AM CDT FRI JUN 22 2012          AREAS AFFECTED...PORTIONS MAINE OUTSIDE COASTAL/DOWN-EAST AREAS.          CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE           VALID 221553Z - 221800Z          PROBABILITY OF WATCH ISSUANCE...40 PERCENT          SUMMARY...POTENTIAL IS INCREASING FOR TSTMS TO PRODUCE DAMAGING     GUSTS AND ISOLATED LARGE HAIL...AND 1630Z OUTLOOK WILL INCLUDE     UPGRADE OF SVR PROBABILITIES AND CATEGORICAL SLGT LINE OVER THIS     AREA.          DISCUSSION...15Z SFC ANALYSIS SHOWED COLD FRONT FROM NRN NY SWD     ACROSS CENTRAL/SWRN PA AND WRN WV.  WARM FRONT WAS DRAWN FROM SERN     QUE SSWWD ACROSS N-CENTRAL/W-CENTRAL MAINE THEN JUST OFFSHORE CAPE     COD.  STRONGEST HEATING/MIXING IS EVIDENT IN SFC OBS AND VIS IMAGERY     BETWEEN THESE BOUNDARIES...WHERE HORIZONTAL CONVECTIVE ROLLS HAVE     DEVELOPED...ALONG WITH ISOLATED YOUNG TSTMS OVER HIGHER TERRAIN NEAR     QUE BORDER.  ADDITIONAL ACTIVITY SHOULD FORM ALONG/AHEAD OF COLD     FRONT AS SFC DIABATIC HEATING CONTINUES...AND CINH WEAKENS.  DEW     POINTS BETWEEN FRONTS ARE GENERALLY LOW-MID 60S...WITH LESS MIXING     AND SOMEWHAT HIGHER MOISTURE ALONG/E OF WARM FRONT OVER NRN MAINE.      WARM FRONT SHOULD SHIFT EWD ACROSS NRN MAINE AMIDST LOW-LEVEL     WLYS...AND CONTINUED MIXING TO ITS W.  GIVEN LACK OF ANTECEDENT     CLOUD COVER...BOTH SIDES OF WARM FRONT WILL DESTABILIZE...ESPECIALLY     AWAY FROM NEAR-COASTAL MARINE INFLUENCES AND RELATIVELY STABLE AIR     MASS OVER DOWN-EAST MAINE.  MLCAPE OVER DISCUSSION AREA SHOULD RISE     INTO 1000-2000 J/KG RANGE...THOUGH MODEST LOW-MIDDLE LEVEL WINDS     INVOF UPPER RIDGE WILL LIMIT VERTICAL SHEAR.  PREDOMINANT CONVECTIVE     MODE WILL BE MULTICELLULAR...OFFERING RISK OF DAMAGING DOWNDRAFTS     ENHANCED BY EVAPORATIVE COOLING IN WELL-MIXED BOUNDARY LAYER.          ..EDWARDS/WEISS.. 06/22/2012               ATTN...WFO...CAR...GYX...          LAT...LON   45736778 44926864 44346971 44427019 45317103 45347097                 45227085 45427080 45407063 45427062 45507071 45577066                 45717039 45817040 45957024 45987035 46147021 46167031                 46387021 46467004 46717004 47466922 47456906 47256905                 47186890 47296849 47266837 47386837 47376827 47046778                 45736778