Possible Severe Thunderstorm Watch To Be Issued

Mesoscale Discussion 1186

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MESOSCALE DISCUSSION 1186 NWS STORM PREDICTION CENTER NORMAN OK 1201 PM CDT SUN JUN 23 2013 AREAS AFFECTED...SWRN THROUGH NERN NY...CNTRL VT AND NH CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 231701Z - 231900Z PROBABILITY OF WATCH ISSUANCE...40 PERCENT SUMMARY...THUNDERSTORMS ARE EXPECTED TO CONTINUE DEVELOPING THIS AFTERNOON FROM SWRN THROUGH ECNTRL/NERN NY INTO CNTRL VT AND NH. THIS ACTIVITY MAY POSE A MODEST RISK FOR MAINLY LOCALLY STRONG WIND GUSTS. SOME SMALL HAIL MIGHT ALSO OCCUR. OVERALL SEVERE RISK DOES NOT APPEAR PARTICULARLY ROBUST...SO ANY WW ISSUANCE WILL ULTIMATELY DEPEND ON CONVECTIVE TRENDS. DISCUSSION...EARLY THIS AFTERNOON STRONG DIABATIC WARMING OF THE MOIST BOUNDARY LAYER IS OCCURRING OVER MUCH OF NY AND SRN NEW ENGLAND WITH MIDDLE TO UPPER 60S DEWPOINTS AND TEMPERATURES RISING THROUGH THE 80S. THE LATEST ANALYSIS SHOWS MLCAPE FROM 1500-2000 J/KG...AND CUMULUS CONGESTUS IS EVIDENT ALONG SW-NE ORIENTED CLOUD STREETS FROM SWRN THROUGH NCNTRL NY. CONVECTIVE INHIBITION IS SUFFICIENTLY WEAK AS TEMPERATURES WARM TO UPPER 80S FOR THUNDERSTORM INITIATION ALONG LAKE BREEZE CIRCULATIONS. THIS REGION RESIDES WITHIN A LOW AMPLITUDE UPPER RIDGE WITH WEAK VERTICAL SHEAR AND MODEST DEEP LAYER WINDS SUPPORTIVE OF MULTICELLS. THE WEAK SHEAR ENVIRONMENT AND WEAK MID-LEVEL LAPSE RATES MAY ULTIMATELY SERVE AS A LIMITING FACTOR FOR A MORE ROBUST SEVERE THREAT. HOWEVER...THE DESTABILIZING BOUNDARY LAYER WITH STEEPENING LOW-LEVEL LAPSE RATES WILL SUPPORT AT LEAST A MODEST THREAT FOR STRONG WIND GUSTS...ESPECIALLY IF STORMS CAN GROW UPSCALE INTO SMALL CLUSTERS OR LINE SEGMENTS. ..DIAL/KERR.. 06/23/2013 ATTN...WFO...GYX...BTV...ALY...BGM...BUF... LAT...LON 42637765 43127655 43637533 44247309 44017174 43387175 42537568 42327737 42637765