Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 251706
SWOMCD
SPC MCD 251706
MAZ000-NHZ000-RIZ000-CTZ000-VTZ000-251900-

MESOSCALE DISCUSSION 1747
NWS STORM PREDICTION CENTER NORMAN OK
1206 PM CDT TUE AUG 25 2015

AREAS AFFECTED...SRN NH...CNTRL MA...NERN CT AND NRN RI

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 251706Z - 251900Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...STORMS MAY BECOME CAPABLE OF PRODUCING A FEW STRONG WIND
GUSTS AND PERHAPS A BRIEF TORNADO OVER SRN NEW ENGLAND THIS
AFTERNOON. WW WILL PROBABLY NOT BE NECESSARY DUE TO EXPECTED LIMITED
COVERAGE OF ANY SEVERE EVENTS. HOWEVER...CONVECTIVE TRENDS WILL
CONTINUE TO BE MONITORED.

DISCUSSION...THIS AFTERNOON A BAND OF SCATTERED SHOWERS AND A FEW
THUNDERSTORMS CONTINUE DEVELOPING OVER SRN NEW ENGLAND WITHIN BELT
OF PRE-FRONTAL LOW-LEVEL CONVERGENCE ASSOCIATED WITH A LEAD
SHORTWAVE TROUGH THAT IS LIFTING NWD THROUGH NH. STRONGEST STORM WAS
LOCATED OVER SRN NH AS OF 17Z WHERE SOME WEAK ROTATION WAS ALSO
INDICATED. THE VISIBLE SATELLITE IMAGERY SHOWS NUMEROUS CLOUD BREAKS
IN THIS REGION PROMOTING BOUNDARY LAYER DESTABILIZATION.
HOWEVER...INSTABILITY IS EXPECTED TO REMAIN MODEST DUE TO WEAK
MID-LEVEL LAPSE RATES. THE STORMS SHOULD CONTINUE A SLOW BUT GRADUAL
INCREASE IN INTENSITY WITHIN AN ENVIRONMENT CHARACTERIZED BY MODEST
/30-35 KT/ EFFECTIVE BULK SHEAR. BOTH MULTICELLS AND SOME MARGINAL
SUPERCELL STRUCTURES ARE POSSIBLE...BUT OVERALL THREAT WILL PROBABLY
REMAIN LIMITED BY THE MARGINAL THERMODYNAMIC ENVIRONMENT
CHARACTERIZED BY SIGNIFICANT DRYING AND WEAK LAPSE RATES IN THE
700-500 MB LAYER WHICH SHOULD LIMIT OVERALL UPDRAFT INTENSITIES.
NEVERTHELESS...A FEW STRONG WIND GUSTS MAY ACCOMPANY SOME OF THE
STORMS...AND A BRIEF TORNADO ALSO CANNOT BE RULED OUT AS STORMS MOVE
NWD AND INTERACT WITH A WARM FRONT THAT STRETCHES ACROSS SRN NH.

..DIAL/CORFIDI.. 08/25/2015

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...GYX...BOX...ALY...

LAT...LON   42637263 43327218 43617180 43707110 43117096 41997137
            41887275 42637263




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