Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS11 KWNS 281823
SWOMCD
SPC MCD 281822
MEZ000-MAZ000-NHZ000-RIZ000-VTZ000-CTZ000-282015-

MESOSCALE DISCUSSION 1563
NWS STORM PREDICTION CENTER NORMAN OK
0122 PM CDT TUE JUL 28 2015

AREAS AFFECTED...PORTIONS OF MAINE...VT...NH...MA...RI...AND CT

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 281822Z - 282015Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...OCCASIONAL INSTANCES OF MARGINAL HAIL AND STRONG/GUSTY
WINDS WILL BE POSSIBLE THROUGH THE AFTERNOON. WW ISSUANCE IS
UNLIKELY DUE TO CONVECTIVE COVERAGE REMAINING TOO ISOLATED.

DISCUSSION...ISOLATED THUNDERSTORMS HAVE FORMED OVER THE PAST HOUR
ACROSS PORTIONS OF CNTRL MAINE TO THE S OF A WEAK FRONT OVER NRN
MAINE. ADDITIONAL CONVECTIVE DEVELOPMENT REMAINS POSSIBLE FURTHER TO
THE SW THIS AFTERNOON. IN THE WAKE OF EARLIER CONVECTION ASSOCIATED
WITH THE PASSAGE OF A SHORTWAVE TROUGH ALOFT...DIURNAL HEATING ALONG
WITH MID-LEVEL DRYING/SUBSIDENCE HAS ALLOWED FOR RE-DESTABILIZATION
OF THE ATMOSPHERE ACROSS MUCH OF NEW ENGLAND. SFC TEMPERATURES HAVE
GENERALLY WARMED INTO THE 80S...AND DEWPOINTS ARE IN THE MID TO
UPPER 60S. WHILE MID-LEVEL LAPSE RATES ARE ONLY AROUND 6.0 DEG
C/KM...SUFFICIENT LOW-LEVEL MOISTURE/HEATING IS CONTRIBUTING TO
MLCAPE OF 500-1500 J/KG ACROSS THE MCD AREA PER LATEST RAP
MESOANALYSIS.

UNDER NWLY FLOW ALOFT...MOST OF THE AREA WILL REMAIN UNDER
LARGE-SCALE SUBSIDENCE THROUGH THE AFTERNOON...WHICH SHOULD TEND TO
LIMIT MORE ROBUST/NUMEROUS THUNDERSTORMS. HOWEVER...ISOLATED
THUNDERSTORMS...SUCH AS ONE CURRENTLY MOVING SWD FROM FRANKLIN INTO
ANDROSCOGGIN COUNTY MAINE AS OF 1820Z...WILL BE CAPABLE OF PRODUCING
OCCASIONAL INSTANCES OF MARGINALLY SEVERE HAIL AND/OR STRONG WINDS
GIVEN SUFFICIENT INSTABILITY AND BULK SHEAR. STRONGER BULK SHEAR ON
THE ORDER OF 40-50 KT IS PRESENT ACROSS NH...VT...AND MUCH OF
MA/RI/CT. BUT...CURRENT VISIBLE SATELLITE LOOPS SHOW LESS TOWERING
CU ACROSS THESE STATES COMPARED TO MUCH OF MAINE...WHICH CASTS DOUBT
ON EVENTUAL COVERAGE THIS AFTERNOON. IF THUNDERSTORMS CAN FORM ALONG
SEA BREEZE BOUNDARIES OR HIGHER TERRAIN IN THIS AREA OF STRONGER
BULK SHEAR...THEN THEY MAY POSE A SLIGHTLY HIGHER RISK FOR SEVERE
HAIL/WIND. REGARDLESS...THE LACK OF LARGE-SCALE LIFT AND A MORE
OBVIOUS FORCING MECHANISM TO INITIATE CONVECTION LOOK TO KEEP THE
SEVERE THREAT TOO MARGINAL FOR WW ISSUANCE.

..GLEASON/GOSS.. 07/28/2015

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

ATTN...WFO...CAR...GYX...BOX...BTV...ALY...

LAT...LON   44937282 45057165 45337128 45417073 45747022 46176970
            46346895 46356768 45766766 45506793 44986830 44506892
            43916991 43597038 43157073 42287098 41977089 41887152
            41867254 42207274 43487291 44937282



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