ZCZC SPCSWOMCD ALL
ACUS11 KWNS 261719 
SPC MCD 261719 
NYZ000-NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-WVZ000-261845-

MESOSCALE DISCUSSION 0454
NWS STORM PREDICTION CENTER NORMAN OK
1219 PM CDT TUE APR 26 2016

AREAS AFFECTED...SRN PA...NJ...NRN MD...NE WV...NRN DE

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 261719Z - 261845Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...AN ISOLATED SEVERE THREAT IS EXPECTED TO DEVELOP THIS
AFTERNOON ACROSS SRN PA...NJ AND NRN MD. DAMAGING WIND GUSTS AND
HAIL WILL BE THE PRIMARY THREATS. WW ISSUANCE WILL LIKELY BE NEEDED
ACROSS THE REGION.

DISCUSSION...LATEST SFC ANALYSIS SHOWS A 1003 MB LOW OVER SE PA WITH
A COLD FRONT EXTENDING WWD FROM THE LOW ACROSS CNTRL AND WRN PA. TO
THE SOUTH OF THE FRONT...SFC TEMPS ARE APPROACHING 80 F AND THIS IS
CONTRIBUTING TO A NARROW BAND OF INSTABILITY WHERE MLCAPE VALUES ARE
ESTIMATED TO BE IN THE 250 TO 500 J/KG RANGE. AS SFC HEATING
CONTINUES THIS AFTERNOON AND LOW-LEVEL CONVERGENCE INCREASES ALONG
THE BOUNDARY...SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP
ACROSS SCNTRL PA WITH CONVECTION GRADUALLY EXPANDING WWD ACROSS SW
PA. FORECAST SOUNDINGS ACROSS SCNTRL PA AND NJ FOR 21Z SHOW 0-6 KM
SHEAR OF 50 KT WITH MLCAPE APPROACHING 1000 J/KG. THIS COMBINED WITH
UNIDIRECTIONAL WIND PROFILES AND MODESTLY STEEP LAPSE RATES SHOULD
BE FAVORABLE FOR DAMAGING WIND GUSTS AND HAIL. THE SEVERE THREAT IS
EXPECTED TO SHIFT SEWD INTO NRN MD AND DELAWARE LATER THIS
AFTERNOON.

..BROYLES/CORFIDI.. 04/26/2016

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

ATTN...WFO...OKX...PHI...CTP...LWX...PBZ...

LAT...LON   40647966 40827809 40837662 40947544 40917443 40777401
            40227391 39567461 39277634 39287924 39908014 40647966 

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