000
ACUS11 KWNS 101228
SWOMCD
SPC MCD 101228
NJZ000-NYZ000-PAZ000-DEZ000-MDZ000-101730-

MESOSCALE DISCUSSION 2075
NWS STORM PREDICTION CENTER NORMAN OK
0628 AM CST TUE DEC 10 2013

AREAS AFFECTED...PORTIONS OF ERN MD...NRN DE...SERN PA...CNTRL/SRN
NJ

CONCERNING...HEAVY SNOW

VALID 101228Z - 101730Z

SUMMARY...HEAVY SNOW WITH RATES AROUND 1 INCH/HOUR WILL SPREAD ENEWD
THROUGH THE MORNING HOURS AND SHOULD TAPER OFF BY EARLY AFTERNOON.

DISCUSSION...ISENTROPIC ASCENT IS BEING ENHANCED IN ADVANCE OF AN
INTENSE OHIO-VALLEY MID-LEVEL IMPULSE TRACKING ENEWD WITHIN STRONG
MID/UPPER-LEVEL FLOW. A NE/SW-ORIENTED SHIELD OF PRECIPITATION OVER
THE MID ATLANTIC WILL CONTINUE TO SPREAD ENEWD THROUGH THE MORNING
HOURS. THIS WILL OCCUR AS LOW/MID-LEVEL FRONTOGENESIS STRENGTHENS IN
TANDEM WITH AN INCREASE IN DEEP ASCENT AMIDST ANTECEDENT
BAROCLINICITY. A CORRIDOR OF DEEP SUB-FREEZING AIR WILL SUPPORT THE
PROGRESSION OF ONGOING MODERATE TO HEAVY SNOW FROM NRN VA TO S-CNTRL
PA ENEWD ACROSS THE DISCUSSION AREA THROUGH THE MORNING HOURS.
FORECAST SOUNDINGS INDICATE ENHANCED ASCENT WITHIN A FAIRLY DEEP
DENDRITIC GROWTH ZONE CENTERED AROUND 500 MB THAT WILL FAVOR
SNOWFALL RATES AROUND 1 INCH/HOUR. SNOW WILL TAPER OFF BY EARLY
AFTERNOON AS STRONGER ASCENT SHIFTS OFFSHORE AND THE MIDDLE
TROPOSPHERE DRIES.

..COHEN.. 12/10/2013

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

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

LAT...LON   40267398 39757423 39427493 39027612 39217677 39747670
            40337559 40607431 40267398