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000
ACUS11 KWNS 081930
SWOMCD
SPC MCD 081930
NJZ000-PAZ000-DEZ000-MDZ000-DCZ000-VAZ000-WVZ000-082130-

MESOSCALE DISCUSSION 2073
NWS STORM PREDICTION CENTER NORMAN OK
0130 PM CST SUN DEC 08 2013

AREAS AFFECTED...NRN VA...NRN MD...NRN DEL...SERN PA AND CNTRL AND
SRN NJ

CONCERNING...WINTER MIXED PRECIPITATION

VALID 081930Z - 082130Z

SUMMARY...MODERATE TO HEAVY SNOW WILL PERSIST FROM SERN PA INTO
EXTREME NRN MD AND CNTRL NJ THIS AFTERNOON. SNOWFALL RATES WILL
LOCALLY EXCEED 1 INCH PER HOUR THROUGH 21Z-22Z. FARTHER SOUTH ACROSS
NRN VA AND PARTS OF CNTRL MD AND DEL...THE SNOW SHOULD BEGIN TO
TRANSITION TO PERIODS OF FREEZING RAIN BY 21Z.

DISCUSSION...A STRIP OF MODERATE TO HEAVY SNOW CONTINUES FROM SRN
PA...NRN VA...NRN MD THROUGH CNTRL NJ AND IS ASSOCIATED WITH AN E-W
FRONTOGENETIC ZONE IN THE 850-700 MB LAYER. THIS ZONE OF STRONGER
FORCING WILL GRADUALLY SHIFT NEWD WITH THE HEAVIEST SNOWS MOVING
OFFSHORE AFTER BY 22Z. SOME BANDED STRUCTURES CONTINUE TO BE
OBSERVED WITH RATES FROM 1 TO 2 INCHES PER HOUR WITHIN THE HEAVIER
SNOW BANDS.

FARTHER SOUTH...THE LLJ IS DEVELOPING NEWD IN ASSOCIATION WITH A
ENEWD EJECTING SHORTWAVE TROUGH. WARM ADVECTION ABOVE THE NEAR SFC
SUBFREEZING LAYER SHOULD RESULT IN NWD ADVANCE OF THE MELTING LAYER
ALOFT AND A TRANSITION FROM SNOW TO FREEZING RAIN. THE THETA-E
ADVECTION HAS ALSO CONTRIBUTED TO A SHALLOW UNSTABLE LAYER
ALOFT...AND FREEZING RAIN RATES WILL BE ENHANCED AT TIMES WITHIN THE
NEWD MOVING SHOWERS.

..DIAL.. 12/08/2013

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

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

LAT...LON   39287477 38827609 38387859 39717780 40527678 40477514
            40297388 39287477