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000
ACUS11 KWNS 081606
SWOMCD
SPC MCD 081605
DEZ000-PAZ000-MDZ000-VAZ000-DCZ000-WVZ000-081900-

MESOSCALE DISCUSSION 2072
NWS STORM PREDICTION CENTER NORMAN OK
1005 AM CST SUN DEC 08 2013

AREAS AFFECTED...CNTRL AND NRN VA...MUCH OF WV...NRN MD...EXTREME
SRN PA

CONCERNING...WINTER MIXED PRECIPITATION

VALID 081605Z - 081900Z

SUMMARY...SNOW WITH RATES LOCALLY UP TO 1 INCH PER HOUR WILL
GRADUALLY TRANSITION TO FREEZING RAIN THIS AFTERNOON FROM NRN
WV...NRN VA AND NRN MD. PRECIPITATION SHOULD REMAIN MOSTLY SNOW
ACROSS SRN PA. FREEZING RAIN SHOULD PERSIST ACROSS PORTIONS OF SRN
WV AND CNTRL VA WITH RATES FROM .01 INCH PER HOUR TO OCCASIONALLY
OVER .1 INCH PER HOUR.

DISCUSSION...A WEDGE OF COLD AIR REMAINS IN PLACE EAST OF THE SRN
AND CNTRL APPALACHIANS WITH SFC TEMPERATURES AOB FREEZING OVER MUCH
OF THE MID ATLANTIC. AN EXPANSIVE AREA OF PRECIPITATION HAS
DEVELOPED AND WILL PERSIST OVER MUCH OF THIS REGION THROUGH THE
AFTERNOON IN ASSOCIATION WITH ISENTROPIC ASCENT ALONG A WARM
CONVEYOR BELT DOWNSTREAM FROM A RAPIDLY EJECTING SHORTWAVE TROUGH.
FREEZING RAIN WILL PERSIST FROM SRN WV THROUGH CNTRL VA INTO THE
AFTERNOON...AND A ZONE OF WEAK ELEVATED INSTABILITY WILL DEVELOP NWD
IN ASSOCIATION WITH THETA-E ADVECTION ALONG A STRENGTHENING LLJ
ACCOMPANYING THE EJECTING SHORTWAVE TROUGH. FREEZING RAIN RATES WILL
BE LOCALLY ENHANCED WITHIN THE NEWD MOVING CONVECTIVE ELEMENTS. THIS
ZONE OF INCREASING WARM ADVECTION WILL RESULT IN THE SNOW CURRENTLY
FROM NRN WV THROUGH NRN VA AND MD GRADUALLY TRANSITIONING TO
FREEZING RAIN AS A SIGNIFICANT WARM NOSE EXPANDS NWD ABOVE THE
SUB-FREEZING LAYER.

..DIAL.. 12/08/2013

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

ATTN...WFO...PHI...AKQ...CTP...LWX...RNK...PBZ...RLX...

LAT...LON   39797561 38937579 38067697 37217847 37228007 37858136
            38578211 39928043 40287811 40107618 39797561