000
ACUS11 KWNS 060937
SWOMCD
SPC MCD 060937
PAZ000-WVZ000-OHZ000-061500-

MESOSCALE DISCUSSION 2064
NWS STORM PREDICTION CENTER NORMAN OK
0337 AM CST FRI DEC 06 2013

AREAS AFFECTED...PORTIONS OF OHIO AND WRN PENNSYLVANIA

CONCERNING...WINTER MIXED PRECIPITATION

VALID 060937Z - 061500Z

SUMMARY...WINTER MIXED PRECIP WILL INCREASE IN COVERAGE AND
INTENSITY THROUGH THE MORNING HOURS. ICING COULD BECOME A DEFINITIVE
CONCERN FOR SOME AREAS AROUND THE I-71 CORRIDOR INTO PARTS OF WRN PA
THIS MORNING.

DISCUSSION...A WIDESPREAD SHIELD OF WINTER MIXED PRECIP WILL
CONTINUE TO SPREAD NEWD FROM THE LOWER AND MIDDLE OHIO VALLEY REGION
ACROSS THE STATE OF OHIO THIS MORNING. THIS ACTIVITY IS LIKELY
RELATED TO WARM ADVECTION ENHANCED BY A SUBTLE IMPULSE EMBEDDED
WITHIN THE EXTENSIVE SW/NE-ORIENTED WARM CONVEYOR STRUCTURE DRAPED
ACROSS THE REGION -- PLEASE REFERENCE MESOSCALE DISCUSSION 2063 FOR
DETAILS. MEANWHILE...SFC ANALYSIS PLACES THE 32F ISOTHERM FROM NEAR
CINCINNATI TO COLUMBUS AND NEWD TO W OF ERIE PA. THE FREEZING LINE
SHOULD CONTINUE TO SHIFT SEWD OWING TO MODEST SFC COLD ADVECTION
ALONG WITH WET BULB EFFECTS WITHIN THE SFC LAYER. THIS WILL ALLOW A
STRIPE OF WINTER MIXED PRECIP TO INCREASE THROUGH THE MORNING HOURS
FROM SW TO NE.

THE HEAVIEST/MOST PERSISTENT PRECIP WILL LIKELY CONTINUE TO
OVERSPREAD THE CINCINNATI METRO AREA THROUGH AROUND 11Z...OVERSPREAD
THE COLUMBUS AND ZANESVILLE AREAS AROUND 11-13Z...AND THEN REACH THE
AKRON-CANTON AND YOUNGSTOWN AREAS AROUND 13-15Z BEFORE POTENTIALLY
AFFECTING ADJACENT WRN PA. PRECIPITATION SHOULD THEN PERSIST THROUGH
A LARGE PART OF THE MORNING...BEFORE MINOR SUBSIDENCE FOLLOWING THE
PASSAGE OF THE IMPULSE POTENTIALLY PROVIDES A TEMPORARY DAMPENING TO
THE COVERAGE/INTENSITY OF PRECIP LATER IN THE MORNING.

OBSERVATIONS FROM THE NSSL PRECIPITATION IDENTIFICATION NEAR THE
GROUND /PING/ PROJECT ACROSS THE MCD AREA AND UPSTREAM SUGGEST THAT
FREEZING RAIN AND SLEET WILL PREDOMINATE JUST NW OF THE FREEZING
LINE AS ELEVATED WARM ADVECTION SUPPORTS PARTIAL/COMPLETE MELTING OF
DESCENDING HYDROMETEORS. THE GREATEST FREEZING RAIN/SLEET POTENTIAL
WILL LIE WITHIN A CORRIDOR EXTENDING FROM AROUND CINCINNATI TO
COLUMBUS TO AKRON-CANTON/YOUNGSTOWN THROUGH THE MORNING HOURS. ICING
COULD BECOME A DEFINITIVE CONCERN...WITH FREEZING RAIN RATES AROUND
0.05 INCH PER HOUR AND SLEET ACCUMULATION RATES AROUND 0.25 INCH PER
HOUR POSSIBLE IN THIS CORRIDOR. AREAS OF MODERATE SNOW WILL BE MORE
LIKELY WITH INCREASING DISPLACEMENT NW OF FREEZING LINE OWING TO A
COOLER LOWER TROPOSPHERIC THERMAL PROFILE...ESPECIALLY AOA 30 MILES
NW OF I-71.

..COHEN.. 12/06/2013

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

ATTN...WFO...PBZ...RLX...CLE...ILN...

LAT...LON   39358473 40068395 41238139 41568002 41187982 40528071
            39618245 38918380 39358473