000
ACUS11 KWNS 121232
SWOMCD
SPC MCD 121231
NYZ000-PAZ000-OHZ000-121700-

MESOSCALE DISCUSSION 0177
NWS STORM PREDICTION CENTER NORMAN OK
0731 AM CDT WED MAR 12 2014

AREAS AFFECTED...WRN NY...FAR NERN OH/NWRN PA

CONCERNING...HEAVY SNOW

VALID 121231Z - 121700Z

SUMMARY...MODERATE TO LOCALLY HEAVY SNOW WILL SHIFT EWD ACROSS THE
LOWER GREAT LAKES. SNOWFALL RATES SHOULD LARGELY AVERAGE AROUND 1
IN/HR...POTENTIALLY EXISTING FOR SEVERAL HOURS ACROSS PARTS OF WRN
NY.

DISCUSSION...12Z SURFACE ANALYSIS PLACED A 990 MB CYCLONE NEAR KCVG
WITH A QUASI-STATIONARY FRONT EXTENDING EWD INTO FAR SRN PA. THIS
CYCLONE WILL CONTINUE TO DEEPEN AS IT TRACKS ALONG THE FRONT THROUGH
MIDDAY...AHEAD OF A PAIR OF AMPLIFYING SHORTWAVE TROUGHS CROSSING
THE GREAT LAKES/MIDWEST. PRECIPITATION HAS EVOLVED INTO TWO DISTINCT
BANDS...ONE WITHIN THE LOW-LEVEL WAA REGION ACROSS THE UPPER OH
VALLEY AND THE OTHER NEAR AND N OF THE SURFACE CYCLONE. THE LATTER
BAND HAS YIELDED MODERATE TO HEAVY SNOW ACROSS LOWER MI/NERN
IND/NWRN OH WITH OBSERVED RATES AROUND 1 IN/HR...EXCEEDING 2 IN/HR
WITHIN EARLIER THUNDERSNOW.

12Z BUF RAOB DEPICTED A SUB-FREEZING THERMAL PROFILE...NEARLY
ISOTHERMAL BELOW 700 MB. THIS SHOULD SUPPORT INITIAL MODERATE SNOW
JUST N OF A MIXED PRECIP CORRIDOR IN WRN NY WITHIN THE WARM CONVEYOR
REGION. SEVERAL HOURS OF ENHANCED RATES MAY PERSIST AS THE BROADER
SWATH OF MODERATE TO LOCALLY HEAVY SNOW SPREADS E ACROSS THE LOWER
GREAT LAKES. LESS CONDUCIVE THERMODYNAMIC PROFILES FOR LIGHTNING
SHOULD TEMPER EXTREME RATES...BUT A LONG DURATION OF 1 IN/HR RATES
APPEARS PROBABLE.

..GRAMS.. 03/12/2014

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

ATTN...WFO...BGM...BUF...CTP...CLE...

LAT...LON   43727617 43537578 43057578 42647632 42227827 41907969
            41448090 41258176 41458208 42757913 43327916 43727617