National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
ACUS11 KWNS 111332
SWOMCD
SPC MCD 111332
NYZ000-111730-

MESOSCALE DISCUSSION 2076
NWS STORM PREDICTION CENTER NORMAN OK
0732 AM CST WED DEC 11 2013

AREAS AFFECTED...EAST END OF LAKE ONTARIO TO THE TUG HILL PLATEAU OF
NEW YORK

CONCERNING...HEAVY SNOW

VALID 111332Z - 111730Z

SUMMARY...THE EARLIER DISRUPTION TO THE OVERNIGHT SOLITARY LAKE
EFFECT SNOW BAND MAY ONLY HAVE BEEN TEMPORARY...AS A NEW SOLITARY
BAND POTENTIALLY BECOMES RE-ESTABLISHED THIS MORNING. IF THIS
CONTINUES TO OCCUR...SNOWFALL RATES OF 2-3 INCHES PER HOUR MAY
REDEVELOP THROUGH THE MORNING WITH THE MOST INTENSE PARTS OF THE
BAND.

DISCUSSION...DURING THE PAST COUPLE OF HOURS...BUF VWP DATA INDICATE
SUBTLE BACKING OF THE FLOW JUST ABOVE THE SFC. THIS COULD BE LINKED
TO ISALLOBARIC FORCING ASSOCIATED WITH A MID-LEVEL PERTURBATION
CROSSING THE LOWER GREAT LAKES REGION THAT IS ELONGATED OVER THE SRN
PERIPHERY OF THE DEEPER POLAR VORTEX -- PER MOISTURE CHANNEL
IMAGERY. THE MINOR WIND SHIFT MAY EXPLAIN THE EARLIER DISRUPTION TO
THE ANTECEDENT SOLITARY SNOW BAND THAT AFFECTED THE LOCAL AREA
THROUGH MUCH OF THE NIGHT. HOWEVER...WITH MASS FIELDS AT THE
MESO-BETA SCALE REESTABLISHING A QUASI-STEADY STATE GIVEN THE
ELONGATION OF THE MID-LEVEL PERTURBATION...IT IS ENTIRELY POSSIBLE
THAT ANOTHER SOLITARY SNOW BAND WILL CONTINUE REFORMING DURING THE
NEXT COUPLE OF HOURS IN A SIMILAR LOCATION AS THE OVERNIGHT
BAND...AND PERSIST THROUGH THE DAY.

THE 12Z BUF RAOB SUGGESTS DEEP WLY/UNIDIRECTIONAL FLOW THROUGH THE
TROPOSPHERE THAT WOULD FAVOR THE DEVELOPMENT OF SUCH A BAND VIA
MAXIMIZATION OF FETCH LENGTH ATOP RELATIVELY WARMER LAKE WATERS.
THIS SHOULD CONTINUE TO SUPPORT THE MAINTENANCE OF AN ABOVE-LAKE
CONVECTIVE BOUNDARY LAYER. MOSAIC RADAR IMAGERY ALREADY INDICATES
REGENERATING CONVECTION ALONG THE LONG AXIS OF THE LAKE THAT COULD
CONTINUE RE-CONSOLIDATING INTO A BAND THIS MORNING. THE MODERATELY
DEEP DENDRITIC GROWTH ZONE CENTERED AROUND H85 AS SAMPLED BY THE 12Z
BUF RAOB AND THE SHALLOW -- THOUGH INTENSE -- CONVECTIVE NATURE OF
THE PRECIPITATION COULD FOSTER SNOWFALL RATES OF 2-3 INCHES PER
HOUR...ESPECIALLY IF A SOLITARY BAND REDEVELOPS. THE HIGHEST
SNOWFALL RATES WOULD OCCUR AROUND W-FACING SLOPES SURROUNDING THE
TUG HILL PLATEAU...AND IN ASSOCIATION WITH ANY ISOLATED
THUNDERSTORMS /SEE DAY-1 CONVECTIVE OUTLOOK FOR ADDITIONAL DETAILS/.

..COHEN.. 12/11/2013

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

ATTN...WFO...BGM...BUF...

LAT...LON   43667641 43787568 43827527 43637513 43477538 43437573
            43437619 43467654 43667641