761  
FXUS61 KBUF 050633  
AFDBUF  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BUFFALO NY  
133 AM EST MON DEC 5 2016  
   
SYNOPSIS
 
 
A TROUGH PUSHING ACROSS THE REGION OVERNIGHT AND EARLY MONDAY WILL  
GENERATE SOME WIDESPREAD LIGHT SNOW...WITH MOST AREAS RECEIVING LESS  
THAN INCH OF ACCUMULATION. HIGH PRESSURE APPROACHING FROM THE OHIO  
VALLEY WILL RETURN US TO FAIR WEATHER DURING THE COURSE OF THE DAY  
MONDAY WITH UNEVENTFUL WEATHER THEN REMAINING IN PLACE THROUGH THE  
FIRST HALF OF TUESDAY. OUR WEATHER WILL BECOME QUITE ACTIVE FOR THE  
REMAINDER OF THE WEEK...INCLUDING SIGNIFICANT LAKE SNOWS THAT WILL  
IMPACT AREAS EAST OF BOTH LAKES.  
 

 
   
NEAR TERM /THROUGH TODAY/
 
 
A NEGATIVELY TILTED TROUGH WILL PIVOT ACROSS THE LOWER GREAT LAKES  
OVERNIGHT WITH AN ATTENDANT STRONG SURGE OF ISENTROPIC LIFT  
COLLOCATED NICELY WITH PLUME OF DEEPER MOISTURE. THIS WILL DRIVE A  
SEVERAL HOUR PERIOD OF LIGHT TO AT TIME MODERATE SNOW WHICH WILL MIX  
WITH OR START AS SOME RAIN AT LOWER ELEVATIONS.  
 
EAST OF LAKE ONTARIO...  
EXPECTING A GENERAL 2-4 INCHES OF GENERAL SNOW ACROSS OSWEGO...  
JEFFERSON AND LEWIS COUNTIES WITH 3-6 CENTERED ON THE SOUTHERN END  
OF THE TUG HILL FROM ABOUT REDFIELD AND WORTH ACROSS MONTAGUE AND  
OSCEOLA TO ABOUT TURIN. BUFKIT PROFILES FOR RME SHOW A CROSSHAIR  
SIGNATURE OF MOISTURE...LIFT AND SNOW GROWTH FROM ABOUT 06Z-18Z.  
SURFACE TEMPERATURES IN THE LOW 20S SHOULD ALLOW SNOW TO STICK AND  
ACCUMULATE DESPITE SOIL TEMPS IN THE MID 30S. TIMING OF THE WORST  
CONDITONS INCLUDING SNOW COVERED AND SLIPPERY ROADS AND REDUCED  
VISIBILITIES FOR THIS EVENT WILL ALSO COME DURING THE MORNING  
COMMUTE.  
 
WESTERN NEW YORK AND THE FINGER LAKES...  
 
SURFACE TEMPERATURES ACROSS WESTERN NY ARE LARGELY STILL ABOVE  
FREEZING. INITIALLY EXPECTING A RAIN/SNOW MIX AS PRECIPITATION  
ARRIVES. MAGNITUDE OF LIFT AND COOLING THROUGH THE MELTING PROCESS  
SHOULD TRANSITION ALL AREAS OVER TO SNOW RATHER QUICKLY ALTHOUGH  
LAKE MODIFICATION MAY KEEP AREAS RIGHT ALONG THE LAKE ERIE AND LAKE  
ONTARIO SHORELINES IN A MIXED PRECIPITATION REGIME A BUT LONGER.  
MESOSCALE MODELS SIMILAR IN SHOWING A RATHER QUICK MOVING SYSTEM,  
BUT GIVEN FORCING AND AVAILABLE MOISTURE...HARD TO ARGUE WITH  
GUIDANCE BLEND QPF TOTALS OF AROUND A QUARTER OR SO. COOLING THERMAL  
PROFILES AND STRONG SUPPORT FOR PERIODS OF ENHANCED LIFT IN THE  
DENDRITIC GROWTH LAYER SUGGESTS SNOW-TO-LIQUID RATIOS PUSHING 12:1  
VALUES, ESPECIALLY FOR INTERIOR SECTION. ALL IN ALL...CONTINUITY  
AMOUNTS OF 1-3" SNOW TOTALS STILL LOOK REASONABLE FOR INTERIOR  
WESTERN NY AND THE FINGER LAKES. PROBABLY NO MORE THAN A COATING TO  
AN INCH FOR THE LOWER ELEVATIONS ALONG THE LAKESHORE. THE WORST  
CONDITONS SHOULD BE WANING ACROSS WESTERN NY BY THE TIME THE MORNING  
COMMUTE IS IN FULL SWING.  
 
CONDITIONS WILL GRADUALLY IMPROVE DURING THE DAY MONDAY AS HIGH  
PRESSURE FROM THE OHIO VALLEY WILL APPROACH THE REGION. THE ONLY AREA  
NOT TO EXPERIENCE SIGNIFICANT IMPROVEMENT WILL BE SITES EAST OF BOTH  
LAKES WHERE VERY MARGINAL CONDITIONS WILL BE IN PLACE FOR SOME  
NUISANCE LAKE EFFECT RAIN OR SNOW SHOWERS.  
 

 
   
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/
 
 
ANY LINGERING LIGHT SNOW/DRIZZLE EAST OF LAKE ONTARIO MONDAY NIGHT  
WILL END THROUGH THE EVENING HOURS AS LAKE INVERSION HEIGHTS FALL,  
AND MOISTURE FALLS BENEATH THE GOOD SNOW DENTRITIC GROWTH ZONES.  
OTHERWISE THE NIGHT WILL BE DRY WITH SOME BREAKS IN THE CLOUDS.  
 
TUESDAY WILL BEGIN DRY AS A RIDGE OF HIGH PRESSURE CROSSES THE  
REGION. A CLOSED LOW SEEN OVER WESTERN MEXICO SUNDAY AFTERNOON WILL  
OPEN UP AS IT RACES NORTHEASTWARD ACROSS THE UNITED STATES MONDAY  
AND MONDAY NIGHT. THIS FEATURE WILL BRING THE NEXT PERIOD OF  
UNSETTLED WEATHER THROUGH THE MIDDAY HOURS TUESDAY, AND THEN INTO  
TUESDAY NIGHT. GIVEN THE SOURCE REGION OF THIS SHORTWAVE WITHIN THE  
SOUTHERN BRANCH OF THE JET STREAM THERE WILL BE MORE RAIN THAN SNOW  
FALLING TUESDAY, THOUGH THROUGH THE NIGHT A FEW LOWER ELEVATIONS  
COULD SEE A MIX OF WET SNOW/RAIN IN ADDITION TO THE SNOW FALLING  
OVER THE HIGHER TERRAIN. SNOW ACCUMULATIONS WILL BE MINOR, WITH  
AGAIN A GENERAL INCH OR TWO ACROSS HIGHER TERRAIN.  
 
THERE MAY BE LINGERING PRECIPITATION EARLY WEDNESDAY ACROSS THE  
REGION, AND LIKELY EAST OF LAKE ONTARIO WHERE A MOIST, UPSLOPE FLOW  
WILL MAINTAIN PRECIPITATION THROUGH THE MORNING HOURS. A RIDGE OF  
HIGH PRESSURE EXTENDING ACROSS THE PLAINS, WILL BRIEFLY EXTEND  
EASTWARD TOWARDS THE EASTERN GREAT LAKES REGION, A SPELL A BRIEF  
PERIOD OF DRY WEATHER BEFORE COLD AIR ADVECTION UNDER CYCLONIC FLOW  
ALOFT, AND MOIST WESTERLY FLOW INCREASES CHANCES FOR LIGHT SNOW EAST  
OF THE LAKES LATER WEDNESDAY NIGHT.  
 
HIGH TEMPERATURES WILL RUN A FEW DEGREES ABOVE NORMAL, WITH  
AFTERNOON TEMPERATURES REACHING THE UPPER 30S TO LOWER 40S MONDAY  
AND TUESDAY. THERE WILL BE NO BITTER COLD THIS PERIOD WITH  
OVERNIGHT LOWS IN THE MID 20S TO MID 30S.  
 

 
   
LONG TERM /THURSDAY THROUGH SUNDAY/
 
 
THE PERIOD WILL FEATURE COLD TEMPERATURES WITH FREQUENT OPPORTUNITIES  
FOR SNOW. 12Z MODEL GUIDANCE HAS TRENDED AWAY A POTENTIAL  
SYNOPTIC SYSTEM, WITH A CONSENSUS NOW SUGGESTING MOST OF THE SNOW  
WILL BE LAKE EFFECT OR AT LEAST LAKE ENHANCED. THERE IS STILL  
UNCERTAINTY IN THE WIND DIRECTION AND THUS THE LOCATION OF LAKE  
EFFECT SNOW. THERE IS THE POTENTIAL FOR SIGNIFICANT SNOWFALL,  
ESPECIALLY CONSIDERING THE PROLONGED NATURE OF THE EVENT WHICH  
RUNS THURSDAY THROUGH SATURDAY. NOW FOR THE DETAILS...  
 
ON THURSDAY A TROUGH WILL DIG ACROSS THE GREAT LAKES REGION,  
WHICH WILL ADVECT MUCH COLDER AIR INTO WESTERN NEW YORK. 850MB  
TEMPERATURES WILL PLUMMET AND WILL AVERAGE -12C TO -14C ACROSS  
THE REGION THURSDAY NIGHT THROUGH SATURDAY. THIS WILL BE COLD  
ENOUGH TO SUPPORT LAKE EFFECT SNOW, WITH PRECIPITATION CHANGING TO  
ALL SNOW BY THURSDAY AFTERNOON. THE CYCLONIC FLOW ALOFT WILL  
PROVIDE AMPLE MOISTURE, WITH EMBEDDED SHORTWAVES LIKELY TO PROVIDE  
PERIODIC ENHANCEMENT. FOR THURSDAY AND THURSDAY NIGHT, IT APPEARS  
THAT A WNW FLOW WILL BE PREDOMINANT. THIS MAY SUPPORT BANDING EAST  
OR SOUTHEAST OF LAKE ONTARIO, WITH LESS ORGANIZED BUT PERSISTENT  
BANDS OFF LAKE ERIE DUE TO UPSLOPING AND MOISTURE FROM LAKE HURON.  
 
ON FRIDAY AND FRIDAY NIGHT, PREDOMINANTLY A NW FLOW IS EXPECTED,  
WHICH WOULD CONTINUE LAKE EFFECT SNOWS BUT PUSH THE STEADIEST  
SNOWS A BIT SOUTHWARD. BY SATURDAY THE UPPER TROUGH AXIS WILL  
SHIFT EAST OF THE NEW ENGLAND COAST, WITH A WEAK SURFACE HIGH  
BUILDING BEHIND IT ACROSS THE GREAT LAKES REGION. THIS SHOULD  
BRING IN SLIGHTLY DRIER AIR AND LOWER EQUILIBRIUM LEVELS, BUT  
CONDITIONS STILL SUPPORT LOCALIZED LAKE EFFECT SNOWS TO CONTINUE.  
WINDS ARE FORECAST TO VEER TO THE SOUTHWEST AND EVENTUALLY THE  
SOUTH BY SUNDAY. THIS WOULD LIFT WHAT IS LEFT OF LAKE EFFECT SNOW  
BANDS NORTHEAST OF THE LAKES.  
 
ALTHOUGH CONSENSUS AGREES ON THE COLD PATTERN, THERE IS STILL A  
CONSIDERABLE SPREAD AMONG MODEL GUIDANCE IN TERMS OF SPECIFICS.  
EVEN A SUBTLE SHIFT IN WINDS WOULD SIGNIFICANTLY IMPACT THE  
LOCATION OF THE HEAVIEST SNOWS. THIS SAID, THE PATTERN GENERALLY  
FAVORS THE GREATEST AMOUNTS SOUTHEAST OF LAKE ONTARIO (PROBABLY FOCUSED  
NEAR OSWEGO COUNTY) AND THE WESTERN SOUTHERN TIER. IT IS STILL TOO  
EARLY FOR SPECIFIC SNOWFALL AMOUNTS AND EVEN THESE AREAS OF FOCUS  
MAY CHANGE AS NEW MODEL GUIDANCE BECOMES AVAILABLE.  
 
OTHERWISE, TEMPERATURES WILL BE CONSIDERABLY COLDER THAN THEY HAVE  
BEEN WITH HIGHS ON FRIDAY AND SATURDAY RANGING FROM THE MID 20S TO  
AROUND FREEZING. THE FORECAST FAVORS A BLEND OF RAW MODEL  
GUIDANCE DUE TO THE WIND AND CLOUD COVER WHICH WILL LIMIT DAYTIME  
HEATING AND RADIATIONAL COOLING.  
 

 
   
AVIATION /07Z MONDAY THROUGH FRIDAY/
 
 
WIDESPREAD LIGHT TO OCCASIONALLY MODERATE SNOW WILL PRODUCE LIFR  
CONDITIONS ACROSS THE WESTERN COUNTIES THROUGH ABOUT 08Z...THEN AS  
THE SNOW SHIELD PUSHES AWAY TO THE NORTHEAST...MVFR CIGS WILL  
REMAIN. EAST OF LAKE ONTARIO...THE SNOW WILL DETERIORATE CONDITIONS  
TO IFR-LIFR AFTER 08Z AND PERSIST THROUGH ABOUT 13Z.  
 
AS WE WORK OUR WAY FROM THE MIDDAY INT THE AFTERNOON...CIGS WILL  
IMPROVE FROM WEST TO EAST WITH ALL AREAS EXPECTED TO RETURN TO VFR  
CONDITIONS.  
 
MAINLY VFR CONDITIONS ARE EXPECTED MONDAY NIGHT AS HIGH PRESSURE  
WILL DRIFT ACROSS THE LOWER GREAT LAKES.  
 
OUTLOOK...  
 
TUESDAY...MAINLY VFR.  
TUESDAY NIGHT AND WEDNESDAY...VFR DETERIORATING TO MVFR WITH SOME  
RAIN BECOMING LIKELY.  
THURSDAY AND FRIDAY...MVFR/IFR WITH SNOW LIKELY.  
 

 
   
MARINE
 
 
A DISTURBANCE WITH WIDESPREAD LIGHT TO MODERATE SNOW WILL PUSH  
ACROSS THE REGION OVERNIGHT, WINDS ARE NOT EXPECTED TO NOTABLY  
FRESHEN UNTIL MONDAY WHEN THE GRADIENT WILL TEMPORARILY TIGHTEN  
BETWEEN THE EXITING SYSTEM AND THE NEXT SURFACE HIGH. A PERIOD OF  
SMALL CRAFT ADVISORIES HAS BEEN ISSUED FOR THE NEARSHORE WATERS ON  
LAKES ERIE AND ONTARIO.  
 
WINDS AND WAVES WILL SUBSIDE WITH THE ARRIVAL OF ANOTHER SURFACE  
HIGH OVERNIGHT MONDAY NIGHT.  
 
WHILE WINDS WILL FRESHEN FROM THE EAST ON TUESDAY, BUT THEY WILL  
REMAIN BELOW SMALL CRAFT ADVISORY LEVELS AS THE HIGHER WAVES WILL BE  
CONFINED TO CANADIAN WATERS.  
 
LOOKING FURTHER AHEAD, A DEEP STORM FORECAST TO TRACK ACROSS  
JAMES BAY LATE IN THE WEEK MAY GENERATE GALE FORCE WINDS OVER THE  
LOWER GREAT LAKES THURSDAY NIGHT AND FRIDAY.  
 

 
   
BUF WATCHES/WARNINGS/ADVISORIES
 
 
NY...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR  
NYZ006>008.  
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEZ040-  
041.  
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 10 PM  
EST THIS EVENING FOR LOZ043-044.  
SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 7 PM EST  
THIS EVENING FOR LOZ042.  
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM EST  
THIS EVENING FOR LOZ045.  
 

 
 

 
 
SYNOPSIS...RSH  
NEAR TERM...RSH/TMA  
SHORT TERM...THOMAS  
LONG TERM...APFFEL  
AVIATION...RSH  
MARINE...SMITH/TMA  
 
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