Area Forecast Discussion
Issued by NWS Buffalo, NY

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000
FXUS61 KBUF 292029
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
329 PM EST THU JAN 29 2015

.SYNOPSIS...
A STORM SYSTEM WILL TRACK ACROSS THE EASTERN GREAT LAKES REGION THIS
EVENING SPREADING LIGHT SNOW ACROSS THE AREA TONIGHT AND TOMORROW.
GREATEST SNOWFALL TOTALS WILL BE FOUND ACROSS THE HIGHER TERRAIN
EAST OF BOTH LAKES. ANOTHER AREA OF HIGH PRESSURE WILL THEN BRING A
RETURN OF FAIR...BUT COLD WEATHER FOR THE START OF THE WEEKEND.

&&

.NEAR TERM /THROUGH FRIDAY/...
THIS AFTERNOON AN AREA OF LOW PRESSURE IS LOCATED NEAR LAKE
HURON...WITH A COLD FRONT DROPPING ACROSS THE OHIO VALLEY AND
TOWARDS THE DEEP SOUTH. REGIONAL RADARS DISPLAY LIGHT SNOW...TO THE
EAST OF LAKE ONTARIO ALONG THE LEADING EDGE OF THE LLJ...AND THEN
FARTHER WESTWARD ACROSS PORTIONS OF WNY AND AHEAD OF THE SURFACE
LOW. SURFACE OBSERVATIONS DISPLAY THE BULK OF THE PRECIPITATION NOW
BACK TO ALL SNOW...THOUGH SOME POCKETS OF SLEET/RAIN ARE STILL
POSSIBLE FOR A FEW HOURS THIS LATE AFTERNOON NEAR LAKE ERIE.

FOR TONIGHT...EVAPORATIVE COOLING FROM FALLING PRECIPITATION INTO A
DRY LOW LEVEL WEDGE OF AIR WILL SUFFICIENTLY COOL THE LOWER LEVELS
TO ALLOW FOR JUST PLAIN SNOW FOR THE EVENING HOURS.

A REGION WIDE LIGHT SNOW EVENT WILL UNFOLD TONIGHT AS SEVERAL
SHORTWAVE SEGMENTS OVER THE CENTRAL GREAT LAKES SLIDE
EASTWARD...AND DRIVE A COLD FRONT ACROSS THE REGION THIS LATE
EVENING AND EARLY OVERNIGHT. MID LEVEL MOISTURE POOLING ALONG AND
AHEAD OF THIS COLD FRONT WILL SUPPLY THE MOISTURE FOR LIGHT SNOW
SHOWERS THIS EVENING. LIFT...FROM BOTH THE COLD FRONT AND MID LEVEL
ACCENT AHEAD OF SHORTWAVE SEGMENTS WILL GENERATE A LIGHT SNOW
THROUGH MUCH OF THE NIGHT. THOUGH THE COLD FRONT WILL PASS THE AREA
EARLY OVERNIGHT CONTINUED LIFT AHEAD OF A VIGOROUS SHORTWAVE
ARRIVING FROM THE WESTERN GREAT LAKES...COMBINED WITH LOW LEVEL
OROGRAPHIC LIFT WILL MAINTAIN LIGHT SNOW SHOWER ACTIVITY INTO THE
MORNING HOURS FRIDAY. IT IS ACROSS THE HIGHER TERRAIN THAT SNOW
TOTALS WILL REACH 4 TO 6 INCHES...FOR WHICH WINTER WEATHER
ADVISORIES WILL CONTINUE TO BE IN PLACE. NEAR THE LAKESHORE...AND
ACROSS THE GENESEE VALLEY TOTAL SNOWFALL WILL ONLY BE A COUPLE OF
INCHES THROUGH TOMORROW.

TEMPERATURES WILL FALL TONIGHT BEHIND THE COLD FRONT...INTO THE
LOWER TEENS ACROSS WNY BY DAWN TOMORROW...AND UPPER TEENS EAST OF
LAKE ONTARIO. THE COLD NORTHWEST FLOW WITHIN CYCLONIC FLOW ALOFT
WILL MAINTAIN LIGHT SNOW SHOWERS SOUTH OF LAKE ONTARIO THROUGH MUCH
OF THE DAY FRIDAY...WITH A COUPLE INCHES OF SNOW POSSIBLE ACROSS THE
CHAUTAUQUA RIDGE AND BOSTON HILLS EAST OF LAKE ERIE...AND TO THE
SOUTHEAST OF LAKE ONTARIO. TEMPERATURES WILL BE NOTABLY COLDER
TOMORROW WITH SINGLE DIGIT TEMPERATURES ACROSS A GOOD PORTION OF THE
REGION BY MID AFTERNOON.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
FRIDAY NIGHT LOW PRESSURE WILL MOVE EAST THROUGH THE GULF OF MAINE.
COLD NORTHWEST FLOW IN THE WAKE OF THIS SYSTEM WILL CONTINUE TO
PRODUCE SOME VERY LIMITED LAKE EFFECT SNOW SHOWERS SOUTHEAST OF LAKE
ONTARIO. DESPITE THE COLD AIR...INVERSION HEIGHTS WILL REMAIN
RELATIVELY LOW AROUND 5K FEET...AND THE SHORT FETCH AND LACK OF
UPSTREAM LAKE CONNECTION WILL PREVENT ANYTHING MORE ORGANIZED.
EXPECT SPOTTY ADDITIONAL AMOUNTS OF AROUND AN INCH FROM MONROE
COUNTY INTO THE NORTHERN FINGER LAKES. THERE MAY STILL BE A FEW
FLURRIES OR LIGHT SNOW SHOWERS ACROSS THE WESTERN SOUTHERN TIER FROM
UPSTREAM LAKE HURON MOISTURE AND LIMITED MOISTURE FROM THE THIN
SPOTS ON LAKE ERIE...BUT THIS SHOULD REMAIN VERY LIGHT WITH JUST A
SPOTTY DUSTING.

TEMPERATURES WILL CONTINUE TO DROP FRIDAY NIGHT WITH LOWS IN THE
LOWER SINGLE NUMBERS ON THE LAKE PLAINS AND SINGLE NUMBERS BELOW
ZERO FARTHER INLAND. EAST OF LAKE ONTARIO WILL GET MUCH COLDER WITH
NO OFF-LAKE FLOW AND SOME POSSIBLE CLEARING LATE. EXPECTED LOWS OF
15 TO 20 BELOW ACROSS THE NORTH COUNTRY. THERE WILL STILL BE A
BREEZE ESPECIALLY DURING THE FIRST HALF OF THE NIGHT...AND THIS MAY
PRODUCE WIND CHILLS NEAR ADVISORY CRITERIA EAST OF LAKE ONTARIO AND
ALSO ACROSS THE WESTERN SOUTHERN TIER...WITH A LESSER CHANCE OF
ADVISORY WIND CHILLS ELSEWHERE. FOLLOWING COORDINATION WITH
SURROUNDING OFFICES WILL HOLD OFF ON WIND CHILL HEADLINES FOR
NOW...BUT THEY MAY EVENTUALLY BE REQUIRED.

ON SATURDAY ANY LINGERING LIGHT LAKE EFFECT FLURRIES OR SNOW SHOWERS
SOUTHEAST OF LAKE ONTARIO SHOULD END BY MIDDAY AS A SURFACE RIDGE
CRESTS OVER THE LOWER LAKES. WARM ADVECTION IN THE MID LEVELS WILL
BRING AN INCREASE IN HIGH CLOUDS FROM WEST TO EAST. AFTER A COLD
START TO THE DAY TEMPERATURES WILL RECOVER INTO THE LOW 20S BY LATE
AFTERNOON ACROSS WESTERN NY...BUT STAY IN THE SINGLE DIGITS ACROSS
THE NORTH COUNTRY DEEPER INTO THE COLD AIRMASS.

SATURDAY NIGHT AND EARLY SUNDAY MORNING A RE-ENFORCING ARCTIC FRONT
WILL MOVE QUICKLY SOUTH ACROSS THE AREA. THE FRONT MAY BE
ACCOMPANIED BY A QUICK BURST OF SNOW SHOWERS...WHICH MAY ALSO PICK
UP SOME ENHANCEMENT OFF LAKE ONTARIO AND THE LIMITED OPEN WATER ON
LAKE ERIE...AND ALSO FROM UPSLOPE FLOW EAST OF THE LAKES. THIS MAY
PRODUCE A QUICK INCH OR TWO OF ACCUMULATION IN SOME SPOTS. ON SUNDAY
BOUNDARY LAYER FLOW WILL QUICKLY BECOME NORTHWEST...WITH LIGHT LAKE
EFFECT SNOW SHOWERS LINGERING SOUTH AND SOUTHEAST OF LAKE ONTARIO
WITH SOME VERY MINOR ADDITIONAL ACCUMULATIONS. A FRESH BATCH OF
COLDER AIR WILL KEEP HIGHS ONLY IN THE MID TEENS IN MOST AREAS WITH
SINGLE NUMBERS ACROSS THE NORTH COUNTRY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
UNCERTAINTY STILL ABOUNDS IN THE FORECAST FOR SUNDAY NIGHT AND
MONDAY. THE 12Z GFS AND ECMWF ARE CONSISTENT WITH THE TREND OF
KEEPING A WEAKER AND FARTHER SOUTH SOLUTION WITH THE LOW FORECAST TO
MOVE OUT OF THE LOWER OHIO VALLEY INTO THE MID ATLANTIC...ALTHOUGH A
SLIGHT NORTHWARD SHIFT AND STRONGER SURFACE LOW IS NOTED IN THE 12Z
ECMWF. THE CANADIAN GEM WHICH HAD BEEN HANGING ONTO THE SYSTEM OVER
THE PAST FEW RUNS HAS ABANDONED IT WITH THE 12Z RUN...TAKING A MUCH
WEAKER LOW WELL SOUTH OF THE AREA. A LOOK THROUGH THE INDIVIDUAL 12Z
GEFS ENSEMBLE MEMBERS SHOW A MAJORITY SIMILAR TO THE OPERATIONAL
GFS...ALTHOUGH THERE ARE STILL SEVERAL RUNS WITH A MUCH STRONGER AND
FARTHER NORTH SOLUTION. WITH THE ONGOING ENSEMBLE UNCERTAINTY AND
THE FACT THAT THE ENERGY WHICH WILL PRODUCE THIS SYSTEM IS STILL
OVER ALASKA...THERE WILL PROBABLY STILL BE SOME FUTURE MODEL CHANGES
WITH THE TIMING AND TRACK. EVEN THE CURRENT GFS AND ECMWF SOLUTIONS
MAY BRUSH THE SOUTHERN TIER WITH SOME LIGHT SNOW...AND COLD
NORTHERLY FLOW TO THE NORTH OF THE SYSTEM WOULD LIKELY PRODUCE SOME
LIMITED LAKE EFFECT SNOW SHOWERS SOUTH OF LAKE ONTARIO SUNDAY NIGHT
AND MONDAY. WITH THIS IN MIND...HAVE MAINTAINED MID RANGE CHANCE
POPS THROUGH THE PERIOD.

REGARDLESS OF THE TRACK OF THE SYSTEM...ANOTHER STRONG PUSH OF COLD
AIR WILL ARRIVE EARLY NEXT WEEK...WITH HIGHS ON MONDAY POSSIBLY NOT
GETTING OUT OF THE SINGLE NUMBERS IN MANY AREAS. LOWS MONDAY NIGHT
MAY DROP BELOW ZERO IN MOST AREAS AND POSSIBLY COLDER THAN 20 BELOW
ACROSS THE NORTH COUNTRY ESPECIALLY IF SKIES CLEAR.

OTHERWISE A SERIES OF WEAK CLIPPER SYSTEMS WILL CROSS THE GREAT
LAKES REGION TUESDAY THROUGH THURSDAY...WITH BOTH THE GFS AND ECMWF
SUGGESTING THE STRONGEST WILL BE ON WEDNESDAY. IF THIS STRONGER
SOLUTION VERIFIES IT WOULD BRIEFLY BRING A PUSH OF MILDER
TEMPERATURES WEDNESDAY BEFORE ANOTHER ARCTIC SURGE BY THURSDAY.
THERE WILL ALSO BE SOME OPPORTUNITY FOR LAKE EFFECT SNOW BY THURSDAY
AS FLOW APPEARS TO ALIGN BETTER AT THAT TIME THAN EARLIER IN THE
WEEK.

&&

.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
AT 18Z VFR FLIGHT CONDITIONS WERE FOUND ACROSS THE REGION...THOUGH
THE IMPACTS FROM THE CENTRAL GREAT LAKES STORM SYSTEM...ARE UPON WNY
AS LIGHT PRECIPITATION IS BEGINNING TO FALL ACROSS WNY. A WEALTH OF
DRY AIR AT THE LOWER LEVELS WILL KEEP THIS PRECIPITATION LIGHT
THROUGH THE FIRST 3-6 HOURS OF THE TAF PERIOD. P-TYPE WILL BE TRICKY
AS A WARM NOSE JUST ABOVE THE SURFACE MAY ALLOW FOR SOME SLEET AND
EVEN PLAIN RAIN/DRIZZLE FOR A TIME THIS AFTERNOON ACROSS
KJHW/KBUF/KIAG. AS PRECIPITATION INTENSITY INCREASES THIS AFTERNOON
EXPECT A CHANGE OVER BACK TO PLAIN SNOW...WITH THE SNOW IMPACTING
ALL TAF SITES THIS EVENING AND OVERNIGHT.

A PERIOD OF IFR OR LOWER VSBYS ARE EXPECTED WITHIN THIS
SNOW...THOUGH CIGS NEAR THE LAKES SHOULD REMAIN LARGELY MVFR...BUT
OCCASIONALLY DIP TO IFR ACROSS THE SOUTHERN TIER.

A COLD FRONT WILL CROSS THE REGION MID EVENING TOWARDS THE WEST AND
JUST PAST MIDNIGHT EAST OF LAKE ONTARIO. WINDS WILL VEER AROUND TO
WEST...THEN LATER NORTHWEST BEHIND THE COLD FRONT AND OCCASIONALLY
GUST 20 TO 25 KNOTS. LIGHT SNOW WILL CONTINUE THROUGH THE END OF THE
TAF PERIOD...BECOMING MORE FOCUSED SOUTH OF LAKE ONTARIO. ANY OF
THESE SNOW SHOWERS MAY BRING IFR VSBYS...IN AN OTHERWISE
PREDOMINATELY MVFR FLIGHT CONDITIONS.

OUTLOOK...
FRIDAY NIGHT...A CHANCE OF SNOW SHOWERS SOUTHEAST OF THE
LAKES.
SATURDAY...NO SIGNIFICANT WEATHER EXPECTED.
SUNDAY AND MONDAY....AREAS OF MVFR IN A CHANCE OF SNOW SHOWERS
SOUTH OF LAKE ONTARIO.
TUESDAY...AREAS OF MVFR WITH A CHANCE OF SNOW SHOWERS.

&&

.MARINE...
A COLD FRONT WILL CROSS LAKE ONTARIO THIS EVENING AND EARLY
OVERNIGHT. SOUTHERLY FLOW AHEAD OF THE COLD FRONT WILL VEER TO
WESTERLY TONIGHT AND NORTHWEST TOMORROW. WINDS WILL REACH 15 TO 25
KNOTS ON THE LAKE TONIGHT AND TOMORROW...AND THIS WILL GENERATE
WAVES UP TO 7 FEET FRIDAY AFTERNOON. SUCH...SCA WILL BE IN PLACE
THROUGH FRIDAY NIGHT.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST FRIDAY FOR NYZ004>008.
     WINTER WEATHER ADVISORY UNTIL 10 AM EST FRIDAY FOR NYZ012-019-
     020-085.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM FRIDAY TO 7 AM EST SATURDAY FOR
         LOZ042>045.

&&

$$

SYNOPSIS...THOMAS
NEAR TERM...THOMAS
SHORT TERM...HITCHCOCK
LONG TERM...HITCHCOCK
AVIATION...THOMAS
MARINE...THOMAS






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