Area Forecast Discussion
Issued by NWS Buffalo, NY

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FXUS61 KBUF 221527
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1027 AM EST SAT NOV 22 2014

.SYNOPSIS...
RAIN WILL DEVELOP ACROSS THE AREA TODAY...WITH SOME OF THE
PRECIPITATION FALLING AS FREEZING RAIN ACROSS THE NIAGARA FRONTIER
AND WESTERN SOUTHERN TIER AND INTERIOR PORTIONS OF THE NORTH
COUNTRY BEFORE TEMPERATURES WARM ABOVE FREEZING THIS AFTERNOON AND
EVENING. TEMPERATURES WILL CONTINUE TO CLIMB THROUGH THE REST OF
THE WEEKEND AND INTO MONDAY WITH ADDITIONAL RAINFALL AND WINDY
CONDITIONS EXPECTED SUNDAY NIGHT INTO MONDAY AS A DEEP AREA OF LOW
PRESSURE PASSES TO OUR NORTHWEST. THIS WILL ACCELERATE MELTING OF
RECENT HEAVY SNOWS...CREATING A SIGNIFICANT FLOODING RISK ACROSS
PORTIONS OF WESTERN AND NORTH-CENTRAL NEW YORK. A COLD FRONT WILL
THEN CROSS THE REGION MONDAY EVENING...BRINGING A RETURN OF MORE
WINTER-LIKE TEMPERATURES AND A CHANCE OF SNOW BY LATER IN THE
WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AFTER AN EXTENDED PERIOD OF COLD AND SNOWY WEATHER...WESTERN AND
NORTH-CENTRAL NEW YORK WILL BEGIN TO THAW OUT STARTING TODAY AS HIGH
PRESSURE MOVES OFF THE EAST COAST...RESULTING IN BROAD WARM
ADVECTION ACROSS THE OHIO VALLEY AND GREAT LAKES.

EXPECT PRECIPITATION TO DEVELOP FROM SOUTHWEST TO NORTHEAST ACROSS
THE FORECAST AREA THROUGH THIS AFTERNOON AS THE FIRST OF A SERIES
OF WARM FRONTS LIFTS ACROSS THE REGION IN CONJUNCTION WITH THE
ARRIVAL OF A 115KT 250MB UPPER LEVEL JET OVER NORTHERN
OH/PA...PLACING THE FORECAST AREA IN THE LEFT EXIT REGION OF THE
JET. THAT SAID...WITHOUT A STRONG MID/UPPER LEVEL SHORTWAVE AS A
FOCAL POINT...LARGE-SCALE LIFT WILL BE RATHER WEAK AND DIFFUSE AND
THIS SHOULD KEEP PRECIP AMOUNTS MODEST...WITH BETWEEN A TENTH AND
A QUARTER INCH EXPECTED THOROUGH TONIGHT...SOMEWHAT OF A RELIEF
GIVEN THE EXTREME SNOWPACK IN PLACE ACROSS PORTIONS OF WESTERN NEW
YORK. HOWEVER...AS PRECIPITATION DEVELOPS LATE THIS MORNING ACROSS
THE NIAGARA FRONTIER AND SOUTHERN TIER AND LATER THIS AFTERNOON
ACROSS THE NORTH COUNTRY...SURFACE AND ROAD TEMPERATURES MAY STILL
REMAIN AT OR BELOW FREEZING AND IT IS EXPECTED THAT SOME OF THESE
LOCATIONS WILL SEE A PERIOD OF FREEZING RAIN. A FREEZING RAIN
ADVISORY WILL BE IN EFFECT FOR THESE AREAS AS OUTLINED BELOW.

LOOK FOR TEMPERATURES TO WARM THROUGH THE DAY WITH HIGHS TOPPING OUT
IN THE LOWER 40S ALONG THE LAKE PLAINS AND THE FINGER LAKES WHILE
HIGHS IN THE MID TO UPPER 30S WILL BE FOUND ACROSS THE HIGHER
ELEVATIONS OF THE SOUTHERN TIER AND NORTH COUNTRY.

TEMPERATURES WILL REMAIN NEARLY STEADY IN THE UPPER 30S TO LOWER 40S
THROUGH THE NIGHT TONIGHT AS WARM ADVECTION CONTINUES ACROSS THE
REGION. THIS WILL KEEP ANY LINGERING PRECIPITATION ENTIRELY IN THE
FORM OF RAIN AS SHOWERS TAPER OFF FROM WEST TO EAST WITH THE EXIT OF
THE AFOREMENTIONED JET-STREAK.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
TWO BIG CONCERNS ARE BEING WATCHED CLOSELY DURING THE LATE SUNDAY
THROUGH MONDAY TIME PERIOD. THESE ARE: 1) FLOODING FROM SNOW MELT
AND 2) A POSSIBLE HIGH WIND EVENT. FIRST WE WILL COVER THE
CONTINUATION OF THE WARMING TREND ON SUNDAY WITH MORE DETAILS ON THE
BIG CONCERNS FOLLOWING.

DEEP SOUTHERLY FLOW ROUNDING THE WEST SIDE OF A BROAD SURFACE HIGH
OVER THE NORTHWEST ATLANTIC WILL ADVECT INCREASINGLY WARMER AND MORE
MOIST AIR ACROSS WESTERN AND CENTRAL NEW YORK SUNDAY AS NORTHERN AND
SOUTHERN STREAM SURFACE LOWS MERGE OVER THE MIDWEST STATES. 850MB
TEMPS WILL RISE FROM +5C TO +10C WHICH SHOULD BOOST SURFACE HIGH
TEMPERATURES INTO TO MID TO UPPER 40S WITH DEWPOINTS CLIMBING ABOVE
THE FREEZING MARK TO NEAR 40 DEGREES. A WEAK WARM FRONT ALOFT WILL
CROSS THE FORECAST AREA BUT LACK OF SIGNIFICANT LIFT SHOULD ONLY
BRING A CHANCE FOR SOME SPRINKLES.

FOCUS SUNDAY NIGHT AND MONDAY THEN TURNS TO A RAPIDLY DEEPENING -3SD
SURFACE LOW CUTTING ACROSS THE UPPER GREAT LAKES TO OUR WEST. THIS
IS A FAVORABLE TRACK FOR HIGH WIND EVENTS AND 00Z MODELS ARE
FORECASTING A SOUTHEASTERLY 850MB JET WHICH RANGES BETWEEN 70KTS
(NAM12) AND 90KTS (GFS40) LIFTING ACROSS WESTERN AND CENTRAL NEW
YORK SUNDAY NIGHT THEN VEERING TO SOUTHWEST BEHIND THE SURFACE WARM
FRONT WHILE SLACKENING TO 50-60KTS. ASSOCIATED HIGH WIND IMPACTS ARE
MENTIONED BELOW.

THE SURFACE WARM FRONT AND LOW LEVEL JET WILL PROVIDE SIGNIFICANT
FORCING IN THE PRESENCE OF PWATS OF AN INCH TO AND INCH AND A
QUARTER TO BRING A 3-5 HOUR PERIOD OF RAIN SHOWERS EARLY MONDAY. QPF
FROM THIS REMAINS AT 0.25-0.50 INCHES WHICH WILL ADD TO A QUICKLY
MELTING SNOWPACK. STRONG SOUTHWEST WINDS WILL BRING A SHARP DRY SLOT
BEHIND THE WARM FRONT THROUGH MONDAY. TEMPERATURES LOOK TO PEAK NEAR
60 DEGREES THEN A COLD FRONT THEN LOOKS TO CROSS THE AREA LATER
MONDAY OR MONDAY EVENING WITH A FEW MORE SHOWERS. THIS FRONT WILL
USHER IN A STEADILY COLDER AIRMASS BY TUESDAY.

SNOWMELT...
ONCE SURFACE DEWPOINTS RISE ABOVE FREEZING SUNDAY THE RIPENING
SNOWPACK WILL BEGIN TO LET LOOSE WITH RAPID SNOW MELT ACROSS AREAS
WHICH RECEIVED LAST WEEKS HEAVY LAKE EFFECT SNOWFALL. SNOW DEPTH
MEASUREMENTS FROM FRIDAY INDICATED SNOWPACK HAS COMPACTED DOWN TO
BETWEEN 20 AND 40 INCHES WITH AN AVERAGE OF 4-6 INCHES OF LIQUID
LOCKED UP. SNOWMELT MODELING COVERING A TIME RANGE FROM LATER SUNDAY
THROUGH MONDAY INDICATED 50 INCHES OF SNOW COULD MELT UNDER
FORECASTED CONDITIONS. THEREFORE...ALL OF THE EXISTING SNOW PACK IS
EXPECTED TO MELT AWAY RAISING THE CONCERNS FOR FLOODING WITH FINER
DETAILS HIGHLIGHTED IN THE FLOOD WATCH AND HYDROLOGY SECTION BELOW.

HIGH WINDS...
THE STRONG SOUTHEASTERLY 850MB JET MONDAY NIGHT IS FAVORABLE FOR
STRONG DOWNSLOPE WINDS ALONG THE LAKE ERIE SHORE AND ALONG OTHER
NORTHWARD FACING SLOPES IN WESTERN NY AND THE FINGER LAKES...AND
POSSIBLY THE BLACK RIVER VALLEY. FOLLOWING THE PASSAGE OF THE WARM
FRONT THE LOW LEVEL JET VEERS TO SOUTHWEST WHICH IS MORE FAVORABLE
FOR WIDESPREAD STRONG WINDS AS WIND ENERGY FROM 50-60KT 850MB WINDS
MIX DOWN. MAX WINDS GUSTS STILL LOOK TO BE BORDERLINE
ADVISORY/WARNING CRITERIA. HAVE OPTED TO JUST HIGHLIGHT STRONG WINDS
IN THE HAZARDOUS WEATHER OUTLOOK FOR THIS SHIFT AND WAIT FOR ANOTHER
MODEL RUN TO SEE IF MODELS REMAIN CONSISTENT ENOUGH TO GO WITH A
HIGH WIND WATCH.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
TEMPERATURES WILL RETURN TO BELOW AVERAGE FOR THE BULK OF NEXT WEEK
INCLUDING THE THANKSGIVING HOLIDAY AS A DEVELOPING RIDGE OVER THE
ROCKIES WILL FORCE A DOWNSTREAM TROUGH TO CARVE INTO THE GREAT LAKES
AND NORTHEAST. THE AIRMASS LOOKS TO BE COLD ENOUGH TUESDAY/WEDNESDAY
FOR A RETURN OF CHANCES FOR LAKE EFFECT SNOW AS LAKE INDUCED
EQUILIBRIUM LEVELS CLIMB TO AROUND 10KFT. AT THIS POINT IT DOES NOT
LOOK UNSTABLE ENOUGH FOR A SIGNIFICANT EVENT.

THE MID LEVEL TROUGH AND A WEAK SURFACE LOW/SURFACE TROUGH MAY BRING
A FEW SNOW SHOWERS FOR THANKSGIVING THURSDAY BEHIND A POSSIBLE
NOREASTER` LIFTING ALONG THE EAST COAST. A FRESH BLAST OF COLD AIR
BEHIND THE WEAK LOW/SURFACE TROUGH LOOKS TO THEN AGAIN BRING RENEWED
CHANCES OF LAKE EFFECT FRIDAY INTO SATURDAY.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
MID-LEVEL CLOUDS CONTINUE TO STREAM ACROSS THE AREA THIS MORNING DUE
TO WARM ADVECTION ALOFT AHEAD OF AN APPROACHING WARM FRONT. CIGS
WILL LOWER BY EARLY AFTERNOON AND LIGHT PRECIPITATION WILL SPREAD
ACROSS THE FORECAST AREA FROM SOUTHWEST TO NORTHEAST AS A WARM FRONT
LIFTS NORTH ACROSS THE REGION. WARM AIR WILL BE SLOWER TO DISPLACE
CURRENTLY SUBFREEZING AIR IN THE VALLEYS OF THE SOUTHERN TIER AND
PORTIONS OF THE NORTH COUNTRY...CONSEQUENTLY PRECIPITATION WILL
START OUT IN THESE AREAS AS A PERIOD OF FREEZING RAIN. THIS IS
EXPECTED TO AFFECT KJHW BETWEEN 17-19Z BEFORE TRANSITIONING OVER TO
LIQUID RAIN THEREAFTER AS TEMPERATURES WARM ABOVE FREEZING. FREEZING
RAIN WILL ALSO  BE AN ISSUE IN THE NORTH COUNTRY...MAINLY ACROSS THE
BLACK RIVER VALLEY THIS EVENING...HOWEVER IT IS NOT EXPECTED TO
AFFECT KART/KGTB.

IN ADDITION TO THE FREEZING RAIN...LLWS WILL ALSO BE AN
ISSUE...BRIEFLY THIS MORNING AT KJHW AND LATER THIS AFTERNOON AND
THIS EVENING ELSEWHERE AS A STRENGTHENING SOUTHWESTERLY LOW LEVEL
JET MOVES OVERHEAD. OTHERWISE...EXPECT SHOWERS TO CONTINUE OVERNIGHT
WITH CIGS LOWERING TO MVFR LATER TONIGHT AS DEEPER MOISTURE ADVECTS
INTO THE REGION.




OUTLOOK...
SATURDAY NIGHT THROUGH MONDAY...PERIODS OF IFR/MVFR IN RAIN.
SIGNIFICANT LLWS POSSIBLE SUNDAY NIGHT AND INTO MONDAY MORNING.
TUESDAY...MAINLY VFR WITH A CHANCE OF RAIN/SNOW SHOWERS.
WEDNESDAY...MAINLY VFR/MVFR EXCEPT IFR POSSIBLE IN LAKE EFFECT SNOW
SHOWERS EAST OF BOTH LAKES.

&&

.MARINE...
SMALL CRAFT ADVISORIES REMAIN IN EFFECT ACROSS THE MAJORITY OF
NEARSHORE ZONES AS HIGH PRESSURE MOVES OFF THE EAST COAST AND THE
SURFACE PRESSURE GRADIENT TIGHTENS BETWEEN THIS DEPARTING HIGH AND
LOW PRESSURE WELL TO OUR NORTHWEST ACROSS JAMES BAY. SOUTH-SOUTHWEST
FLOW WILL CONTINUE TO BE BRISK THROUGH THE WEEKEND WITH GALES
POSSIBLE BY SUNDAY NIGHT INTO MONDAY AS A MUCH DEEPER AREA OF LOW
PRESSURE TRACKS ACROSS THE UPPER GREAT LAKES. A COLD FRONT EXPECTED
TO SWEEP ACROSS THE LAKES MONDAY WILL USHER IN AN EXTENDED PERIOD OF
COLD AND BRISK WEST-SOUTHWEST FLOW ACROSS THE LOWER GREAT LAKES THAT
WILL LIKELY KEEP SMALL-CRAFT ADVISORIES IN PLAY THROUGH TUESDAY.

&&

.HYDROLOGY...
A SNOW SURVEY WAS COMPLETED FRIDAY TO GET SNOW DEPTH AND SNOW WATER
EQUIVALENTS FROM THE HARDEST HIT AREAS. THE SURVEY CAME UP WITH A
GENERAL 4 TO 6 INCHES OF SWE IN THE HARDEST HIT AREAS. SEE
BUFPNSBUF FOR THE SPECIFICS.

TEMPERATURES WILL RISE TO NEAR 50 ON SUNDAY...THEN INTO THE LOWER
60S ON MONDAY WITH VERY MILD LOWS SUNDAY NIGHT. DEWPOINTS WILL
RISE INTO THE UPPER 40S TO AROUND 50 SUNDAY NIGHT AND MONDAY. THE
HIGHER DEWPOINTS COMBINED WITH STRONG WINDS WILL RESULT IN VERY
RAPID SNOWMELT. THIS WILL COMBINE WITH RAIN AMOUNTS AVERAGING
ABOUT A HALF INCH FROM SUNDAY THROUGH MONDAY.

THE FLOOD POTENTIAL WILL BE TWO FOLD. FIRST...THERE IS A GENERAL
RISK OF URBAN FLOODING IN THE TOWNS HARDEST HIT BY THE SNOW AS
MELT WATER POOLS IN LOW LYING AND POOR DRAINAGE AREAS. EXCESSIVE
SNOW PILES AND LEAVES BENEATH THE SNOW MAY BLOCK STORM DRAINS.

THERE MAY ALSO BE A RISK FOR RIVER AND CREEK FLOODING. THE
GREATEST RISK IS ON THE BUFFALO CREEKS WHICH DRAIN THE HARDEST HIT
AREAS. THIS INCLUDES CAZENOVIA...BUFFALO...CAYUGA...AND ELLICOTT.
THERE MAY ALSO BE SOME FLOOD RISK FOR CATTARAUGUS CREEK AND SOME
OF THE SMALLER CREEKS THAT FLOW THROUGH DUNKIRK AND SILVER CREEK.
WITH THIS IN MIND WE HAVE EXPANDED THE FLOOD WATCH INTO THE
WESTERN SOUTHERN TIER IN ADDITION TO ERIE...GENESEE...AND WYOMING
COUNTIES.

THERE IS ALSO A FAIRLY HEAVY SNOWPACK IN THE UPPER REACHES OF THE
OATKA WATERSHED...BUT NOT AS HIGH AS THE BUFFALO CREEKS. WE WILL
CONTINUE TO MONITOR THIS BASIN FOR POSSIBLE FUTURE INCLUSION IN
THE FLOOD WATCH. THE EASTERN LAKE ONTARIO REGION HAD LESS SNOW...
WITH TOTALS OF 2 TO 2.5 FEET ON THE TUG HILL. THIS SNOWPACK IS NOT
EXCESSIVE FOR THAT AREA...SO HAVE NOT INCLUDED THE NORTH COUNTRY
IN A FLOOD WATCH AT THIS TIME.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FLOOD WATCH FROM SUNDAY AFTERNOON THROUGH WEDNESDAY MORNING
     FOR NYZ010>012-019-020-085.
     FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NYZ001-002-
     010>012-085.
     FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
     NYZ019>021.
     FREEZING RAIN ADVISORY FROM 2 PM THIS AFTERNOON TO MIDNIGHT
     EST TONIGHT FOR NYZ008.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR LEZ040-041.
         SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR LEZ020.
         SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR
         LOZ043>045.
         SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR LOZ042.

&&

$$

SYNOPSIS...TMA/WOOD
NEAR TERM...TMA/WOOD
SHORT TERM...SMITH
LONG TERM...HITCHCOCK/SMITH
AVIATION...HITCHCOCK/WOOD
MARINE...WOOD
HYDROLOGY...HITCHCOCK




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