Area Forecast Discussion
Issued by NWS Buffalo, NY

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000
FXUS61 KBUF 010033
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
833 PM EDT FRI OCT 31 2014

.SYNOPSIS...
LOW PRESSURE OVER THE UPPER OHIO VALLEY WILL REDEVELOP OFF THE MID
ATLANTIC COAST TONIGHT AND SATURDAY...THEN WILL LIFT NORTHWARD
OFFSHORE OF THE EASTERN SEABOARD THROUGH THE REMAINDER OF THE
WEEKEND. ON THE BACKSIDE OF THIS SYSTEM...EXPECT OCCASIONAL LIGHT
RAIN TO CONTINUE ACROSS MUCH OF WESTERN NEW YORK THROUGH SATURDAY
MORNING...BEFORE GRADUALLY DIMINISHING SATURDAY AFTERNOON AND
NIGHT. OTHERWISE...EXPECT CHILLY TEMPERATURES FOR THE WEEKEND AS
THE LOW BRIEFLY PULLS MUCH COLDER AIR ACROSS OUR REGION...WITH A
WARMING TREND THEN FOLLOWING EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 0030Z...REGIONAL SURFACE ANALYSIS SHOWS THE CENTER OF THE
ORIGINAL AND NOW WEAKENING PRIMARY LOW OVER THE UPPER OHIO VALLEY...
WITH A SECONDARY SURFACE WAVE DEVELOPING OFF THE CAROLINA COAST IN
RESPONSE TO DIGGING UPPER LEVEL TROUGHING OVER THE EASTERN CONUS.
MEANWHILE...REGIONAL RADARS SHOW A FAIR AMOUNT OF STRATIFORM LIGHT
RAIN ASSOCIATED WITH THE ORIGINAL PRIMARY LOW EXTENDING ACROSS AREAS
FROM THE WESTERN FINGER LAKES WESTWARD...WHILE AREAS FURTHER EAST
REMAIN LARGELY DRY AS OF THIS WRITING.

THROUGH THE BALANCE OF TONIGHT AND SATURDAY...EXPECT CONTINUED
GRADUAL WEAKENING OF THE PRIMARY LOW AS ITS ENERGY TRANSFERS TO THE
SECONDARY COASTAL SYSTEM. THIS STATED...WIDESPREAD CLOUD COVER AND
OCCASIONAL LIGHT RAIN SHOULD PERSIST ACROSS MOST LOCATIONS SOUTH OF
LAKE ONTARIO TONIGHT AND MUCH IF NOT ALL OF SATURDAY WITH PLENTY OF
MOISTURE AND A LINGERING CYCLONIC/INCREASINGLY UPSLOPE FLOW
REMAINING IN PLACE ACROSS OUR REGION. FURTHER TO THE EAST...EXPECT
JUST A CHANCE OF SOME SPOTTIER LIGHT RAIN ACROSS THE NORTH COUNTRY
THROUGH SATURDAY.

WITH RESPECT TO TEMPS...DEVELOPING COLD AIR ADVECTION AROUND THE
BACKSIDE OF THE DEVELOPING COASTAL SYSTEM WILL SEND A PROGRESSIVELY
COLDER AIRMASS SOUTHWARD ACROSS OUR REGION TONIGHT AND SATURDAY.
THIS WILL RESULT IN READINGS FALLING TO THE MID 30S TO LOWER 40S
TONIGHT...WITH ONLY VERY LIMITED RECOVERY THEN EXPECTED ON SATURDAY
WHEN ALSO TAKING INTO ACCOUNT THE EXPECTED CLOUD COVER AND
PRECIPITATION.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
BY SATURDAY EVENING THE 850MB THERMAL TROUGH OF -7C TO -8C WILL BE
CROSSING THE EASTERN GREAT LAKES BASIN AND NEW YORK STATE. WHILE
THIS IS SUFFICIENTLY COLD TO PRODUCE A LAKE EFFECT RESPONSE...THE
MID AND UPPER LEVELS ARE DRYING SO LAKE EFFECT PRECIPITATION WILL BE
LIMITED. A NORTHERLY BOUNDARY LAYER WIND WILL PROVIDE OROGRAPHIC
LIFT DOWNWIND OF THE LAKES...SO WILL MAINTAIN CHANCE TO LOW LIKELY
POPS EARLY IN THE EVENING...DWINDLING TO CHANCE AND LOW CHANCE POPS
LATER IN THE NIGHT...ESPECIALLY AS DRYING AND WARMING ALOFT LOWER
THE INFLUENCE OF THE LAKE EFFECT. LOW TEMPS SATURDAY NIGHT WILL BE
IN THE UPPER 20S TO LOWER 30S ALONG AND WEST OF THE GENESEE
VALLEY...THE LOWER TO MID 30S ACROSS THE NORTHERN FINGER LAKES TO
THE LAKE ONTARIO SHORE AND THE MID TO UPPER 20S ACROSS THE EASTERN
LAKE ONTARIO COUNTIES.

HIGH PRESSURE WILL RIDGE IN FROM THE WEST ON SUNDAY...BRINGING FAIR
WEATHER AND GRADUALLY CLEARING SKIES. CLOUDS SHOULD LAST MUCH OF THE
DAY ACROSS INTERIOR SECTIONS WITH COOL AIR ALOFT RESULTING IN LAKE
ENHANCED STRATUS. SOME BREAKS OF SUN ARE LIKELY SUNDAY AFTERNOON
NEAR THE LAKES AND IN WESTERN SECTIONS. WITH THE CONTINUED COLD
ADVECTION ACROSS THE REGION ON SUNDAY...HIGHS WILL CHILLY...ONLY BE
IN THE UPPER 30S TO LOWER 40S. LOWS SUNDAY NIGHT WILL BE IN THE
MIDDLE TO UPPER 20S EAST OF LAKE ONTARIO...THE UPPER 20S TO LOW 30S
ALONG THE GENESEE VALLEY...AND LOWER TO MID 30S ALONG THE LAKE ERIE
SHORE AND THE NORTHERN FINGER LAKES REGION.

THE AXIS OF SURFACE HIGH PRESSURE WILL BE CENTERED ON THE FORECAST
AREA ON MONDAY...MOVING EAST OF THE AREA MONDAY NIGHT. SOUTHWESTERLY
WINDS ON THE WESTERN FLANK OF THE HIGH PRESSURE RIDGE WILL BRING
WARMING TO THE AREA WITH HIGH TEMPS 40S EAST OF LAKE ONTARIO AND THE
LOW 50S ACROSS THE REST OF THE REGION. LOWS MONDAY NIGHT SHOULD STAY
ABOVE FREEZING WITH MOST LOCATIONS FALLING TO THE MIDDLE TO UPPER
30S INLAND AND THE LOWER TO MID 40S ALONG THE SHORES OF LAKES ERIE
AND ONTARIO.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
GFS AND ECMWF SHOWING BETTER AGREEMENT MONDAY NIGHT THROUGH EARLY
WEDNESDAY WITH A SURFACE AND UPPER LOW MOVING FROM THE UPPER PLAINS
AND PRAIRIE PROVINCES TO SOUTHWESTERN HUDSON BAY...AN OCCLUSION
EXTENDING SOUTH FROM THE LOW TO A COLD FRONT MOVING SLOWLY TOWARD
NEW YORK STATE BY TUESDAY NIGHT. BOTH MODELS ARE SHOWING A SHEARING
OF THE FRONT DURING TUESDAY NIGHT...AND ALTHOUGH POPS ARE IN THE
LIKELY RANGE...QPF IS EXPECTED TO BE LOW...ONLY A COUPLE HUNDREDTHS
OF AN INCH.

GFS AND ECMWF SHOW GREATEST DIFFERENCES DURING THE SECOND HALF OF
THE WEEK. BY 00Z FRIDAY...GFS DEEPENS THE UPPER TROUGH ACROSS
EASTERN ONTARIO AND WESTERN QUEBEC TO THE NORTHERN GREAT
LAKES...WITH THE ASSOCIATED SURFACE LOW JUST NORTH OF LAKE ONTARIO.
FOR THE SAME TIMEFRAME...ECMWF HAS DEVELOPED A NEGATIVELY TILTED
UPPER TROUGH FROM JUST EAST OF JAME BAY TO THE MID ATLANTIC COAST
AND ITS ATTENDANT SURFACE LOW OFFSHORE OF SOUTHERN NEW ENGLAND. BOTH
MODEL SOLUTIONS PROVIDE CHANCE POPS WED THROUGH THU NIGHT WITH THE
HIGHER POPS DURING THE DAY THU. GFS BRINGS IN A SECONDARY COLD FRONT
THU NIGHT AND FRIDAY WHEREAS ECMWF BRINGS THE COLDER AIR IN ACROSS
EASTERN LAKE ONTARIO AND THE EASTERN HALF OF THE STATE. WILL SPLIT
THE DIFFERENCE AND HAVE A COLD FRONTAL PASSAGE AT THE END OF THE
WEEK WITH THE CHANCE OF MIXED RAIN/SNOW ON THURSDAY NIGHT.

AFTER A WARMING TREND DURING THE FIRST HALF OF THE WEEK...THE SECOND
HALF WILL EXPERIENCE A DOWNWARD TREND...FROM HIGHS IN THE LOW TO MID
50S ON WEDNESDAY TO THE MID TO UPPER 40S ON FRIDAY.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
LOW PRESSURE OVER THE UPPER OHIO VALLEY WILL GRADUALLY REDEVELOP OFF
THE MID ATLANTIC COAST TONIGHT AND SATURDAY...WITH A MOIST CYCLONIC
AND INCREASINGLY UPSLOPE NORTHERLY FLOW LINGERING ACROSS WESTERN AND
NORTH CENTRAL NEW YORK IN ITS WAKE. THIS WILL MAINTAIN THE CURRENT
WIDESPREAD CLOUD COVER AND OCCASIONAL LIGHT RAIN ACROSS AREAS SOUTH
OF LAKE ONTARIO THOUGH MUCH IF NOT ALL OF SATURDAY...WHILE THE NORTH
COUNTRY REMAINS CLOUDY WITH MUCH SPOTTIER LIGHT RAIN.

IN TERMS OF FLIGHT CONDITIONS...EXPECT GENERAL MVFR TO LOW-END VFR
CEILINGS TO DETERIORATE TO IFR/MVFR TONIGHT AS THE LOW LEVEL FLOW
BACKS TO NORTHWESTERLY/NORTHERLY AND BECOMES PROGRESSIVELY MORE
UPSLOPE IN NATURE...WITH GENERAL IFR/MVFR CONDITIONS /MAINLY DUE TO
CEILINGS/ THEN LINGERING THROUGH SATURDAY. WHILE THE BEST OVERALL
CHANCES FOR IFR CONDITIONS WILL BE ACROSS THE HIGHER TERRAIN OF THE
SOUTHERN TIER AND FINGER LAKES...CANNOT TOTALLY RULE THESE OUT AT
KBUF/KIAG/KROC EITHER DUE TO THE AFOREMENTIONED UPSLOPE FLOW.

OUTLOOK...
SATURDAY NIGHT...MVFR/VFR WITH DIMINISHING LEFTOVER RAIN AND WET
SNOW SHOWERS.
SUNDAY...MVFR IMPROVING TO VFR WITH SCATTERED SPRINKLES AND
FLURRIES.
MONDAY...MAINLY VFR.
TUESDAY AND WEDNESDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.

&&

.MARINE...
STRONG LOW PRESSURE WILL DEVELOP OFF THE MID ATLANTIC COASTLINE THIS
WEEKEND...BRINGING A PERIOD OF BRISK NORTHEASTERLY AND THEN
NORTHERLY WINDS TO THE LOWER LAKES REGION AND RESULTING IN FAIRLY
WIDESPREAD ADVISORY LEVEL CONDITIONS. ON LAKE ONTARIO...THE STRONGER
WINDS WILL DEVELOP THIS EVENING AND LAST THROUGH SUNDAY...WHILE ON
LAKE ERIE THE STRONGER WINDS WILL DEVELOP OVERNIGHT AND LAST INTO
SATURDAY NIGHT. DUE TO ALL THIS...SMALL CRAFT ADVISORIES ARE IN
EFFECT AS OUTLINED BELOW.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM EDT SATURDAY TO 4 AM EST SUNDAY
         FOR LEZ040-041.
         SMALL CRAFT ADVISORY FROM MIDNIGHT EDT TONIGHT TO 1
         AM EST SUNDAY FOR LOZ030.
         SMALL CRAFT ADVISORY UNTIL 7 AM EST MONDAY FOR LOZ043-044.
         SMALL CRAFT ADVISORY UNTIL 1 AM EST MONDAY FOR LOZ042.
         SMALL CRAFT ADVISORY FROM 6 AM TO 8 PM EDT SATURDAY FOR
         LOZ045.

&&

$$

SYNOPSIS...CHURCH/JJR
NEAR TERM...JJR
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...CHURCH/JJR
MARINE...JJR







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