Area Forecast Discussion
Issued by NWS Buffalo, NY

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FXUS61 KBUF 161824
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
224 PM EDT TUE SEP 16 2014

.SYNOPSIS...
AN AREA OF HIGH PRESSURE WILL BUILD EAST ACROSS THE REGION BRINGING
COOL AND DRY CONDITIONS INTO WEDNESDAY. A WEAK COLD FRONT WILL THEN
CROSS THE REGION WEDNESDAY NIGHT INTO THURSDAY MORNING BRINGING A
SLIGHT CHANCE FOR RAIN SHOWERS...WITH A REINFORCING SHOT OF COOLER
AIR BEHIND THE BOUNDARY FOR THURSDAY AND THURSDAY NIGHT AS HIGH
PRESSURE ONCE AGAIN BUILDS ACROSS THE REGION THROUGH THE END OF THE
WEEK. A COMPLEX FRONTAL SYSTEM IS THEN FORECAST TO CROSS OUR REGION
LATE IN THE WEEKEND BRINGING A CHANCE FOR SHOWERS.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
THE BROAD UPPER LEVEL TROUGH WILL REMAIN PARKED OVER THE NORTHEAST
THROUGH THE PERIOD KEEPING TEMPERATURES COOLER THAN
AVERAGE...HOWEVER SURFACE HIGH PRESSURE BUILDING IN FROM THE WEST
WILL KEEP CONDITIONS DRY ACROSS THE REGION.

COOL TEMPS ALOFT COMBINED WITH LINGERING LOW LEVEL MOISTURE WILL
KEEP SOME DIURNAL CUMULUS AROUND THIS AFTERNOON MAKING FOR PARTLY TO
MOSTLY SUNNY SKIES ACROSS THE AREA...WITH THE MOST SUN BEING SEEN
RIGHT ALONG THE LAKESHORES THANKS TO LAKE SHADOWING. COOL
NORTHWESTERLY FLOW WILL HELP KEEP HIGH TEMPERATURES BELOW AVERAGE
TODAY WITH HIGHS TOPPING OUT IN THE UPPER 50S TO MID 60S.

TONIGHT HIGH PRESSURE OVER THE MIDWEST STATES WILL RIDGE EAST ACROSS
THE LOWER GREAT LAKES. EXPECT THIS TO TRAP SOME LOW LEVEL MOISTURE
BENEATH A SUBSIDENCE INVERSION PROVIDING SOME SCATTERED CLOUDS
INLAND FROM THE LAKES...WITH THICKER CLOUD COVER POSSIBLE ACROSS
INLAND AREAS OF THE SOUTHERN TIER THANKS TO UPSLOPING. OTHERWISE
MAINLY CLEAR SKIES NEAR THE LAKE SHORES. SOME PATCHY RIVER VALLEY
FOG WILL AGAIN BE POSSIBLE ACROSS THE SOUTHERN TIER AS WELL. THE
CLOUDS WILL HELP KEEP OVERNIGHT LOWS ON THE WARMER SIDE WITH LOWS
ONLY SLIDING BACK INTO THE LOW TO MID 40S.

AS MENTIONED ABOVE...THE BROAD UPPER LEVEL TROUGH WILL REMAIN PARKED
OVERHEAD WEDNESDAY. MEANWHILE SURFACE HIGH PRESSURE WILL DRIFT
SOUTHEAST OF THE REGION DURING THE COURSE OF THE DAY PROVIDING
ANOTHER DAY OF DRY...BUT CONTINUED COOL WEATHER. EXPECT SOME DIURNAL
CUMULUS DURING THE AFTERNOON HOURS AGAIN WEDNESDAY INLAND FROM THE
LAKES...WITH SOME MID AND UPPER LEVEL CLOUDINESS OVERSPREADING THE
NORTHCOUNTRY OUT AHEAD OF AN APPROACHING COLD FRONTAL BOUNDARY.
TEMPERATURES SHOULD BE A COUPLE DEGREES WARMER AS 850MB TEMPERATURES
CLIMB FROM AROUND +4C TO +6C BY THE AFTERNOON. THIS WILL SUPPORT
HIGHS IN THE LOWER TO MID 60S ACROSS THE REGION.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
A HIGH AMPLITUDE UPPER LEVEL PATTERN WILL BE IN PLACE ACROSS NORTH
AMERICA AS WE OPEN THE PERIOD WITH A DEEP TROUGH ACROSS THE EASTERN
UNITED STATES EXTENDING FROM A POLAR LOW OVER NORTHERN QUEBEC WHILE
STRONG RIDGING WILL BE FOUND OVER THE WEST. A POTENT SHORTWAVE
DROPPING AROUND THE BASE OF THE AFOREMENTIONED UPPER LOW WILL
SHUNT A COLD FRONT SOUTH TOWARDS OUR REGION. WHILE THE BULK OF
THE DPVA AND ASSOCIATED SHOWER ACTIVITY SHOULD REMAIN NORTH OF THE
BORDER...THERE WILL BE A CHANCE OF A FEW SPRINKLES WEDNESDAY NIGHT
AS THE SURFACE COLD FRONT SAGS SOUTH ACROSS LAKE ONTARIO.

WEDNESDAY NIGHT...ENCROACHING CLOUD COVER ASSOCIATED WITH THE
COLD FRONT WILL KEEP TEMPERATURES LOWS IN THE MID TO UPPER 40S
ALONG THE LAKE PLAINS AND INTO THE NORTH COUNTRY WHILE ACROSS THE
SOUTHERN TIER THERE MAY BE JUST ENOUGH SOUTHWESTERLY FLOW AHEAD OF
THE APPROACHING COLD FRONT TO LIMIT RADIATIONAL COOLING AND ONLY
PRODUCE LOWS IN THE LOW TO MID 40S.

THE COLD FRONT WILL DROP SOUTH OF LAKE ONTARIO AROUND DAYBREAK
THURSDAY MORNING AND CONTINUE TO SAG SOUTH ACROSS THE FORECAST AREA
DURING THE DAY. UPSLOPE NORTHERLY FLOW OFF LAKE ONTARIO BEHIND THE
FRONT COUPLED WITH 850MB TEMPS DROPPING TO AROUND +2C WILL GENERATE
PLENTY OF STRATUS ACROSS MUCH OF WESTERN AND NORTH-CENTRAL NEW
YORK...THOUGH THE NORTH COUNTRY SHOULD SEE SUNSHINE IN THE
AFTERNOON AS IT WILL ESCAPE THE INFLUENCE OF THE LAKE. THE
COMBINATION OF COLD ADVECTION AND ABUNDANT CLOUD COVER WILL MAKE
FOR A CHILLY DAY ACROSS THE AREA WITH HIGHS ONLY EXPECTED TO TOP
OUT IN THE MID 50S.

THE CLOUD COVER SHOULD DIMINISH THURSDAY NIGHT AS THE CENTER OF
THE SURFACE HIGH PASSES TO OUR NORTH AND LOW LEVEL FLOW VEERS AROUND
TO THE EAST...PARTICULARLY EAST OF THE GENESEE VALLEY AND THE
NORTH COUNTRY. THIS CLEARING COUPLED WITH THE VERY DRY AIR
ADVECTING INTO THE REGION COULD RESULT IN THE FIRST WIDESPREAD
FREEZE OF THE SEASON ACROSS THE NORTH COUNTRY WHILE FROST MAY BE
POSSIBLE ELSEWHERE WITH THE EXCEPTIONS OF AREAS NEAR THE LAKE ERIE
AND ONTARIO SHORELINES.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE ARCTIC HIGH AND ASSOCIATED COLD AIR WILL MOVE OFF TO THE EAST
ON FRIDAY AS THE HIGH AMPLITUDE PATTERN OF EARLIER IN THE WEEK
BRIEFLY GIVES WAY TO A MORE ZONAL FLOW ACROSS THE NORTHERN TIER OF
THE COUNTRY. WITH THE SURFACE HIGH MOVING OFF TO OUR EAST ON
FRIDAY...INCREASING SOUTHERLY RETURN FLOW WILL ALLOW FOR
TEMPERATURES TO WARM BACK INTO THE 60S ON FRIDAY BEFORE BOOSTING
READINGS INTO THE 70S ON SATURDAY WITH AN ABUNDANCE OF SUNSHINE BOTH
DAYS THANKS TO THE ABUNDANCE OF DRY AIR ACROSS THE REGION.

A MUCH MORE COMPLEX PATTERN EVOLVES FOR THE LATTER HALF OF THE
WEEKEND INTO THE BEGINNING OF NEXT WEEK. THERE ARE ESSENTIALLY THREE
TIERS OF UPPER LEVEL ENERGY THAT WILL BE MAKING THEIR WAY ACROSS
NORTH AMERICA DURING THIS PERIOD. THE FIRST IS OVER HUDSON BAY
ASSOCIATED WITH THE POLAR VORTEX. THE SECOND IS A SHORTWAVE
TRACKING OUT OF THE NORTHERN ROCKIES WITH AN ATTENDANT SURFACE LOW
THAT MOVES INTO THE WESTERN GREAT LAKES SATURDAY. THE THIRD AND
FINAL FACTOR IS THE REMNANTS OF HURRICANE ODILE THAT WILL BE
MEANDERING ACROSS THE SOUTHERN PLAINS BY SATURDAY. TO VARYING
DEGREES THE GLOBAL MODELS PHASE ALL THREE OF THESE SYSTEMS AND BRING
THEM ACROSS EASTERN NORTH AMERICA WITH THE X-FACTOR BEING THE SPEED
AND INTENSITY OF YET ANOTHER PLAYER...A POTENT SHORTWAVE DROPPING
OUT OF THE MACKENZIE BASIN OF FAR NORTHWESTERN CANADA SATURDAY NIGHT
INTO SUNDAY. THIS PARTICULAR FEATURE MAY END UP DIGGING FAR
ENOUGH SOUTH TO GENERATE A LARGE SURFACE CYCLONE OVER WESTERN
ONTARIO ON SUNDAY...AS DEPICTED BY THE ECMWF...OR ARRIVE TOO LATE
TO DO SO AND INSTEAD REINVIGORATE THE WESTERN GREAT LAKES SURFACE
LOW AS IT LIFTS INTO WESTERN QUEBEC. THE GLOBAL GEM IS EVEN
FARTHER NORTH AND EAST WITH THIS FEATURE...HAVING IT MISS OUR
GREAT LAKES LOW ENTIRELY.

IN SPITE OF THE SIGNIFICANT DIFFERENCES IN DETAILS BETWEEN THESE
SCENARIOS...THE TIMING OF IMPACTS ON SENSIBLE WEATHER ACROSS THE
LOWER GREAT LAKES IS SURPRISINGLY SIMILAR. AFTER ONE MORE WARM AND
DRY DAY SUNDAY...SHOWERS WILL LIKELY BREAK OUT ACROSS WESTERN NEW
YORK SOMETIME SUNDAY NIGHT AS THE SURFACE/UPPER LEVEL TROUGHS
APPROACH THE AREA. GIVEN THE STRONG DYNAMICS AT WORK ALONG WITH A
DECENT RETURN FLOW OFF OF MOISTURE OFF OF THE GULF OF MEXICO AND
POTENTIAL CONTRIBUTIONS FROM WHATEVER IS LEFT FROM ODILE...WE COULD
SEE A PERIOD OF MODERATE TO HEAVY RAINFALL SUNDAY NIGHT INTO MONDAY.
A COLD FRONT WILL LIKELY CROSS THE REGION MONDAY BRINGING A
POTENTIALLY SIGNIFICANT COOL-DOWN...ALTHOUGH SIGNIFICANCE OF THIS
COOL-DOWN WILL BE A FUNCTION OF THE FINAL TRACK OF THE AFOREMENTIONED
NORTHWEST CANADIAN SHORTWAVE AND THE DEGREE TO WHICH IT ENHANCES THE
LOW OVER WESTERN ONTARIO AND SUBSEQUENT POSSIBLE OCCLUSION ACROSS
THE GREAT LAKES.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
WIDESPREAD VFR FLIGHT CONDITIONS SEEN ACROSS THE REGION THIS
AFTERNOON...WITH DIURNAL CUMULUS PROVIDING JUST SOME LOW VFR CIGS
AROUND 4K FEET ACROSS THE SOUTHERN TIER INCLUDING KJHW. JUST FEW TO
SCT LOW CLOUDS ELSEWHERE...KEEPING VFR CONDITIONS LOCKED IN FOR THE
REST FOR THE AFTERNOON.

TONIGHT HIGH PRESSURE WILL RIDGE EAST FROM THE MIDWEST STATES. THIS
MAY TRAP ENOUGH MOISTURE FOR SOME MAINLY VFR LOW LEVEL SCATTERED
CLOUDS INLAND FROM THE LAKES OVERNIGHT...WITH SOME MVFR/ISOLATED IFR
CIGS POSSIBLE ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER
INCLUDING KJHW. RIVER VALLEY FOG MAY ALSO DEVELOP LATE TONIGHT
ACROSS THE SOUTHERN TIER...POSSIBLY IMPACTING THE KJHW TERMINAL AS
WELL.

SURFACE HIGH PRESSURE WILL DRIFT SOUTHEAST OF THE REGION DURING THE
COURSE OF THE DAY WEDNESDAY PROVIDING ANOTHER DAY OF DRY...BUT
CONTINUED COOL WEATHER. ANY EARLY MORNING MVFR/IFR CIGS/VSBYS ACROSS
THE INLAND SOUTHERN TIER SHOULD IMPROVE TO VFR BY MID
MORNING...LASTING THROUGH THE END OF THE PERIOD. DO EXPECT SOME
DIURNAL CUMULUS TO DEVELOP BY EARLY AFTERNOON WEDNESDAY INLAND FROM
THE LAKES...WITH SOME MID AND UPPER LEVEL CLOUDINESS OVERSPREADING
THE NORTHCOUNTRY OUT AHEAD OF AN APPROACHING COLD FRONTAL
BOUNDARY...HOWEVER VFR CONDITIONS ARE EXPECTED THROUGH THE END OF
THE PERIOD.

OUTLOOK...
WEDNESDAY THROUGH SATURDAY...GENERALLY VFR. SOME PATCHES OF MVFR
CIGS WEDNESDAY NIGHT. SOME VALLEY FOG WITH LOCALIZED IFR FLIGHT
VSBYS ACROSS THE SOUTHERN TIER EACH MORNING.

&&

.MARINE...
WESTERLY WINDS WILL INCREASE LATER THIS AFTERNOON BEHIND A WEAK
SURFACE TROUGH. CONVERGENT FLOW ALONG THE SOUTHEAST LAKE ONTARIO
NEAR SHORE WATERS HAS ALLOWED A SMALL CRAFT ADVISORY TO CONTINUE
BETWEEN SODUS BAY AND MEXICO BAY OTHERWISE WINDS AND WAVES IN OTHER
ZONES WILL REMAIN BELOW CRITERIA. WINDS AND WAVES WILL GRADUALLY
SUBSIDE LATE TONIGHT INTO WEDNESDAY BEFORE BUILDING ONCE AGAIN
WEDNESDAY NIGHT AS ANOTHER WEAK COLD FRONT DROPS SOUTH OUT OF CANADA.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 2 AM EDT
         WEDNESDAY FOR LOZ044.

&&

$$

SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...JM
MARINE...JM/SMITH






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