Area Forecast Discussion
Issued by NWS Buffalo, NY

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FXUS61 KBUF 190812
AFDBUF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
412 AM EDT FRI SEP 19 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE SAINT LAWRENCE VALLEY WILL DRIFT
EASTWARD ACROSS NEW ENGLAND THIS AFTERNOON BEFORE MOVING OFF THE
COAST TONIGHT AND SATURDAY. THIS WILL NOT ONLY PROVIDE US WITH FAIR
WEATHER THROUGH THE FIRST HALF OF THE WEEKEND...BUT THE CLOCKWISE
CIRCULATION AROUND THE HIGH WILL PUMP NOTABLY WARMER AIR ACROSS OUR
REGION FOR SATURDAY. TEMPERATURES ACROSS THE WESTERN COUNTIES WILL
BE MORE TYPICAL OF THE SECOND HALF OF AUGUST. A FRONTAL SYSTEM WILL
THEN LIKELY GENERATE SOME SHOWERS FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE CENTERED OVER THE ST LAWRENCE VALLEY THIS MORNING WILL
DRIFT EASTWARD ACROSS NEW ENGLAND DURING THE MIDDAY AND AFTERNOON.
THIS WILL PROVIDE PLENTY OF SUNSHINE ACROSS THE REGION TODAY...WITH
H85 TEMPS IN THE SINGLE DIGITS SUPPORTING AFTERNOON TEMPERATURES IN
THE 60S.

TONIGHT...THE SFC HIGH WILL MOVE OFF THE NEW ENGLAND COAST WHILE A
SHORTWAVE DIGGING ACROSS THE CANADIAN PRAIRIES WILL PUSH A
DEVELOPING FRONTAL SYSTEM ACROSS THE UPPER MISSISSIPPI VALLEY. WHILE
FAIR DRY WEATHER WILL REMAIN IN PLACE ACROSS OUR FORECAST AREA...
THE AFOREMENTIONED SYNOPTIC PATTERN WILL ESTABLISH A DEEPENING
SOUTHERLY FLOW OVER THE LOWER GREAT LAKES. THE WARMER FLOW WILL BE
HIGHLIGHTED BY A 40KT LOW LEVEL JET THAT WILL HELP TO HOLD OUR
TEMPERATURES IN THE 50S (UP 40S LEWIS CO) DURING THE OVERNIGHT
HOURS. THESE OVERNIGHT READINGS WILL AVERAGE SOME 15 DEG F HIGHER
THAN THOSE FROM EARLY THIS MORNING.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
ON SATURDAY...SPRAWLING SURFACE HIGH PRESSURE OFF THE NEW ENGLAND
COAST WILL CONTINUE TO SLOWLY DRIFT EASTWARD THROUGH THE DAY...WHILE
A COMPLEX LOW PRESSURE SYSTEM WILL SLIDE FROM CENTRAL ONTARIO AND
THE UPPER GREAT LAKES TO THE ONTARIO/QUEBEC BORDER. AT THIS POINT...
IT STILL APPEARS THAT THE UPSTREAM LOW WILL REMAIN FAR ENOUGH TO OUR
NORTH AND WEST TO ALLOW FOR ANOTHER DRY DAY...SAVE FOR A SLIGHT
CHANCE OF A STRAY SHOWER OR TWO ACROSS THE SAINT LAWRENCE VALLEY.
IN TERMS OF CLOUD COVER...A SLUG OF LOW LEVEL MOISTURE CIRCULATING
NORTHEASTWARD AROUND THE BACK SIDE OF THE DEPARTING RIDGE WILL BRING
SOME CLOUDS TO PORTIONS OF THE FINGER LAKES AND NORTH COUNTRY DURING
THE MORNING...OTHERWISE A PARTLY TO MOSTLY SUNNY DAY CAN BE EXPECTED
WITH OUR REGION SITUATED WITHIN THE DEEPENING WARM SECTOR OF THE
SLOWLY ENCROACHING LOW.

WITH RESPECT TO TEMPERATURES...THE STRENGTHENING WARM AIR ADVECTION
PATTERN ACROSS OUR REGION WILL HELP TO PUMP 850 MB READINGS UP TO
THE +10C TO +13C RANGE BY EARLY SATURDAY AFTERNOON. COUPLED WITH THE
AFOREMENTIONED SUNSHINE AND A TIGHTENING PRESSURE GRADIENT THAT WILL
PROMOTE INCREASINGLY BREEZY CONDITIONS AND RESULTANT GOOD MIXING...
THIS WILL ALLOW SURFACE TEMPERATURES TO REBOUND TO SUMMERTIME
LEVELS. EXPECT HIGHS TO CLIMB INTO THE MID TO UPPER 70S IN MANY
AREAS...EXCEPT ACROSS INTERIOR PORTIONS OF THE NORTH COUNTRY WHERE
READINGS WILL PEAK IN THE UPPER 60S TO LOWER 70S. THE WARMEST
READINGS OF ALL WILL BE FOUND ACROSS THE LAKE PLAINS OF FAR WESTERN
NEW YORK...WHERE THE AIRMASS WILL BE WARMEST...SKIES WILL BE
SUNNIEST...AND GOOD DOWNSLOPING FROM A STRONG SOUTH-SOUTHWESTERLY
BREEZE WILL GIVE TEMPS AN ADDED BOOST. IF THINGS WORK OUT RIGHT...
WOULD NOT BE SURPRISED TO SEE A FEW LOCATIONS IN THIS LATTER REGION
BREACH THE 80 DEGREE MARK. AS MENTIONED ABOVE...IT WILL BE BREEZY AS
WELL WITH WIND GUSTS AS HIGH AS THE 30-35 MPH RANGE LIKELY ACROSS
FAR WESTERN NEW YORK.

SATURDAY NIGHT AND SUNDAY...DEEPENING LARGE-SCALE TROUGHING WILL DIG
ACROSS THE GREAT LAKES REGION...WHILE ITS ATTENDANT COMPLEX SURFACE
REFLECTION SLIDES EASTWARD ACROSS QUEBEC PROVINCE. IN THE PROCESS...
THIS LATTER FEATURE WILL PUSH ITS TRAILING COLD FRONT ACROSS WESTERN
AND NORTH CENTRAL NEW YORK DURING SUNDAY. LARGE-SCALE FORCING AND
MOISTURE ALONG/AHEAD OF THE FRONT STILL APPEAR PLENTY SUFFICIENT TO
SUPPORT A LIKELIHOOD OF SHOWERS LATER SATURDAY NIGHT AND SUNDAY...
WHEN A FEW THUNDERSTORMS MAY ALSO BE POSSIBLE GIVEN THE PRESENCE OF
SOME LIMITED INSTABILITY. AT THIS POINT...WILL CONTINUE TO COVER THE
APPROACH AND PASSAGE OF THE FRONT WITH A SWATH OF HIGH LIKELY POPS
LATER SATURDAY NIGHT AND SUNDAY...WITH DRY SLOTTING BEHIND THE FRONT
THEN LEADING TO A NOTICEABLE WEST-EAST REDUCTION IN SHOWER CHANCES
SUNDAY AFTERNOON. TEMPERATURE-WISE...VERY MILD CONDITIONS WILL
PERSIST SATURDAY NIGHT WITH OUR REGION REMAINING FIRMLY WITHIN THE
WARM SECTOR AND CONSEQUENTLY UNDER THE INFLUENCE OF A DEEP
SOUTHWESTERLY FLOW...WHICH SHOULD RESULT IN READINGS DROPPING NO
LOWER THAN THE LOWER TO MID 60S. INCREASED CLOUD COVER/PRECIPITATION
COVERAGE ALONG WITH THE COLD FRONTAL PASSAGE WILL THEN HELP TO HOLD
READINGS DOWN CLOSER TO SEASONAL AVERAGES ON SUNDAY...WHEN HIGHS
WILL GENERALLY RANGE FROM THE UPPER 60S TO LOWER 70S.

SUNDAY NIGHT...THE MAIN UPPER LEVEL TROUGH AXIS WILL PASS ACROSS THE
REGION...ALONG WITH AN ASSOCIATED SECONDARY SWATH OF WRAPAROUND
MOISTURE. THIS WILL SUPPORT MOSTLY CLOUDY SKIES AND ANOTHER ROUND OF
MUCH MORE SCATTERED SHOWERS...WHILE STEADY COOL AIR ADVECTION FORCES
TEMPERATURES TO FALL BACK TO THE UPPER 40S TO LOWER 50S TO CLOSE OUT
THE SHORT TERM PERIOD.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
MONDAY AND TUESDAY...UPPER LEVEL TROUGHING WILL LINGER ACROSS
EASTERN CANADA AND THE NORTHEASTERN CONUS...WITH THE RESULTANT COOL
CYCLONIC FLOW LEADING TO ANOTHER ROUND OF BELOW NORMAL TEMPERATURES.
THE COOLEST WEATHER WILL BE ON MONDAY...WHEN 850 MB TEMPS WITHIN A
FEW DEGREES OF ZERO CELSIUS WILL ONLY BE SUPPORTIVE OF HIGHS IN THE
MID TO UPPER 50S IN MOST LOCATIONS.

WHILE THIS AIRMASS WILL BE ON THE COOL SIDE...IT WILL ALSO BE RATHER
DRY...WITH THE BULK OF ANY MOISTURE LARGELY CONFINED TO THE LOWEST 5
KFT OR SO OF THE TROPOSPHERE. THIS WILL SERVE TO GREATLY LIMIT
SHOWER CHANCES...WITH THE BULK OF THESE MAINLY DRIVEN BY THE
PASSAGE OF A TRAILING SHORTWAVE ON MONDAY AND A SECONDARY SURFACE
TROUGH LATER MONDAY NIGHT/TUESDAY...WITH THE LATTER PRIMARILY
AFFECTING NORTHERN NEW YORK. WITH THE ABOVE IN MIND...WILL JUST KEEP
SOME LOW CHANCE POPS IN PLAY AS APPROPRIATE...WITH ANY LAKE RESPONSE
EXPECTED TO BE SEVERELY LIMITED BY BOTH THE DRY NATURE OF THE
AIRMASS AND RELATIVELY LOW INVERSION HEIGHTS.

AFTER THAT...CONDITIONS SHOULD IMPROVE MARKEDLY FOR WEDNESDAY AND
THURSDAY AS STRONG RIDGING BUILDS ACROSS THE REGION AT ALL LEVELS.
PLENTY OF ASSOCIATED DRY AIR AND SUBSIDENCE/WARMING ALOFT SHOULD
RESULT IN DRY WEATHER AND A NICE RECOVERY IN TEMPERATURES...WITH
DAYTIME HIGHS WARMING TO AROUND 70 DEGREES OR SO BY THE END OF THE
PERIOD.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL DRIFT EAST ACROSS THE ST LAWRENCE VALLEY DURING
THE REMAINING PRE DAWN HOURS...AND THIS WILL PROVIDE THE VAST
MAJORITY OF WESTERN AND NORTH CENTRAL NEW YORK WITH VFR CONDITIONS
AND LIGHT WINDS. THE EXCEPTION WILL BE ACROSS THE SRN TIER...AND
WITHIN A FEW MILES OF LAKE ONTARIO FROM KIAG AND KROC. FOR THE
LATTER...LAKE ENHANCED CLOUDS WILL REDUCE CIGS TO BETWEEN 800 AND
2500 FT AT TIMES...BUT A MORE WIDESPREAD AREA OF LOW STRATUS WILL BE
FOUND ACROSS THE SRN TIER. SEVERAL HOURS OF IFR CONDITIONS CAN BE
EXPECTED FOR BOTH KELZ AND KJHW.

AS WE PUSH PAST SUNRISE...TODAY WILL BE A PROBLEM FREE DAY FOR
AVIATORS AS WIDESPREAD SUBSIDENCE WILL PROVIDE LITTLE IN THE WAY OF
ANY CLOUD COVER AND WINDS WILL BE LIGHT.

FOR TONIGHT...A STRENGTHENING LOW LEVEL JET WILL PRESENT THE RISK
FOR SOME LOW LEVEL WIND SHEAR. WILL MENTION THIS LATE IN THE TAF
PERIOD FOR THE FAR WESTERN SITES.

OUTLOOK...
SATURDAY...VFR.
SUNDAY...VFR/MVFR WITH SHOWERS LIKELY.
MONDAY AND TUESDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.

&&

.MARINE...
HIGH PRESSURE WILL DRIFT EAST ACROSS THE ST LAWRENCE VALLEY DURING
THE REMAINDER OF THE PRE DAWN HOURS. THIS WILL PRODUCE A LIGHT
EASTERLY FLOW ACROSS THE LOWER GREAT LAKES WITH NEGLIGIBLE WAVES.
THE EXCEPTION WILL BE OVER CANADIAN WATERS OF LK ONTARIO WHERE
SOMEWHAT STRONGER WINDS WILL PRODUCE WAVES THAT WILL APPROACH SMALL
CRAFT ADVISORY CRITERIA.

LATER TODAY...THE SFC WILL DRIFT EAST ACROSS NEW ENGLAND. THIS WILL
KEEP AN EASTERLY FLOW IN PLACE FOR LAKES ERIE AND ONTARIO WITH WINDS
AND WAVES REMAINING WELL BELOW SCA CRITERIA.

WINDS WILL FRESHEN AND VEER TO THE SOUTH FRIDAY NIGHT AND SATURDAY
AS THE SFC HIGH WILL MOVE OFF THE COAST AND A FRONTAL SYSTEM WILL
START TO MAKE ITS WAY ACROSS THE UPPER GREAT LAKES. THIS COULD
RESULT IN SOME WIND BASED SMALL CRAFT ADVISORIES...WITH THE HIGHEST
WAVES BEING CONCENTRATED IN CANADIAN WATERS.

SUNDAY WILL BE UNSETTLED ACROSS THE LOWER GREAT LAKES AS THE PASSAGE
OF A COLD FRONT WILL RESULT IN THE LIKELIHOOD OF SHOWERS AND POSSIBLY
A THUNDERSTORM OR TWO.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR NYZ007-008.
     FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR NYZ006.
MARINE...NONE.

&&

$$

SYNOPSIS...RSH
NEAR TERM...RSH
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...RSH
MARINE...RSH







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