Area Forecast Discussion
Issued by NWS Boston, MA

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FXUS61 KBOX 190539
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
139 AM EDT FRI SEP 19 2014

.SYNOPSIS...
A WEAK...DRY COLD FRONT WILL CROSS THE AREA THIS EVENING. COLD
HIGH PRESSURE BUILDS INTO NEW ENGLAND TONIGHT AND FRIDAY. SOME
FROST MAY FORM ACROSS PORTIONS OF SOUTHERN NEW HAMPSHIRE LATE
TONIGHT. THE HIGH WILL DRIFT OFFSHORE THROUGH THE WEEKEND
RESULTING IN A BRIEF RETURN TO MILDER TEMPERATURES. A COLD FRONT
MOVES THROUGH EARLY MONDAY...FOLLOWED BY COOLER WEATHER TOWARD THE
MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
130 AM UPDATE...

COLD FRONT HAS MOVED OFFSHORE WITHIN THE LAST FEW HOURS. NNE WINDS
MAINLY AROUND 10 KT CONTINUE BEHIND THIS FRONT EXCEPT IN THE
VALLEYS OF NW MA AND SW NH WHICH SHOWS SOME DECOUPLING.
THEREFORE...FORECAST AND FROST POTENTIAL STILL ON TRACK THIS
UPDATE.

PREVIOUS DISCUSSION..

TONIGHT...HIGH PRES BRING PUSH OF COLD AIR ACROSS THE REGION...
THOUGH SHORT RANGE MODELS INDICATING CORE OF COLDEST H85  AIR
WILL REMAIN N OF THE REGION. EXPECT SKIES TO CLEAR FROM N-S
OVERNIGHT...FIRST ACROSS S NH BY AROUND MIDNIGHT OR 1 AM. SOME
CLOUDS MAY LINGER ALONG THE S COAST THROUGH THE NIGHT.

NOTING PRES SURGE BEHIND THE FRONT ON THE MODEL WIND FIELDS.
EXPECT N-NE WINDS TO INCREASE QUICKLY EARLY TONIGHT ACROSS THE
WATERS E OF CAPE ANN THEN WORKING DOWN THE COAST. COULD SEE GUSTS
UP TO 20-25 KT ALONG THE IMMEDIATE E COAST FROM ABOUT BOSTON
SOUTHWARD TO THE CAPE AND ISLANDS THROUGH THE NIGHT. FURTHER
INLAND...WINDS WILL DROP OFF TO LIGHT/VRBL OR CALM ESPECIALLY
ACROSS THE NORMALLY PRONE AREAS NEAR THE CT VALLEY AND CHESHIRE
COUNTY.

WITH THE LIGHT WINDS AND CLEARING SKIES...THIS WILL ALLOW FOR A
PERIOD OF RADIATIONAL COOLING AFTER MIDNIGHT. EXPECT THE BEST
CHANCE FOR VERY CHILLY TEMPS ACROSS NORTHERN CHESHIRE AND NW
HILLSBOROUGH COUNTIES...AND COULD SEE SOME POCKETS OF FROST. HAVE
ISSUED FROST ADVISORY FOR THESE AREAS.

OVERNIGHT LOWS WILL DROP TO THE LOWER-MID 30S IN THE FROST ADVISORY
AREA...RANGING TO THE LOWER-MID 50S ALONG THE IMMEDIATE E COAST.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
FRIDAY...THE CENTER OF LARGE HIGH PRES BUILDS ACROSS NEW ENGLAND
DURING THE DAY. WILL SEE LEFTOVER GUSTY WINDS ALONG THE E COAST
FRIDAY MORNING THEN...AS HIGH PRES BUILDS IN...WINDS WILL
DIMINISH. EXPECT MAINLY CLEAR SKIES BUT TEMPS WILL BE MUCH COOLER.
HIGHS WILL ONLY BE IN THE MID 50S IN THE NORMALLY COLDER INLAND
LOCALES TO THE MID 60S IN THE LOWER CT VALLEY.

FRIDAY NIGHT...HIGH PRES SLOWLY PUSHES OFFSHORE SO...WHILE SKIES
WILL BE MAINLY CLEAR...NOTING THAT THE DEWPTS WILL BEGIN TO RISE
AS LIGHT WINDS SHIFT TO S-SE OVERNIGHT. WILL ALSO START TO SEE
HIGH CLOUDS PUSH INTO WESTERN AREAS AFTER MIDNIGHT. MAY STILL SEE
TEMPS FALL TO THE UPPER 30S IN THE NORMALLY PRONE COOLER SPOTS...
THOUGH MOST LOCALES WILL BE IN THE 40S TO LOWER 50S.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
OVERVIEW AND MODEL PREFERENCES...THIS PORTION OF THE FORECAST
STILL LOOKS LIKE IT WILL BE DEFINED BY A DEVELOPING MID-LEVEL
TROUGH ACROSS THE NORTHEAST USA LATE THIS WEEKEND AND EARLY NEXT
WEEK. THIS TROUGH LOOKS LIKE IT MOVES INTO THE MARITIMES TOWARD
THE MIDDLE OF NEXT WEEK. OVERALL...THERE IS DECENT AGREEMENT AMONG
THE 18/12Z GUIDANCE SUITE THROUGH THE MIDDLE OF NEXT WEEK. AFTER
THEN...TIMING DIFFERENCES BECOME MORE PREVALENT...BUT SHOULD NOT
HAVE A MAJOR IMPACT ON THE SENSIBLE WEATHER. WILL CONTINUE TO
FAVOR A CONSENSUS BLEND TO MINIMIZE THESE DETAIL DIFFERENCES.

SATURDAY AND SATURDAY NIGHT...A LARGE HIGH PRESSURE OVER THE
NORTH ATLANTIC NEAR NOVA SCOTIA CONTINUES TO MOVE FARTHER OUT TO
SEA. THIS LEAVES SOUTHERN NEW ENGLAND IN A PROGRESSIVELY WEAKER
RIDGE AXIS WITH TIME. DRY WEATHER THE MOST LIKELY OUTCOME AS THE
AIRMASS REMAINS QUITE DRY. SLIGHTLY BELOW NORMAL HIGH TEMPERATURES
EXPECTED SATURDAY...WITH ABOVE NORMAL LOW TEMPERATURES SATURDAY
NIGHT AS SOUTHERLY WINDS CONTINUE.

SUNDAY INTO MONDAY...
THIS PERIOD IS STARTING TO LOOK LIKE A RACE BETWEEN A WEAK
COASTAL LOW PRESSURE MOVING NORTH AND A COLD FRONT MOVING EAST.
THIS FRONT IS INCREASINGLY LOOKING MOISTURE-STARVED AS IT CROSSES
SOUTHERN NEW ENGLAND. THE 18/12Z GFS APPEARS TO BE A WESTERN AND
FASTER OUTLIER...WHEN COMPARED TO THE OTHER GUIDANCE
SOURCES...WITH ITS HANDLING OF THIS COASTAL LOW PRESSURE. WHILE
NOT EXPECTED TO BE A POTENT STORM...IT COULD SUPPLY THE MOISTURE
THIS PASSING FRONT WOULD NEED TO PRODUCE MORE SIGNIFICANT
RAINFALL. THERE ARE MANY AREAS ACROSS CT...RI AND SOUTHEAST MA
WHICH COULD REALLY USE SOME RAINFALL.

AT THIS TIME...WILL ONLY MENTION A CHANCE OF SHOWERS WITH RAINFALL
TOTALS LESS THAN ONE QUARTER INCH. THERE HAS BEEN A RECENT TREND IN
THE GUIDANCE OF BEING TOO AGGRESSIVE WITH RAINFALL AMOUNTS. WILL
WAIT UNTIL THE TIMING ISSUES BETWEEN THIS FRONT AND COASTAL LOW CAN
BE IRONED OUT. THINKING IT MOST LIKELY THIS COASTAL LOW PASSES BY
TOO FAR OFFSHORE TO HAVE MUCH IMPACT.

HIGH TEMPERATURES EXPECTED TO BE WELL ABOVE NORMAL
SUNDAY...BEFORE RETURNING TO MORE SEASONABLE VALUES BY MONDAY
MORNING.

TUESDAY INTO THURSDAY...
A LARGE HIGH PRESSURE MOVES INTO OUR REGION...PROVIDING PROLONGED
DRY WEATHER AND SLIGHTLY BELOW NORMAL TEMPERATURES.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH SATURDAY/...HIGH CONFIDENCE.

MAINLY VFR THROUGH THE PERIOD...ALTHOUGH SOME EARLY MORNING FOG IS
POSSIBLE AT THE TYPICAL TERMINALS.

WINDS SUSTAINED AROUND 10 KT CONTINUE THROUGH THE EARLY HALF OF
THE DAY WITH A FEW GUSTS TO 20 KT POSSIBLE. THE WINDS RECEDE
OVERNIGHT. WINDS OUT OF THE S-SW ON SAT...WITH AFTERNOON GUSTS TO
20 KT POSSIBLE ONCE AGAIN.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SATURDAY NIGHT INTO SUNDAY MORNING...HIGH CONFIDENCE. MAINLY VFR
THROUGH THIS PERIOD. ALTHOUGH SOME PATCHY GROUND FOG IS POSSIBLE
BOTH SATURDAY AND SUNDAY MORNINGS AT TYPICALLY PRONE AIRPORTS.
WINDS MAINLY S-SW...WITH GUSTS UP TO 20 KT POSSIBLE SUNDAY.

SUNDAY AFTERNOON INTO MONDAY...MODERATE CONFIDENCE. A COLD FRONT
CROSSES THE REGION DURING THE EARLY MORNING HOURS MONDAY. SCATTERED
SHOWERS WITH MVFR/IFR CONDITIONS MAY MOVE THROUGH WITH THIS FRONT.
OTHERWISE...IMPROVING BACK TO VFR BY LATE DAY MONDAY.

TUESDAY...HIGH CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH FRIDAY NIGHT/...HIGH CONFIDENCE.

THROUGH 00Z...COLD FRONT CROSSES THE WATERS BY THIS EVENING.
EXPECT NW WINDS TO SHIFT TO N-NE. LONG GROUND SWELLS OF 3 TO 4 FT
CONTINUE FROM DISTANT HURRICANE EDOUARD. MAY SEE BRIEF SWELLS TO 5
FT ON THE OUTER WATERS S AND E OF CAPE COD AND NANTUCKET WHICH
SHOULD SLOWLY SUBSIDE.

TONIGHT...WILL SEE PRESSURE SURGE WORKING DOWN FROM THE N ACROSS
THE WATERS AS COLDER AIR MOVES ACROSS THE MILDER WATERS. EXPECT N-NE
WIND GUSTS UP TO 25-30 KT MAINLY AFTER MIDNIGHT. HAVE RAISED SMALL
CRAFT FOR RI SOUND.

FRIDAY...NE WINDS REMAIN GUSTY FRI MORNING...THEN DIMINISH AS HIGH
PRES BUILDS N OF THE WATERS. SEAS BUILD UP TO 6-7 FT ON THE OUTER
WATERS. SMALL CRAFTS CONTINUE...THOUGH CONDITIONS SHOULD IMPROVE
ON THE NEAR SHORE SOUNDS AND BAYS BY EARLY AFTERNOON.

FRIDAY NIGHT...LIGHT E WINDS IN PLACE. LEFTOVER SEAS ON THE OUTER
WATERS SHOULD SUBSIDE BELOW SMALL CRAFT CRITERIA BY AROUND
MIDNIGHT.

OUTLOOK...SATURDAY THROUGH TUESDAY...MODERATE CONFIDENCE.

SATURDAY-SUNDAY...WINDS SHIFT TO SOUTH WITH DAYTIME GUSTS UP TO 20
KNOTS NEARSHORE. SEAS WILL REMAIN 2-4 FEET. A COLD FRONT APPROACHES
LATE SUNDAY WITH A CHANCE OF SHOWERS SUNDAY NIGHT.

MONDAY...A COLD FRONT CROSSES THE WATERS EARLY IN THE DAY. WEST
WINDS BEHIND THIS FRONT WILL REMAIN LESS THAN 20 KNOTS. SEAS WILL
BUILD TO 5-7 FEET ON THE OUTER AND EXPOSED WATERS...AS A SOUTH
SWELL INCREASES TO 3-5 FEET. SMALL CRAFT ADVISORIES MAY BE NEEDED.

TUESDAY...NORTHWEST WINDS AND SUBSIDING SEAS EXPECTED AS A HIGH
PRESSURE MOVES OVER THE WATERS. SEAS WILL TAKE LONGEST TO
DIMINISH ACROSS THE OUTER COASTAL WATERS.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NHZ011-015.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
     ANZ232>235-237.
     SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR ANZ231-
     251.
     SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ250.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ254-255.
     SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ256.

&&

$$
SYNOPSIS...BELK/EVT
NEAR TERM...DOODY/EVT
SHORT TERM...EVT
LONG TERM...BELK
AVIATION...BELK/DOODY
MARINE...BELK/EVT



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