Area Forecast Discussion
Issued by NWS Boston, MA

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000
FXUS61 KBOX 161735
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
135 PM EDT TUE SEP 16 2014

.SYNOPSIS...

A WEAK COLD FRONT WILL BRING SHOWERS TO THE REGION THROUGH MID
AFTERNOON. WITH HIGH PRESSURE OVERHEAD...DRY AND SLIGHTLY COOLER
THAN NORMAL WEATHER FOLLOWS WEDNESDAY THROUGH SATURDAY. SOME FROST
IS POSSIBLE EARLY FRIDAY MORNING IN SOME AREAS. THE HIGH WILL THEN
SLIP OFFSHORE AND SOUTHWEST FLOW BEHIND IT WILL ALLOW TEMPERATURES
TO WARM TO NEAR OR ABOVE NORMAL SUNDAY AND MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

130 PM UPDATE...

WITH THE MAIN IMPULSE OF MID-LEVEL ENERGY STRETCHED EASTWARD AND
OFFSHORE....MUCH OF THE ASSOCIATED DEEP-LAYER LIFT HAS WEAKENED.
SHOWERS CONTINUE TO DISSIPATE WITH JUST SOME SCATTERED BATCHES
OVER E MA INTO S RI. SHOWERS WILL DISSIPATE WITH AS ENERGY LIFTS
OUT OF THE REGION AND AS PREVAILING SUBSIDENCE REARWARD ALLOWS FOR
CLEARING CONDITIONS...ALBEIT BRIEF AS A COOL-MOIST AIRMASS POURS
SE BEHIND AN ATTENDANT COLD FRONT...MIXING OUT WITH DIURNAL HEATING
OF THE BOUNDARY LAYER.

OBSERVING SCATTERED TO BROKEN 2-4 KFT CLOUD DECKS FILLING IN THE
BRIEF CLEARING IN WAKE OF THE COLD FRONT. WINDS BACKING OUT OF
THE W/NW AS TEMPERATURES WARM EVER BRIEFLY WITH SUNSHINE INTO THE
MID- TO UPPER-60S. QUIET WEATHER PREVAILING INTO EVENING.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...

TONIGHT...
GRADUAL CLEARING CONDITIONS AWAY FROM THE COASTLINE IS EXPECTED
AS NOSE OF COOL HIGH PRES BEGINS TO BUILD IN FROM THE W. THE
COMBINATION OF CLEARING SKIES AND SLACKENING SFC PRES GRADIENT
SHOULD YIELD ANOTHER ROUND OF RADIATIONAL COOLING...WITH TEMPS
LIKELY FALLING BACK INTO THE 40S AWAY FROM THE URBAN HEAT ISLANDS.
NOT OUT OF THE QUESTION A LOCALIZED COOLER VALLEY IN NW MA OR
CHESHIRE COUNTY NH FALLS BACK INTO THE UPPER 30S. NOT CONFIDENT
ENOUGH IN WIDESPREAD FROST AT THIS TIME MAINLY THAT DWPTS WILL BE
A BIT SLOWER TO FALL WITH THE LACK OF DIURNAL MIXING TODAY...BUT
SOMETHING THAT THE DAY CREW WILL HAVE TO GIVE ANOTHER LOOK THROUGH
THE DAY.

WEDNESDAY...
ANOTHER PLEASANT MID SEPTEMBER DAY. SHOULD SEE MOSTLY SUNNY
CONDITIONS EVEN AS WEAK CLIPPER SYSTEM PASSES TO THE N AND LOW
PRES DEVELOPS WELL TO THE S. DESPITE THE SUNSHINE...THE COOL START
AND H85 TEMPS AVERAGING +7C WILL KEEP HIGH TEMPS NEAR OR SLIGHTLY
BELOW NORMAL. EXPECT HIGHS ONCE AGAIN HOVERING IN THE UPPER 60S
AND LOW 70S. OF SOME CONCERN IS THE CHANCE FOR RIP CURRENTS ON
WED...AS LINGERING SWELL FROM EDOUARD INCHES TOWARD SRN NEW
ENGLAND. NOT CONFIDENT ENOUGH TO HOIST ANY STATEMENTS AT THIS
TIME...BUT SOMETHING TO BE MONITORED.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...

HIGHLIGHTS...

* DRY AND SLIGHTLY COOLER THAN NORMAL WEATHER THROUGH SATURDAY
  WITH SOME FROST POSSIBLE FRIDAY MORNING.
* MUCH WARMER SUNDAY AND MONDAY
* COLD FRONT BRINGS A CHANCE OF MEASURABLE RAIN LATER ON MONDAY

MODELS ARE IN REASONABLY GOOD AGREEMENT THROUGH MUCH OF THE LONG
TERM WITH ONLY SOME MINOR DETAIL DIFFERENCES. THEREFORE... WILL
USE A BLEND OF AVAILABLE GUIDANCE FOR MUCH OF THE FORECAST. POINTS
OF INTEREST INCLUDE THE POTENTIAL FOR COLD TEMPERATURES AND FROST
FOR EARLY FRIDAY MORNING AND A COLD FRONT THAT MAY BRING SHOWERS
TO THE REGION THURSDAY NIGHT INTO FRIDAY AND A COLD FRONT
BRINGING RAIN TO THE REGION BY LATE MONDAY.

WEDNESDAY NIGHT...A WEAK FRONT WILL MOVE THROUGH LATE WED NIGHT
BRINGING A REINFORCEMENT OF COOLER AIR. THE FRONTAL PASSAGE IS
EXPECTED TO BE DRY. LOWS IN THE 40S EXCEPT 50S SOUTHEAST COAST.

THURSDAY INTO EARLY SATURDAY...STRONG HIGH PRESSURE OVER NEW
ENGLAND WILL DOMINATE THE WEATHER WITH SUNNY DAYS AND CLEAR NIGHTS.
HIGHS THURSDAY WILL BE IN THE 60S TO LOWER 70S. BUT THE COLDEST
AIR SETTLES IN OVERNIGHT THURSDAY INTO FRIDAY. THERE COULD BE SOME
FROST IN SOUTHERN NH AND NORTHERN AND CENTRAL MA AS LOW
TEMPERATURES DIP TO THE MID 30S FRIDAY MORNING IN THOSE AREAS.
HIGHS FRIDAY WILL STRUGGLE TO MAKE IT TO THE LOWER TO MID
60S...AND MAY ONLY REACH THE UPPER 50S IN SOUTHERN NH.

REST OF SATURDAY THROUGH MONDAY...THE HIGH PRESSURE SYSTEM MOVES
OFF THE COAST THROUGH THIS PERIOD. THE SOUTH TO SOUTHWEST FLOW
BEHIND THE HIGH WILL ALLOW TEMPERATURES TO CLIMB BACK TO NEAR OR
EVEN ABOVE NORMAL READINGS BOTH SUNDAY AND MONDAY. HIGHS SATURDAY
SHOULD REACH 65 TO 70. BUT HIGHS ON SUNDAY COULD REACH THE MID AND
UPPER 70S OVER MUCH OF THE AREA. AN 80 DEGREE READING IS NOT OUT
OF THE QUESTION IN A FEW LOCATIONS ON SUNDAY. MONDAY SHOULD AGAIN
TOP OUT WELL INTO THE 70S. SATURDAY AND SUNDAY WILL BE MOSTLY
SUNNY BUT CLOUDS WILL BE INCREASING ON MONDAY IN ADVANCE OF A COLD
FRONT THAT WILL APPROACH FROM THE WEST LATE IN THE DAY. THE FRONT
COULD BRING A CHANCE OF SHOWERS MONDAY AFTERNOON AND MONDAY NIGHT.
MODELS SHOW A LITTLE INSTABILITY AND WIND SHEAR OUT AHEAD OF THAT
FRONT MONDAY BUT IT IS TOO FAR OUT IN TIME TO MENTION THE
POSSIBILITY OF ANY THUNDER.

THERE IS ONE POTENTIAL WRINKLE IN THE FORECAST FOR LATE SUNDAY...
PERHAPS WORTH MENTIONING. MODELS HINT AT LOW PRESSURE WELL TO THE
SOUTHEAST OF NANTUCKET. BOTH MODELS BRING CLOUDS AND EVEN SOME
SHOWERS OVER THE SOUTHEASTERN OUTER WATERS AND PERHAPS AS FAR WES
AS NANTUCKET AND OUTER CAPE COD SUNDAY NIGHT. HAVE INTRODUCED SOME
CLOUDINESS THERE BUT TOO UNCERTAIN AT THIS TIME TO INCREASE POPS.
WILL NEED TO WATCH FOR MORE MODEL CONSISTENCY WITH THIS FEATURE.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...

FORECASTER CONFIDENCE LEVELS...

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

SHORT-TERM FORECAST /THROUGH WEDNESDAY/...HIGH CONFIDENCE.

REMAINDER OF TODAY...
-SHRA DISSIPATING. SCT-BKN CIGS AROUND 3 KFT PREVAIL INTO EVENING.
WINDS BACKING OUT OF THE W/NW ERODING WEAK SEA-BREEZES ALONG THE
SHORELINES WITH COLD FRONTAL PASSAGE.

TONIGHT...
IFR-VLIFR DENSE FOG CERTAINLY POSSIBLE ACROSS INTERIOR NEW ENGLAND
WITH 1/2SM VV002. HIGHEST CONFIDENCE FOR THOSE TERMINALS WHICH SAW
RAIN EARLIER TODAY AND ARE SHELTERED FROM THE WIND AND TYPICALLY
PRONE TO FOG.

WEDNESDAY INTO WEDNESDAY NIGHT...
IFR-VLIFR FOG BURNS OFF IN THE MORNING. FEW-SCT CIGS AROUND 5 KFT
FOR INTERIOR TERMINALS. SEA-BREEZES ALONG THE SHORES TOWARDS
MIDDAY...ERODING TOWARDS EVENING. NOT ENOUGH CONFIDENCE AT THIS
TIME TO BELIEVE THERE WILL BE FOG ISSUES TOWARDS THURSDAY MORNING.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF. PRESENT N/NE WINDS WILL
BECOME VRB WITH COLD FRONTAL PASSAGE THIS AFTERNOON...TURNING W/NW
INTO THE OVERNIGHT. LOW CONFIDENCE ON FOG.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF. THERE IS SOME CONFIDENCE
OF POTENTIAL FOG IMPACTS TOWARDS WEDNESDAY MORNING.

OUTLOOK...THURSDAY THROUGH SATURDAY.

THURSDAY THROUGH SATURDAY...HIGH CONFIDENCE. VFR.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

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

SHORT-TERM FORECAST /THROUGH WEDNESDAY/...MODERATE CONFIDENCE.

EVEN AS A WEAK COLD FRONT SWEEPS ACROSS THE WATERS LATE TODAY...
WINDS SHOULD REMAIN BELOW THE 25 KT THRESHOLD FOR SMALL CRAFT
ADVISORIES...ALTHOUGH THE WILL SHIFT TO THE W-NW AND CONTINUE AS
SUCH INTO WEDNESDAY.

HOWEVER...GRADUALLY BUILDING SWELL FROM EDOUARD WELL TO THE SE MAY
LEAD TO DOMINANT SEAS OF AROUND 5-6FT ESPECIALLY ON THE S AND SE
WATERS BEGINNING LATE TONIGHT OR EARLY TOMORROW MORNING. A SMALL
CRAFT ADVISORY MAY BE NEEDED...BUT WOULD LIKE TO SEE HOW THINGS
CONTINUE THROUGH THE DAY AS GUIDANCE CONTINUES TO BE A LITTLE ON
THE HIGH SIDE INITIALIZING.

OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...

WEDNESDAY NIGHT AND THURSDAY...LINGERING SWELL FROM DISTANT
HURRICANE EDOUARD WILL BE 5 TO 6 FT WED NIGHT ON THE OUTER WATERS
AND THEN SLOWLY SUBSIDE TO BELOW 5 FT THU. WINDS WILL REMAIN
FAIRLY LIGHT AND VARIABLE THROUGH THURSDAY WITH HIGH PRESSURE
ADVANCING ACROSS ONTARIO.

THURSDAY NIGHT INTO FRIDAY EVENING... STRONG HIGH PRESSURE WILL
BUILD OVER NEW ENGLAND. A NORTHEASTERLY GRADIENT WILL INCREASE
OVER THE WATERS LEADING TO 15-20 KT SUSTAINED WINDS AND SOME GUSTS
TO 25 KT. SEAS ARE FORECAST TO AGAIN BUILD TO 5 TO 6 FT. SMALL
CRAFT ADVISORIES FOR BOTH WINDS AND SEAS WILL BE LIKELY.

LATE FRIDAY NIGHT AND SATURDAY...QUIET BOATING WEATHER EXPECTED.
WINDS DIMINISHING AND SEAS SUBSIDING TO BELOW SMALL CRAFT ADVISORY
CRITERIA.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...DOODY/GAF
NEAR TERM...SIPPRELL
SHORT TERM...DOODY
LONG TERM...GAF
AVIATION...DOODY/GAF
MARINE...DOODY/GAF



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