Area Forecast Discussion
Issued by NWS Boston, MA

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000
FXUS61 KBOX 041732
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
132 PM EDT FRI SEP 4 2015

.SYNOPSIS...
CANADIAN HIGH PRESSURE BUILDS INTO NEW ENGLAND TODAY...BRINGING A
BRIEF END TO THE RECENT WARM AND HUMID WEATHER. THE HIGH WILL
PROVIDE THE REGION WITH MILD DAYS AND COOL NIGHTS THROUGH SATURDAY.
AS THE HIGH SHIFTS SOUTH OF NEW ENGLAND SUNDAY A WARMING TREND
DEVELOPS WITH TEMPERATURES BECOMING MUCH WARMER THAN NORMAL ALONG
WITH INCREASING HUMIDITY MONDAY THROUGH WEDNESDAY. DRY WEATHER
CONTINUES UNTIL LATE NEXT WEEK WHEN A COLD FRONT MAY YIELD THE RISK
FOR SCATTERED SHOWERS AND T-STORMS.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...
130 PM UPDATE...
STILL FAIR AMOUNT OF STRATO-CU ACROSS SNE WITH CLEARING NOTED
ACROSS NH AND MAINE. TREND WILL BE FOR DECREASING CLOUDS THROUGH
THE AFTERNOON FROM N TO S BUT LOW CLOUDS WILL HANG ON ACROSS SE
MA FOR MUCH OF THE AFTERNOON BASED ON SHALLOW LOW LEVEL MOISTURE.
UPDATED SKY/T/TD GRIDS FOR CURRENT TRENDS...OTHERWISE FORECAST ON
TRACK.

PREVIOUS DISCUSSION...
BACKDOOR FRONT HAS MOVED TO THE S WITH NE FLOW USHERING IN COOLER
AND DRIER AIR. DEWPOINTS HAVE FALLEN INTO THE 50S ACROSS MUCH OF
SNE. GUSTY NE WINDS WILL GRADUALLY SUBSIDE FROM N TO S THIS
AFTERNOON AS THE RIDGE BUILDS SWD INTO SNE BUT GUSTY WINDS WILL
PERSIST ALONG THE SOUTH COAST THROUGH MUCH OF THE AFTERNOON.

MODELS INDICATING DRYING MORNING IN FROM THE NE BUT THERE IS
SHALLOW LOW LEVEL MOISTURE DEVELOPING ACROSS SE MA THIS
AFTERNOON. SO WHILE INCREASING SUNSHINE IS EXPECTED IN E NEW ENG
MAY SEE SOME SHALLOW SC DEVELOPING ACROSS SE MA. ALSO EXPECT
DEVELOPING SC IN W NEW ENG WHERE MOISTURE IS MORE ROBUST.

SOUNDINGS SHOW SHALLOW MIXING ONLY TO 950 MB IN THE EAST AND 900
MB IN THE WEST. EXPECT TEMPS HOLDING AROUND 70 DEGREES IN E
COASTAL MA DUE TO NE FLOW WITH MAXES NEAR 80 IN THE CT
VALLEY...AND 70S ELSEWHERE.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT...
HIGH PRES WILL SLIDE FROM THE NE BEHIND EXITING BACKDOOR FRONT.
MASS FIELDS ALL SUGGEST RAPID SLACKENING. THIS WEAK PRES GRADIENT
COMBINED WITH CLEAR SKIES SUGGEST GOOD SETUP FOR RADIATIONAL
COOLING. WITH COOL MID LVL TEMPS AND HIGHS TODAY BELOW
NORMAL...EXPECT LOWS TO DIP INTO THE LOW 50S IN NORMAL RADIATIONAL
SPOTS. NOT OUT OF THE QUESTION...DEEPER VALLEYS OF NW MA MAY
APPROACH THE UPPER 40S. A GOOD...COOL...OPEN THE WINDOWS KIND OF
NIGHT.

SAT...
ANOTHER DRY DAY WITH HIGH PRES. CLEAR SKIES AND SOME ONSHORE
FLOW CONTINUES. HOWEVER SLIGHT WARMING ALOFT AND WINDS SHIFTING
SOMEWHAT EXPECT HIGHS MAINLY NEAR NORMAL. IN THE MID 70S /NEAR
SHORE/ TO LOW 80S INTERIOR.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGHLIGHTS...

* WARMER THAN NORMAL TEMPS RETURN SUN AND INTO MOST OF NEXT WEEK
* DRY WEATHER CONTINUES INTO AT LEAST THE MIDDLE OF NEXT WEEK

SYNOPTIC OVERVIEW AND GUIDANCE EVALUATION...

04/00Z GEFS AND ECENS ENSEMBLES ALONG WITH DETERMINISTIC GUIDANCE
ARE TRENDING TOWARD THE SUBTROPICAL RIDGE LINGERING LONGER ALONG THE
EAST COAST NEXT WEEK. THIS SUGGEST WARMER THAN NORMAL TEMPS ARRIVING
SUNDAY WILL PERSIST MUCH OF NEXT WEEK ALONG WITH INCREASING
HUMIDITY. HEAT AND HUMIDITY MAY NOT BREAK UNTIL NEXT THU OR FRI AS
NORTHERN STREAM ENERGY FINALLY EJECTS SOUTHEAST INTO NEW ENGLAND AND
ERODES THE NORTHERN PERIPHERY OF THE RIDGE.

SAT NIGHT/SUNDAY...

NOT AS COOL AS FRI NIGHT BUT STILL SEASONABLE COOL ALONG WITH
COMFORTABLE HUMIDITY. THEN SUNDAY AIRMASS GRADUAL WARMS BUT WITH
RIDGE AXIS OVER THE AREA HUMIDITY REMAINS IN CHECK WITH DEW PTS ONLY
CLIMBING INTO THE MU50S. HIGHS SHOULD CLIMB INTO THE LOW TO MID 80S
INLAND...70S AT THE SHORE IN RESPONSE TO COOLING AFTERNOON
SEABREEZES.

MONDAY THRU WEDNESDAY...

RIDGE AXIS SHIFTS SOUTH OF NEW ENGLAND ALLOWING ANOMALOUS HEAT TO
ADVECT INTO NEW ENGLAND WITH H85 TEMPS CLIMBING TO +18C TUE AND WED.
THIS WARMTH ALOFT COMBINED WITH WSW SURFACE WINDS WILL SUPPORT HIGHS
85 TO 90. HUMIDITY INCREASES TOO WITH DEW PTS RISING INTO THE 60S
TUE AND WED.

THURSDAY...

AS MENTIONED ABOVE ENSEMBLES AND DETERMINISTIC GUIDANCE HAVE SLOWED
THE ARRIVAL OF NEXT FRONTAL PASSAGE TO NEXT THU OR FRI. THUS NEXT
CHANCE FOR SHOWERS/T-STORMS NOT UNTIL LATE NEXT WEEK.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH SUNDAY/...HIGH CONFIDENCE.

THROUGH 00Z...AREAS OF MVFR CIGS WILL PERSIST ACROSS SE
MA AND CAPE/ISLANDS...CLEARING 21-00Z. OTHERWISE VFR CIGS THEN
CLEARING.

TONIGHT THROUGH SUNDAY...VFR. PATCHY IFR RADIATION FOG LATE
TONIGHT AND AGAIN LATE SATURDAY NIGHT IN TYPICALLY PRONE
LOCATIONS. COASTAL SEABREEZES SATURDAY. SEABREEZES POSSIBLE
SUNDAY BUT LOWER CONFIDENCE.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SEABREEZE DEVELOPING BY
16Z SAT.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

OUTLOOK /SUNDAY NIGHT THROUGH TUESDAY/...HIGH CONFIDENCE.

VFR THROUGH THE PERIOD. AREAS OF EARLY MORNING IFR CIGS/VSBYS
POSSIBLE IN FOG. INCREASING WEST-SOUTHWEST FLOW MONDAY-TUESDAY.

&&

.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.

TODAY INTO TONIGHT...
WITH STRONG HIGH PRES MOVING IN FROM THE NE...N-NE FLOW WILL
INCREASE TO AROUND 25 KT OVER THE WATERS THROUGH THE
MORNING...SHIFTING TO THE SRN WATERS BY MID DAY. THIS WILL ALSO
ALLOW SEAS TO REACH 4-5 FT. SMALL CRAFT ADVISORY TIMING/PLACEMENT
CURRENTLY LOOK GOOD SO NO PROPOSED CHANGES. CONDITIONS SUBSIDE
OVERNIGHT.

SAT...
HIGH PRES WILL LEAD TO QUIET WX ACROSS THE WATERS.

OUTLOOK /SATURDAY NIGHT THROUGH TUESDAY/...HIGH CONFIDENCE.

TRANQUIL BOATING WEATHER THIS PERIOD AS A LARGE HIGH PRESSURE
REMAINS OVER...OR NEAR...THE WATERS. MAINLY LIGHT AND VARIABLE
WINDS WITH LOCAL SEA BREEZES NEARSHORE...GIVING WAY TO A MORE
SUSTAINED SOUTH TO SOUTHWEST FLOW EARLY NEXT WEEK.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
     ANZ231>235-237.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ250-
     251.
     SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ254>256.

&&

$$
SYNOPSIS...NOCERA/DOODY
NEAR TERM...KJC
SHORT TERM...DOODY
LONG TERM...NOCERA
AVIATION...KJC/NOCERA
MARINE...NOCERA/DOODY



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