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Area Forecast Discussion
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000
FXUS61 KBOX 011858
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
258 PM EDT TUE SEP 1 2015

.SYNOPSIS...

HOT AND HUMID WEATHER PREVAILS BENEATH HIGH PRESSURE TOWARDS
THURSDAY BY WHICH TIME A COLD FRONT SHOULD BRING SCATTERED
SHOWERS AND THUNDERSTORMS FOR MUCH OF THE REGION. THEN NOT AS
WARM AND NOTICEABLY LESS HUMID WEATHER FRIDAY INTO SAT MORNING. A
WARMING TREND FOLLOWS FOR THE HOLIDAY WEEKEND WITH TEMPERATURES
WELL INTO THE 80S TO PERHAPS NEAR 90 BY SUNDAY AND MONDAY ALONG
WITH DRY WEATHER.

&&

.NEAR TERM /THROUGH 6 AM WEDNESDAY/...

MID-LEVEL RIDGING PREVALENT BENEATH WHICH WINDS WILL BE LIGHT OVER-
NIGHT. STOUT DRY-SUBSIDENCE INVERSION IN PLACE YIELDS THE POTENTIAL 
FOR SURFACE MOISTURE-POOLING. LOOKING AT A LOW-CLOUD / FOG POTENTIAL 
AS THE COMBINATION OF LIGHT WINDS AND MOSTLY CLEAR CONDITIONS NET AN 
ENVIRONMENT FAVORABLE FOR RADIATIONAL COOLING. GOT A FEW DEGREES 
COOLER INTO TUESDAY MORNING THAN INITIALLY THOUGHT...SO WILL GO A 
DEGREE OR TWO COOLER THAN MOS WITH LOWS AROUND THE LOW-60S AND A 
HIGHER FOG POTENTIAL ACROSS THE INTERIOR. 

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...

WEDNESDAY...

CERTAINLY HOT AND HUMID WITH SEVERAL LOCALES SEEING TEMPERATURES 
INTO THE LOW-90S BENEATH INFLUENTIAL MID-LEVEL RIDGING AND DRY-AIR 
SUBSIDENCE AND A H85 AIRMASS ALOFT OF +18-20C. A MOSTLY CLEAR DAY 
WITH SOME SCATTERED CUMULUS OUT TO THE W PARENT WITH INCREASING LOW- 
TO MID-LEVEL THETAE. ECHOING THE PREVIOUS FORECASTER...MOISTURE AND 
INSTABILITY APPEAR INTERESTING BENEATH FAVORABLE LAPSE RATES MORE TO 
THE N. BUT ABSENT ARE THE FORCING MECHANISMS. BUFKIT PROFILES SHOW A 
STRONG WARM-DRY CAP AROUND H85 WITH PARENT DEEP-LAYER SUBSIDENCE. SO 
LOOKING TO REMAIN DRY. LIGHT WINDS OVERALL WITH SEA-BREEZES ALONG 
THE SHORES. 

WEDNESDAY NIGHT...

NOTEWORTHY MID-ATLANTIC LOW PUSHING E AND OFFSHORE TO OUR S AS A 
COLD FRONT APPROACHES FROM THE N. LOOK TO BE IN THE SQUEEZE-PLAY OF 
THE TWO WITH MORE DOMINANT SUBSIDENCE AND DRY AIR ASSOCIATED WITH 
RIDGING OF LINGERING HIGH PRESSURE. WILL KEEP WITH A DRY FORECAST 
WITH LIGHT WINDS. ANOTHER NIGHT OF LOW CLOUDS / PATCHY DENSE FOG IS 
POSSIBLE AS MOISTURE POOLS AGAIN BENEATH A DECOUPLING BOUNDARY-LAYER 
AND DRY-SUBSIDENCE INVERSION. OTHERWISE INCREASING MID-HIGH LEVEL 
CLOUDS WORKING IN TOWARDS MORNING. 

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...

HIGHLIGHTS... 

* SCATTERED T-STORMS THU...OTHERWISE DRY WEATHER PREVAILS
* COOLER AND LESS HUMID THU NIGHT/FRI INTO SAT MORNING
* DRY WITH A GRADUAL WARMING TREND FOR THE HOLIDAY WEEKEND

WED NIGHT...QUIET/DRY WEATHER WITH RIDGING HOLDING ON AND ASSOCIATED 
DEEP LAYER DRY AIR OVER THE REGION. IT WILL BE A WARM NIGHT AFTER 
DAYTIME TEMPS WED PEAK IN THE U80S AND L90S. THIS COMBINED WITH DEW 
PTS REMAINING IN THE 60S WILL RESULT IN MINS ONLY FALLING TO 65 TO 
70...WITH LOW 70S IN THE URBAN AREAS. 

THURSDAY...BEST CHANCE FOR A BRIEF END TO OUR DRY WEATHER AS MID 
LEVEL TROUGH MOVES ACROSS THE MARITIMES AND DRAGS A COLD FRONT 
ACROSS SNE. BEST SYNOPTIC SCALE FORCING IS DISPLACED WELL EAST OF 
NEW ENGLAND...HOWEVER SHALLOW LIFT/CONVERGENCE ASSOCIATED WITH THE 
FRONT WILL COMBINE WITH MODEST DEEP LAYER MOISTURE TO YIELD A RISK 
FOR SCATTERED SHOWERS/T-STORMS. MODERATE INSTABILITY WITH PROJECTED 
CAPES ON THE ORDER OF 1000-2000J/KG. HOWEVER LIMITING FACTOR IS LACK 
OF DEEP LAYER SHEAR. THUS CONVECTION WILL BE DIFFICULT TO SUSTAIN 
AND THIS WILL REDUCE THE THREAT OF STRONG TO SEVERE STORMS. HOWEVER 
IF CAPES CAN GROW TO 2000 J/KG OR GREATER INSTABILITY MAY COMPENSATE 
FOR LACK OF DEEP LAYER SHEAR WITH THE RISK OF A FEW STORMS BECOMING 
STRONG TO PERHAPS SEVERE. ALTHOUGH WEAK WIND FIELDS ALOFT SUGGEST 
ONLY A LOW RISK OF STRONG STORMS. PWATS CLIMB TO ABOUT +1 STD 
DEVIATIONS GREATER THAN CLIMO. THIS COMBINED WITH WEAK WIND FIELDS 
ALOFT MAY POSE A LOW RISK OF SLOW MOVING STORMS AND ASSOCIATED FLOOD 
THREAT. OTHERWISE EXPECT ANOTHER VERY WARM AND HUMID DAY WITH HIGHS 
85 TO 90. SO BY NO MEANS A WASHOUT OUT...A TYPICAL LATE SUMMER DAY 
WITH VERY WARM TEMPS AND A THREAT OF SCT AFTN/EVENING T-STORMS.

THURSDAY NIGHT/FRIDAY/FRI NIGHT...NOTICEABLE AIRMASS CHANGE WITH 
COOLER AND LESS HUMID AIRMASS ADVECTS INTO THE REGION THU NIGHT AS 
1027 MB CANADIAN HIGH BUILDS SOUTHWARD THRU QUEBEC. IN FACT COULD 
SEE NE WINDS GUSTS UP TO 20-25 MPH OVER SE MA FRI MORNING! ALTHOUGH 
THIS BACKDOOR COLD FRONT WON/T HAVE THE SAME PUNCH/COOL DOWN AS AN 
EARLY SUMMER/LATE SPRING EVENT AS SSTS IN GULF OF ME AND EASTERN MA 
WATERS ARE RUNNING 65-70! NEVERTHELESS REFRESHING CHANGE FRI INTO 
SAT AM AS 1027 HIGH BUILDS OVER THE AREA WITH DEW PTS IN THE 50S. 
THUS BREEZY NE WINDS FRI AM WILL SLACKEN IN THE AFTN. THIS WILL SET 
THE STAGE FOR A COOL FRI NIGHT WITH MINS EARLY SAT MORNING IN THE 
50S REGIONWIDE...EXCEPT NEAR 60 IN THE URBAN AREAS AND ALONG THE 
COAST.

HOLIDAY WEEKEND...AFTER A COOL/COMFORTABLE SAT MORNING A GRADUAL 
WARMING TREND AS MID LEVEL RIDGE BUILDS OVER THE AREA...RESULTING IN 
SURFACE RIDGE SLIDING SOUTH OF NEW ENGLAND YIELDING A WESTERLY 
SURFACE FLOW. THIS WEST WIND SHOULD KEEP HUMIDITY IN CHECK WITH DEW 
PTS LIKELY REMAINING IN THE 50S AND ONLY CREEPING UPWARD TOWARD 60 
GIVEN DOWNSLOPE COMPONENT OF SFC WND. THUS EARLY INDICATIONS SUGGEST 
A DRY HOLIDAY WEEKEND WITH A GRADUAL WARMING TREND.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...

FORECASTER CONFIDENCE LEVELS...

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

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

VFR. ONSHORE FLOW DIMINISHES OVERNIGHT. LIGHT WINDS AND SKC ALLOW
FOR IFR FOG DEVELOPMENT IN SHELTERED / LOW-LYING TERMINALS ACROSS
INTERIOR NEW ENGLAND. BURNING OFF DURING THE MORNING...LIGHT W/SW-
FLOW RETURNS WITH SEA-BREEZES ALONG THE SHORES FOR WEDNESDAY. SCT
5 KFT CIGS TO THE W. A RETURN OF MVFR-IFR CIGS / VSBYS FOR THE
WEDNESDAY OVERNIGHT PERIOD INTO THURSDAY MORNING.

KBOS TERMINAL...HIGH CONFIDENCE IN TAF. SEA BREEZE POSSIBLE ALBEIT
LATER FOR WEDNESDAY. 

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

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

MAINLY VFR CONDITIONS THROUGHOUT THE PERIOD. LOW PROBABILITY OF 
BRIEF MVFR CONDITIONS IN SCT SHRA/TSRA THU. ALSO...IFR VSBYS 
POSSIBLE IN PATCHY FOG EACH NIGHT.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

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

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

SEAS AT OR BELOW 4-FEET. ONLY ISSUES ARE W/SW-WINDS OVER THE WATERS
WITH GUSTS UP TO AROUND 15 KTS ACROSS THE E-OUTER WATERS FOR A
MAJORITY OF THE PERIOD...PERHAPS SOME PATCHY DENSE FOG ALONG THE
SHORES WITH ONSHORE FLOW DURING THE DAY. MAINLY QUIET BOATING
WEATHER PREVAILS THROUGH WED.

OUTLOOK /WEDNESDAY THROUGH SATURDAY/...HIGH CONFIDENCE.

FAIRLY TRANQUIL BOATING WEATHER THIS PERIOD. THE EXCEPTION WILL BE 
LATE THU NIGHT INTO FRI MORNING WHEN 1027 MB HIGH OVER QUEBEC YIELDS 
A STIFF NE WIND OF 15 TO 20 KT WITH GUSTS UP TO 25 KT POSSIBLE. 
WINDS DROP OFF LATE FRI HOWEVER LOW PRES MAY DEVELOP WELL SE OF NOVA 
SCOTIA NEXT WEEKEND. THIS MAY RESULT IN EASTERLY SWELLS IMPACTING 
THE EASTERN MA WATERS. DRY WEATHER MUCH OF THE PERIOD WITH THE 
EXCEPTION OF SCATTERED T-STORMS POSSIBLE THU AFTN AND EVENING.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SYNOPSIS...NOCERA/SIPPRELL 
NEAR TERM...SIPPRELL 
SHORT TERM...SIPPRELL 
LONG TERM...NOCERA 
AVIATION...NOCERA/SIPPRELL 
MARINE...NOCERA/SIPPRELL



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