Area Forecast Discussion
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000
FXUS61 KBOX 051101
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
701 AM EDT SAT SEP 5 2015

.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE THE WEATHER THROUGH THE MIDDLE OF
NEXT WEEK. AFTER A COOL START TO THIS WEEKEND...A SIGNIFICANT
WARMING TREND DEVELOPS THROUGH THE MIDDLE OF NEXT WEEK WITH
TEMPERATURES BECOMING MUCH WARMER THAN NORMAL ALONG WITH INCREASING
HUMIDITY. A COLD FRONT MAY YIELD THE RISK FOR SCATTERED SHOWERS AND
THUNDERSTORMS BEGINNING WEDNESDAY...WITH A GREATER RISK THURSDAY
AND FRIDAY.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...

7 AM UPDATE...

A TOUCH OF AUTUMN THIS MORNING WITH MANY LOCATIONS IN THE MU40S AT
630 AM. THIS INCLUDES MVY/TAN/OWD/BED/CEF AND ORE. THIS IS IN
RESPONSE TO 1027 MB HIGH OVER SOUTHERN NH PROVIDING A DRY
AIRMASS...LIGHT WINDS AND CLEAR SKIES. ONLY CHANGE WITH THIS
FORECAST UPDATE WAS TO MODIFY HOURLY TEMPS/DEW PTS AND WINDS TO
BETTER MATCH CURRENT CONDITIONS. OTHERWISE FORECAST REMAINS ON
TRACK. EARLIER DISCUSSION BELOW.

==================================================================

THE MAINLY CLEAR SKIES...COOL START...LIMITED MIXING THANKS TO
STRONG SUBSIDENCE AND SEA BREEZES THANKS TO WEAK FLOW...WILL ALL
COMBINE TO IMPACT HIGH TEMPERATURES. WERE MOST MIXING IS
REALIZED...AND H85 TEMPS REMAIN AROUND +12C EXPECT LOW
80S...MAINLY WRN MA/CT. FURTHER E...WHERE SEA BREEZES ARE
EXPECTED...HIGH TEMPS WILL ONCE AGAIN REMAIN IN THE LOW TO MID
70S...UPPER 70S INLAND OF THE IMMEDIATE COAST. DEWPOINTS REMAIN
LOW...MAINLY UPPER 40S AND LOW 50S...SO VERY COMFORTABLE HUMIDITY.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TONIGHT...
VERY WEAK PRES GRADIENT AND CLEAR SKIES THANKS TO DRY AIR THROUGH
THE COLUMN WILL ONCE AGAIN ALLOW FOR RADIATIONAL COOLING THROUGH
THE NIGHT. THEREFORE...LOWS ONCE AGAIN SLIDE INTO THE UPPER 40S
AND LOW 50S.

SUN...
H85 TEMPS WILL INCREASE CLOSER TO +15C AND BETTER MIXING IS
EXPECTED. IN SPITE OF THE COOL START...HIGHS WILL BE WARMER
SUN...MORE WIDESPREAD LOW-MID 80S. UPPER 80S IN THE W. SEA BREEZES
ARE LIKELY AGAIN...SO NEAR SHORE LOCATIONS SHOULD SEE HIGHS
REMAIN IN THE LOW 80S...MID 70S CAPE/ISLANDS. HUMIDITY SHOULD
STILL REMAIN COMFORTABLE THANKS TO DWPTS REMAINING IN THE
50S...ALTHOUGH A LITTLE HIGHER /MAINLY MID 50S/. THE INCREASE IN
TEMPS THOUGH WILL COUNTER THE DWPTS...KEEPING RH VALUES CLOSE TO
THOSE OBSERVED SAT.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...

HIGHLIGHTS...

* SUMMER HEAT RETURNS MON THRU WED W/90+ TEMPS POSSIBLE EACH DAY
* REMAINING DRY THRU TUE WITH SHOWERS/T-STORMS POSSIBLE WED THRU FRI

SYNOPTIC OVERVIEW AND GUIDANCE EVALUATION...

SUBTROPICAL RIDGE DOMINATES OUR WEATHER INTO WEDNESDAY AS RIDGE
HOLDS FIRM FROM TEXAS NORTHEASTWARD INTO SOUTHERN NEW ENGLAND. BY
WED ENSEMBLES AND DETERMINISTIC GUIDANCE SUGGEST LEAD NORTHERN
STREAM SHORT WAVE TROUGH BEGINS TO ERODE THE RIDGE ACROSS NEW
ENGLAND. THIS WILL BE ACCOMPANIED BY A FRONTAL BOUNDARY DROPPING
SOUTHEAST INTO THE REGION. HOWEVER WITH THIS TROUGH DEAMPLIFYING
WITH TIME ITS FRONTAL BOUNDARY LIKELY STALLS SOMEWHERE ACROSS THE
NORTHEAST/NEW ENGLAND. HOWEVER BY FRIDAY ENSEMBLES AND DETERMINISTIC
GUIDANCE SUGGEST AMPLIFYING MID LEVEL TROUGH OVER THE GREAT LAKES
AND MS VLY WITH POSSIBLE SURFACE WAVE DEVELOPING ALONG THE EASTERN
SEABOARD ON THE STALLED FRONTAL BOUNDARY. DETERMINISTIC GUIDANCE
/00Z GFS AND ECMWF/ IN FAIRLY GOOD AGREEMENT THRU TUE BUT THEN SHOW
SIGNIFICANT DIFFERENCES WED THRU FRI WITH TIMING AND AMPLITUDE OF
INDIVIDUAL SHORT WAVES. THUS AS USUALLY LEANED MORE ON THE ENSEMBLES
AT THIS TIME RANGE /WED THRU FRI/.

DAILY DETAILS...

SUN NIGHT/MONDAY...

AIRMASS REMAINS DRY AS RIDGE AXIS HOLDS FIRM OVER THE AREA WITH MORE
HUMID AIRMASS ADVECTING WEST AND NORTH OF NEW ENGLAND. SO DRY
WEATHER PREVAILS WITH SEASONABLE TEMPS SUN NGT BUT AIRMASS GRADUAL
WARMS BY MONDAY WITH 850 TEMPS +16C TO 18C BY DAYS END MONDAY. THIS
WILL SUPPORT HIGHS OF 85 TO 90 AWAY FROM THE SOUTH COAST. HUMIDITY
WILL REMAIN TOLERABLE WITH DEW PTS IN THE U50S TO L60S.

TUESDAY AND WEDNESDAY...

BECOMING HUMID BY TUE AS DEW PTS CLIMB INTO THE 60S REGIONWIDE. GEFS
AND ECENS ENSEMBLES BOTH SUPPORT AIRMASS WARMING AND ADVECTING 850
TEMPS OF +18C AND +22C AT 925 MB ACROSS SNE. THIS WILL SUPPORT TEMPS
IN THE 90S BOTH DAYS AWAY FROM THE SOUTH COAST...WHERE SW WINDS OFF
THE OCEAN WILL KEEP HIGHS IN THE 80S. IN FACT 2 METER TEMPS FROM THE
00Z GFS AND ECMWF OFFER 90-95 BOTH TUE AND WED. RECORD HIGHS TUE ARE
IN THE M90S WITH RECORDS WED IN THE L90S. LOW TO MODERATE
PROBABILITY WE COME CLOSE TO RECORD HIGH TEMPS BOTH DAYS.

LOW RISK OF CONVECTION WED ACROSS WESTERN MA/CT ASSOCIATED WITH WEAK
HEIGHT FALLS AND SURFACE TROUGH APPROACHING FROM NY STATE. GEFS
SUGGESTING SOME INSTABILITY ACROSS WESTERN NEW ENGLAND INTO NY.
NONETHELESS DRY TUE WITH MUCH OF THE REGION REMAINING DRY WED AS
WELL EXCEPT VERY LOW RISK OF STORMS WESTERN MA/CT.

THURSDAY AND FRIDAY...

WITH LONG WAVE TROUGH SETTING UP ACROSS THE GREAT LAKES AND MS VLY A
COLD FRONT WILL ENTER THE NORTHEAST AND LIKELY STALL FOR A TIME AS
THE MID LEVEL FLOW PARALLELS THE FRONT. THIS COMBINED WITH PWATS
ABOVE NORMAL ACROSS THE NORTHEAST COUPLED WITH SOME INSTABILITY
SHOULD YIELD SCATTERED SHOWER/T-STORMS. BOTH GEFS AND ECENS
ENSEMBLES SUGGEST A FRONTAL WAVE POSSIBLY TRACKING INTO THE REGION
IN RESPONSE TO MID LEVEL TROUGH AMPLIFICATION. THUS PRECIP COULD BE
WIDESPREAD AND APPRECIABLE.

&&

.AVIATION /12Z SATURDAY 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.

7 AM UPDATE...

NO MAJOR CHANGES TO 06Z AND 09Z TAF ISSUANCES. PREVIOUS DISCUSSION
BELOW.

==================================================================

MAINLY VFR. ONLY CAVEAT WILL BE OCCASIONAL MVFR/IFR FOG AT
TYPICALLY PRONE LOW-LYING TERMINALS DURING THE EARLY MORNING
HOURS. NE WINDS ASSISTED BY SEA BREEZES TODAY. SW WINDS WITH SEA
BREEZES SUN.

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

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

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

VFR THROUGH THE PERIOD. AREAS OF EARLY MORNING IFR CIGS/VSBYS
POSSIBLE IN FOG. INCREASING WEST-SOUTHWEST FLOW MONDAY-TUESDAY. LOW
RISK OF AFTN/EVENING SHOWERS/T-STORMS WED ACROSS WESTERN MA/CT.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

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

STRONG HIGH PRES WILL BUILD ACROSS THE WATERS THROUGH THE WEEKEND.
ALTHOUGH SOME WIND GUSTS ALONG THE SRN WATERS WILL REACH ABOUT 15
KTS...EXPECT MAINLY QUIET BOATING WEATHER THROUGH THE PERIOD.

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

TRANQUIL BOATING WEATHER THIS PERIOD AS A LARGE HIGH PRESSURE
REMAINS OVER...OR NEAR...THE WATERS SUN NIGHT THEN SHIFTING SOUTH OF
NEW ENGLAND NEXT WEEK YIELDING SW WINDS.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.

&&

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



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