Area Forecast Discussion
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FXUS61 KBOX 302016
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
416 PM EDT TUE SEP 30 2014

.SYNOPSIS...
COOL DAMP CONDITIONS REMAIN IN PLACE INTO THURSDAY...WITH MORE
WIDESPREAD RAINFALL EXPECTED TOMORROW. DRY WEATHER RETURNS LATER
THURSDAY INTO FRIDAY AS HIGH PRESSURE BUILDS BACK ACROSS THE
REGION. A COLD FRONT WITH ASSOCIATED LOW PRESSURE WILL LIKELY
BRING A PERIOD OF RAIN SATURDAY FOLLOWED BY COOLER AND DRIER
CONDITIONS FOR SUNDAY INTO MONDAY.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
BAND OF LIGHT WITH A FEW POCKETS OF MOD RAINFALL CONTINUES TO
SLOWLY DISSIPATE LATE THIS AFTERNOON AND SHIFT E. THIS IS THE
EXPECTED TREND WITH TIME AS OCEAN LOW PRES CONTINUES TO DEVELOP
WELL SOUTHEAST OF THE 40/70 BENCHMARK AND BEGINS PULLING MOISTURE
TO THE E AT LEAST THROUGH THE EVENING HOURS. HOWEVER...GIVEN ALL
THE N-NE FLOW OFF THE COOL GULF OF MAINE...THE CLOUDY DAMP
CONDITIONS WILL REMAIN WITH SHOWERS POSSIBLY TRANSITIONING TO MIX
OF FOG AND DRIZZLE THROUGH THE EVENING HOURS. GIVEN THIS
FACT...EXPECT MINS TO BE NOT TOO FAR AWAY FROM CURRENT HIGH
TEMPS...ONLY DIPPING BACK INTO THE LOW-MID 50S WITH MAYBE A SPOT
UPPER 40F.

THROUGH THE EARLY MORNING HOURS HOWEVER...EXPECT INVERTED TROF
BETWEEN THE OFFSHORE LOW PRES AND THE E MOVING UPPER CUTOFF TO
BEGIN TO ENHANCE. NOTE INCREASE IN BAROCLINICITY AND DEFORMATION
ACROSS THE AREA THROUGH THE MORNING...WHICH COMBINED WITH
DEEPENING MOISTURE FROM THE SFC TO H4 OR SO...SUSPECT INCREASE IN
MORE WIDESPREAD RAINFALL ACROSS SRN NEW ENGLAND DURING THE EARLY
MORNING HOURS...SUCH THAT IT/S LIKELY RAINING AT OVER MUCH OF THE
BOX CWA BY 12Z. MORE ON THIS FOR IN THE TOMORROW DISCUSSION
BELOW. HAVE POPS INCREASING AFTER 06Z TO LIKELY...BUT IT/S LIKELY
CATEGORICAL POPS WILL BE NEEDED.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
TOMORROW...
AS MENTIONED ABOVE...AS UPPER LVL CUTOFF SHIFTS ALMOST DIRECTLY
OVERHEAD AND LOW PRES CONTINUES WELL TO THE SE OF THE
BENCHMARK...A MODERATE INVERTED TROF IS LIKELY TO CONTINUE TO
DEVELOP THROUGH THE MORNING AND INTO THE AFTERNOON. THIS PROVIDES
BETTER F-GEN AND EVEN A DEFORMATION AXIS FOR DEEPER LIFT ACROSS
THE AREA. THIS IS ALSO COMBINED WITH MODEST ELY LLJ WITH WIND
SPEEDS AT H85 AROUND 25-30 KT /2+ STD DEVIATIONS ABOVE NORMAL/
AND PWATS TO AROUND 1.5 INCHES WHICH IS 1-2 STD DEVIATIONS ABOVE
NORMAL FOR EARLY OCTOBER. THEREFORE...EXPECT MORE WIDESPREAD
RAINFALL ACROSS MOST OF SRN NEW ENGLAND THROUGH THE DAY...ITS NOT
UNTIL THE SFC OCEAN SYSTEM PULLS E LATE IN THE DAY THAT THE
MOISTURE BEGINS TO DECREASE. MANY AREAS MAY RECEIVE SOME OF THE
STEADY SOAKING RAINFALL THEY HAVE NEEDED FOR SOME TIME NOW WITH
THE POSSIBILITY OF RAINFALL AMOUNTS RANGING 0.25-0.75 INCHES.
POCKETS OF HEAVIER RAIN ARE ALSO POSSIBLE GIVEN THE BANDING
POTENTIAL WHICH MAY BE ENHANCED THANKS TO K-VALUES IN THE LOW
30S...BUT IT/S DIFFICULT TO SAY EXACTLY WHERE THIS WILL SET UP. SO
WILL AT LEAST HIGHLIGHT THE POTENTIAL FOR SOME LOCALIZED AREAS OF
1.0+ INCHES. FOR NOW...THE BEST CHANCE LOOKS LIKE SE MA...WHERE
THE INVERTED TROF HOLDS IN THE LONGEST...BUT IT/S NOT OUT OF THE
QUESTION IT IS OBSERVED INLAND...ESPECIALLY WHERE AN E COMPONENT
TO THE FLOW ENHANCES UPSLOPE.

OTHER THAN THE RAINFALL...COOL TEMPS ARE EXPECTED AS MANY
LOCATIONS REMAIN IN THE UPPER 50S TO AROUND 60 DEGREES.

TOMORROW NIGHT...
RAINFALL WILL SLOWLY COME TO AN END FROM W TO E THROUGH THE
EVENING...POSSIBLY LINGERING ACROSS RI AND SE MA INTO THE EARLY
MORNING HOURS. HOWEVER...WITH E COMPONENT TO THE FLOW...AND LOW
LVL MOISTURE REMAINING IN PLACE...EXPECT ANOTHER CHANCE FOR FOG
AND DRIZZLE AT TIMES THROUGH THE OVERNIGHT HOURS. MIN TEMPS REMAIN
LIKELY IN THE 50S.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...

* SUNSHINE AND LIGHT WINDS FRIDAY
* RAIN LIKELY SATURDAY
* COOLER AND MAINLY DRY WEATHER SUNDAY INTO MONDAY
* MORE SHOWERS POSSIBLE TUESDAY

OVERVIEW...
MEDIUM RANGE DETERMINISTIC AND ENSEMBLE GUIDANCE IN GENERAL
AGREEMENT ON THE LARGE SCALE PATTERN DURING THE EXTENDED PERIOD. MID
LEVEL LOW EXITS THE REGION TOWARD THE END OF THE WEEK...THEN MAIN
FEATURE WILL BE AN ANOMALOUS MID LEVEL TROF/LOW DIGGING INTO THE
UPPER MIDWEST AND WESTERN GT LAKES BY SAT. A PIECE OF ENERGY
ROTATING AROUND THE MID LEVEL LOW WILL BRING A FRONTAL SYSTEM INTO
NEW ENG LATE SAT/SAT NIGHT WHICH WILL BE ACCOMPANIED BY A PERIOD OF
RAIN WHICH MAY BE LOCALLY HEAVY...BUT EXACT TIMING IS UNCERTAIN.
AFTER SHORTWAVE EXITS...BROAD TROF WILL REMAIN ACROSS SOUTHERN
CANADA AND GT LAKES SUNDAY INTO EARLY NEXT WEEK WITH NEXT SHORTWAVE
AND FRONT APPROACHING NEXT TUESDAY. THERE ARE ALSO TIMING
DIFFERENCES WITH THIS FRONT AS THE GFS IS MORE PROGRESSIVE THAN THE
ECMWF WHICH WILL AFFECT TIMING OF POTENTIAL SHOWERS EARLY NEXT WEEK.

DAILIES...

THURSDAY...
MID LEVEL LOW WILL GRADUALLY PULL AWAY FROM SE NEW ENG AS HIGH PRES
BUILDS INTO THE REGION.  CROSS SECTIONS SUGGEST MOCLDY SKIES DURING
THE MORNING AND CANT RULE OUT A FEW SHOWERS NEAR THE COAST IN
PERSISTENT CYCLONIC FLOW...THEN BECOMING PTSUNNY FROM WEST TO EAST
IN THE AFTERNOON AS DRIER AIR MOVES IN. WITH NE FLOW... TEMPS WILL
HOLD IN THE 60S.

FRIDAY...
SNE WILL BE IN BETWEEN SYSTEMS WITH HIGH PRES OVERHEAD LEADING TO
MOSUNNY SKIES AND LIGHT WINDS.  WILL HAVE TO WATCH CLOUDS BACKING IN
FROM THE OCEAN ASSOCIATED WITH OFFSHORE STORM WHICH MAY BRING MORE
CLOUDS TO THE OUTER CAPE.  GFS AND NAM ARE SUGGESTING THIS INCREASED
CLOUD COVER WHILE ECMWF KEEPS CLOUDS TO THE EAST.  WITH CONTINUED
ONSHORE FLOW TEMPS EXPECTED TO BE IN THE 60S...COOLEST E MA COAST.

SATURDAY INTO SATURDAY NIGHT...
MODELS ARE IN GOOD AGREEMENT ON TIMING OF COLD FRONT INTO SNE LATE
SAT INTO SAT NIGHT. DECENT LOW LEVEL JET AND ANOMALOUS PWAT PLUME
AHEAD OF THE FRONT WILL BRING A PERIOD OF RAIN TO SNE WHICH MAY BE
LOCALLY HEAVY...BUT THIS SYSTEM IS FAIRLY PROGRESSIVE. TIMING IS
STILL UNCERTAIN BUT IT APPEARS BULK OF RAIN WILL FALL DURING
SAT...WHICH MAY LINGER INTO SAT EVENING ACROSS E NEW ENG.

SUNDAY...
FRONT IS OFFSHORE SUNDAY WITH DRY WESTERLY FLOW WHICH WILL LEAD TO
SUNSHINE AND BLUSTERY CONDITIONS. 850 MB TEMPS BELOW NORMAL AND WILL
LEAD TO BELOW NORMAL TEMPS SUNDAY.

MONDAY AND TUESDAY...
NEXT FRONT APPROACHES FROM THE WEST BUT THERE ARE DIFFERENCES IN
TIMING AND AMPLITUDE OF THE SHORTWAVE AND HOW PROGRESSIVE THE FRONT
WILL BE. EVEN FASTER GFS IS MAINLY DRY FOR MON SO WE ARE GOING WITH
A DRY FORECAST FOR NOW.  THE MAIN UNCERTAINTY IS WITH TUE AS
PROGRESSIVE GFS MOVES THE SHOWERS OFFSHORE WHILE MORE AMPLIFIED
ECMWF IS WET.

&&

.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...HIGH CONFIDENCE ON TRENDS BUT LOWER CONFIDENCE IN
TIMING.

THROUGH TONIGHT...
MAINLY IFR IN EAST OF AN IJD-ORH-MHT LINE...WITH MVFR WEST. THIS
IS MAINLY DUE TO CIGS THROUGH EVENING...BUT AROUND 23Z AND AFTER
VSBYS MAY BEGIN TO DIP AS WELL IN A MIX OF DRIZZLE/FOG/LIGHT RAIN.
POSSIBILITY OF PERIODIC IFR VSBYS...BUT MAINLY VFR EXPECTED. CIGS
REMAIN LOW...BUT VSBYS LIFT DURING THE MORNING HOURS AS RAIN
BECOMES MORE WIDESPREAD AND ALLOWS VSBYS TO LIFT TO MAINLY
MVFR/VFR. WINDS PICK UP NEAR SHORE IN THE EAST...WITH A FEW GUSTS
APPROACHING 20 KT AT COASTAL TERMINALS.

TOMORROW AND TOMORROW NIGHT....
MUCH OF THE SAME...MAINLY IFR/MVFR CIGS WITH SOME MVFR CONDITIONS
IN RAIN. EXPECT A VERY SLOW IMPROVEMENT FROM W TO E LATE IN THE
DAY AND OVERNIGHT...BUT THIS WILL BE MAINLY TOWARD RAIN
ENDING...WITH CATEGORIES ONLY REALLY IMPROVING DURING THE DAYLIGHT
HOURS ON THU.

KBOS...HIGH CONFIDENCE ON TRENDS...LOWER CONFIDENCE ON TIMING.
ALSO LOW CONFIDENCE OF A BRIEF PERIOD OF LIFR CONDITIONS POSSIBLE
DURING THE OVERNIGHT HOURS BEFORE IMPROVEMENT IN THE MORNING.

KBDL...HIGH CONFIDENCE ON TRENDS...LOWER CONFIDENCE ON TIMING.

OUTLOOK...THURSDAY THROUGH SUNDAY...

THU...MODERATE CONFIDENCE. AREAS OF IFR IN THE MORNING SHOULD
IMPROVE TO VFR IN THE AFTERNOON AS CIGS LIFT AND CLOUDS BREAK UP.

FRI...HIGH CONFIDENCE. VFR.

SAT...MODERATE CONFIDENCE.  CONDITIONS LOWERING TO MVFR/IFR AS
SHOWERS MOVE INTO THE REGION. LOWER CONFIDENCE ON TIMING. GUSTY
SOUTHERLY WINDS POSSIBLE AHEAD OF A COLD FRONT SHIFTING TO WEST SAT
NIGHT.

SUN...MODERATE CONFIDENCE. VFR.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM...HIGH CONFIDENCE THROUGH TOMORROW NIGHT.

N-NE FLOW WILL GRADUALLY INCREASE THROUGH THE EARLY MORNING HOURS
INTO TOMORROW...WITH WIND GUSTS AROUND 25 KT AT TIMES POSSIBLE
PARTICULARLY BY TOMORROW AFTERNOON AND OVERNIGHT. SMALL CRAFT
ADVISORIES HAVE BEEN ISSUED FOR THE OCEAN WATERS AS WELL AS RI/BI
SOUND FOR THESE WINDS...AND MAY NEED TO BE ADDED FOR THE WATERS
SURROUNDING CAPE COD FOR LATE IN THE DAY TOMORROW.

OTHERWISE...SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY DUE TO
INCREASING SWELL ALONE...WHICH HAS THE POTENTIAL TO REACH 7-8FT
BY TOMORROW AFTERNOON ON THE OCEAN WATERS. IT/S LIKELY THAT THESE
SMALL CRAFT ADVISORIES WILL NEED TO LINGER INTO THURSDAY.

OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE.

THU INTO FRI...EXPECT NE WIND GUSTS TO 25-30 KT THU MORNING OVER SE
WATERS WHICH WILL GRADUALLY DIMINISH THU AFTERNOON AND NIGHT.
CONTINUED NE WINDS FRI BUT SPEEDS LESS THAN SCA.  HAZARDOUS SEA
CONDITIONS EXPECTED THU INTO FRI OVER OUTER WATERS.

SAT...SOUTHERLY WINDS DEVELOPING AHEAD OF A COLD FRONT WITH GUSTS
INCREASING TO 25-30 KT. WINDS SHIFTING TO WEST DURING SAT NIGHT.
HAZARDOUS SEA CONDITIONS CONTINUE OVER OUTER WATERS.  VSBYS MAY BE
REDUCED IN SHOWERS AND FOG.

SUN...WEST WINDS MAY GUST TO 25-30 KT IN POST FRONTAL AIRMASS.
HAZARDOUS SEAS CONTINUE OVER OUTER WATERS.


&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM WEDNESDAY TO 8 AM EDT THURSDAY
     FOR ANZ235-237.
     SMALL CRAFT ADVISORY UNTIL 8 AM EDT THURSDAY FOR ANZ250-251.
     SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 8 AM EDT
     THURSDAY FOR ANZ254>256.

&&

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



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