Area Forecast Discussion
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053
FXUS61 KBOX 040145
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
945 PM EDT TUE MAY 3 2016

.SYNOPSIS...
CLOUDY...DREARY AND COOL WEATHER CONTINUES THROUGH FRIDAY WITH PERIODS
OF RAIN AS WEAK WAVES OF LOW PRESSURE PASS SOUTH AND EAST OF OUR
REGION. SOME SHOWERS ARE STILL POSSIBLE AT TIMES THIS WEEKEND...BUT
TEMPERATURES WILL BEGIN TO MODERATE. SIGNIFICANT IMPROVEMENT WILL
LIKELY OCCUR EARLY TO MIDDLE OF NEXT WEEK AS HIGH PRESSURE BUILDS
IN WITH MUCH MILDER TEMPERATURES.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...

940 PM UPDATE...

SCATTERED SHOWERS CONTINUE EARLY THIS EVENING IN RESPONSE TO THE
MOIST CYCLONIC FLOW ACROSS NEW ENGLAND. HOWEVER AS THE EVENING AND
NIGHT PROGRESS SHORT WAVE RIDGING AND ASSOCIATED MID LEVEL
ANTICYCLONIC FLOW DEVELOPS OVER THE AREA. THIS RESULTS IN HIGH
PRES OVER THE MARITIMES TO BUILD SOUTHWARD INTO NEW ENGLAND.
THIS SHORT WAVE RIDGING OVER THE AREA IS IN RESPONSE TO A POTENT
SHORT WAVE TROUGH UPSTREAM MOVING ACROSS THE GREAT LAKES AND OH
VLY. SO THE NET AFFECT IS A DRYING TREND EXPECTED OVERNIGHT.
PREVIOUS FORECAST CAPTURES THIS NICELY SO NO MAJOR CHANGES
EXPECTED.

IT WILL REMAIN COOL WITH NORTHEAST WINDS AND DEW PTS IN THE U30S
TO M40S.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...

*** NEXT BAND OF STEADY RAIN AFFECTS MOST OF THE REGION LATE
WEDNESDAY AFTERNOON/EVENING PARTICULARLY EASTERN MA/RI ***

WEDNESDAY AND WEDNESDAY NIGHT...

MOIST EAST TO NORTHEAST FLOW WILL DOMINATE INTO EARLY WEDNESDAY
AFTERNOON WITH LOW CLOUDS TRAPPED BENEATH THE SUBSIDENCE INVERSION.
FORCING WILL BE LIMITED THROUGH THAT TIME...BUT GIVEN THE DEEP LOW
LEVEL MOISTURE A FEW SHOWERS ARE EXPECTED. HIGH TEMPS WILL MAINLY BE
IN THE 50S.  PORTIONS OF THE EASTERN MA COAST MAY STRUGGLE TO GET
PASSED THE 50 DEGREE MARK.

THINGS BECOME MORE INTERESTING LATE WEDNESDAY AFTERNOON AND EVENING.
CLOSED UPPER LEVEL LOW PRESSURE DIGGING ACROSS THE OHIO VALLEY WILL
BACK THE MID LEVEL FLOW AND INCREASE THE FORCING FOR ASCENT.  STEADY
RAIN SHOULD OVERSPREAD MOST OF THE REGION LATE WEDNESDAY
AFTERNOON/EARLY EVENING.  APPEARS MOST OF THE GUIDANCE INDICATES
BETTER MID LEVEL FORCING/LIFT ACROSS EASTERN MA/RI...SO EXPECT THE
HIGHER RAINFALL TOTALS IN THESE LOCATIONS.  THERE IS SOME MARGINAL
ELEVATED INSTABILITY...SO A LOW RISK FOR A FEW EMBEDDED
THUNDERSTORMS EXISTS ACROSS THE SOUTHEAST NEW ENGLAND COAST
WEDNESDAY EVENING.

THE BULK OF THE HEAVIER RAIN SHOULD BE OVER BY MIDNIGHT...BUT MOIST
NORTH NORTHEAST LOW LEVEL FLOW WILL RESULT IN SOME SCATTERED SHOWERS
AND AREAS OF DRIZZLE PERSISTING...ESPECIALLY NEAR THE COAST. LOW
TEMPS WILL BE IN THE 40S.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
BIG PICTURE... LONGWAVE SCALE HAS A TROUGH OVER THE EASTERN USA
WITH AXIS CENTERED OVER THE GREAT LAKES. LONGWAVE RIDGE OVER THE
WEST COAST. CLOSED UPPER LOW WITHIN THE LONGWAVE TROUGH LINGERS
OVER THE EAST COAST THURSDAY THROUGH SATURDAY. NORTHERN STREAM
SHORTWAVE THEN DIVES SOUTHEAST INTO THE NORTHEAST USA
SUNDAY...KICKING THE OFFSHORE LOW OUT TO SEA. THE SHORTWAVE FORMS
A NEW CUTOFF LOW THAT MIGRATES FROM NORTHERN NEW ENGLAND TO
NEWFOUNDLAND EARLY NEXT WEEK.

THE DAILIES...

THURSDAY-FRIDAY...

CLOSED UPPER LOW AND ASSOCIATED COLD POOL OVER THE APPALACHIANS
SHIFT EAST. UPPER FLOW OVER NEW ENGLAND IS SOUTHERLY AND DIFLUENT.
GFS INDICATES ONE DEPARTING JET STREAK IN THIS FLOW AT 12Z
THURSDAY...A SECOND STREAK APPROACHING FROM THE SOUTH MIDDAY.
ADDITIONAL STREAKS MOVE PAST US DURING FRIDAY AS WELL. MEANWHILE
COLD ADVECTION FROM THE ADVANCING COLD POOL WILL FURTHER DESTABILIZE
THE AIRMASS. THIS WILL MAINTAIN A CHANCE OF SHOWERS BOTH DAYS...WITH
FOG AND DRIZZLE IN BETWEEN ANY SHOWERS.  EAST-NORTHEAST LOW LEVEL
FLOW OFF THE GULF OF MAINE/MASS BAY WILL MAINTAIN COOL MOIST AIR
NEAR THE SURFACE WITH DAY TEMPS IN THE UPPER 40S AND 50S WHILE DEW
POINTS IN THE 40S WILL ALLOW MIN TEMPS IN THE 40S. WE WILL TREND A
COUPLE OF DEGREES COOLER THAN GUIDENCE ON FRIDAY MAX TEMPS.

SATURDAY-SUNDAY...

UPPER TROUGH AND COLD POOL STILL OVERHEAD BUT JET SUPPORT MOVES OFF
FARTHER EAST.  PROBABILITY OF SHOWERS WILL BE LESS...BUT STILL A LOT
OF LOW LEVEL MOISTURE SO LINGERING SCATTERED TO WIDELY SCATTERED
SHOWERS. WITH THE EAST-NORTHEAST FLOW DIMINISHING...DAYTIME TEMPS
SHOULD REACH A LITTLE MILDER. MIXING DEPTHS SUPPORT MAX SFC TEMPS
MID 60S EACH DAY.

NORTHERN STREAM SHORTWAVE PUSHES SOUTHEAST FROM ONTARIO SUNDAY. THIS
WILL BRING A BETTER CHANCE OF SHOWERS AS A COLD FRONT SWINGS THROUGH
NEW ENGLAND. SOME SIGNS OF NORTHWEST GUSTS TO 30 KNOTS IN COLD
ADVECTION BEHIND THE COLD FRONT.

MONDAY-TUESDAY...

HIGH PRESSURE BUILDS OVER THE REGION. LINGERING COLD POOL MOISTURE
ALOFT MAY BRING DIURNAL CLOUDS MONDAY...OTHERWISE A FAIR PERIOD.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...

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

945 PM UPDATE ... NOT MUCH CHANGE FROM 00Z TAFS. DRYING TREND
OVERNIGHT STILL EXPECTED.

SHORT TERM /THROUGH WEDNESDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE.  MVFR CONDITIONS WILL PROBABLY
DOMINATE WITH LOW CLOUDS TRAPPED BENEATH THE SUBSIDENCE INVERSION.
HOWEVER...SOME LOCATIONS NORTH OF THE PIKE AND ESPECIALLY NORTHEAST
MA WILL IMPROVE TO VFR FOR A TIME AS DRIER AIR TEMPORARILY TRIES
TO WORK INTO THIS REGION. MEANWHILE...MAINLY IFR CONDITIONS
PROBABLY PERSIST ACROSS THE CAPE AND ISLANDS.

WEDNESDAY...MODERATE CONFIDENCE.  MVFR CONDITIONS AGAIN EXPECTED TO
BE THE RULE FOR MUCH OF THE DAY...BUT SOME MARGINAL VFR CONDITIONS
MAY OCCUR.  MEANWHILE...IFR CONDITIONS MAY PERSIST ACROSS THE
CAPE/ISLANDS GIVEN NORTHEAST FLOW.  A FEW SHOWERS POSSIBLE THROUGH
MID AFTERNOON...BUT A BAND OF STEADY RAIN WILL LIKELY MOVE INTO THE
REGION FROM SOUTHWEST TO NORTHEAST LATE IN THE AFTERNOON/EVENING.
LOW RISK OF AN EMBEDDED THUNDERSTORM OR TWO ACROSS SOUTHEAST NEW
ENGLAND WEDNESDAY EVENING.

WEDNESDAY NIGHT...MODERATE CONFIDENCE.  LOW END MVFR TO IFR
CONDITIONS EXPECTED. STEADY RAIN FOR MUCH OF THE REGION DURING THE
EVENING DIMINISHES TO SCATTERED SHOWERS AND AREAS OF DRIZZLE AFTER
MIDNIGHT.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.  MVFR CONDITIONS MAY
IMPROVE TO VFR FOR A TIME TONIGHT.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK /THURSDAY THROUGH SUNDAY/...MODERATE CONFIDENCE

THURSDAY-FRIDAY...MIXED IFR/MVFR IN SHOWERS AND FOG. LOW LEVEL EAST-
NORTHEAST FLOW UP THROUGH 3000 FEET WITH GUSTS TO 25 KNOTS ALONG THE
EAST MASS SHORE.

SATURDAY-SUNDAY... MIXED MVFR/IFR SATURDAY. WINDS BECOMING SOUTH
WITH IMPROVEMENT TO VFR BY SUNDAY...THEN SCATTERED MVFR/IFR IN
SHOWERS AS A COLD FRONT MOVES THROUGH. WINDS TURN FROM THE NORTHWEST
SUNDAY AFTERNOON WITH GUSTS 20 TO 25 KNOTS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

945 PM UPDATE ... NOT MUCH CHANGE FROM PREVIOUS FORECAST. A DRYING
TREND STILL EXPECTED OVERNIGHT WITH RAIN BECOMING LESS NUMEROUS.

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

TONIGHT AND WEDNESDAY...PERSISTENT NORTHEAST FLOW WILL BUILD SEAS TO
BETWEEN 3 AND 5 FEET ACROSS OUR SOUTHERN OUTER-WATERS.  SO WHILE
WIND SPEEDS WILL GENERALLY NOT EXCEED 20 KNOTS THROUGH MIDDAY
WEDNESDAY...WILL STILL NEED SMALL CRAFT HEADLINES FOR SOME 5 FOOT
SEAS.  PATCHY FOG POSSIBLE AT TIMES AS WELL.

WEDNESDAY NIGHT...PRESSURE GRADIENT INCREASES AS WAVE OF LOW
PRESSURE APPROACHES FROM THE SOUTH AND COMBINES WITH HIGH PRESSURE
OVER THE CANADIAN MARITIMES.  NORTHEAST WIND GUSTS TO 25 KNOTS MAY
DEVELOP ACROSS A GOOD CHUNK OF OUR WATERS ALONG WITH SEAS BUILDING
TO BETWEEN 4 AND 7 FEET.  ADDITIONAL SCA HEADLINES WILL LIKELY BE
NEEDED...BUT SINCE ITS 3RD PERIOD WILL WAIT UNTIL THE NEXT SHIFT
GETS A LOOK AT IT.

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

NORTHEAST WIND GUSTING 20 TO 25 KNOTS THURSDAY...BEST CHANCE ALONG
THE WATERS EAST OF MASS. WINDS TURN FROM SOUTH SATURDAY AND SUNDAY
MORNING...THEN FROM NORTHWEST SUNDAY AFTERNOON AFTER A COLD FRONT
MOVES THROUGH. NORTHWEST GUSTS BEHIND THE COLD FRONT MAY REACH 25
KNOTS.  SEAS 5 TO 7 FEET MUCH OF THE PERIOD. SMALL CRAFT ADVISORY
MAY BE NEEDED.

&&

.TIDES/COASTAL FLOODING...
HIGH ASTRONOMICAL TIDES ARE EXPECTED...WITH PRIME CONCERN ON THE
HIGHER OF THE TWO HIGH TIDE CYCLES THURSDAY NIGHT AND FRIDAY
NIGHT.

ASTRO HEIGHTS ARE PROJECTED JUST BELOW 12 FEET AT BOSTON BOTH
NIGHTS. ASTRO HEIGHTS NEAR PROVIDENCE ARE PROJECTED AT 6 FEET
THURSDAY NIGHT AND 6.5 FEET FRIDAY NIGHT. IT WON/T TAKE MUCH OF A
SURGE ON TOP OF THOSE ASTRO HEIGHTS TO CAUSE SOME SPLASHOVER OR EVEN
POSSIBLY SOME MINOR COASTAL FLOODING. PERSISTANT NORTHEAST WINDS
AGAINST THE EAST MASSACHUSETTS COAST WILL ADD TO POTENTIAL FOR
SURGE ALONG THAT COASTLINE. THIS WILL NEED TO BE MONITORED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THURSDAY FOR ANZ254>256.

&&

$$
SYNOPSIS...WTB/FRANK
NEAR TERM...FRANK/NOCERA
SHORT TERM...FRANK
LONG TERM...WTB
AVIATION...WTB/FRANK/NOCERA
MARINE...WTB/FRANK/NOCERA
TIDES/COASTAL FLOODING...STAFF



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