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Area Forecast Discussion
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000
FXUS61 KBOX 312020
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
420 PM EDT FRI OCT 31 2014

.SYNOPSIS...
AN INTENSIFYING COASTAL STORM WILL MOVE UP THE COAST SATURDAY AND 
PASS OFFSHORE SATURDAY NIGHT AND EARLY SUNDAY POTENTIALLY BRINGING 
DAMAGING WINDS AND RAIN TO THE REGION.  HIGH PRESSURE BUILDS OVER
THE EASTERN USA EARLY NEXT WEEK. ONE OR TWO COLD FRONTS MAY CROSS
SOUTHERN NEW ENGLAND WEDNESDAY THROUGH FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
STRONG HIGH PRESSURE IN THE GREAT LAKES WILL COMBINE WITH LOW 
PRESSURE MOVING NORTHEAST TOWARDS SOUTHERN NEW ENGLAND TO RESULT IN 
WINDS BEGINNING TO INCREASE OVERNIGHT.  NORTHEASTERLY WINDS WILL 
PICK UP TO AROUND 15 MPH BY EARLY SATURDAY MORNING.  IN ADDITION... 
OVERCAST SKIES WILL COMBINE WITH THE WINDS TO PREVENT RADIATIONAL 
COOLING.  THIS WILL RESULT IN LOW TEMPERATURES GENERALLY IN THE 
UPPER 30S TO MID 40S.  

WHILE WE EXPECT THE LOW PRESSURE AND THE ATTENDANT RAIN SHIELD TO 
REMAIN SOUTH OF SOUTHERN NEW ENGLAND...COULD SEE A FEW SPOTTY 
SHOWERS OFF AND ON THROUGH THE NIGHT PARTICULARLY SOUTH OF THE MASS 
PIKE.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
***STRONG TO DAMAGING WINDS ARE LIKELY WITH AN INTENSIFYING COASTAL 
  STORM SATURDAY NIGHT AND SUNDAY***

31/12Z MODELS ARE IN FAIRLY GOOD AGREEMENT ON AN INTENSIFYING LOW 
PRESSURE SYSTEM MOVING UP THE COAST FROM NORTH CAROLINA AND PASSING 
JUST OUTSIDE THE 40/70 BENCHMARK SATURDAY NIGHT.  THIS IS ASSOCIATED 
WITH A DIGGING TROUGH MOVING EASTWARD FROM THE GREAT LAKES AND A 
COUPLE OF SHORTWAVES ROTATING AROUND THE EAST SIDE OF THE TROUGH.  
THIS COMBINED WITH A STRONG HIGH PRESSURE SYSTEM THAT WILL MOVE FROM 
THE NORTHERN PLAINS INTO THE GREAT LAKES REGION WILL RESULT IN A 
TIGHT PRESSURE GRADIENT ACROSS SOUTHERN NEW ENGLAND.

WIND: THIS IS A FAIRLY HIGH CONFIDENCE FORECAST FOR WIND. THE TIGHT 
PRESSURE GRADIENT...ALONG WITH A NORTHEASTERLY 50 KT LOW LEVEL JET 
BRINGING MUCH COLDER AIR OVER THE RELATIVELY WARM OCEAN WATERS WILL 
RESULT IN STRONG TO DAMAGING WIND GUSTS ACROSS MUCH OF SOUTHERN NEW 
ENGLAND SATURDAY NIGHT INTO SUNDAY.  THE COLDER AIR WILL ALLOW LAPSE 
RATES TO STEEPEN AND WINDS TO EASILY MIX DOWN TO THE SURFACE.  

THE MOST LIKELY LOCATION FOR WIND GUSTS TO REACH 58 MPH OR GREATER 
IS ACROSS COASTAL PLYMOUTH COUNTY...THE CAPE...AND ISLANDS WHERE WE 
HAVE ISSUED A HIGH WIND WARNING.  EXPECT THAT MUCH OF EASTERN 
MASSACHUSETTS AND RHODE ISLAND WILL LIKELY HAVE WINDS GUSTING TO AT 
LEAST 50 MPH AND THAT WITH PARTIALLY TO FULLY LEAVED TREES... DAMAGE 
MAY BE DONE TO TREES AND POWER LINES.  HAVE KEPT THE HIGH WIND WATCH 
UP FOR THESE AREAS AND ALLOW THE NEXT SHIFT TO EVALUATE ANOTHER 
ROUND OF MODEL DATA BEFORE DECIDING HOW TO UPGRADE.  THE WIND IN 
THESE AREAS IS EXPECTED TO PICK UP SATURDAY EVENING AND CONTINUE 
THROUGH MUCH OF SUNDAY.

ACROSS THE REMAINDER OF SOUTHERN NEW ENGLAND /CONNECTICUT...SOUTHERN 
NEW HAMPSHIRE...AND WESTERN AND CENTRAL MASSACHUSETTS/ EXPECT WIND 
GUSTS TO REACH UP TO 45 MPH.  HOWEVER...RATHER THAN BEING ASSOCIATED 
WITH THE LOW LEVEL JET...THESE WINDS WILL BE MORE A RESULT OF STRONG 
COLD ADVECTION INTO THE REGION ON SUNDAY.  WIND ADVISORIES WILL 
LIKELY BE NEEDED FOR THESE AREAS BUT GIVEN THAT WINDS ARENT EXPECTED 
TO INCREASE UNTIL SUNDAY...FELT WE COULD WAIT FOR ANOTHER MODEL RUN.

COASTAL FLOODING: PLEASE SEE TIDES/COASTAL FLOODING SECTION BELOW 
FOR MORE INFORMATION.

RAIN: MODERATE CONFIDENCE.  EXPECTING RAINFALL AMOUNTS OF GENERALLY 
AN INCH OR LESS WEST OF INTERSTATE 95.  AMOUNTS MAY BE A BIT HIGHER 
EAST OF 95 BUT SHOULD STILL REMAIN UNDER 2 INCHES.  THERE IS A 
POSSIBILITY THAT DRIER AIR MAY WORK ITS WAY IN AT THE MID LEVELS AND 
CUT OFF PRECIPITATION FOR A PERIOD AND THAT WOULD UNDERCUT RAIN 
TOTALS A BIT.

SNOW: LOW CONFIDENCE.  WHILE NOT A HIGH PROBABILITY...THERE IS A 
POSSIBILITY THAT OUR RAIN WILL END AS A BRIEF PERIOD OF SNOW SUNDAY 
MORNING IN SOME AREAS.  THE MOST LIKELY LOCATION FOR THIS IS 
ACTUALLY ALONG THE INTERSTATE 95 CORRIDOR WHERE THE COLD CONVEYOR 
BELT WRAPS AROUND THE LOW PRESSURE SUNDAY MORNING. THIS MAY PROVIDE 
ENOUGH DYNAMIC COOLING TO RESULT IN SOME WET SNOWFLAKES FALLING.  IF 
IT WERE ABLE TO ACCUMULATE AT ALL...IT WOULD BE A COATING TO LESS 
THAN AN INCH.  THERE IS ALSO A POSSIBILITY THAT SOME SNOW MAY FALL 
IN THE HIGHER TERRAIN OF THE MONADNOCKS AND WORCESTER HILLS.  THIS 
IS ALSO A LOW PROBABILITY BUT IF IT OCCURS COULD RESULT IN ONE TO 
MAYBE TWO INCHES OF ACCUMULATION.  AGAIN THIS WOULD ONLY BE AT THE 
HIGHER ELEVATIONS.

&&

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

THE LONG TERM PERIOD STARTS WITH A CLOSED LOW OVER THE NORTHEAST USA 
A TROUGH OVER THE ROCKIES...AND A RIDGE IN BETWEEN.  THE CLOSED LOW 
LIFTS NORTHEAST INTO THE MARITIMES EARLY IN THE WEEK. THE RIDGE AND 
TROUGH TO OUR WEST MOVE EAST...BUT THE OVERALL FLOW BECOMES MORE 
ZONAL WITH TIME WITH A DETACHED SOUTHERN STREAM WAVE NEAR THE 
MEXICAN BORDER.  HEIGHTS START THE PERIOD BELOW NORMAL DUE TO THE 
CLOSED LOW...THEN CLIMB TO NORMAL OR A LITTLE ABOVE NORMAL IN THE 
ZONAL FLOW. DEPENDING ON TIMING...COULD BE COOLING BACK TO BELOW 
NORMAL LATE IN WEEK.

THIS SUGGESTS A COLD START TO THE WEEK BUT QUICKLY TRENDING BACK TO 
NORMAL MID WEEK...THEN COOLING AT END OF WEEK. ONCE THE UPPER FLOW 
BECOMES ZONAL...CONFIDENCE IN THE TIMING OF INDIVIDUAL WAVES IN THE 
FLOW AND THEIR ASSOCIATED SURFACE SYSTEMS WILL BE REDUCED.

THE DAILIES... 

SUNDAY NIGHT-MONDAY-TUESDAY... THE AXIS OF THE UPPER LOW AND COLD 
POOL START SUNDAY NIGHT OVERHEAD AND MOVE OFF THROUGH THE MARITIMES 
BY MONDAY. DRIER AIR MOVES IN AT ALL LEVELS SUNDAY NIGHT AND REMAINS 
OVERHEAD MONDAY.  FAIR MIXING SHOULD REACH TO AROUND 900 MB. TEMPS 
OF ZERO TO -1C AT THAT LEVEL TRANSLATE TO MAX SFC TEMPS IN THE
UPPER 40S AND AROUND 50. THE HIGH MOVES OFF TO THE EAST TUESDAY
WITH MILDER AIR MOVING IN ESPECIALLY ALOFT. CROSS SECTIONS SHOW
INCREASING MOISTURE AT MID AND HIGH LEVELS...SO EXPECT SOME MID
AND HIGH CLOUDS TOGETHER WITH THE SUN. TEMPS WARM UP A LITTLE BUT
MIXING WILL BE SHALLOWER...950 MB TEMPS SUPPORT MAX TEMPS MID 50S.

WEDNESDAY THROUGH FRIDAY... TWO SHORTWAVES MOVE ACROSS THE NORTHEAST 
AND EASTERN CANADA DURING MID TO LATE WEEK. THE FIRST WAVE LIFTS 
THROUGH QUEBEC WITH LIMITED CURVATURE IN NEW ENGLAND. THE SECOND 
WAVE DIGS DEEPER OVER THE GREAT LAKES AND SWEEPS ACROSS NEW ENGLAND 
24-36 HOURS LATER THAN THE FIRST. AS THE UPPER FLOW IS ROUGHLY 
ZONAL...EXACT TIMING OF THE TWO PASSAGES IS LOW CONFIDENCE AT THIS 
TIME.

WITH THE FIRST WAVE DIRECTED THROUGH CANADA AND THE UPPER FLOW 
REMAINING SOUTHWEST...THERE IS A GOOD CHANCE THE SURFACE FRONT 
STALLS OVER OR NEAR SOUTHERN NEW ENGLAND. THE SECOND DEEPER WAVE 
TURNS THE UPPER FLOW NORTHWEST AND SHOULD PUSH A COLD FRONT WELL 
OFFSHORE WITH COLDER AIR THEN FLOWING IN. WE WILL GO WITH CHANCE 
POPS NORTH OF THE PIKE LATE WEDNESDAY/NIGHT WITH THE FIRST WAVE AND 
FRONT...THEN MORE WIDESPREAD CHANCE POPS THURSDAY WITH THE SECOND 
WAVE AND FRONT. TIMING ON THIS WILL LIKELY CHANGE SOMEWHAT WITH 
SUCCESSIVE MODEL RUNS.

&&

.AVIATION /20Z 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/...

THROUGH 00Z...HIGH CONFIDENCE. VFR. THERE ARE A FEW LOCATIONS ON
THE CAPE AND ISLANDS THAT ARE HAVING PATCHY MVFR CIGS.

TONIGHT...MODERATE CONFIDENCE. CONDITIONS DETERIORATE THROUGH THE
NIGHT TO MVFR-IFR FROM SOUTH TO NORTH WITH LOWEST CONDITIONS ALONG
THE COAST. EXPECT SCATTERED SHOWERS SOUTH OF THE MASS PIKE WITH
THE GREATEST CHANCE OF STEADIER RAINFALL ALONG THE SOUTH COAST.

SATURDAY THROUGH SUNDAY...MODERATE TO HIGH CONFIDENCE. MVFR/IFR
CONDITIONS CONTINUE THROUGH 12Z SUNDAY WHEN CEILINGS START TO RISE
FROM WEST TO EAST AS LOW PRESSURE PULLS AWAY FROM SOUTHERN NEW
ENGLAND. NORTHEASTERLY WINDS INCREASE THROUGH THE PERIOD...PEAKING
IN THE 40 TO 50 KT RANGE SATURDAY NIGHT INTO SUNDAY MORNING FOR
THE EASTERN TERMINALS. WINDSPEEDS WILL BE LOWER ACROSS THE WESTERN
TERMINALS BUT STILL GUSTING UP TO 35 TO 45 KTS PEAKING MORE ON
SUNDAY. WIDESPREAD RAIN EXPECTED THROUGH SUNDAY MORNING MOST
LOCATIONS AND CONTINUING ON THE EAST COAST...CAPE...AND ISLANDS
INTO SUNDAY AFTERNOON.

KBOS...HIGH CONFIDENCE IN TAF TRENDS. LOWER CONFIDENCE ON EXACT
TIMING OF ONSET OF RAIN AND HIGHER WINDS.

KBDL...HIGH CONFIDENCE IN TAF TRENDS. LOWER CONFIDENCE ON EXACT
TIMING OF ONSET OF RAIN AND HIGHER WINDS.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...MODERATE CONFIDENCE

SUNDAY NIGHT THROUGH TUESDAY...VFR. NORTHWEST WINDS MONDAY WILL GUST 
25 TO 30 KNOTS DURING THE DAY.

WEDNESDAY...VFR. POSSIBLE BRIEF MVFR CIGS/VSBYS IN SHOWERS LATE
IN THE DAY AND AT NIGHT.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

***DANGEROUS COASTAL STORM FOR MARINERS EXPECTED THIS WEEKEND***

HIGH CONFIDENCE THROUGH SUNDAY.  NORTHEASTERLY WINDS BEGIN
INCREASING THIS EVENING REACHING 25 KTS OVERNIGHT AND STEADILY
INCREASING THROUGH SATURDAY AND SATURDAY NIGHT AS AN INTENSIFYING
LOW PRESSURE PASSES SOUTHEAST OF NANTUCKET. WINDS ARE EXPECTED TO
INCREASE TO STORM FORCE...PARTICULARLY ON THE WATERS EAST OF
MASSACHUSETTS. HAVE UPGRADED THE STORM WATCH TO A STORM WARNING ON
THOSE WATERS. LESS CONFIDENT ON THE POTENTIAL FOR STORM FORCE
WINDS SOUTH OF NEW ENGLAND. THEREFORE HAVE KEPT THE STORM WATCH
WITH THE PEAK OF THE WINDS EXPECTED SATURDAY NIGHT INTO SUNDAY.
THIS WILL LIKELY NEED TO BE UPGRADED TO EITHER A STORM WARNING OR
POSSIBLY HIGH END GALES DEPENDING ON THE TRACK OF THE LOW.

WITH NORTHEASTERLY WINDS GUSTING TO 50 KTS...SEAS WILL INCREASE 
SUBSTANTIALLY REACHING 15 TO 20 FEET EASILY ON THE EASTERN COASTAL 
WATERS.  THERE IS A POSSIBILITY THAT THEY INCREASE TO AS MUCH AS 25 
FEET EAST OF CAPE COD.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...MODERATE CONFIDENCE.

SUNDAY NIGHT AND MONDAY...GUSTY NORTHWEST WINDS AT GALE FORCE EARLY 
SUNDAY NIGHT. WINDS THEN DIMINISH BUT REMAIN 25 TO 30 KNOTS THROUGH 
MONDAY. SEAS DIMINISH SUNDAY NIGHT BUT LINGER 5 TO 10 FEET
THROUGH MONDAY.

TUESDAY...WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT LEVELS.

WEDNESDAY...SEAS WILL REMAIN BELOW 5 FEET. SOUTHWEST WINDS WILL 
INCREASE WITH FREQUENT GUSTS 20 TO 25 KNOTS.

&&

.TIDES/COASTAL FLOODING...
A COASTAL FLOOD WATCH CONTINUES FOR THE SATURDAY EVENING AND EARLY 
SUNDAY MORNING HIGH TIDE CYCLES FOR THE EASTERN MA COAST...INCLUDING 
THE NORTH FACING PORTION OF CAPE COD AND NANTUCKET. THIS IS FOR THE 
POTENTIAL OF MINOR TO ISOLATED POCKETS OF MODERATE COASTAL FLOODING 
POSSIBLE ALONG WITH BEACH EROSION.

ASTRONOMICAL HIGH TIDES ARE RATHER LOW SATURDAY EVENING AND AGAIN 
EARLY SUNDAY MORNING. HOWEVER...STRONG NORTH TO NORTHEAST WIND GUSTS 
UP TO 50 KNOTS MAY RESULT IN SEAS BUILDING TO AROUND 20 FEET OVER 
THE OPEN WATERS.  STILL SOME UNCERTAINTY AS TO HOW STRONG THE WINDS 
WILL GET...BUT THE POTENTIAL IS THERE FOR A 2 TO 2.5 STORM SURGE 
ALONG WITH SIGNIFICANT WAVE ACTION.  BASED ON THE LATEST DATA...WE 
ARE MOST CONCERNED ABOUT THE SATURDAY EVENING HIGH TIDE CYCLE.  THE 
WINDS APPEAR STRONGEST AT THAT TIME WITH A LITTLE MORE OF AN 
EASTERLY COMPONENT TO THE WIND.

THE HIGHEST RISK AREAS APPEAR TO BE HULL AND SCITUATE.  WE ALSO HAVE 
TO BE CONCERNED WITH THE TYPICAL HOT SPOTS...SUCH AS SALISBURY AND 
PLUM ISLAND WHICH ARE VERY SUSCEPTIBLE TO BEACH EROSION.  FINALLY... 
WILL ALSO HAVE TO KEEP AN EYE ON NANTUCKET HARBOR...AS STRONG 
NORTHERLY WINDS CAN CAUSE ISSUES FOR THEM.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY MORNING 
     FOR MAZ005>007-013>018-020.
     HIGH WIND WARNING FROM 5 PM EDT SATURDAY TO 4 PM EST SUNDAY 
     FOR MAZ019-021>024.
     COASTAL FLOOD WATCH FROM SATURDAY EVENING THROUGH SUNDAY 
     MORNING FOR MAZ007-015-016-019-022-024.
NH...NONE.
RI...HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY MORNING 
     FOR RIZ001>008.
MARINE...STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY AFTERNOON FOR 
     ANZ232>237-255-256.
     STORM WARNING FROM 6 PM EDT SATURDAY TO 5 PM EST SUNDAY FOR 
     ANZ230-231-250-251-254.

&&

$$
SYNOPSIS...WTB/RLG
NEAR TERM...RLG
SHORT TERM...RLG
LONG TERM...WTB
AVIATION...WTB/RLG
MARINE...WTB/RLG
TIDES/COASTAL FLOODING...



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