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Area Forecast Discussion
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000
FXUS61 KBOX 230203
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1003 PM EDT WED OCT 22 2014

.SYNOPSIS...
A POWERFUL EARLY SEASON COASTAL STORM WILL BRING STRONG TO DAMAGING
WINDS IN HEAVY RAIN SQUALLS AND ISOLATED THUNDERSTORMS OVERNIGHT
INTO THURSDAY MORNING.  SHOWERS WILL LINGER FRIDAY AS THE STORM
SLOWLY PULLS AWAY FROM NEW ENGLAND. SHOWERS POSSIBLE AGAIN
SATURDAY AS LOW PRES MOVES INTO SOUTHERN QUEBEC. DRY...SEASONABLE
WEATHER RETURNS EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...

*** A POWERFUL EARLY SEASON COASTAL STORM WILL BRING STRONG TO
 DAMAGING WINDS OVERNIGHT INTO EARLY THU MORNING ***

10 PM UPDATE...

VERY IMPRESSIVE/VIGOROUS SHORT WAVE-JET STREAK ROTATING AROUND A
MID LEVEL LOW SOUTH OF LONG ISLAND AND ADVECTING INTO SOUTHEAST MA
AND RI. ON THE NOSE OF SHORT WAVE AND DRY SLOT MID LEVEL LAPSE
RATES ARE ON THE ORDER OF 7C/KM PER SPC MESOANALYSIS AND THIS HAS
BEEN SUFFICIENT COMBINED WITH STRONG FORCING FOR ASCENT /LFQ OF
UPPER LEVEL JET STREAK/ TO YIELD NUMEROUS CONVECTION OVER EASTERN
CT/RI AND SOUTHEAST MA THIS EVENING. MUCH OF THE MODEL GUIDANCE
HAS ADDITIONAL CONVECTION FIRING SOUTH OF NEW ENGLAND OVERNIGHT
AND ADVECTING NW INTO EASTERN MA AND EVENTUALLY SOUTHERN NH TOWARD
MORNING.

STRONG WIND GUSTS HAVE BEEN OBSERVED IN THIS CONVECTION GIVEN THE
STRONG LOW LEVEL NORTHEAST JET ACROSS THE EASTERN HALF OF THE
REGION. THEREFORE HAVE EXPANDED THE WIND ADVISORY TO INCLUDE ALL
OF RI/EASTERN CT NORTHWARD INTO THE WORCESTER HILLS AND MUCH OF
SOUTHEAST MA. FARTHER WEST INTO CT RVR VLY OF CT AND MA WIND GUSTS
SHOULD BE NOT AS STRONG GIVEN CORE OF LOW LEVEL JET WILL REMAIN
FARTHER EAST OVER RI...EASTERN MA INTO SOUTHEAST NH. AS MENTIONED
ABOVE NEW CONVECTION SOUTH OF NEW ENGLAND SHOULD PIVOT NW INTO
EASTERN MA OVERNIGHT /POSSIBLY RI TOO/ AND THEN INTO SOUTHEAST NH
TOWARD MORNING. THUS HEAVIEST RAIN AND STRONGEST WINDS OVERNIGHT
WILL BE FOCUSED ACROSS THIS REGION. EARLIER DISCUSSION BELOW.

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

POTENT CLOSED UPPER LEVEL LOW WILL CONTINUE TO AMPLIFY TONIGHT.
THIS WILL ALLOW SURFACE LOW PRESSURE TO INTENSIFY AS IT SLOWLY
LIFTS TO THE NORTHEAST PASSING NEAR THE BENCHMARK ON THURSDAY.
GIVEN THAT THIS SYSTEM HAS CLOSED MID LEVEL CIRCULATIONS...WERE
EXPECTING A BREAK DOWN IN PRECIPITATION FIELDS THAT WE OFTEN SEE
DURING WINTER STORMS.

1) HEAVY RAIN POTENTIAL:

IN A NUTSHELL...PERIODS OF HEAVY RAIN ARE EXPECTED TONIGHT ACROSS 
THE ENTIRE REGION.  THE BIGGEST UNCERTAINTY IS TRYING TO LOCATE 
WHERE THE HEAVIEST RAIN BANDS WILL SET UP.  THERE ARE A LOT OF 
MOVING PARTS TO THIS FORECAST...WHICH MAKES THIS A DIFFICULT TASK.  

WE EXPECT HEAVY RAIN TO INITIALLY OVERSPREAD SOUTHEAST NEW ENGLAND 
AND WORK NORTHWARD ACROSS THE REST OF THE REGION THIS EVENING.  
THE MID LEVEL DRY SLOT WILL THEN APPROACH SOUTHEAST NEW ENGLAND BY 
LATE EVENING.  THIS MAY RESULT IN THE PRECIPITATION FIELD MORE 
SCATTERED AT TIMES ACROSS SOUTHEAST SECTIONS OVERNIGHT...BUT ALSO 
MORE CONVECTIVE GIVEN SOME ELEVATED CAPE. SO WHILE WE MAY SEE SOME 
BREAKS IN THE PRECIPITATION SHIELD ACROSS SOUTHEAST 
SECTIONS...ISOLATED THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL WILL 
ALSO BE POSSIBLE.  IN ADDITION...WE PROBABLY WILL SEE A SUBTLE 
COASTAL FRONT SET UP ACROSS SOUTHEAST MA LATE TONIGHT INTO THURSDAY 
MORNING SO SOME ENHANCEMENT IS POSSIBLE.  

WILL ALSO HAVE TO WATCH FOR A SECOND AREA OF HEAVIER PRECIPITATION 
IN ASSOCIATION WITH THE MID LEVEL DEFORMATION ZONE/BACK BENT WARM 
FRONT.  LOCATION OF THIS IS TRICKY BUT PERHAPS FURTHER BACK INTO 
THE INTERIOR ACROSS  SOUTHERN NH AND EAST SLOPES OF BERKSHIRES?  

FINALLY IN BETWEEN THE TWO BANDS OF HEAVIEST RAIN THERE WILL LIKELY 
BE A MINIMUM.  SO BASICALLY...A WIDESPREAD 1 TO 2.50 INCHES OF RAIN 
IS EXPECTED FOR MUCH OF THE REGION...BUT LOCALIZED 4+ INCH AMOUNTS 
ARE CERTAINLY POSSIBLE ACROSS A PORTION OF THE REGION.  WILL JUST 
HAVE TO CONTINUE TO MONITOR RADAR/SATELLITE TRENDS OVERNIGHT AND 
FINE TUNE OUR QPF FORECAST.  THE FLOOD WATCH IS IN EFFECT ACROSS 
EASTERN NEW ENGLAND FOR THE POTENTIAL FOR LOCALIZED FLOODING IF THE 
HIGHER AMOUNTS ARE REALIZED.

2) TIMING:

HEAVY RAIN OVER SPREADS THE REGION FROM SOUTHEAST TO NORTHWEST THIS 
EVENING.  PERIODS OF HEAVY RAIN WILL OCCUR TONIGHT INTO THURSDAY 
MORNING...WHICH WILL LIKELY IMPACT THE MORNING RUSH HOUR.  ISOLATED 
THUNDERSTORMS ARE POSSIBLE TONIGHT INTO THURSDAY MORNING ACROSS 
SOUTHEAST NEW ENGLAND NEAR THE DRY SLOT.  THE STEADIEST 
RAIN SHOULD BE OVER BY THURSDAY AFTERNOON...BUT SCATTERED SHOWERS 
WILL CONTINUE.

3) STRONG WIND POTENTIAL:

NORTHEAST LOW LEVEL JET OVER 50 KNOTS WILL IMPINGE ON EASTERN NEW 
ENGLAND THROUGH EARLY THURSDAY MORNING.  IN FACT...BUFKIT SOUNDINGS 
SHOWING SOME PRETTY IMPRESSIVE WIND FIELDS BELOW 1000 FEET.  THE 
UNCERTAINTY IS THAT AN INVERSION WILL ATTEMPT TO KEEP THE STRONGEST 
WINDS JUST OFF THE DECK.  HOWEVER...HEAVY RAIN BANDS MAY BE ABLE TO 
PULL BRIEF STRONG WIND GUSTS TO THE GROUND.  THE WIND ADVISORY 
CONTINUES FOR NORTHEAST MA INTO COASTAL PLYMOUTH COUNTY.  PROBLEMS 
MAY BE EXACERBATED GIVEN THE MANY FULLY LEAFED TREES...RESULTING IN 
SOME DOWNED TREE LIMBS AND EVEN ISOLATED POWER OUTAGES.  THERE 
IS THE CHANCE THAT THE WIND ADVISORY MAY NEED TO BE EXPANDED FURTHER 
NORTHWEST...BUT AGAIN ITS UNCERTAIN HOW MUCH WIND WILL MIX DOWN.  
THE WINDS SHOULD DIMINISH BY MID MORNING ON THURSDAY AS THE LOW 
LEVEL JET WEAKENS.


&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
* LINGERING SHOWERS POSSIBLE ON FRIDAY
* SHOWERS POSSIBLE AGAIN SATURDAY AS LOW PRES MOVES INTO QUEBEC
* MAINLY DRY AND SEASONABLE WEATHER EARLY NEXT WEEK

OVERALL THE 12Z MODEL SUITE IS IN FAIRLY GOOD AGREEMENT THROUGH THE 
LONG TERM. THERE ARE SOME DISCREPANCIES IN THE MESOSCALE DETAILS BUT 
OTHERWISE THEY ARE IN GOOD AGREEMENT.  AFTER THE COASTAL STORM 
CURRENTLY AFFECTING THE REGION MOVES AWAY FROM SOUTHERN NEW 
ENGLAND...THE WEATHER STARTS TO DRY OUT AND BECOME MORE SEASONABLE. 
THERE ARE A COUPLE OF COLD FRONTS EXPECTED TO MOVE THROUGH THE 
REGION AND EACH OF THESE MAY BRING SOME SHOWERS WITH THEM.

THURSDAY NIGHT AND FRIDAY...LOW PRESSURE SLOWLY MOVES INTO THE GULF 
OF MAINE AND THEN THE MARITIMES FRIDAY.  WHILE THE BULK OF THE RAIN 
WILL BE ENDING BY THURSDAY NIGHT...COULD SEE SOME LINGERING SHOWERS. 
HOWEVER...WINDS SHIFT TO THE NORTHWEST EARLY FRIDAY BRINGING 
SOMEWHAT DRIER AIR INTO THE REGION.  OVERALL EXPECT DRIER WEATHER 
AND A GRADUAL IMPROVEMENT AS WE MOVE INTO FRIDAY AFTERNOON.

SATURDAY...ANOTHER UPPER LEVEL TROUGH MOVES OVER THE NORTHEAST WITH 
LOW PRESSURE MOVING THROUGH SOUTHERN QUEBEC AND INTO THE MARITIMES.  
THE MODELS DON/T SHOW A WHOLE LOT OF MOISTURE OR A BIG WIND SHIFT 
WITH THIS FRONT BUT WE COULD SEE SOME SHOWERS. THE GFS HAS A 
STRONGER LOW LEVEL JET THAN THE ECMWF WHICH COULD ENHANCE THE AMOUNT 
OF RAINFALL BUT THERE IS STILL MUCH TO BE SEEN WITH THIS SYSTEM.

SUNDAY THROUGH TUESDAY...HIGH PRESSURE STARTS TO BUILD INTO SOUTHERN 
NEW ENGLAND BRINGING DRY AND SEASONABLE WEATHER.  TEMPERATURES BEGIN 
TO CLIMB AND MAY WARM TO WELL ABOVE NORMAL BY TUESDAY.

WEDNESDAY...LOW PRESSURE MOVING THROUGH THE GREAT LAKES AND INTO 
QUEBEC MAY BRING A COLD FRONT THROUGH SOUTHERN NEW ENGLAND.  ANOTHER 
CHANCE OF SOME SHOWERS POSSIBLE WITH THIS FRONT BUT PLENTY OF 
UNCERTAINTY.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH THU/...

TONIGHT...HIGH CONFIDENCE.  MAINLY IFR CONDITIONS IN PERIODS OF 
HEAVY RAIN.  ISOLATED THUNDER LIKELY ACROSS SOUTHEAST NEW ENGLAND.
NORTHEAST WIND GUSTS OF 30 TO 40 KNOTS EXPECTED ACROSS NORTHEAST 
MA...WITH 50 KT GUSTS ALONG THE IMMEDIATE COAST...INCLUDING AT
KBOS. LLWS WILL ALSO AFFECT SOME OF THE AREA FOR A TIME.

THURSDAY...MODERATE TO HIGH CONFIDENCE.  IFR CONDITIONS MAY IMPROVE 
TO LOW END MVFR THRESHOLDS IN THE INTERIOR...BUT NOT MUCH 
IMPROVEMENT IS EXPECTED ON THE COAST.  SCATTERED SHOWERS ARE 
EXPECTED AND THERE WILL REMAIN THE THREAT FOR ISOLATED THUNDERSTORMS 
ACROSS SOUTHEAST NEW ENGLAND...ESPECIALLY DURING THE FIRST PART OF 
THE DAY.

KBOS...MODERATE TO HIGH CONFIDENCE IN TAF.  NORTHEAST WIND GUSTS UP 
TO 50 KNOTS TONIGHT.

KBDL...MODERATE TO HIGH CONFIDENCE IN TAF. 

OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...

THURSDAY NIGHT AND FRIDAY...HIGH CONFIDENCE.  A FEW LINGERING 
SHOWERS MAY BRING MVFR/IFR CONDITIONS BUT OVERALL A SLOW IMPROVEMENT 
TO VFR EXPECTED.

SATURDAY THROUGH MONDAY...MODERATE CONFIDENCE. VFR.  LOW PROBABILITY 
OF SCATTERED SHOWERS SATURDAY.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH THURSDAY/...

***20 FOOT SEAS AND STORM FORCE NORTHEAST WIND GUSTS CONTINUE
 INTO THURSDAY ACROSS THE EASTERN MASSACHUSETTS WATERS***

LOW LEVEL JET WILL CONTINUE TO RESULT IN NORTHEAST WIND GUSTS OF
40 TO 50 KNOTS ACROSS THE NORTHERN MASSACHUSETTS WATERS INCLUDING
BOSTON HARBOR THROUGH THURSDAY MORNING BEFORE GRADUALLY
DIMINISHING. STRONG WINDS AND LONG NORTHEAST FETCH WILL RESULT IN
20 FOOT SEAS ACROSS PORTIONS OF OUR NORTHERN MASSACHUSETTS WATERS.
GALE FORCE NORTHEAST WIND GUSTS WILL CONTINUE ACROSS THE SOUTHERN
WATERS THROUGH THURSDAY MORNING.

OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...

THURSDAY NIGHT AND FRIDAY...HIGH CONFIDENCE.  8 TO 11 FOOT SEAS WILL 
SLOWLY DIMINISH AS LOW PRESSURE MOVES INTO THE MARITIMES.  NORTHEAST 
WINDS GUSTING TO NEAR 30 KTS WILL DIMINISH AND SHIFT TO THE 
NORTHWEST.  VISIBILITIES MAY BE REDUCED IN SCATTERED SHOWERS.

SATURDAY AND SUNDAY...MODERATE CONFIDENCE. AFTER A BRIEF LULL...SEAS 
AND WINDS WILL INCREASE AHEAD OF A COLD FRONT.  SMALL CRAFT 
ADVISORIES WILL LIKELY BE NEEDED FOR AT LEAST A PORTION OF THE 
WATERS.

MONDAY...MODERATE CONFIDENCE.  WINDS AND SEAS DIMINISH AS HIGH 
PRESSURE BUILDS OVER THE WATERS.

&&

.TIDES/COASTAL FLOODING...
DESPITE RATHER LOW ASTRONOMICAL HIGH TIDE CYCLES LATE TONIGHT AND
AGAIN MIDDAY THURSDAY...OPTED TO ISSUE A COASTAL FLOOD ADVISORY
FOR A PORTION OF THE EASTERN MA COAST. THIS IS MAINLY FOR THE AREA
NORTH OF CAPE ANN AND THE SCITUATE AREA. A LONG DURATION OF
NORTHEAST WINDS COMBINED WITH 15 TO 20 FOOT SEAS ACROSS OUR
NORTHERN MA WATERS MAY YIELD POCKETS OF SPLASH OVER AND POCKETS OF
MINOR COASTAL FLOODING. CERTAINLY NOT EXPECTING A SIGNIFICANT
COASTAL FLOOD EVENT...BUT FELT IT WAS WORTH AN ADVISORY. 

IN ADDITION...THERE IS POTENTIAL FOR SIGNIFICANT BEACH EROSION ALONG
THE EXPOSED BEACHES FROM SALISBURY TO PLUM ISLAND.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WIND ADVISORY UNTIL 8 AM EDT THURSDAY FOR CTZ004.
MA...HIGH WIND WARNING UNTIL 8 AM EDT THURSDAY FOR MAZ007-014>016-
     019.
     FLOOD WATCH THROUGH THURSDAY MORNING FOR MAZ005>007-013>022-
     026.
     COASTAL FLOOD ADVISORY UNTIL 2 PM EDT THURSDAY FOR MAZ007-019.
     WIND ADVISORY UNTIL 8 AM EDT THURSDAY FOR MAZ005-006-012-013-
     017-018-020-021.
NH...FLOOD WATCH THROUGH THURSDAY MORNING FOR NHZ012-015.
     WIND ADVISORY UNTIL 8 AM EDT THURSDAY FOR NHZ012.
RI...WIND ADVISORY UNTIL 8 AM EDT THURSDAY FOR RIZ001>007.
MARINE...GALE WARNING UNTIL 5 AM EDT THURSDAY FOR ANZ231>237-254>256.
     STORM WARNING UNTIL 5 AM EDT THURSDAY FOR ANZ230.
     STORM WARNING UNTIL 6 AM EDT THURSDAY FOR ANZ250-251.

&&

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



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