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Area Forecast Discussion
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000
FXUS61 KBOX 202301
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
701 PM EDT SAT SEP 20 2014

.SYNOPSIS...
SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM OR TWO ARE EXPECTED 
VERY LATE TONIGHT INTO SUN MORNING...WITH MOST AREAS DRY AND RATHER 
MILD BY SUN AFTERNOON.  A COLD FRONT CROSSES THE REGION BY DAYBREAK 
MONDAY WITH HIGH PRESSURE BRINGING DRY WEATHER FOR THE REST OF NEXT 
WEEK.  TEMPS START OFF COOL EARLY NEXT WEEK...BUT MODERATE TO ABOVE 
NORMAL BY THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
7 PM UPDATE...NO SIGNIFICANT CHANGES TO THE FORECAST. MADE SOME
ADJUSTMENTS TO THE SKY COVER FORECAST TO ACCOUNT FOR THE LATEST
TRENDS. OTHERWISE...THE FORECAST IS ON TRACK.

THIS EVENING WILL FEATURE DRY WEATHER WITH PLEASANT TEMPERATURES.  
MOST LOCATIONS WILL SEE TEMPS IN THE UPPER 50S AND 60S THIS 
EVENING...AS SURFACE WINDS WILL NOT DECOUPLE WITH A DEVELOPING LOW 
LEVEL JET.

&&

.SHORT TERM /MIDNIGHT TONIGHT THROUGH SUNDAY NIGHT/...
OVERNIGHT INTO SUNDAY AFTERNOON...

A SHORTWAVE/LOW PRESSURE SYSTEM OFF THE CAROLINA COAST WILL BE 
LIFTING NORTHEAST OVERNIGHT. THIS WILL INDUCE A 30 TO 40 KNOT 
SOUTHERLY LOW LEVEL JET...TRANSPORTING DEEPER MOISTURE NORTHWARD 
INTO SOUTHERN NEW ENGLAND.  THIS WILL RESULT IN A BURST OF 
INSTABILITY AND A BAND OF SCATTERED SHOWERS MOVING FROM WEST TO 
EAST.  TIMING LOOKS TO BE AFTER MIDNIGHT INTO SUNDAY 
MORNING...APPROXIMATELY BETWEEN 6Z AND 15Z. INSTABILITY PARAMETERS 
ARE MARGINAL...BUT THERE MIGHT BE ENOUGH ELEVATED CAPE FOR A FEW 
EMBEDDED THUNDERSTORMS.  THIS RISK FOR SEVERE WEATHER IS EXTREMELY 
LOW SUNDAY MORNING.  HOWEVER...WITH 0 TO 6 KM SHEAR OF 25 TO 30 
KNOTS/0 TO 1 KM HELICITY AROUND 100...AND A FEW HUNDRED J/KG OF 
CAPE....CAN/T COMPLETELY RULE OUT AN ISOLATED STRONG STORM NEAR THE 
SOUTH COAST SUNDAY MORNING.  AGAIN THOUGH...THAT APPEARS TO BE A 
VERY LOW PROBABILITY BUT SOMETHING WILL NEED TO WATCH.

THE STEADY AND HEAVIEST RAIN WILL LIKELY REMAIN OFF THE COAST WITH 
THE SURFACE LOW PRESSURE SYSTEM GIVEN LIMITED 
BAROCLINICITY/FRONTOGENESIS.  HOWEVER...IT STILL MAY SCRAPE THE FAR 
SOUTHEAST NEW ENGLAND COAST FOR A TIME WHERE PWATS APPROACH 2 INCHES 
SO BRIEF HEAVY RAIN IS POSSIBLE.

IN A NUTSHELL...SCATTERED SHOWERS AND PERHAPS A FEW THUNDERSTORMS 
ARE EXPECTED MAINLY SUNDAY MORNING.  WE ARE NOT EXPECTING A SOAKING 
RAIN BY ANY MEANS...BUT A PERIOD OF HEAVY RAIN IS POSSIBLE NEAR THE 
FAR SOUTHEAST NEW ENGLAND COAST IF THE PLUME OF TROPICAL MOISTURE 
CAN MAKE IT THAT FAR NORTHWEST.  OTHERWISE...MOST OF SUNDAY 
AFTERNOON SHOULD BE DRY WITH JUST A LOT OF CLOUDS AROUND THE 
REGION...EXCEPT PERHAPS THE FAR SOUTHEAST NEW ENGLAND COAST WHERE 
SHOWERS MAY LINGER A BIT LONGER.  

LOW TEMPS OVERNIGHT WILL BE MUCH MILDER THAN LAST NIGHT WITH A  
DEVELOPING LOW LEVEL JET NOT ALLOWING WINDS TO DECOUPLE.  LOWS WILL 
MAINLY BE IN THE UPPER 50S AND LOWER 60S BY DAYBREAK SUNDAY.  HIGHS 
ON SUNDAY WILL BE IN THE MIDDLE TO UPPER 70S AND IT WILL FEEL A BIT 
HUMID WITH DEWPOINTS WELL INTO THE 60S!

LATE SUNDAY AFTERNOON AND SUNDAY NIGHT...

A COLD FRONT WILL APPROACH FROM THE WEST LATE SUNDAY AFTERNOON AND 
SLOWLY MAKE ITS WAY THROUGH THE REGION BY DAYBREAK MONDAY.  A LOT OF 
MID LEVEL DRY AIR AND A LACK OF INSTABILITY WILL LIMIT PRECIPITATION 
POTENTIAL ALONG THE FRONT.  THERE STILL MAY BE A FEW SPOT SHOWERS 
AND PERHAPS A THUNDERSTORM ACROSS THE INTERIOR LATE SUN AFTERNOON 
INTO THE EVENING ACROSS THE INTERIOR...BUT THAT IS ABOUT IT.  MOST 
OF SUNDAY NIGHT SHOULD BE DRY IN A GIVEN LOCATION.  LOW TEMPS WILL 
MAINLY IN THE UPPER 50S AND LOWER 60S BY DAYBREAK MONDAY.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
HEADLINES...

*LOW CHANCE SHOWERS MON. THEN DRY THE REST OF THE WEEK
*COOL TEMPERATURES DURING THE WEEK...MODERATING BY WEEKEND

OVERVIEW...

THE PERIOD STARTS OFF WITH GOOD AGREEMENT ON A TROUGH DRAPED OVER 
THE EAST COAST AND A RIDGE OVER THE WEST COAST. THE RIDGE SLOWLY 
MOVES EAST AS TIME GOES ON AND THE UPPER LEVEL MOVES NORTH INTO 
CANADA. GOOD AGREEMENT IN THE ENSEMBLE NAO AND AO TELECONNECTION 
FORECASTS TO STAY IN THE POSITIVE PHASES. THE PNA LOOKS TO START 
POSITIVE AND GO NEUTRAL AS TIME GOES ON...BUT THEN MODELS DIVERGE IN 
THEIR OUTPUTS AS A WEAKNESS IN THE RIDGE ALLOWS FOR SOME SPREAD.

DAILIES...

MONDAY...THE MORNING BEGINS WITH A DEPARTING COLD FRONT THAT IS 
FIGHTING WITH SOME DRY MIDLEVELS ALLOWING SOME OF THE PRECIP TO DRY 
UP. MOST OF THE PRECIPITATION SHOULD FALL IN NORTHWESTERN PORTIONS 
OF THE AREA AND OFFSHORE. BEHIND THE FRONT...STRONG MIXING OCCURS UP 
TO AROUND 850 MB WHERE 20 TO 25 KT WINDS EXIST SO GUSTS UP TO 25 KTS 
IS NOT OUT OF THE QUESTION. 850 MB TEMPS AHEAD OF THE FRONT ARE 
AROUND 10C SO MID TO UPPER 70S ARE NOT OUT OF THE QUESTION THERE. 
NORTHWESTERN SECTIONS WON/T GET THAT HIGH AS THE FRONT CROSS THROUGH 
TOO EARLY.

TUESDAY THROUGH FRIDAY...BEHIND THE COLD FRONT...A STRONG 1035 MB 
HIGH PRESSURE SYSTEM COMES INTO THE REGION WITH COOLER 
TEMPERATURES...BUT NOT AS COLD AS THE PREVIOUS COLD FRONT. DRY 
WEATHER WILL ALSO PREVAIL DURING THIS PERIOD. SOME MODEL 
DISAGREEMENT AS TO THE PLACEMENT OF THE UPPER LEVEL JET APPROACHING 
THE REGION FROM THE SOUTH TOWARDS THE END OF THE PERIOD. THINK THE 
ECMWF MAY HAVE IT TOO FAR NORTH WHILE THE 6Z GFS HAS IT FURTHER 
SOUTH. THE EXACT PLACEMENT OF THIS JET WILL GIVE US WHEN CIRRUS 
CLOUDS MOVE NORTH FROM MOISTURE OFF OF THE SOUTHEAST US. WINDS WILL 
BE LIGHT DURING THIS PERIOD WITH THE UPPER JET UP NORTH SO BETTER 
CHANCE FOR COOLING TEMPS AT NIGHT ESPECIALLY WITH THE RECENT 
DRY SPELL WE/VE BEEN HAVING. IN PERIODS OF ONSHORE WINDS...FOG COULD 
OCCUR.

SATURDAY...A COLD FRONT APPROACHES THE REGION FROM SOUTHEAST CANADA

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE.  VFR CONDITIONS THROUGH 04Z.  
INCREASING LOW LEVEL MOISTURE SHOULD ALLOW MVFR-IFR CIGS/VSBYS TO 
OVER SPREAD THE REGION VERY LATE THIS EVENING AND INTO THE OVERNIGHT 
HOURS.  SCATTERED SHOWERS AND PERHAPS A FEW EMBEDDED THUNDERSTORMS 
MAY WORK INTO THE REGION AFTER 06Z.

SUNDAY...MODERATE CONFIDENCE.  MAINLY IFR CONDITIONS EXPECTED IN THE 
MORNING WITH SCATTERED SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM 
OR TWO.  CONDITIONS SHOULD IMPROVE TO MVFR AND PERHAPS EVEN VFR 
DURING THE AFTERNOON ACROSS THE INTERIOR.  HOWEVER...LOWER 
CIGS/VSBYS MAY HANG TOUGH THOUGH ALONG THE SOUTHEAST NEW ENGLAND 
COAST.

SUNDAY NIGHT...LOW TO MODERATE CONFIDENCE.  SCATTERED LOW CLOUDS AND 
FOG PATCHES ARE POSSIBLE ESPECIALLY ACROSS EASTERN NEW ENGLAND.  

KBOS TERMINAL...HIGH CONFIDENCE IN TAF THROUGH 06Z.  MODERATE 
CONFIDENCE AFTER 06Z.

KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE IN TAF THROUGH 04Z.  
MODERATE CONFIDENCE AFTER 04Z.

OUTLOOK...MONDAY THROUGH THURSDAY...

HIGH CONFIDENCE THROUGHOUT THE PERIOD

VFR THRU THE PERIOD EXCEPT FOR ANY SHOWERS ON MONDAY IN THE 
NORTHWESTERN AREAS WHERE MVFR COULD BE NEEDED. WINDS AROUND 10KTS 
DURING THE DAY MONDAY WITH GUSTS TO 20 OR 25KTS IN PLACES. THESE 
WINDS DIE OFF ON TUESDAY AND FOR THE REST OF THE WEEK.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...

TONIGHT...MODERATE CONFIDENCE.  SOUTH WINDS OF 10 TO 15 KNOTS WITH 
HIGH PRESSURE WELL OFF THE COAST.  THERE IS A LOW PROBABILITY THAT 5 
FOOT SEAS COULD DEVELOP FOR A TIME ACROSS THE OUTER-WATERS...BUT 
DECIDED TO KEEP WAVES JUST BELOW FOR NOW.  LATER SHIFTS WILL HAVE TO 
KEEP A CLOSE EYE ON THIS POTENTIAL AND PERHAPS THE NEED FOR A SHORT 
FUSED SCA ADVISORY.

SUNDAY AND SUNDAY NIGHT...MODERATE CONFIDENCE.  SOUTHEAST WINDS AT 
10 TO 15 KNOTS ON SUNDAY WILL SHIFT TO THE SOUTHWEST SUNDAY NIGHT 
AHEAD OF A COLD FRONT.  HOWEVER...SWELL FROM LOW PRESSURE NEAR THE 
BENCHMARK WILL LIKELY RESULT IN SCA SEAS ACROSS THE OUTER-WATERS BY 
SUNDAY NIGHT.  SINCE ITS MAINLY 3RD PERIOD...WILL DEFER THE ISSUANCE 
OF HEADLINES TO THE NEXT SHIFT.  SCATTERED SHOWERS AND PERHAPS A 
THUNDERSTORM MAY AFFECT THE WATERS THIS MORNING.  THERE MAY ALSO BE 
SOME VISIBILITY RESTRICTIONS IN PATCHY FOG...ESPECIALLY DURING THE 
SUNDAY MORNING.

OUTLOOK...MONDAY THROUGH THURSDAY...

HIGH CONFIDENCE...

SEAS FROM 5 TO 8FT ON MONDAY AND INTO TUESDAY WITH THE PASSAGE OF A 
LOW TO THE SOUTHEAST OF THE REGION. EVEN WITH WINDS BELOW SCA 
THRESHOLDS...AN SCA MAY BE NEEDED FOR THIS PERIOD FOR THE SWELLS.

&&

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

&&

$$
SYNOPSIS...FRANK/99
NEAR TERM...FRANK/RLG
SHORT TERM...FRANK
LONG TERM...99
AVIATION...FRANK/99
MARINE...FRANK/99



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