Area Forecast Discussion
Issued by NWS Boston, MA

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KBOX 052003 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 403 PM EDT THU MAY 5 2016 .SYNOPSIS... CLOUDY...DREARY AND COOL WEATHER CONTINUES THROUGH FRIDAY WITH PERIODS OF RAIN AS WAVES OF LOW PRESSURE TRACK NEAR SOUTHERN NEW ENGLAND. DESPITE SOME SHOWERS POSSIBLE THIS WEEKEND THERE WILL BE MANY HOURS OF DRY WEATHER ALONG WITH MODERATING TEMPERATURES. 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 FRIDAY MORNING/...
-- Changed Discussion --
215 PM UPDATE... LOW PRESSURE WAS PROGRESSING TO THE NORTHEAST...NOW 996 MB WELL TO THE SOUTH OF NANTUCKET. SOUTHERN NEW ENGLAND IS SOCKED IN WITH LOW CLOUDS...AREAS OF DRIZZLE IN EASTERN MA AND RI...AND LOCALLY HEAVY RAIN SHOWERS OVER SOUTHEAST MA INCLUDING CAPE COD AND THE ISLANDS. FORECAST IS RIGHT ON TRACK. EXPECTING A SLIGHT WESTWARD PUSH OF THE RAIN INTO EASTERN RI AND PERHAPS TO AS FAR WEST AS THE I-95 CORRIDOR IN EASTERN MA INTO THE EARLY EVENING BEFORE HEADING NORTHEAST OUT TO SEA TONIGHT. NORTHEAST WINDS HAVE BEEN GUSTING TO 25-35 MPH EAST OF A LINE FROM WILLIMANTIC CT TO BOSTON MA...BUT HAVE REMAINED BELOW WIND ADVISORY CRITERIA. MODELS ARE A LITTLE WEAKER WITH THE WINDS FOR TONIGHT AND WE MAY BE ABLE TO LOWER GALES TO SMALL CRAFT ADVISORIES IN SOME BAYS AND HARBORS IN THE EVENING FORECAST PACKAGE. TEMPERATURES ON TRACK...HAVE MADE IT TO THE MID 50S IN NORTHERN CT AND WESTERN MA...WITH MID AND UPPER 40S ELSEWHERE.
-- End Changed Discussion --
&& .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... TONIGHT... RAIN SHIELD ASSOCIATED WITH COASTAL LOW WILL PULL AWAY FROM CAPE COD AND THE ISLANDS AS DRY SLOT APPROACHES FROM THE SOUTH. THIS MAY RESULT IN AREAS OF DRIZZLE AND FOG FORMING WITH DRY AIR ALOFT AND MOIST NE LOW LEVEL FLOW ACROSS SOUTHERN NEW ENGLAND. FRIDAY... OTHER THAN SPOTTY LIGHT RAIN/DRIZZLE THE DAY SHOULD START OFF MAINLY DRY. IN FACT SOME OF THE MODEL GUID SUGGEST THERE COULD BE A FEW BREAKS OF SUNSHINE ACROSS CAPE COD AND NANTUCKET EARLY IN THE MORNING. ALTHOUGH THIS WILL BE SHORT LIVED AS VERTICALLY STACKED LOW TRACKS FROM THE MID ATLC TO THE NJ COAST. THIS ADVECTS DEEP LAYER MOISTURE IN THE FORM OF RAIN INTO CT AND WESTERN- CENTRAL MA FRI AFTN. PRECIP MAY NOT REACH EASTERN MA UNTIL AFTER DARK. IT WILL BECOME BREEZY ONCE AGAIN ACROSS EASTERN MA AS EAST WINDS INCREASE. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
-- Changed Discussion --
*/ HIGHLIGHTS... - DREARY WEATHER OF LIGHT RAIN / DRIZZLE SATURDAY - COLD FRONT AND BEST CHANCES OF RAIN ON SUNDAY - QUICK BLAST OF COLDER AIR MONDAY MORNING BEHIND THE FRONT...DRY - POSSIBLE PROLONGED PERIOD OF UNSETTLED WEATHER THRU THE WEEK OVERVIEW AND MODEL PREFERENCES... FINAL BREAKDOWN OF THE AMPLIFIED FLOW PATTERN ACROSS THE CONUS BEGINS LATE SAT INTO SUN AS ARCTIC VORT MAX WITHIN THE NRN STREAM IS FINALLY ABLE TO SHIFT THE STUBBORN CUTOFF E OF THE REGION. THIS WILL COME WITH SOME CONSEQUENCE IN THE FORM OF A COLD FRONTAL PASSAGE ON SUN...BUT AT THE VERY LEAST...SOME MODERATION IN TYPES AND DRYING OF THE COLUMN IS EXPECTED. BEYOND THE WEEKEND...CONFIDENCE IN THE FORECAST WAINS. AT ISSUE IS THE DEVELOPMENT OF YET ANOTHER CUTOFF DEVELOPS TO THE N AS THE NRN STREAM VORT MAX PHASES WITH SRN STREAM ENERGY EARLY IN THE WEEK. THE RESULTING CUTOFF COULD END UP ANYWHERE FROM ONTARIO TO S OF GREENLAND...AND THIS LOCATION WILL ULTIMATELY HELP TO DEFINE THE DAILY SENSIBLE WX ACROSS SRN NEW ENGLAND. AGREE WITH THE PREVIOUS FORECASTER THAT AN ENSEMBLE APPROACH IS BEST HERE...AND GIVEN WPC/S LEANING ON AN ECENS ENSEMBLE MEAN...WILL BE FOLLOWING SUIT WITH THIS UPDATE. THE OVERALL RESULT WILL BE THE RISK FOR MORE WET/GRAY CONDITIONS MID-LATE WEEK AS A BAROCLINIC ZONE SETTLES NEAR NEW ENGLAND S OF THE THE DEVELOPING CUTOFF. DETAILS... SAT AND SAT NIGHT... FILLING OCCLUSION WILL BE SHIFTING E OF THE REGION AND GRADUALLY ALLOWING MORE DRY AIR THROUGH THE COLUMN. AFTER A DAMP/SHOWERY/DRIZZLE START TO THE DAY...SOME BREAKS ARE EXPECTED IN THE AFTERNOON AND EVENING...WITH EVEN THE LOW POSSIBILITY OF A FEW PEAKS OF SUN. WITH FLOW SHIFTING S...TEMPS WILL BE MODERATING ALLOWING FOR A FEW MORE 50S AND LOW 60S THAN PREVIOUS DAYS WITH LOWS NOW FALLING INTO THE 40S. SUN... STRONG COLD FRONT WILL SWEEP THROUGH THE REGION DURING THE MID DAY PERIOD. THE COMBINATION OF PWATS APPROACHING AN INCH WITH A MODEST ELEVATED UNSTABLE LAYER BETWEEN H9 AND H7 SUGGESTS SOME SHRA COULD BE BRIEFLY HEAVY AT TIMES...PARTICULARLY ACROSS THE NRN HALF OF THE AREA...CLOSER TO THE INFLUENCE OF A LLJ. SOME WETTING PRECIP EXPECTED ACROSS ALL OF SRN NEW ENGLAND HOWEVER...WITH HIGHEST TOTALS MAINLY N OF THE MASS PIKE IN THE 0.25-0.50 RANGE WITH LOCALLY HIGHER AMOUNTS. MON... BRIEF REPRIEVE FROM EXPECTED RAINFALL WITH COLD FRONT SHIFTING E OF THE REGION...ALLOWING A DRIER...BUT COLDER AIRMASS TO SPILL ACROSS SRN NEW ENGLAND. BREEZY NW FLOW EXPECTED WITH SOME CLOUD COVER...THE RESULT OF A SECONDARY SHORTWAVE MOVING THROUGH LATE IN THE DAY. TEMPS MAINLY NEAR TO BELOW SEASONAL NORMALS. TUE... CONFIDENCE IN THE FORECAST DROPS RAPIDLY AT THIS POINT DUE TO A WIDE ARRAY OF POSSIBILITIES FOR A BAROCLINIC ZONE AND UPPER LVL CUTOFF. FOR NOW...FEEL THAT WITH A DRY COLUMN TO START...TUE WILL ITSELF BE MAINLY DRY BUT TRANSITIONING BACK TO GRAY/DAMP CONDITIONS LATE. ECENS/GEFS PROBABILITIES FOR PRECIP ARE RATHER LOW...HENCE THE DECISION TO LEAN CLOSER TO A DRY FORECAST FOR TUE. TEMPS WILL BE DETERMINED BY THE FINAL LOCATION OF THE BAROCLINIC ZONE. LATE WEEK... ALTHOUGH NOT LIKELY AS PERSISTENTLY GRAY AND DAMP AS THIS WEEK...A SHIFT IN THE PATTERN SUGGESTS THAT SEVERAL WAVES ACTINGALONG THE BAROCLINIC ZONE COULD PROVIDE PERIODS OF RAIN AND EVEN SOME POSSIBLE THUNDER. OVERALL..NOT AS COLD AS THIS WEEK THANKS TO INFLUENCE OF THE SRN STREAM WITH THIS FEATURE.
-- End Changed Discussion --
&& .AVIATION /20Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. 1815Z UPDATE... SHORT TERM /THROUGH FRIDAY/... THIS AFTERNOON...WIDESPREAD IFR AND LOWER-END MVFR CIGS WITH THE LOWEST CEILINGS NEAR THE COAST AND AT ORH. PATCHY FOG EASTERN HALF. RAIN...WITH LOCALLY HEAVY SHOWERS OVER THE CAPE AND ISLANDS. RAIN MAY SPREAD WEST TO THE I-95 CORRIDOR LATE THIS AFTERNOON/EARLY EVENING. NE WINDS GUSTING TO 25-30 KT ACROSS E MA AND RI TERMINALS THROUGH THIS EVENING. TONIGHT... TRENDS OF MVFR W AND IFR-LIFR E CONTINUE. -RA OVER E/SE NEW ENGLAND WITH 25 TO 30 KT NE WINDS CONTINUES DURING THE EVENING HOURS CONCLUDING TOWARDS MIDNIGHT. SOME IMPROVEMENT EXPECTED INTO THE MORNING HOURS. FRIDAY... GRADUAL IMPROVEMENT IF EVER BRIEFLY. MVFR LIKELY. -RA DEVELOPING LATE ALONG WITH NE WINDS. KBOS TERMINAL...MODERATE CONFIDENCE CONCERNING THE TAF. WILL BRING RAIN IN ON 20Z AND KEEP CONDITIONS LOW PRIOR TOWARDS IMPROVING CONDITIONS SHORTLY AFTER MIDNIGHT. KBDL TERMINAL...WILL KEEP -RA WEST. CONDITIONS IMPROVING LATER TODAY POTENTIALLY UP TO LOW END VFR. OUTLOOK /TUE THROUGH MON/... SAT...HIGH CONFIDENCE. MIX OF MVFR/IFR GIVES WAY TO MORE WIDESPREAD VFR LATER IN THE DAY AS RAIN/DRIZZLE COMES TO AN END. LOW RISK OF A MID DAY TS. SUN...MODERATE CONFIDENCE. VFR TO START THE DAY...BUT MIX OF SHOWERS WITH MVFR CONDITIONS THROUGH MID AFTERNOON WITH A COLD FRONTAL PASSAGE. VFR FOLLOWS INTO SUN NIGHT. MON AND TUE...HIGH CONFIDENCE. MAINLY VFR WITH BRIEF RIDGE OF HIGH PRES.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. 215 PM UPDATE... THIS AFTERNOON... GALE WARNING IS IN EFFECT. NE WINDS WILL HAVE FREQUENT GUSTS TO 30 TO 35 KT MOST WATERS. RAIN...WITH EMBEDDED LOCALLY HEAVY SHOWERS WITH AREAS OF FOG WILL RESTRICT VISIBILITY TO 3 MILES OR LESS AT TIMES OVER THE WATERS. SEAS BUILDING TO 8 TO 12 FEET ON THE OUTER WATERS. TONIGHT... WE MAY BE ABLE TO LOWER GALE WARNINGS TO SMALL CRAFT ADVISORIES FOR SOME INNER BAYS AND HARBORS. OTHERWISE NE LOW-END GALES CONTINUE DURING THE EVENING FOLLOWED BY WINDS DIMINISHING AFTER MIDNIGHT. VSBY MAY BE REDUCED IN AREAS OF FOG AND DRIZZLE AT TIMES. FRIDAY... LOW PRES MOVES UP THE COAST FROM THE MID ATLC TO NJ. THIS WILL RESULT IN EAST WINDS INCREASING AS THE DAY PROGRESSES ALONG WITH RAIN OVERSPREADING THE RI WATERS IN THE AFTERNOON. OUTLOOK /SAT THROUGH TUE/...MODERATE CONFIDENCE. SAT AND SUN... ALTHOUGH WINDS WILL BE SHIFTING TO THE S AND RECEDING...LINGERING SWELL ON THE OCEAN WATERS REMAINS NEAR 5-6FT. THEREFORE...SMALL CRAFT ADVISORIES ARE LIKELY TO LINGER FOR AT LEAST SEAS. MON AND TUE... HIGH PRES BRIEFLY BUILDS OVER THE WATERS BUT WITH SUSTAINED NW FLOW SEAS HOLD NEAR 5 FT ON THE OCEAN WATERS. QUIETER BOATING WEATHER CLOSER TO SHORE.
-- End Changed Discussion --
&& .TIDES/COASTAL FLOODING... 930 AM UPDATE... PRIOR FORECAST AND ADVISORY LOCATION LOOKS GOOD. HAVE ADJUSTED SURGE AND SEAS UP A LITTLE BASED ON LATEST TRENDS AND HIGH RESOLUTION WIND GUIDANCE. SURGE IS PRESENTLY RUNNING A LITTLE OVER A FOOT AT BOSTON...CHATHAM AND NANTUCKET HARBOR OR ABOUT A HALF FOOT ABOVE BOTH THE ESTOFS AND ETSS GUIDANCE. WOULD ANTICIPATE THE PERSISTENT NE FLOW WHICH MAY STRENGTHEN A TAD THIS EVENING TO RESULT IN A MODEST AND GRADUAL INCREASE IN SURGE. IT IS NOT OUT OF THE QUESTION THAT A FEW SPOTS...SUCH AS SCITUATE AND NANTUCKET HARBOR...MAY APPROACH THE HIGH END OF MINOR IMPACTS FOR THIS EVENING/S HIGH TIDE. HAVE KEPT THE ESSEX COUNTY COASTLINE OUT OF THE ADVISORY AREA FOR NOW BUT WILL REEVALUATE LATER TODAY. AT LEAST POCKETS OF MINOR COASTAL FLOODING POSSIBLE AGAIN FRI EVENING DUE TO HIGH ASTRO TIDE AND PROBABLE SLOWNESS FOR THE SURGE TO EVACUATE...BUT WE DO NOT THINK THIS WARRANTS A DOUBLE HEADLINE AT THIS TIME. COASTAL FLOOD ADVISORY HAS BEEN POSTED FOR THIS EVENING/S HIGH TIDE. ASTRO TIDE AT BOSTON IS 11.95 FT AT 10:55 PM. NE WINDS OF 25 TO 35 KT THIS AFTERNOON AND EVENING WILL RESULT IN A STORM SURGE AROUND 1 FT. THIS COMBINED WITH SOME WAVE ACTION ONTOP OF THE SURGE WILL BE SUFFICIENT TO PRODUCE MINOR COASTAL FLOODING ALONG THE EASTERN MA COASTLINE FROM BOSTON SOUTHWARD THRU PLYMOUTH COUNTY...CAPE COD BAY AND NANTUCKET. RISK IS LOWER NORTH OF BOSTON BUT LATER SHIFTS WILL HAVE TO EVALUATE FOR POTENTIAL HEADLINES. && .BOX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...NONE. MA...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO 1 AM EDT FRIDAY FOR MAZ015-016-019-022-024. RI...NONE. MARINE...GALE WARNING UNTIL 2 AM EDT FRIDAY FOR ANZ232>235-237. GALE WARNING UNTIL 5 AM EDT FRIDAY FOR ANZ230-231-250-251- 254>256. GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR ANZ236. GALE WARNING FROM 9 PM FRIDAY TO 2 AM EDT SATURDAY FOR ANZ250- 251-254>256.
-- End Changed Discussion --
&& $$ SYNOPSIS...NOCERA/DOODY NEAR TERM...NOCERA/GAF SHORT TERM...NOCERA LONG TERM...DOODY AVIATION...DOODY/GAF MARINE...DOODY/GAF TIDES/COASTAL FLOODING...

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.