Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 271100 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 700 AM EDT MON APR 27 2015 .SYNOPSIS... UNSETTLED WEATHER AND BELOW NORMAL TEMPS WILL CONTINUE INTO TUESDAY. WEAK HIGH PRESSURE WILL BRIEFLY VISIT THE AREA DURING MIDWEEK...WITH TEMPERATURES NEAR OR SLIGHTLY ABOVE NORMAL. BELOW NORMAL TEMPS AND UNSETTLED WEATHER RETURN THURSDAY NIGHT INTO FRIDAY...WITH IMPROVEMENTS FOR THIS WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 700 AM UPDATE... OVERALL TREND IN THE FORECAST REMAINS ON TRACK THIS MORNING. MADE SOME MINOR ADJUSTMENT TO ACCOUNT FOR CURRENT CONDITIONS. FIRST SHORTWAVE IS MOVING THROUGH THE FLOW TRIGGERING OFF THE SCT SHOWERS OUT WEST. COULD SEE A BRIEF SPRINKLE OR LIGHT SHOWERS EARLY THIS MORNING...SO HAVE INSERTED THAT INTO THE FORECAST. OTHERWISE ADJUSTED TIMING AND LOCATION OF HEAVIEST RAIN LATE THE AFTERNOON...CONFINED TO THE EAST MASS COASTLINE. PREVIOUS DISCUSSION... MID LEVEL CLOUDS BLANKETED SOUTHERN NEW ENGLAND ONCE AGAIN. THERE WERE SOME BREAKS IN THESE CLOUDS TOWARD THE EAST COAST OF MA. TEMPERATURES WERE CONTINUING TO SLOWLY FALL. A FEW LOCATIONS COULD SEE A QUICK DROP OF A FEW DEGREES...THEN RISE AGAIN AS THE CLOUDS RETURN. RATHER GOOD MODEL AGREEMENT WITH THE OVERALL SYNOPTIC FEATURES THIS GUIDANCE SUITE. AS SUCH WILL USE A CONSENSUS APPROACH TO PROVIDE THE BASE OF THIS FORECAST...THEN ADD DETAILS FROM HIGH- RESOLUTION GUIDANCE WHERE PRACTICAL. DEEP UPPER LEVEL CUTOFF LOW OVER THE MARITIMES MOVES EVEN FARTHER WEST TODAY...AND INDUCE A SURFACE FUJIWARA EFFECT NEAR THE MARITIMES. IN ADDITION...A SERIES OF SHORTWAVES WILL ROTATE SOUTH AROUND THE WESTERN EDGE OF THIS CIRCULATION. THESE BURSTS OF ENERGY WILL ENHANCE THE CHANCES FOR MEASURABLE RAINFALL AT VARIOUS TIMES THOUGH TODAY. THE STRONGEST OF THESE WAVES SHOULD ARRIVE LATER THIS AFTERNOON INTO THIS EVENING. THUS THE GREATEST RISK FOR SHOWERS WILL BE THIS AFTERNOON AND EVENING...ESPECIALLY ACROSS EASTERN MA. DESPITE A WARMER START TO THE DAY...TEMPERATURES WILL ONCE AGAIN STAY IN THE 50S WITH COOL NORTHERLY WINDS AND MAINLY OVERCAST SKIES. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... THE CORE OF THE UPPER LEVEL CUTOFF MAKES ITS CLOSET APPROACH TO SOUTHERN NEW ENGLAND THIS EVENING...THEN STARTS TO ROTATE BACK OUT TO SEA LATE TONIGHT INTO TUESDAY. AS IT DOES...SOUTHERN NEW ENGLAND GETS INTO A PATTERN OF DECREASING MOISTURE. IN TURN...THIS MEANS A LOWER RISK FOR RAINFALL THROUGH THE DAY TUESDAY. WINDS ARE EXPECTED TO BE NORTH TO NORTHWEST TONIGHT INTO TUESDAY. THERE IS STILL SOME QUESTION IF THE PRESSURE GRADIENT RELAXES ENOUGH...AND WE SEE ENOUGH SUNSHINE...WHERE SEABREEZES COULD DEVELOP. THAT WOULD HAVE A MAJOR IMPACT ON TEMPERATURES TOWARD THE COASTS. AT THIS TIME...THINKING THE PRESSURE GRADIENT STAYS STRONG ENOUGH TO PREVENT SEABREEZE DEVELOPMENT TUESDAY. THIS WILL NEED TO BE MONITORED. TEMPERATURES RISE SLIGHTLY TUESDAY WITH THE ADDITIONAL SUNSHINE... BUT SHOULD STILL BE SLIGHTLY LOWER THAN NORMAL FOR THIS TIME OF YEAR. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... HIGHLIGHTS... * RELIEF ON WEDNESDAY WITH ABOVE AVERAGE TEMPS * DIGGING TROUGH/COASTAL LOW ON THURS/FRIDAY BRINGS BELOW NORMAL TEMPS * IMPROVEMENTS FOR THE WEEKEND OVERVIEW... CLOSED LOW WHICH HAS PLAGUED THE REGION FOR SEVERAL DAYS NOW WILL EJECT OFFSHORE BY TUES ALLOWING FOR BRIEF RIDGING ON WED. STILL WATCHING TWO SYSTEMS WHICH WILL PUT THE NORTHEAST BACK INTO A DEEP TROUGH BY THURSDAY/FRIDAY. STILL A LOT OF UNCERTAINTY ON HOW THE NORTHERN STREAM PHASES WITH THE SOUTHERN STREAM WHICH HAS ALLOWED FOR LARGE MODEL SPREAD OVER THE PAST SEVERAL DAYS. OVERALL THE 00Z GUIDANCE GENERALLY SHOWS A STRONGER OH VLY/MID ATLC UPPER LOW THUS LEADING TO A FARTHER WESTWARD SURFACE TRACK THURSDAY. THE 00Z GFS IS LOOKING LIKE A DEEP EXTREME WITH ITS UPR LOW THOUGH...WITH THE GEFS MEAN AND NEW ECMWF SUPPORTING MORE MODERATE DEPTH. THEREFORE BELIEVE GFS TO BE AN OUTLIER COMPARED THE OTHER GUIDANCE AND TRENDED TOWARDS WPC/EC/UKMET. ONCE THE SYSTEMS PHASE...SURFACE LOW PRESSURE WILL DEVELOP OVER THE CAROLINAS AND MOVE UP THE EASTERN SEABOARD. APPEARS THAT THIS COASTAL LOW WILL STAY SOUTH AND EAST OF THE BENCHMARK...WHICH IS SUPPORTED BY THE 12Z EC ENSEMBLES. BEGINNING OF THE WEEKEND SHOULD BE IMPROVEMENTS AS CENTRAL CONUS RIDGE WILL MOVE EASTWARD. DETAILS... * WEDNESDAY...HIGH CONFIDENCE. DIGGING TROUGH ACROSS THE CENTRAL CONUS WILL PUSH A WEAK RIDGE OVER THE REGION. THIS WILL GIVE SOUTHERN NEW ENGLAND A BREAK IN PRECIP AND TEMPS ABOVE NORMAL. COASTAL COMMUNITIES WILL BE COOLER THANKS TO SEA BREEZE DEVELOPMENT. * THURSDAY AND FRIDAY...LOW CONFIDENCE. STILL SOME UNCERTAINTY IN THIS PORTION OF THE FORECAST. EVERYTHING IS DEPENDENT ON HOW THE LOW CURRENTLY LOCATED OVER THE 4 CORNERS AND THE DIGGING NORTHERN STREAM WAVES BEHAVES. REGARDLESS APPEARS DEEP TROUGH WILL DEVELOP PUTTING SOUTHERN NEW ENGLAND BACK BELOW NORMAL FOR TEMPS. THIS TROUGH WILL DEVELOP A COASTAL LOW OFF THE CAROLINAS AND PUSH NORTHWARDS. THE GFS APPEARS TO BE THE OUTLIER STALLING THE LOW INSIDE THE BENCHMARK FOR SEVERAL HOURS. TRENDED TOWARDS THE CONSISTENT EC WHICH STILL KEEPS IT SOUTH AND EAST OF THE BENCHMARK...YET SLIGHTLY STRONGER THEN PREV RUNS. BELIEVE THURS AND FRI WILL BE MORE HIT OF MISS SHOWERS AND CONTINUE TO KEEP HIGHER POPS ALONG THE CAPE AND ISLANDS FOR COASTAL SYSTEM. ALSO KNOCKED TEMPS DOWN A FEW DEGREES FROM GUIDANCE AS CLOUDS WILL LIMIT DIURNAL HEATING. * THE WEEKEND...MODERATE CONFIDENCE. UPPER LEVEL TROUGH WILL BEGIN TO MOVE OFFSHORE BY SATURDAY AS WEAK RIDGE BUILDS OVER NEW ENGLAND. MAY NEED TO WATCH QUICK MOVING NORTHERN STREAM ENERGY WHICH COULD GIVE SHOWERS TO THE AREA ON SUNDAY...BUT OVERALL HOPING FOR A NICE WEEKEND WITH TEMPS NEAR NORMAL. * MONDAY...LOW CONFIDENCE. MONDAY IS LOOKING WARM BUT STILL UNCERTAIN ON PRECIP CHANCES AS PATTERN WILL ALL BE DEPENDENT ON THE THURS/FRI SYSTEM. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. TODAY...HIGH CONFIDENCE. VFR MOST OF THE TIME. COULD SEE AREAS OF MVFR CIGS/VSBYS IN SCATTERED SHOWERS...ESPECIALLY THIS AFTERNOON. TONIGHT...HIGH CONFIDENCE. VFR MOST OF THE TIME. AREAS OF MVFR CIGS/VSBYS POSSIBLE IN SCATTERED SHOWERS...ESPECIALLY ACROSS THE EASTERN HALF OF SOUTHERN NEW ENGLAND. TUESDAY...MODERATE CONFIDENCE. VFR WITH MVFR CONDITIONS IN ISOLATED SHOWERS. SEA BREEZE DEVELOPMENT IS POSSIBLE ALONG THE EAST COAST. KBOS TAF...HIGH CONFIDENCE IN OVERALL TAF. LOW CONFIDENCE ON SEABREEZE LATE THIS AFTERNOON. A HEAVY SHOWER MAY DISRUPT THE WIND BRIEFLY. KBDL TAF...HIGH CONFIDENCE IN OVERALL TAF. OUTLOOK...WEDNESDAY THROUGH FRIDAY... WEDNESDAY...MODERATE CONFIDENCE. VFR CONDITIONS. SEA BREEZE DEVELOPMENT POSSIBLE. THURSDAY INTO FRIDAY...LOW CONFIDENCE. VFR CONDITIONS WITH MVFR POSSIBLE IN SCT SHOWERS ACROSS THE EASTERN HALF COASTLINE. CIGS/VSBYS COULD BE LOWER DEPENDENT ON THE TRACK OF A LOW PRESSURE SYSTEM. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. HIGH CONFIDENCE. QUIET BOATING WEATHER EXPECTED INTO THIS EVENING. WINDS AND SEAS START TO INCREASE LATE TONIGHT INTO TUESDAY A AS LOW PRESSURE MOVES CLOSER TO THE WATERS. ENOUGH NORTHERLY GRADIENT ANTICIPATED TUESDAY THAT SMALL CRAFT ADVISORY CONDITIONS ARE PROBABLE FOR MOST OF THE COASTAL WATERS... ESPECIALLY EAST OF THE MASSACHUSETTS SHORELINE. WINDS GRADUALLY DIMINISH LATE TUESDAY...BUT SMALL CRAFT ADVISORY CONDITIONS MAY LINGER INTO TUESDAY NIGHT FOR SOME OF THE OUTER COASTAL WATERS. ISSUED A SMALL CRAFT ADVISORY WHERE CONFIDENCE IS GREATEST. THIS ADVISORY MAY NEED TO BE EXPANDED FARTHER WEST WITH LATER FORECASTS. OUTLOOK...TUESDAY NIGHT THROUGH WEDNESDAY...HIGH CONFIDENCE. THURSDAY AND FRIDAY...MODERATE CONFIDENCE. WEDNESDAY...GOOD BOATING WEATHER AS WIND AND SEAS WILL BE BELOW SCA. THURSDAY AND FRIDAY...A LOW PRESSURE SYSTEM EMERGES FROM THE CAROLINA COASTLINE AND IS EXPECTED TO TRACK NORTHEASTWARD. THERE IS CONSIDERABLE UNCERTAINTY IN HOW CLOSE THE CENTER OF THIS SYSTEM MAKES IT TO THE SOUTHERN NEW ENGLAND COASTLINE. IF IT STAYS WELL OFFSHORE...SWELLS COULD BRING A PERIOD OF ROUGH SEAS TO OUR COASTAL WATERS. A CLOSER APPROACH WOULD HAVE SIGNIFICANT MARINE IMPACTS FOR FRIDAY. AGAIN HAVE UNDERCUT WNA WAVE GUIDANCE BY 40 TO 50 PERCENT. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 2 PM EDT TUESDAY FOR ANZ232. SMALL CRAFT ADVISORY FROM 6 AM TO 10 AM EDT TUESDAY FOR ANZ230. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 2 PM EDT TUESDAY FOR ANZ231. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EDT TUESDAY FOR ANZ250-254-255. SMALL CRAFT ADVISORY FROM 4 AM TO 6 PM EDT TUESDAY FOR ANZ251. && $$ SYNOPSIS...BELK/DUNTEN NEAR TERM...BELK/DUNTEN SHORT TERM...BELK LONG TERM...DUNTEN AVIATION...BELK/DUNTEN MARINE...BELK/DUNTEN

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