Area Forecast Discussion
Issued by NWS Boston, MA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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 310300 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 1100 PM EDT THU OCT 30 2014 .SYNOPSIS...
-- Changed Discussion --
HIGH PRESSURE WILL BRING DRY AND SEASONABLE CONDITIONS THROUGH THE END OF THE WORK WEEK. A DEVELOPING COASTAL STORM WILL MOVE UP THE COAST SATURDAY AND PASS OFFSHORE SATURDAY NIGHT AND EARLY SUNDAY. HIGH PRESSURE BUILDS OVER THE EASTERN U.S. FOR EARLY NEXT WEEK. ONE OR TWO COLD FRONTS MAY CROSS SOUTHERN NEW ENGLAND WEDNESDAY AND THURSDAY.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
-- Changed Discussion --
1030 PM UPDATE... LIGHT PRES GRADIENT CONTINUES AS HIGH PRES REMAINS ACROSS THE REGION AT 02Z. WINDS ARE GENERALLY CALM...THOUGH HIGHER TERRAIN HAS A BIT MORE WINDS. NOTING NW WIND AT 8-10 KT AT KORH AND NNW WIND AT 8 KT AT KMQE...BOTH ELEVATED LOCATIONS. TEMPS HAVE FALLEN BACK TO THE MID-UPPER 30S AT THE NORMALLY COLDER LOCATIONS THANKS TO RADIATIONAL COOLING...DOWN TO 36 AT KORE AND 37 AT KTAN. SKIES WERE BECOMING MOSTLY CLEAR AT MOST LOCATIONS AS NOTED ON LATEST IR SATELLITE TRENDS...THOUGH AREA OF CLOUDS CONTINUES ACROSS SE MA AS WELL AS ACROSS S NH/NW MA. WHERE TEMPS WERE FALLING BACK CLOSE TO DEWPTS...HAVE ADDED MENTION OF PATCHY FOG AFTER MIDNIGHT...GENERALLY IN THE NORMALLY PRONE AREAS ACROSS E INTERIOR MA AS WELL AS THE CT VALLEY INTO NE CT AND EVEN ON MARTHAS VINEYARD WHERE TEMPS HAVE ALSO FALLEN BELOW 40 WITH CALM WINDS. HAVE UPDATED FORECAST TO BRING CONDITIONS CURRENT AND WORK CHANGES MENTIONED ABOVE INTO NEAR TERM. PREVIOUS DISCUSSION... EXPECT LIGHT NORTHWESTERLY WINDS TO SHIFT TO THE NORTHEAST OVERNIGHT...WHICH MAY BE ENOUGH TO KEEP TEMPERATURES FROM COMPLETELY RADIATING. ANYWHERE THE WINDS DO DROP OFF TO CALM... THE TEMPERATURES WILL DROP SEVERAL DEGREES FAIRLY QUICKLY. OVERALL...EXPECT LOWS IN THE 30S AWAY FROM THE COAST.
-- End Changed Discussion --
&& .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... FRIDAY...ANOTHER QUIET DAY AS HIGH PRESSURE LIFTS TO THE NORTH. WITH WINDS SHIFTING TO THE EAST AS LOW PRESSURE MOVES TOWARDS SOUTHERN NEW ENGLAND FROM THE CAROLINA COAST...EXPECT IT TO FEEL A BIT COOLER THAN TODAY. OTHERWISE...INCREASING CLOUDS FROM THE APPROACHING COASTAL LOW. FRIDAY NIGHT...WHILE THERE IS SOME UNCERTAINTY IN THE MODEL SOLUTIONS WITH THE UPCOMING STORM MOST OF THIS WILL AFFECT THE WEEKENDS WEATHER SO WILL MOSTLY DISCUSS IT IN THE LONG TERM SECTION. SHOULD MOSTLY SEE AN INCREASE IN CLOUDS OVERNIGHT. THIS WILL KEEP TEMPERATURES A FEW DEGREES WARMER THAN TONIGHT. IN ADDITION...RAIN AND/OR SHOWERS WILL LIKELY MOVE ONTO THE SOUTH COAST AND INTO SOUTHEAST MASSACHUSETTS TOWARDS DAYBREAK SATURDAY MORNING. && .LONG TERM /SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --
BIG PICTURE... DEEP AMPLITUDE TROUGHS ON BOTH COASTS SATURDAY WITH A RIDGE IN BETWEEN. SHORTWAVE MOVING THROUGH THE EASTERN TROUGH GENERATES A CUTOFF UPPER LOW WITH TWO JET STREAMS...A NORTHERN STREAM ALONG THE CANADIAN BORDER AND A SOUTHERN STREAM MOVING WITH THE SHORT WAVE. THE PATTERN SHIFTS EAST DURING THE WEEK WITH THE RIDGE BUILDING OVER NEW ENGLAND. THE PATTERN THEN TRANSFORMS TO A MORE ZONAL FLOW. REMAINS OF THE PACIFIC COAST TROUGH MOVE ACROSS NEW ENGLAND MIDWEEK. COLDER THAN NORMAL HEIGHTS WITH THE WEEKEND TROUGH. THESE BUILD TO NORMAL OR A LITTLE MILDER THAN NORMAL BY MIDWEEK. THIS POINTS TO A COLDER THAN NORMAL WEEKEND TRENDING TO NORMAL TEMPS BY MIDWEEK. THE GFS...WHILE SERVICEABLE...IS A BIT OF AN OUTLIER. FOR THE GRIDS WE WILL USE A BLEND OF MODEL DATA INCLUDING HPC AND /WHERE POSSIBLE/ THE 12Z ECMWF. THE DAILIES... SATURDAY-SUNDAY... COASTAL STORM CONTINUES TO BE INDICATED FOR SATURDAY AND EARLY SUNDAY. SUPPORT COMES FROM TWO SETS OF FORCING MECHANISMS...SUGGESTING A TWO-PART EVENT. BUT FINE-TUNING THE TIMING OF THESE PARTS IS DIFFICULT THIS FAR OUT. INITIAL FORCING COMES FROM RIGHT ENTRANCE REGION OF NORTHERN STREAM JET SATURDAY MORNING. SECOND FORCING COMES FROM LEFT EXIT REGION OF JET SUPPORTING SHORTWAVE ROUNDING THE BASE OF THE EASTERN TROUGH LATE SATURDAY/SATURDAY NIGHT. EVEN SO...MOST OF THE FRONTOGENETIC FORCING WITH EACH SEGMENT IS FOCUSED ON THE MARITIMES AND MAINE. THE WESTERN EDGE OF THIS FORCING SHOULD EXTEND INTO SOUTHERN NEW ENGLAND WITH THE FIRST AND POSSIBLY THE SECOND OF THE SEGMENTS. WE EXPECT RAIN SATURDAY AND SATURDAY NIGHT WITH HIGHEST POPS OVER CAPE COD AND THE ISLANDS...LESSER VALUES NORTH AND WEST. STRONG PRESSURE GRADIENT AT THE SURFACE AND A 50 KNOT LOW LEVEL JET WILL CONTRIBUTE TO WINDY CONDITIONS. THE STRONGEST WINDS WILL BE OVER THE EASTERN/SOUTHEAST WATERS. STRONGEST LAND WINDS WILL BE OVER THE OUTER CAPE AND ISLANDS...DIMINISHING FARTHER WEST. HAVE FEATURED 45 KNOTS FOR THE STRONGEST WINDS AND 20-25 KNOTS IN THE INTERIOR. THE COASTAL STORM WILL PASS US IN PIECES SATURDAY AND LATER SATURDAY NIGHT...AS NOTED ABOVE. EXPECT PRECIPITATION TO DIMINISH WEST TO EAST AFTER MIDNIGHT AND END ON THE MASS EAST COAST AROUND OR SHORTLY AFTER SUNRISE SUNDAY. TEMPERATURES THROUGH MOST OF THE STORM SHOULD REMAIN FAVORABLE FOR RAIN. AS THE WINDS SHIFT FROM NORTHEAST TO NORTHWEST SATURDAY NIGHT...COLDER AIR WILL BE DRAWN IN WHICH COULD CHANGE THE LAST SHOWERS OVER TO SNOW. ANY ACCUMULATIONS SHOULD BE NO MORE THAN A TRACE. SOME HIGHLANDS SUCH AS IN THE MONADNOCK COULD PICK UP A LIGHT ACCUMULATION AT STORM/S END. DRIER AIR SUNDAY WILL BRING CLEARING SKIES. COLD ADVECTION WILL PROMOTE MIXING THROUGH AT LEAST 850 MB. WINDS IN THIS LAYER WILL BE 35 TO 40 KNOTS...SO EXPECT NORTHWEST GUSTS TO AT LEAST THE LOWER END OF THIS RANGE. WINDS DIMINISH SUNDAY NIGHT AS THE STORM MOVES FARTHER AWAY. MONDAY-TUESDAY... HIGH PRESSURE BUILDS OVER THE REGION. MONDAY SHOULD BE SUNNY AS THE HIGH MOVES OVERHEAD. MIXING WILL AGAIN BRING INCREASED WIND GUSTS DURING THE AFTERNOON. WINDS IN THE MIXED LAYER ARE EXPECTED AROUND 30 KNOTS WITH POTENTIAL FOR A LITTLE STRONGER SPEEDS. WINDS WILL DIMINISH WITH SUNSET. THE HIGH MOVES OFFSHORE TUESDAY. THIS WILL MAKE ROOM FOR A WARM FRONT TO SWING PAST. SUFFICIENT LIFT AND MOISTURE TO SUPPORT MID AND HIGH CLOUDS...BUT THE BEST WARM FRONTAL LIFT WILL REMAIN TO OUR NORTH AND WEST SO EXPECT AT LEAST SOME SUN THROUGH THE DAY. WEDNESDAY-THURSDAY... LOW CONFIDENCE ON MIDWEEK WEATHER. AT LEAST ONE TROUGH IN THE ZONAL FLOW WILL SWING ACROSS THE REGION DURING THIS TIME. GFS AND ECMWF ARE HINTING AT ONE ON WEDNESDAY...BUT SHOWING A MORE SUBSTANTIAL TROUGH PASSING ON THURSDAY. THE FORECAST WILL HAVE CLOUDS AND LOW-END CHANCE OR SLIGHT CHANCE POPS.
-- End Changed Discussion --
&& .AVIATION /03Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. OVERNIGHT AND FRIDAY...HIGH CONFIDENCE. VFR. FRIDAY NIGHT...MODERATE CONFIDENCE. CONDITIONS DETERIORATE THROUGH THE NIGHT TO MVFR/IFR FROM SOUTH TO NORTH. RAIN/SHOWERS EXPECTED ALONG THE SOUTH COAST AND INTO SOUTHEASTERN MASSACHUSETTS AS WE NEAR DAYBREAK SATURDAY. KBOS...HIGH CONFIDENCE IN TAF. KBDL...HIGH CONFIDENCE IN TAF. OUTLOOK...SATURDAY THROUGH TUESDAY...MODERATE CONFIDENCE SATURDAY-SUNDAY...IFR CIGS AND MVFR OR IFR VSBYS IN PERIODS OF RAIN SATURDAY AND SATURDAY NIGHT. VFR AND DRIER WEATHER MOVE IN FROM WEST TO EAST EARLY SUNDAY. NORTHEAST WINDS SATURDAY GUSTING 30-40 KNOTS ON THE CAPE AND ISLANDS AND 25-30 KNOTS IN THE COASTAL PLAIN. WINDS SHIFT TO NORTH SATURDAY NIGHT AND NORTHWEST ON SUNDAY WITH GUSTS 40- 45 KNOTS CAPE AND ISLANDS AND 30-35 KNOTS ACROSS SOUTHERN NEW ENGLAND. MONDAY...VFR. DAYTIME WIND GUSTS WILL INCREASE TO NEAR 30 KNOTS INLAND AND 35 KNOTS CAPE AND ISLANDS...DIMINISHING TOWARD EVENING. TUESDAY...VFR WITH INCREASING HIGH CLOUDS.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH FRIDAY NIGHT/...HIGH CONFIDENCE. HIGH PRESSURE DOMINATES THROUGH FRIDAY WITH WINDS AND SEAS REMAINING BELOW SMALL CRAFT CRITERIA. WINDS SHIFT FROM THE NORTHWEST TO THE NORTHEAST THEN EAST DURING FRIDAY. THESE EASTERLY WINDS AND SEAS INCREASE FRIDAY NIGHT AS LOW PRESSURE APPROACHES THE WATERS FROM THE CAROLINAS. SMALL CRAFT ADVISORIES HAVE BEEN ISSUED FOR ALL OF THE WATERS FOR AT LEAST A PORTION OF FRIDAY NIGHT. OUTLOOK...SATURDAY THROUGH TUESDAY...MODERATE CONFIDENCE. SATURDAY...STRONG POTENTIAL FOR HIGH END GALES ON THE OUTER WATERS WITH GUSTS TO 45 KNOTS. LOW POTENTIAL OF STORM FORCE WINDS ON THE OUTER WATERS. RAIN WITH INCREASING NORTHEAST WINDS. GALE FORCE GUSTS EXPECTED ON MOST WATERS.WAVEWATCH MODEL FORECASTS OF SEA HEIGHTS ARE LOWER THAN OUR PREVIOUS FORECAST. WE HAVE BUMPED SEAS UP 2-3 FEET WITH 15 FOOT SEAS DEVELOPING EAST OF MASSACHUSETTS. A MARINE WEATHER STATEMENT CONTINUES TO ADDRESS THIS CONCERN. SUNDAY...RAIN MOVES OFF TO THE EAST. WINDS SHIFT NORTHWEST WITH GALE FORCE GUSTS 40-45 KNOTS. EXPECT THESE WINDS TO DIMINISH BELOW GALE FORCE SUNDAY NIGHT. WITH THE WIND SHIFT...THE ROUGH SEAS WILL MIGRATE FARTHER OFFSHORE WITH DIMINISHING SEAS CLOSER TO SHORE. GALE WARNINGS WILL LIKELY LINGER INTO THE EVENING HOURS. MONDAY... GUSTY NORTHWEST WINDS WITH SPEEDS APPROACHING GALE FORCE AGAIN DURING THE DAY. WINDS DIMINISH TOWARD EVENING. SEAS WILL LINGER AT 5-9 FEET ESPECIALLY ON THE OUTER WATERS. SMALL CRAFT ADVISORY IS LIKELY...LOW-END CHANCE THAT GALES MAY BE NEEDED ON SOME OF THE WATERS. TUESDAY...WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT LEVELS.
-- End Changed Discussion --
&& .TIDES/COASTAL FLOODING... ASTRONOMICAL HIGH TIDES ARE RATHER LOW SATURDAY EVENING AND AGAIN EARLY SUNDAY MORNING. HOWEVER...STRONG NORTHERLY WINDS AND HIGH SEAS WILL HAVE THE POTENTIAL TO RESULT IN MINOR COASTAL FLOODING AND BEACH EROSION ALONG THE EASTERN MA COAST...PARTICULARLY THE NORTH SIDE OF CAPE COD AND NANTUCKET HARBOR DURING BOTH HIGH TIDE CYCLES. THE MAIN UNCERTAINTY REVOLVES AROUND WHEN AND HOW STRONG THE WINDS/SEAS WILL GET. THE MODELS SEEM TO BE SHOWING TWO PULSES OF WIND WITH TWO WAVES OF LOW PRESSURE. THE FIRST ONE APPEARS TO BE SATURDAY EVENING WITH THE SECOND ONE SUNDAY MORNING. THE POTENTIAL CONTINUES FOR WIND GUSTS UP TO 50 KNOTS AND SEAS BUILDING TO 20 FEET ACROSS THE OPEN WATERS EAST OF MASSACHUSETTS. THE TREND OF THE 12Z GUIDANCE HAS BEEN TO SHOW THE STRONGEST WINDS/HIGHEST SEAS WITH THE SATURDAY EVENING PULSE. WILL HAVE TO WAIT AND SEE HOW THE MODELS TREND...BUT STILL FEEL BOTH HIGH TIDE CYCLES ARE AT RISK WITH A 1 TO 2 FOOT STORM SURGE. AREAS OF GREATEST CONCERN APPEAR TO BE THE NORTH SIDE OF CAPE COD...SUCH AS SANDWICH...BARNSTABLE...DENNIS...BREWSTER AND POSSIBLY EASTHAM. OTHER TYPICAL HOT SPOTS WILL BE SALISBURY AND PLUM ISLAND...HULL...SCITUATE AND PERHAPS SANDWICH HARBOR AND NANTUCKET HARBOR. AGAIN...THE MAIN CONCERNS WILL BE MINOR COASTAL FLOODING AS WELL AS BEACH EROSION. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT FRIDAY NIGHT TO 8 AM EDT SATURDAY FOR ANZ231>234-250. SMALL CRAFT ADVISORY FROM 5 AM TO 8 AM EDT SATURDAY FOR ANZ230- 236-251. SMALL CRAFT ADVISORY FROM 8 PM FRIDAY TO 8 AM EDT SATURDAY FOR ANZ235-237-254>256. && $$ SYNOPSIS...WTB/RLG NEAR TERM...WTB/EVT SHORT TERM...RLG LONG TERM...WTB AVIATION...WTB/RLG MARINE...WTB/RLG/EVT TIDES/COASTAL FLOODING...STAFF

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