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 040925 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 425 AM EST THU FEB 4 2016 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL MOVE ACROSS THE REGION EARLY THIS MORNING. THE COLD FRONT WILL STALL JUST OFF THE COAST...THEN LOW PRESSURE WILL DEVELOP ALONG THE MID ATLC COAST TONIGHT AND TRACK ALONG THE FRONT PASSING SOUTH AND EAST OF NANTUCKET FRIDAY. THIS STORM WILL LIKELY BRING ACCUMULATING SNOW TO SOUTHEAST NEW ENG LATE TONIGHT INTO FRIDAY. HIGH PRESSURE BRINGS DRY WEATHER OVER THE WEEKEND...ALTHOUGH A WEAK COLD FRONT SUNDAY MAY BRING A FEW CLOUD. A COMPLEX COASTAL STORM SHOULD AFFECT THE REGION LATER MONDAY INTO TUESDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... 1 AM UPDATE... BULK OF THE PRECIP HAS MOVED OVER THE CAPE AND ISLANDS THIS MORNING. SCATTERED SHOWERS CONTINUE TO DEVELOP ACROSS UPSTATE NY AND WILL MOVE INTO WESTERN MASS OVER THE NEXT FEW HOURS. THIS IS IN LINE WITH SHORTWAVE MOVING THROUGH THE FLOW. OTHERWISE FORECAST REMAINS ON TRACK EARLY THIS MORNING. PREVIOUS DISCUSSION... SEVERAL UPDATES TO THIS FORECAST AS WAA/HIGHER THETA-E VALUE RAIN CONTINUES TO PUSH EASTWARD OVER THE NEXT FEW HOURS. BULK OF THE RAIN IS NOT AT A BOS TO PVD LINE AND POINTS EASTWARD. SHOULD MOVE OFFSHORE AFTER MIDNIGHT. HOWEVER LOOKING UPSTREAM...A FEW SHOWERS CONTINUE TO DEVELOP ACROSS UPSTATE NY WHERE SURFACE COLD FRONT IS LOCATED. CANNOT RULE OUT A FEW ISOLATED SHOWERS TO DEVELOP OVERNIGHT BEHIND THE RAIN AS WEAK SHORTWAVE MOVES THROUGH THE FLOW. GUSTY WINDS WILL CONTINUE OVERNIGHT AS POTENT LLJ CONTINUES TO STRENGTHEN OVER SOUTHERN NEW ENGLAND. THIS JET SEAMS TO STALL OVER THE CAPE AND ISLANDS KEEPING GUSTS UP DURING THE OVERNIGHT HOURS. HAVE RECEIVED A LOT OF DAMAGE REPORTS EVEN THOUGH GUSTS ARE IN 30-40 MPH RANGE. A FEW LOCATIONS HAVE GUSTED TO 45 MPH BUT THAT HAS BEEN FOCUSED ACROSS THE HIGHER TERRAIN AND ACROSS NORTHEAST MASS...WHICH IS NEAR THE CORE OF THE JET. GUSTY WINDS SHOULD BEGIN TO SUBSIDE AFTER MIDNIGHT FROM WEST TO EAST. LASTLY ONE THING TO KEEP A CLOSE EYE ON IS THE FOG POTENTIAL. HAVE NOTICED DOWN STREAM THAT SEVERAL SITES HAVE DROPPED DOWN TO DENSE FOG...ESP ACROSS EASTERN PA. WILL NEED TO CONTINUE TO MONITOR AS THE REGION IS IN A VERY MOIST AIRMASS AND IF SKIES END UP CLEARING A BIT...THEN VSBYS WILL GO DOWN. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/... THE COLD FRONT STALLS OFF THE SOUTH COAST OF SOUTHERN NEW ENGLAND THURSDAY MORNING. THIS WILL KEEP SOME SHOWERS ON THE SOUTH COAST THROUGH MUCH OF THE DAY. THE BIG STORY FOR THURSDAY WILL BE THE TEMPERATURES. AFTER STARTING OUT WITH MINS WARMER THAN OUR NORMAL MAXES...TEMPS WILL CLIMB QUICKLY THROUGH THE MORNING INTO THE 50S TO EVEN AROUND 60 ON THE COASTAL PLAIN. AS WINDS SHIFT TO THE NORTHWEST DURING THE AFTERNOON...EXPECT TEMPERATURES TO COOL BACK INTO THE 40S. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... BIG PICTURE... LONGWAVE SCALE PATTERN SHOWS DIGGING TROUGH EAST AND BUILDING RIDGE WEST. THIS POINTS TO COLDER AND MORE UNSETTLED WEATHER OVER THE WEEKEND AND FIRST HALF OF NEXT WEEK. SEVERAL SHORTWAVES MOVE THROUGH THE EASTERN TROUGH WITH CONTINUED VARIATIONS BETWEEN MODELS ESPECIALLY ON POSITIONS AND EFFECTS. TWO KEY SHORTWAVES ARE EITHER OVER THE PACIFIC OR JUST MOVING ASHORE OVER THE WESTERN USA AND ITS DENSER OBSERVATION NETWORK. THEREFORE CHANGEABLE RUN-RUN DIFFERENCES IN THE MODELS ARE TO BE EXPECTED. CONFIDENCE FOR THE EVOLVING WEATHER FOR EARLY NEXT WEEK REMAINS LOW. THE DAILIES... FRIDAY NIGHT-SATURDAY... HIGH PRESSURE BUILDS OVER THE REGION. EXPECT DRY WEATHER WITH CLEAR SKIES FRIDAY NIGHT AND INCREASING MID AND HIGH CLOUDS SATURDAY. OBSERVED TEMPS UPSTREAM UNDER THE RIDGE SUGGEST MIN TEMPS HERE IN THE 20S. MIXING SHOULD REACH A LITTLE ABOVE 900 MB...WITH TEMPS AT THE TOP OF THE LAYER SUPPORTING MAX SFC TEMPS IN THE LOWER 40S. SUNDAY... NORTHERN STREAM SHORTWAVE SWEEPS SOUTH AND EAST FROM CENTRAL CANADA TO QUEBEC AND NEW ENGLAND. THIS DRIVES A COLD FRONT THROUGH OUR AREA EARLY SUNDAY. MOISTURE FIELDS ARE MORE ROBUST IN NORTHERN NEW ENGLAND AS IS THE DYNAMICS. EXPECT SOME SKY COVER LATE SATURDAY NIGHT AND PART OF SUNDAY BUT AT BEST SOME WIDELY SCATTERED MORNING SNOW SHOWERS. MODEL GUIDENCE BRINGS MAX SFC TEMPS INTO THE 40S. BUT AFTERNOON MIXING SUGGESTS HIGHS IN THE MID AND UPPER 30S. WILL NUDGE MODEL FORECAST DOWN 1-2 DEGREES. MONDAY-TUESDAY... SOUTHERN STREAM SHORTWAVE STARTS TODAY OVER THE PACIFIC NORTHWEST AND CROSSES TO THE SOUTHEAST USA...FORMING A CLOSED UPPER LOW ALONG THE CAROLINA COAST SUNDAY. THE LOW THEN PASSES WELL OFFSHORE OF NANTUCKET ON MONDAY. MODEL SOLUTIONS FOR THE UPPER LOW DIVERGE BY SUNDAY WITH THE ECMWF FARTHEST WEST AND CLOSEST TO THE ATLANTIC COAST. IN MOST CASES THE CLOUDS AND PCPN STAY WELL OFFSHORE. BUT THE ECMWF IS CLOSE ENOUGH AND BRINGS ENOUGH OF AN EAST FLOW TO BRING MEASUREABLE PCPN TO SOUTHERN NEW ENGLAND. AS IT IS THE OUTLIER SOLUTION WE WOULD TEND TO DISCOUNT IT. BUT WITH DIGGING TROUGH OVER THE MIDWEST/APPALACHIANS AND BENDING OF THE FLOW MORE UP THE COAST...A MORE WESTERN TRACK IS IN THE REALM OF POSSIBILITY. THIS WILL NEED TO BE MONITORED. WE WILL BRING SLIGHT CHANCE POPS TO SOUTHERN NEW ENGLAND MONDAY AND VERY-LOW-END CHANCE POPS TO CAPE COD AND ISLANDS. THE NEXT SHORTWAVE STARTS SOUTH OF THE ALEUTIANS THIS MORNING AND MOVES ACROSS THE PACIFIC NORTHWEST FRIDAY NIGHT TO THE WESTERN LAKES SUNDAY. IT THEN DIGS AND CARVES A DEEP TROUGH/CLOSED LOW OVER THE EASTERN USA WITH A SOUTH-TO-NORTH FLOW OVER THE EASTERN USA BY MONDAY EVENING. AT THIS TIME THE BEST CHANCE FOR PCPN LOOKS TO BE MONDAY NIGHT AND TUESDAY. TEMPERATURES BEHIND SUNDAY/S FRONT AND WITH THE DIGGING UPPER TROUGH SUGGEST MAINLY SNOW. UNCERTAINTIES IN THE EVOLUTION AND TRACK OF THE SURFACE SYSTEM LEAVE THE CHANCE OF A CHANGE TO RAIN IN THE COASTAL PLAIN TUESDAY. WEDNESDAY... YET ANOTHER SHORTWAVE MOVES THROUGH THE TROUGH AND KICKS IT NORTHEAST THROUGH NEW ENGLAND INTO THE MARITIMES. THIS SHOULD BRING DRYING AND IMPROVING SKIES BUT WITH LINGERING WIDELY SCATTERED SNOW SHOWERS AS THE COLD POOL SWINGS OVERHEAD. && .AVIATION /10Z THURSDAY THROUGH MONDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH FRIDAY/...MODERATE CONFIDENCE. BEFORE 12Z...MAINLY MVFR/IFR CONDITIONS. HEAVY RAIN MAY LINGER ACROSS THE CAPE AND ISLANDS. OTHERWISE EXPECT ONLY SCT SHOWERS THROUGH THE OVERNIGHT HOURS. GUSTY WINDS WILL SUBSIDE AFTER 9Z. TODAY...HIGH CONFIDENCE. IMPROVEMENT TO VFR ACROSS THE AREA ALTHOUGH CLOUDS WILL LINGER THROUGH MUCH OF THE DAY. CANNOT RULE OUT A STRAY SHOWER BEFORE 15Z. TONIGHT INTO FRIDAY...VFR FOR WESTERN MASS. HIGH CONFIDENCE IN IFR/LIFR DEVELOPING SE NEW ENG AND CAPE/ISLANDS WITH RAIN CHANGING TO ACCUMULATING SNOW LATE THU NIGHT INTO FRI MORNING...IMPROVING FRI AFTERNOON. LOW CONFIDENCE ON WHERE TRANSITION FROM IFR TO VFR OCCURS. ANTICIPATE ACCUMULATING SNOW FOR RUNWAYS. KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN TIMING OF WINDS/PRECIP. KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN TIMING OF WINDS/PRECIP. OUTLOOK...FRIDAY NIGHT THROUGH MONDAY... FRIDAY NIGHT THROUGH SUNDAY...MODERATE CONFIDENCE. VFR. MONDAY...LOW CONFIDENCE. POTENTIAL FOR MVFR CIGS/VSBYS IN DEVELOPING LIGHT RAIN/SNOW LATE IN THE DAY. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH FRIDAY/...HIGH CONFIDENCE. TONIGHT...MODERATE CONFIDENCE. STRONG SOUTHERLY WINDS WILL CONTINUE TO BUILD THROUGH THE EVENING AND INTO TONIGHT. HAVE UPGRADED THE SOUTHERN INNER WATERS TO GALE WARNINGS FOR THIS AFTERNOON AND INTO TONIGHT. SEAS INCREASE TO 6 TO 10 FEET ON THE OUTER WATERS AS A COLD FRONT MOVES ACROSS THE WATERS LATE TONIGHT INTO EARLY THURSDAY MORNING. THURSDAY...MODERATE CONFIDENCE. SEAS DIMINISH SLOWLY...ESPECIALLY ON THE EASTERN WATERS WHERE THE FRONT WILL MOVE THROUGH EARLIER. THE COLD FRONT STALLS ACROSS THE SOUTHERN WATERS WHICH WILL SLOW THE DIMINISHING OF THE SEAS. SMALL CRAFT ADVISORIES WILL NEED TO CONTINUE FOR SEAS ON MOST OF THE OUTER WATERS. SOUTHERLY WINDS WILL SLOWLY SHIFT TO THE NORTHWEST DURING THE AFTERNOON...REMAINING BELOW SMALL CRAFT CRITERIA. OUTLOOK...FRIDAY NIGHT THROUGH MONDAY...MODERATE CONFIDENCE... FRIDAY NIGHT...LOW PRESSURE MOVES OFF ACROSS NOVA SCOTIA AND HIGH PRESSURE BUILDS IN. NORTHWEST WINDS GUSTING TO 25 KNOTS WILL DIMINISH OVERNIGHT. SEAS 5 TO 9 FEET WILL ALSO DIMINISH. SMALL CRAFT ADVISORY WILL BE NEEDED FOR AT LEAST THE OUTER WATERS. SATURDAY-SUNDAY...SOUTHWEST WINDS SATURDAY BECOME NORTHWEST SUNDAY AS A COLD FRONT SWINGS ACROSS THE WATERS. A FEW GUSTS TO 25 KNOTS ARE POSSIBLE ESPECIALLY EAST OF CAPE ANN. SEAS 5 TO 6 FEET MAINLY ON THE OUTER WATERS. A SMALL CRAFT ADVISORY MAY BE NEEDED ON THE OUTER WATERS. SUNDAY NIGHT-MONDAY...NORTH WINDS TURNING NORTHEAST AND INCREASING WITH GUSTS TO AT LEAST 30 KNOTS. SEAS WILL SUBSIDE BELOW 5 FEET INITIALLY...BUT THEN INCREASE FROM THE SOUTH AGAIN MONDAY NIGHT. && .CLIMATE... RECORD HIGHS FOR FEB 4TH... BOS...64/1991 BDL...64/1991 PVD...66/1991 ORH...61/1991 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...WINTER STORM WATCH FROM LATE TONIGHT THROUGH FRIDAY AFTERNOON FOR MAZ017>023. RI...WINTER STORM WATCH FROM LATE TONIGHT THROUGH FRIDAY AFTERNOON FOR RIZ002-004>008. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ231>234-251. SMALL CRAFT ADVISORY UNTIL 7 AM EST FRIDAY FOR ANZ235-237. SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ250-254. SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR ANZ255-256. && $$ SYNOPSIS...WTB/RLG NEAR TERM...DUNTEN SHORT TERM...RLG LONG TERM...WTB/JWD AVIATION...WTB/RLG MARINE...WTB/RLG CLIMATE...

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