Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 122328 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 728 PM EDT SAT APR 12 2014 .SYNOPSIS... HIGH PRESSURE MOVES OFFSHORE TONIGHT. A WARM FRONT WILL LIFT NORTH ACROSS THE REGION SUNDAY BRINGING EVEN MILDER TEMPERATURES INTO MONDAY. A SLOW MOVING FRONT WILL BRING A SOAKING RAIN TUESDAY INTO TUESDAY NIGHT FOLLOWED BY DRY AND MUCH COOLER CONDITIONS FOR THE MIDDLE AND END OF THE WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
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715 PM UPDATE... ONLY MINOR TWEAKS NEEDED THIS EVENING TO BRING THE NEAR TERM FORECAST BACK IN LINE WITH OBSERVED TRENDS. DRY WEATHER TO PREVAIL OVERNIGHT ACROSS MOST OF SOUTHERN NEW ENGLAND. PREVIOUS DISCUSSION... WARM FRONT EXTENDING EAST FROM THE GREAT LAKES WILL MOVE INTO CENTRAL NY BY DAYBREAK. MODELS SHOW GOOD ISENTROPIC LIFT DEVELOPING TO THE NORTH OF THE FRONT...PRIMARILY ACROSS NORTHERN NY INTO VT WHERE SHOWERS ARE MOST LIKELY OVERNIGHT. EXPECT AN INCREASE IN MID/HIGH CLOUDS TONIGHT...ESPECIALLY N ZONES BUT LOW LEVELS REMAIN QUITE DRY SO WE WILL KEEP A DRY FORECAST TONIGHT. MIN TEMPS UPPER 30S TO MID 40S.
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&& .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... SUNDAY...SFC WARM FRONT LIFTS NORTH ACROSS THE REGION. BEST MOISTURE AND LIFT REMAINS TO THE NORTH...BUT LOW LEVELS MOISTEN UP AND THERE COULD BE A FEW SHOWERS IN THE MORNING MAINLY ACROSS N MA AND S NH. ECMWF IS MOST AGGRESSIVE WITH THE SHOWERS BUT WE FOLLOWED NAM/GFS SOLUTION WHICH KEEP BULK OF RAIN TO THE NORTH. MOST CLOUD COVER WILL BE ACROSS NORTHERN AREAS...OTHERWISE PTSUNNY SKIES EXPECTED. SW LOW LEVEL JET STRENGTHENS ACROSS THE REGION AND IT WILL BECOME BREEZY WITH WIND GUSTS TO 30 MPH. MIXING DEPTH IS SHALLOW BUT MAX TEMPS EXPECTED TO REACH INTO THE LOWER 70S IN THE INTERIOR VALLEYS. COOLEST TEMPS NEAR THE S COAST WITH READINGS IN THE UPPER 50S TO LOWER 60S. SUNDAY NIGHT... WARM FRONT LIFTS TO THE NORTH AND REGION WILL BE IN THE WARM SECTOR LEADING TO A MILD NIGHT WITH MINS IN THE UPPER 40S TO LOWER 50S. HIGHER DEWPOINT AIR MOVING OVER THE COLDER OCEAN WILL LEAD TO DEVELOPMENT OF STRATUS AND FOG WHICH IS EXPECTED TO MOVE INLAND ACROSS THE SOUTH COAST. && .LONG TERM /MONDAY THROUGH SATURDAY/... HIGHLIGHTS... * ABOVE AVERAGE TEMPERATURES ARE EXPECTED MONDAY * STRONG COLD FRONTAL PASSAGE NEXT TUES/WED * BELOW AVERAGE TEMPERATURES RETURN FOR THE REMAINDER OF THE WORK WEEK MODELS AND CONFIDENCE... HAVE HIGH CONFIDENCE IN THE WARMING TREND IN THE FORECAST OVER THIS WEEKEND...WITH MODERATE CONFIDENCE FOR THE TIMING OF A LOW PRESSURE TOWARD THE MIDDLE OF NEXT WEEK. INCREASING CONFIDENCE THAT PRECIP WILL OCCUR DURING THE MID-WEEK...BUT THE EXACT TIMING AND LOCATION OF MODERATE RAINFALL ARE STILL UNCERTAIN. IN FACT GUIDANCE IS TRYING TO STALL A FRONT JUST SOUTH OF THE AREA. HAVE LOW CONFIDENCE THAT THIS WILL OCCUR. FINALLY...BELIEVE TEMPS WILL DROP BELOW AVERAGE BY WEDNESDAY. OVERALL 12/12Z MODEL GUIDANCE IS GENERALLY IN GOOD AGREEMENT. FOR EARLY NEXT WEEK...THE UPPER PATTERN WILL BEGIN TO FAVOR A DIGGING TROUGH ACROSS THE CENTRAL CONUS AS UPPER LEVEL RIDGING BUILDS OVER BOTH COASTLINES. THIS WILL PUSH A WAVY COLD FRONT ACROSS THE CONUS AND INTO SOUTHERN NEW ENGLAND BY TUES/WED. THE UPPER LEVEL FLOW APPEARS TO RAPIDLY FLATTEN...LEAVING THIS FRONT OVER THE WESTERN ATLANTIC FOR THE REST OF THIS FORECAST PERIOD. THE DETERMINISTIC AND ENSEMBLE GUIDANCE CONTINUE TO SHOW BETTER AGREEMENT ON THE EVOLUTION OF THIS SYSTEM. THE 12/12Z ECMWF SHOWED A COASTAL LOW DEVELOPING ALONG THIS STALLED FRONT AND MOVING CLOSER TO SOUTHERN NEW ENGLAND. THIS STILL APPEARS TO BE AN OUTLIER SOLUTION. WILL CONTINUE TO FAVOR A STRONG HIGH PRESSURE DOMINATING OUR WEATHER THROUGH THE END OF NEXT WEEK BEHIND A COLD FRONT. DETAILS... MONDAY... AS A WARM FRONT MOVES THROUGH NEW ENGLAND...EXCELLENT WARM AIR ADVECTION WILL DEVELOP. SOUNDINGS SHOW BOUNDARY LAYER MIXING TO ABOUT 900 MB. WITH 925 MB TEMPS AROUND 14-16C...HIGH TEMPERATURES WILL FLIRT INTO THE MID TO PERHAPS UPPER 70S. IF THE ATMOSPHERE IS SUPER ADIABATIC AND CLOUD COVER AHEAD OF THE FRONT BREAKS UP... THEN TEMPERATURES MAY REACH 80F...ESPECIALLY NORTH OF THE MA PIKE. HOWEVER IF YOU ARE ALONG THE SOUTH COASTLINE...SOUTHERLY WINDS WILL BRING THE COOL MARITIME AIR ONSHORE...KEEPING TEMPS IN THE LOWER 60S. 925 MB LOW LEVEL JET WILL BE INCREASING THROUGHOUT THE DAY AS AN ANOMALOUS COLD FRONT APPROACHES FROM THE WEST. THIS LOW LEVEL JET WILL INCREASE TO ABOUT 40-50 KT. WITH EXCELLENT MIXING IN PLACE...WE COULD SEE GUSTS BETWEEN 25-35 MPH...AND POSSIBLY FLIRT WITH WIND ADVISORY CRITERIA. MONDAY NIGHT INTO WEDNESDAY.... GUIDANCE IS BEGINNING TO CLUSTER MORE ON THE TIMING AND INTENSITY OF AN APPROACHING COLD FRONTAL SYSTEM. THE LATEST GUIDANCE CONTINUE TO INDICATE SEVERAL WAVES WILL DEVELOP ALONG THIS SLOW MOVING COLD FRONT...ALLOWING FOR MULTIPLE CHANCES FOR MODERATE TO HEAVY RAINFALL. ANTICIPATING A FEW SHOWERS TO DEVELOP AHEAD OF THE FRONT MONDAY NIGHT INTO TUESDAY EARLY MORNING. BUT AS SOON AS THE FRONT APPROACHES EXPECT MODERATE TO HEAVY RAINFALL TO FALL. THIS PRECIP MAY CAUSE URBAN AND POOR DRAINAGE FLOODING...AND IT MAY ALSO HELP ELEVATE THE RIVER LEVELS IF EVERYTHING LINES UP. GUIDANCE IS SHOWING EXCELLENT MOISTURE TRANSPORT...AND PRECIPITABLE WATER VALUES ARE OVER 1.5 INCHES...WHICH IS 4 STANDARD DEVIATIONS ABOVE NORMAL. VERY STRONG COLD AIR ADVECTION WILL OCCUR AS THIS FRONT PASSES THROUGH BY WEDNESDAY. THIS WILL LIKELY RESULT IN AN INCREASE OF WIND SPEEDS IMMEDIATELY BEHIND THIS FRONT. TEMPERATURES ARE EXPECTED TO DROP VERY QUICKLY BEHIND THIS FRONT TUESDAY NIGHT. IF ANY PRECIP LINGERS BEHIND THE MAIN FRONT...WE COULD HAVE SOME MIXED PRECIPITATION...ESPECIALLY ACROSS THE BERKSHIRES AND IN SOUTHERN NEW HAMPSHIRE. CURRENT THINKING IS DRIER AIR ARRIVES QUICKLY TUESDAY EVENING...MAKING THIS MORE OF A MINOR RISK. LASTLY WITH THE STRONG ONSHORE FLOW FROM THE SOUTH...WE WILL NEED TO WATCH FOR THE POTENTIAL FOR SOME MINOR SPLASHOVER ALONG THE SOUTH SHORE AND INTO NARRAGANSETT BAY. TIDES ARE SLOWLY INCREASING WITH HIGH ASTRONOMICAL TIDE PEAKING NEXT FRIDAY/SATURDAY. HOWEVER WE WOULD NEED CLOSE TO A 2 FT SURGE INTO NARRAGANSETT BAY AND A 5 FT SURGE ALONG THE SOUTH COAST TO RESULT IN COASTAL ISSUES. YET THE BIGGEST CONCERN ACROSS THE SOUTH COASTLINE WOULD BE THE POTENTIAL WAVE ACTION AHEAD OF A COLD FRONT. THURSDAY THROUGH SATURDAY... STRONG HIGH PRESSURE WILL QUICKLY USHER INTO THE REGION BEHIND A STALLED FRONT TO OUR SOUTH. TEMPERATURES WILL DROP WELL BELOW NORMAL. WE WILL NEED TO MONITOR THE FRONT FOR ANY POTENTIAL WAVES THAT COULD DEVELOP ALONG IT ON THURSDAY OR FRIDAY. RIGHT NOW BELIEVE THAT THE HIGH PRESSURE WILL WIN OUT...OVERALL HAVE MODERATE CONFIDENCE IN THE CURRENT FORECAST. && .AVIATION /23Z SATURDAY THROUGH THURSDAY/... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SUNDAY NIGHT/... THROUGH TONIGHT...HIGH CONFIDENCE. VFR. SOUTH COAST SEABREEZES DEVELOPING. SUNDAY...MODERATE CONFIDENCE. MAINLY VFR WITH LOW PROB OF A FEW SHOWERS NORTH OF ROUTE 2. BRIEF MVFR CIGS MAY DEVELOP AROUND MIDDAY NEAR THE SOUTH COAST BUT CONFIDENCE IS LOW. GUSTY SW WINDS DEVELOPING WITH GUSTS TO 25 KT. SUNDAY NIGHT...IFR STRATUS AND FOG DEVELOP MAY DEVELOP NEAR THE S COAST BUT LOW CONFIDENCE ON AREAL EXTENT. INCREASING LOW LEVEL JET WILL LEAD TO AREAS OF LLWS. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. WE LEFT A SEABREEZE OUT OF THE TAF AS THERE SHOULD BE ENOUGH MIXING TO KEEP IT OFFSHORE. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...MONDAY THROUGH THURSDAY... MONDAY...MODERATE CONFIDENCE. LOCAL MVFR-IFR CIGS/VSBYS ALONG S COAST EARLY MON SHOULD IMPROVE...OTHERWISE VFR. S-SW WINDS GUSTING UP 25-35 KTS. TUESDAY-WEDNESDAY...LOW CONFIDENCE. EXPECT MVFR CONDITIONS TO DEVELOP FROM W-E DURING TUE IN RAIN SHOWERS. PERIODS OF HEAVY RAIN POSSIBLE TUE AFTERNOON/EVENING ACROSS CENTRAL AND WESTERN AREAS WITH AREAS OF IFR. PRECIP MAY MIX WITH LIGHT SNOW AND/OR SLEET ACROSS S NH/W MA BEFORE ENDING LATE TUE NIGHT OR WED MORNING. CONDITIONS SHOULD IMPROVE TO VFR FROM W-E DURING WED. THURSDAY...MODERATE CONFIDENCE. VFR. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SUNDAY NIGHT/...HIGH CONFIDENCE. SCA FOR SEAS REMAIN IN EFFECT FOR THE SOUTHERN WATERS WHERE SEAS HOVERING AROUND 5 FT. EXPECT SEAS TO SUBSIDE THIS EVENING. LIGHT WINDS TONIGHT...THEN INCREASING SW FLOW DEVELOPING SUNDAY AFTERNOON INTO SUN NIGHT AS LOW LEVEL JET STRENGTHENS OVER THE WATERS. HOWEVER...STRONG INVERSION WILL LIMIT GUSTS AND BEST CHANCE FOR GUSTS TO 25 KT WILL BE OVER NEARSHORE WATERS AND ESPECIALLY BOS HARBOR AND NARRAGANSETT BAY. SEAS WILL BE BUILDING TO 5-7 FT OVER THE OUTER WATERS SUN AFTERNOON INTO SUN NIGHT. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED. AREAS OF FOG LIKELY SUN NIGHT WHICH WILL REDUCE VSBYS. OUTLOOK...MONDAY THROUGH THURSDAY... MONDAY...HIGH CONFIDENCE. AREAS OF FOG MAY LINGER INTO MID-MORNING. DURING THE DAY...EXPECT S-SW WINDS TO GUST UP TO 25 KTS DURING THE DAY. FOG WILL DEVELOP AGAIN MONDAY NIGHT. SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED. TUESDAY INTO THURSDAY...MODERATE CONFIDENCE. STRONG COLD FRONT WILL MOVE ACROSS THE WATERS TUESDAY INTO WEDNESDAY. EXPECTING GUSTY WINDS AROUND THIS FRONT DUE TO STRONG COLD AIR ADVECTION. SEAS WILL BUILD IN RESPONSE AND MAY START RELAXING LATE WEDNESDAY INTO THURSDAY. THERE IS A LOW PROBABILITY OF GALES TUESDAY EVENING INTO THE OVERNIGHT HOURS. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED...ESPECIALLY ACROSS THE OUTER COASTAL WATERS. && .HYDROLOGY...
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NERFC FORECASTS BRING LOWER CT RIVER FROM HARTFORD THROUGH MIDDLE HADDAM INTO MINOR FLOOD STARTING DURING SUNDAY...BASED ON WATER BEING ROUTED DOWNSTREAM FROM THE UPPER CT BASIN. FLOOD WARNINGS ISSUED FOR THE CT RIVER AT HARTFORD AND AT MIDDLE HADDAM. THOSE WITH INTERESTS ALONG LOWER REACHES OF CT RIVER SHOULD PAY ATTENTION TO THE LATEST FORECASTS AND CURRENT WATER LEVELS.
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&& .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM EDT THIS EVENING FOR ANZ254>256. && $$ SYNOPSIS...BELK/KJC NEAR TERM...BELK/KJC SHORT TERM...KJC LONG TERM...BELK/99 AVIATION...BELK/KJC/99 MARINE...BELK/KJC/99 HYDROLOGY...STAFF

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