Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 270912 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 412 AM EST SAT DEC 27 2014 .SYNOPSIS... LARGE HIGH PRESSURE ACROSS THE MID ATLANTIC STATES WILL DRIFT EASTWARD OFF NORTH CAROLINA COAST THIS AFTERNOON. SOUTHWEST WINDS AROUND THIS HIGH WILL BRING DRY CONDITIONS WITH ABOVE NORMAL TEMPERATURES TO THE REGION. A COLD FRONT WILL BRING SCATTERED RAIN SHOWERS ON SUNDAY. LOW PRESSURE MAY PASS TO OUR SOUTH EARLY NEXT WEEK. OTHERWISE MAINLY DRY AND NEAR NORMAL TO BELOW NORMAL TEMPERATURES ARE EXPECTED FOR MUCH OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 4 AM UPDATE... SKIES WERE STILL MOSTLY CLEAR ACROSS SOUTHERN NEW ENGLAND WITH JUST SOME HIGH THIN CIRRUS CLOUDS. HOWEVER...OVERCAST LOW CLOUDINESS WAS CREEPING SOUTHWARD ACROSS SOUTHERN VERMONT AND SOUTHERN NEW HAMPSHIRE. THE 925 MB RH FIELD ON THE NAM DEPICTS THIS WELL AND INDICATES THAT IT WILL SPREAD INTO NORTHERNMOST MASSACHUSETTS...MAINLY NORTH OF ROUTE 2...INTO THE MID MORNING HOURS BEFORE RETREATING TO THE NORTHWEST FOR THE AFTERNOON. OTHERWISE...STRONG HIGH PRESSURE OFF THE MID ATLANTIC COAST WILL DOMINATE OUR WEATHER WITH A GOOD DEAL OF SUNSHINE AND A LIGHT SOUTHWESTERLY FLOW OF MILD AIR. 925 MB TEMPERATURES ARE FORECAST TO NOT BE QUITE AS HIGH AS WE THOUGHT LAST NIGHT...BUT STILL +3 TO +4.5C...SO WE ARE STILL EXPECTING HIGHS TO REACH INTO THE LOWER 50S IN SOUTHERN PORTIONS OF THE AREA...WITH UPPER 40S TO AROUND 50 IN THE NORTH. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... TONIGHT...LOW PRESSURE MOVES NE FROM THE GREAT LAKES INTO QUEBEC WITH ITS TRAILING COLD FRONT APPROACHING THE BERKSHIRES BY DAYBREAK SUNDAY MORNING. CLOUDS WILL BE ON THE INCREASE TONIGHT ACROSS OUR AREA IN ADVANCE OF THE FRONT. SCATTERED RAIN SHOWERS ARE POSSIBLE AFTER 3 AM IN THE SLOPES OF THE BERKSHIRES. HAVE GONE WITH A NON-DIURNAL TEMPERATURE TREND FOR TONIGHT. AM THINKING THAT IT WILL COOL DOWN EARLY IN THE EVENING BEFORE THE THICK CLOUD COVER COMES IN...THEN TEMPERATURES WILL HOLD NEARLY STEADY OR EVEN RISE A FEW DEGREES DURING THE OVERNIGHT HOURS. SUNDAY...A COLD FRONT WILL MOVE ACROSS SOUTHERN NEW ENGLAND BRINGING SCATTERED SHOWERS. HAVE UPPED PROBABILITIES TO 40-50 PERCENT. AMOUNTS ARE EXPECTED TO BE LIGHT...WITH LESS THAN ONE-QUARTER INCH OF RAINFALL FORECAST. SOUTHWEST WINDS WILL SHIFT TO THE NORTHWEST DURING THE AFTERNOON BEHIND THE FRONT. HIGHS WILL BE IN THE 40S BUT WE COULD SEE SOME 30S WORKING INTO WESTERN ZONES LATE IN THE DAY. THE OPERATIONAL GFS RUN WAS THE SLOWEST OF THE MODELS TO HAVE THE PRECIPITATION EXIT...AND A RESULT...IT WOULD IMPLY THAT THERE COULD EVEN BE A CHANCE OF A FEW SNOWFLAKES ON THE BACK END...OVER NORTHERN CT. HAVE DISCOUNTED THIS FOR NOW...THINKING THAT THE FRONT WILL MOVE STEADILY THROUGH AND THAT SHOWERS WILL HAVE ENDED BY THE TIME THE AIR GETS COLD ENOUGH TO SUPPORT SNOW. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... HIGHLIGHTS... * A LOW PRESSURE SYSTEM MAY PASS SOUTH OF OUR AREA EARLY NEXT WEEK * TURNING COLDER DURING THE WORK WEEK AND MAINLY DRY DETAILS... SUNDAY NIGHT THROUGH MONDAY...MODERATE TO HIGH CONFIDENCE. THERE IS THE POTENTIAL FOR AN OPEN WAVE DEVELOPING TO THE SOUTH OF OUR AREA ALONG THE COLD FRONT...AND AS A RESULT THERE MAY STILL BE LINGERING SHOWERS OVER THE SOUTHEASTERN ZONES SUNDAY NIGHT AND MONDAY. IN THAT AREA HAVE LOW TO SLIGHT CHANCE POPS...OTHERWISE DRY FOR MOST OF THE AREA WITH DECREASING CLOUDS EXPECTED ON MONDAY. TEMPERATURES SHOULD REMAIN WARM ENOUGH FOR THE PRECIP TYPE TO BE MAINLY RAIN...ALTHOUGH THERE IS A SLIGHT CHANCE FOR SNOW SHOWERS ON SUNDAY NIGHT OR MONDAY IF PRECIPITATION LINGERS. SUNDAY HIGH TEMPS ARE COOLER BUT STILL ABOVE NORMAL WITH HIGHS IN THE 40S. MONDAY`S HIGHS ARE CLOSE TO SEASONABLE...IN THE 30S TO LOW 40S. TUESDAY AND WEDNESDAY...MODERATE CONFIDENCE. THERE IS STILL SOME MODEL DISCREPANCIES DURING THIS PERIOD. HOWEVER THE 12Z OPERATIONAL GFS/ECMWF INDICATE MAINLY DRY CONDITIONS FOR MIDWEEK. GFS/ECMWF SHOW THE POTENTIAL FOR A COLD FRONT/SHORT WAVE CROSSING THE AREA NEXT WED...BUT NOT A LOT OF MOISTURE WITH THIS FEATURE SO CONTINUE TO THINK RESULT WILL BE LIMITED TO SOME CLOUDS. OTHERWISE OUR AREA IS IN THE PERIPHERY OF SURFACE HIGH PRESSURE. SOME GFS ENSEMBLE MEMBERS SHOW A LOW PRESSURE MAKING A PASS SOUTH OF OUR AREA...BUT CONFIDENCE CONTINUES TO BE LOW ON WHETHER THIS SCENARIO BRINGS PRECIPITATION AS FAR NORTH AS OUR AREA. CONTINUING WITH THE CONSENSUS DRIER SCENARIO FOR THIS FORECAST PACKAGE. A COOLING TREND IS EXPECTED THROUGH MIDWEEK. LOOKING FOR HIGHS IN THE MID 20S TO MID 30S AND LOWS IN THE MID TEENS TO MID 20S...NORMAL TO A FEW DEGREES COLDER THAN NORMAL. THURSDAY...MODERATE CONFIDENCE. OUR AREA IS MORE UNDER THE INFLUENCE OF HIGH PRESSURE CENTERED OVER THE SOUTHEASTERN U.S. THAN A DISTANT LOW PRESSURE...PASSING THROUGH HUDSON BAY AND NEWFOUNDLAND/LABRADOR. TIGHTENING PRESSURE GRADIENT BETWEEN THESE TWO FEATURES MAY MAKE FOR A BREEZY DAY. OTHERWISE DRY AND SEASONABLY COLD CONDITIONS ARE EXPECTED. FRIDAY...MODERATE CONFIDENCE. MODELS CONTINUE TO INDICATE HIGH PRESSURE OVER OUR AREA FOR FRIDAY...BUT THERE IS ALSO THE CONTINUED INDICATION OF A LOW PRESSURE SYSTEM APPROACHING FROM THE SOUTHWEST FRIDAY NIGHT. MAIN PRECIP CHANCES LOOK TO HOLD OFF UNTIL SAT...BUT SINCE THIS IS 7 DAYS OUT TIMING COULD EASILY CHANGE. AT THIS TIME FRIDAY IS EXPECTED TO BE DRY...WITH CHANCE POPS FRIDAY NIGHT IN WESTERN ZONES. && .AVIATION /09Z SATURDAY THROUGH WEDNESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SATURDAY NIGHT/... TODAY...MODERATE TO HIGH CONFIDENCE. VFR WITH MAINLY CLEAR SKIES AND JUST SOME HIGH CIRRUS CLOUDS OVER MOST OF THE REGION. ONLY EXCEPTION IS AN AREA OF LOW CLOUDINESS WITH CEILINGS NEAR MVFR SAGGING SOUTHWARD ACROSS SOUTHERN VT AND SOUTHERN NH. THESE ARE EXPECTED TO MOVE INTO NORTHERNMOST MA...NORTH OF ROUTE 2...UNTIL MID-MORNING AND THEN RETREAT NORTHWESTWARD THIS AFTERNOON. TONIGHT...MODERATE TO HIGH CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF MVFR CIGS/LOCAL MVFR VSBYS IN SCATTERED SHOWERS ACROSS WESTERN MA AND NW CT WELL AFTER MIDNIGHT. SUNDAY...MODERATE CONFIDENCE. MVFR CEILINGS AND VSBYS POSSIBLE IN SCATTERED RAIN SHOWERS. SW WINDS 10 TO 20 KT SHIFTING TO THE NW. KBOS TERMINAL...HIGH CONFIDENCE IN TAF. KBDL TERMINAL...HIGH CONFIDENCE IN TAF. OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY... SUNDAY NIGHT THROUGH WEDNESDAY...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/...MODERATE TO HIGH CONFIDENCE. TODAY...WINDS AND SEAS BELOW SMALL CRAFT ADVISORY CRITERIA. W WINDS BECOME SW AND MAY GUST TO AROUND 15 KT AT TIMES. SEAS WERE STILL RUNNING NEAR 5 FT AT BUOY 44097 SOUTHEAST OF BLOCK ISLAND. HOWEVER AM EXPECTING THEM TO SUBSIDE TO 4 FT THEN 3 FT FOR THE MAJORITY OF TODAY. USED SWANNAM GUIDANCE WHICH IS HANDLING THE SEAS SOMEWHAT BETTER THAN THE WAVEWATCH HERE IN THE NEAR TERM PART OF THE FORECAST. TONIGHT... SW WINDS WILL INCREASE AHEAD OF AN APPROACHING COLD FRONT. SOUTHWEST WIND GUSTS COULD REACH 20 TO ALMOST 25 KT TOWARD DAYBREAK...ESPECIALLY OVER THE SOUTHERN WATERS. SUNDAY...A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE SOUTHERN AND EASTERN OUTER WATERS...AND FOR RHODE ISLAND SOUND. SEAS ARE EXPECTED TO BUILD TO 5 OR 6 FEET IN THOSE AREAS...AND THERE COULD BE WIND GUSTS TO 25 KT FROM THE SOUTHWEST AHEAD OF THE COLD FRONT. SCATTERED SHOWERS COULD CAUSE SOME VISIBILITY RESTRICTIONS. WINDS SHOULD SHIFT TO THE WEST LATE IN THE AFTERNOON BEHIND THE FRONT. OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...MODERATE CONFIDENCE. SUNDAY NIGHT THROUGH WEDNESDAY...WINDS AND SEAS SHOULD REMAIN BELOW SCA THRESHOLDS. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EST SUNDAY FOR ANZ235- 250-254>256. && $$ SYNOPSIS...NMB/GAF NEAR TERM...GAF SHORT TERM...GAF LONG TERM...NMB/GAF AVIATION...NMB/GAF MARINE...NMB/GAF

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