Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 190325 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 1025 PM EST TUE NOV 18 2014 .SYNOPSIS... HIGH PRESSURE BUILDS DRY BUT COLDER THAN NORMAL AIR OVER NEW ENGLAND TONIGHT AND WEDNESDAY. A WEAK COLD FRONT MOVES THROUGH ON THURSDAY FOLLOWED BY ANOTHER SHOT OF COLD AIR TO FINISH THE WEEK. A SIGNIFICANT WARM-UP IS IN STORE BY SUNDAY INTO EARLY NEXT WEEK. A STORM MOVING OUT OF TEXAS FOR THE GREAT LAKES MAY BRING RAIN TO SOUTHERN NEW ENGLAND EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 1015 PM UPDATE... MID LEVEL TROF PASSAGE WILL BRING ANOTHER PULSE OF GUSTY WINDS OVERNIGHT AS PRESSURE GRADIENT INCREASES A BIT. OTHERWISE...MAINLY CLEAR SKIES WITH OCEAN EFFECT CLOUDS S OF NEW ENGLAND WHICH MAY FLIRT WITH THE ISLANDS FROM TIME TO TIME. LOW TEMPS WILL BE MOSTLY IN THE UPPER TEENS TO LOWER 20S...A BIT MILDER OVER THE OUTER CAPE AND ISLANDS. WITH THE WIND IN PLAY...WIND CHILLS WILL DROP INTO THE SINGLE NUMBERS TO LOWER TEENS MOST PLACES. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... WEDNESDAY... HIGH PRESSURE MOVES ACROSS AND WILL PROVIDE SUNNY SKIES. AS THE HIGH SHIFTS EAST...THERE WILL BE SOME INCREASE IN MID AND HIGH CLOUDS DURING THE AFTERNOON. WINDS WILL DIMINISH A LITTLE AND TURN SOUTHWEST...BUT STILL GUSTY AT TIMES. TEMPS AT THE TOP OF THE MIXED LAYER -12C/-13C SUGGEST MAX SFC TEMPS IN THE 30S. WEDNESDAY NIGHT... ANOTHER SHORTWAVE MOVING THROUGH THE UPPER TROUGH WILL PUSH A CLIPPER SURFACE LOW ACROSS THE GREAT LAKES AND INTO CANADA. THE APPROACH OF THIS LOW WILL BRING INCREASING CLOUDS TO SOUTHERN NEW ENGLAND...BUT THE AIRMASS WILL STILL BE DRY SO ANY PRECIPITATION WILL BE CHALLENGED TO REACH THE SURFACE. WE ARE FORECASTING SLIGHT CHANCE POPS MAINLY ACROSS NORTHERN MASS AND SOUTHERN NH DURING THE NIGHT. IF ANYTHING DOES REACH THE GROUND...TEMPERATURE PROFILES SUGGEST SNOW AS P-TYPE. THE CLOUDS SHOULD ALLOW SURFACE TEMPS TO BE A LITTLE LESS COLD THAN TONIGHT. WE STAYED CLOSE TO GUIDANCE VALUES...WHICH INDICATE THIS. && .LONG TERM /THURSDAY THROUGH TUESDAY/... HIGHLIGHTS... * STILL ANOMALOUS COLD THROUGH SATURDAY * SNOW FLURRIES/SHOWERS AROUND THE REGION WED NIGHT/THURS * WARMER SUNDAY THROUGH END OF PERIOD * MAINLY RAIN LIKELY MONDAY OVERVIEW... THE ANOMALOUS TROUGH REMAINS OVER THE REGION ALLOWING FOR COLD WEATHER EARLY IN THE PERIOD. WINDY WEATHER CONTINUES AS THE LOW LEVEL JET REMAINS OVER THE REGION AS WELL. A RIDGE OVER THE WESTERN STATES PUSHES EAST AS A LOW DIVES INTO THE SOUTHWESTERN US. THIS PUSHES THE TROUGH EAST AND EVENTUALLY OUT TO SEA. THE AFOREMENTIONED RIDGE COMES IN FOR THE LATTER PART OF THE WEEKEND WITH WARMER TEMPS WHICH LAST THROUGH THE REST OF THE PERIOD. THIS RIDGE COMBINES WITH THE SUBTROPICAL HIGH PUSHING A LOW PRESSURE SYSTEM NORTH EARLY NEXT WEEK. THIS WILL RESULT IN MORE OF AN INSIDE RUNNER THAN A COASTAL STORM. THE GFS HAS TRENDED FARTHER WEST WITH EACH RUN FOR THAT STORM. MODELS HAVE DECENT AGREEMENT OVER THE PERIOD. ONE QUESTION WOULD BE THE EXTENT OF A SNOW SHOWER/FLURRY EVENT ON THURSDAY. THIS WOULD BE CONTINGENT ON THE PLACEMENT AND TIMING OF A WEAK DEVELOPING LOW THAT GETS ITS ACT TOGETHER JUST EAST OF THE CAPE. DAILIES... THURSDAY...A SHORTWAVE DIVES DOWN OUT OF CANADA AND AROUND THE BASE OF THE TROUGH. THIS ACTS AS THE TRIGGER FOR SCATTERED SNOW SHOWERS AND FLURRIES AROUND THE REGION ESPECIALLY DURING THE MORNING. A LOW PRESSURE SYSTEM IS ALSO HINTED AT DEVELOPING EAST OF THE CAPE AROUND AN AREA OF 6 TO 7 C/KM ML LAPSE RATES. PRECIPITATION SHOULD FALL ALONG THE CAPE FROM THIS LOW AND COULD BE WINTRY IF THE LOW DEVELOPS EARLY ENOUGH. TEMPS AROUND THAT TIME FRAME LOOK TO BE RIGHT AROUND FREEZING FROM THE UPPER CAPE TOWARDS SOUTHEAST MASSACHUSETTS. HIGHS ARE AROUND 40 ACROSS THE INTERIOR AND CLOSER TO MID TO UPPER 40S ON THE CAPE AND ISLANDS. A COLD FRONT WILL PASS THROUGH THE REGION DURING THE EVENING HOURS BRINGING COLDER AIR BACK IN. FRIDAY AND SATURDAY...BEHIND THE AFOREMENTIONED COLD FRONT...COLD AIR SPILLS IN AIDED BY THE HIGH PRESSURE SYSTEM TO THE SOUTHWEST AS WELL AS NORTHWEST WINDS. BOTH DAYS SHOULD BE DRY AND COLD WITH HIGHS RANGING FROM LOW TO MID 30S INLAND TO LOW TO MID 40S ON THE CAPE AND ISLANDS. SUNDAY...IN THE EARLY MORNING...HIGH PRESSURE IS SOUTHEAST OF THE REGION AND A WARM FRONT IS ABLE TO PASS THROUGH THE REGION EARLY IN THE DAY. SHOWERS ARE POSSIBLE IN THE NORTHWESTERN ZONES OF THE AREA WITH LIFT FROM THE FRONT. EVEN WITH THE CLOUDS AND SHOWERS...TEMPS SHOULD BE WARMER THAN SATURDAY BY AT LEAST 10 AND MAYBE EVEN 15 DEGREES. THICKER CLOUDS THEN MOVE IN AS A LOW PRESSURE SYSTEM APPROACHES. PRECIPITATION STARTS OVERNIGHT SUNDAY AND CONTINUES INTO MONDAY. THIS MAY START AS SNOW OR A MIX OF RAIN AND SNOW EARLY ON ACROSS THE INTERIOR...THEN CHANGING OVER TO RAIN. MONDAY...HIGH PRESSURE CONTINUES TO BACK WEST FROM THE SOUTH CENTRAL ATLANTIC TO THE SOUTHWEST ATLANTIC. AS A RESULT...THE LOW PRESSURE TAKES A MORE INSIDE-RUNNER-LIKE TRACK. PHASED UPPER LEVEL JETS OCCUR ALONG WITH A STRONG LOW LEVEL JET FOR STRONG WIND GUSTS OVER THE AREA. PWATS ARE ON THE ORDER OF 1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL AND PROBABLY CLOSER TO 2 WHICH WILL LIKELY LEAD TO PERIODS OF HEAVY RAIN. ANOMALOUS 850MB TEMPS SHOULD BE SEEN TO THE TUNE OF 1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL AS WELL INDICATING WARMER THAN NORMAL TEMPERATURES. HIGHS ARE CURRENTLY FORECAST TO BE IN THE 60S. TUESDAY...A DRY SLOT IS ABLE TO COME IN AS THE UPPER LEVEL JET WORKS INTO THE REGION ALOFT. THIS SHUTS OFF PRECIPITATION AND CLOUDS SHOULD BEGIN TO BREAK UP. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...HIGH CONFIDENCE. TONIGHT...VFR. WEST WIND GUSTS TO 20-25 KT WEDNESDAY...VFR. WEST WINDS GUSTS TO 25 KT NEAR THE COAST IN THE MORNING...DIMINISHING IN THE AFTERNOON. WEDNESDAY NIGHT...VFR. A WEAK WEATHER DISTURBANCE MOVES ACROSS CANADA AND BRINGS A PERIOD OF CLOUDS TO SOUTHERN NEW ENGLAND AND MAY BRING A FEW SNOW FLURRIES/SHOWERS WITH BRIEF MVFR. KBOS TERMINAL...HIGH CONFIDENCE. KBDL TERMINAL...HIGH CONFIDENCE. OUTLOOK...THURSDAY THROUGH SUNDAY... THURSDAY...MODERATE CONFIDENCE...MVFR/IFR IN SCATTERED SNOW SHOWERS ESPECIALLY DURING THE MORNING HOURS. OTHERWISE VFR. SW WIND GUSTS POSSIBLE 20 TO 25 KTS. FRIDAY AND SATURDAY...MODERATE CONFIDENCE. MAINLY VFR. NW GUSTS POSSIBLE 20 TO 25 KTS ON FRI. LIGHTER WINDS SAT. SUNDAY...MODERATE CONFIDENCE. MAINLY VFR. SW WIND GUSTS INCREASE TO AROUND 25 KTS AGAIN. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. HIGH CONFIDENCE THROUGH WEDNESDAY NIGHT. TONIGHT...GALE WARNINGS REMAIN IN PLACE THROUGH THE NIGHT WITH CONTINUED COLD AIR ADVECTION OVER THE WARMER WATERS. SMALL CRAFT ADVISORY WINDS WILL LINGER OVER BOSTON HARBOR AND NARRAGANSETT BAY. THE COLD AIR WILL SUPPORT FREQUENT WEST WIND GUSTS TO 35 KNOTS MUCH OF THE NIGHT OVER MOST OF THE WATERS AND 25 TO 30 KNOTS OVER BOSTON HARBOR AND NARRAGANSETT BAY. SEAS WILL BE VERY ROUGH WITH 5 TO 10 FOOT LEVELS ON MOST OF THE SOUTHERN WATERS AND OUTER EASTERN WATERS. WEDNESDAY...WINDS GRADUALLY DIMINISH...FALLING BELOW 25 KNOTS DURING THE AFTERNOON. SEAS WILL ALSO SUBSIDE...BUT THE OUTER WATERS WILL RETAIN SEAS OF 5 FEET OR HIGHER THROUGH THE DAY. GALES WILL LIKELY BE REPLACED BY SMALL CRAFT HEADLINES AS CONDITIONS SUBSIDE. WEDNESDAY NIGHT... SOUTHWEST WINDS WITH GUSTS 25 TO 30 KNOTS ON ALL BUT THE MOST SHELTERED OF WATERS. SEAS WILL BUILD AGAIN ON THE EXPOSED SOUTHERN WATERS WITH HEIGHTS OF 5 TO 8 FEET. A FEW FLURRIES ARE POSSIBLE MAINLY EAST OF MASSACHUSETTS BUT WITH MINIMAL VISIBILITY RESTRICTIONS. OUTLOOK...THURSDAY THROUGH SUNDAY... THURSDAY...MODERATE CONFIDENCE. SOUTHWESTERLY WINDS EXCEED SCA CRITERIA AND MAY REACH GALE FORCE OVER THE WATERS. STRONGEST WINDS SHOULD BE JUST SOUTH OF SOUTHERN NEW ENGLAND. SEAS ALSO LOOK TO BUILD TO BETWEEN 6 TO 10 FT. VISIBILITIES MAY DROP IN LIGHT SNOW SHOWERS EARLY. FRIDAY...HIGH CONFIDENCE. WESTERLY WINDS GUST UP TO GALE FORCE DURING THIS TIME. 6 TO 10 FT SEAS POSSIBLE ON THE OUTER WATERS. SATURDAY...HIGH CONFIDENCE. NORTHWEST WINDS DIMINISHING TO BELOW SCA CRITERIA AND SEAS ALSO BELOW SCA THRESHOLDS. SUNDAY...SW WIND GUSTS INCREASE TO JUST ABOVE SCA CRITERIA...25 KTS...OVER SOUTHERN WATERS AS A LOW PRESSURE SYSTEM APPROACHES. && .CLIMATE... LOCATION...RECORD LOW TONIGHT... RECORD HIGH WED... BOSTON 14 - 193630 - 1897 BLUE HILL10 - 193627 - 1897 PROVIDENCE14 - 1936 33 - 1936 HARTFORD12 - 192433 - 1955 WORCESTER9 - 192429 - 2008 && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...GALE WARNING UNTIL 8 AM EST WEDNESDAY FOR ANZ231>235-237-251- 255-256. SMALL CRAFT ADVISORY UNTIL 1 PM EST WEDNESDAY FOR ANZ230. SMALL CRAFT ADVISORY UNTIL 3 PM EST WEDNESDAY FOR ANZ236. GALE WARNING UNTIL 10 AM EST WEDNESDAY FOR ANZ250-254. && $$ SYNOPSIS...WTB/HR NEAR TERM...KJC SHORT TERM...WTB LONG TERM...HR AVIATION...WTB/HR MARINE...WTB/HR CLIMATE...RLG

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