Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 172010 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 410 PM EDT FRI APR 17 2015 .SYNOPSIS... MILDER WEATHER RETURNS SAT AHEAD OF A COLD FRONT WHICH MOVES THROUGH DURING THE AFTERNOON. CANADIAN HIGH PRESSURE BRINGS COOLER WEATHER SUNDAY. THEN A COASTAL LOW DELIVERS A WIND SWEPT SOAKING RAIN TO THE REGION LATE MON INTO MON NIGHT. COOLER WEATHER SHOULD DOMINATE NEXT WEEK WITH A FEW SHOWERS FROM TIME TO TIME. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AREAS OF STRATUS AND PATCHY FOG ARE LINGERING ALONG THE S COAST. VSBYS HAVE IMPROVED AND LOW CLOUDS WILL LIFT LATE AFTERNOON AND EARLY THIS EVENING AS WINDS SHIFT TO WEST. ALREADY SEEING IMPROVING CONDITIONS ACROSS COASTAL CT. LOW PROB FOR AN ISOLD SHOWER CT/RI THROUGH 00Z...BUT BETTER CHANCE TO THE S WHERE ELEVATED INSTABILITY AXIS LOCATED. SECONDARY COLD FRONT MOVES THROUGH LATER TONIGHT WITH WEAK SFC RIDGING BUILDING IN. DRY CONDITIONS WITH CLEARING SKIES FROM NORTH TO SOUTH. WITH LIGHT WINDS AND DEWPOINTS IN REMAINING MOSTLY IN THE 40S...PATCHY INTERIOR VALLEY FOG MAY DEVELOP LATE TONIGHT. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... SATURDAY... ROBUST MID LEVEL SHORTWAVE SWINGS THROUGH NORTHERN NEW ENG DURING THE AFTERNOON WITH 500 MB TEMPS NEAR -30C WHICH IS FOCUSED TO THE N. SFC INSTABILITY IS MARGINAL AT BEST BUT CONFINED TO N NEW ENG WHERE SBCAPES LESS THAN 500 J/KG. TT SPIKE INTO THE MID 50S ALONG WITH STEEP MID LEVEL LAPSE RATES OVER 7 C/KM BUT THIS ALSO ACROSS N NEW ENG. THUS...BEST CHANCE FOR ANY CONVECTION SAT AFTERNOON WILL BE TO THE N. INSTABILITY PARAMETERS DROP OFF CONSIDERABLY ACROSS SNE. WE WILL HAVE 20-30 PERCENT POPS FOR SHOWERS ACROSS NORTHERN AND E MA ASSOCD WITH MODEST QG FORCING WITH THE SHORTWAVE...BUT BEST CHANCE IN SNE WILL BE ACROSS NE MA. AFTER FROPA MOVES THROUGH IN THE AFTERNOON...DEEP MIXING ABOVE 850 MB WILL PROMOTE GUSTY NW WINDS...ESPECIALLY INTERIOR WHERE A FEW GUSTS TO 35-40 MPH POSSIBLE. BRIEF STRONGER WINDS NEAR THE COAST POSSIBLE LATE AFTERNOON/EARLY EVENING. MAX TEMPS WILL REACH UPPER 60S TO LOWER 70S...BUT COOLER ALONG THE COAST WHERE SEABREEZES ARE LIKELY. TEMPS MAY STRUGGLE TO 60 ACROSS THE OUTER CAPE AND PORTIONS OF NE MA. FOR MORE ON POTENTIAL FIRE WEATHER CONDITIONS...PLEASE CONSULT THE FIRE WEATHER DISCUSSION BELOW. SATURDAY NIGHT... STRONG HIGH PRES BUILDS TO THE NORTH WITH MAINLY CLEAR SKIES AND DIMINISHING NORTHERLY WINDS. MIN TEMPS DROPPING INTO THE 30S...EXCEPT LOWER 40S ALONG THE COAST AND URBAN CENTERS. && .LONG TERM /SUNDAY THROUGH FRIDAY/... HIGHLIGHTS... * COOLER TEMPS FOR SUNDAY * WIND SWEPT SOAKING RAIN LATE MON INTO EARLY TUE * COOLER WITH PERIODS OF SHOWERS MID TO LATE NEXT WEEK OVERVIEW... OVERALL THE 12Z GUIDANCE IS IN GOOD AGREEMENT WITHIN THE MEDIUM AND LONG RANGE. HOWEVER EXACT TIMING AND STRENGTH OF EACH SYSTEM ESPECIALLY MID TO LATE NEXT WEEK STILL NEEDS TO BE WORKED OUT. UPPER LEVEL RIDGE WILL MOVE OVERHEAD SUNDAY AND EXIT THE REGION BY THE OVERNIGHT HOURS. UPPER LEVEL LOW WILL MOVE OVER THE GREAT LAKES PUSHING SEVERAL SHORTWAVE OVER THE REGION. THIS LOW BECOMES CUT-OFF BY MID-WEEK PINWHEELING BETWEEN THE GREAT LAKES AND NEW ENGLAND THROUGH THE REST OF THE PERIOD. THIS WILL YIELD TO A MORE SHOWERY AND COOLER FORECAST FOR NEXT WEEK. DETAILS... * SUNDAY...HIGH CONFIDENCE. HIGH PRESSURE OVERHEAD WILL ALLOW FOR PLENTY OF SUNSHINE AND DRY WEATHER. TEMPS WILL WARM INTO THE MID 50S TO UPPER 60S. ANTICIPATE SEA BREEZE DEVELOPMENT AS WINDS ALOFT WILL BE QUITE CALM ALLOWING FOR TEMPS ALONG THE COASTLINE TO BE IN THE LOW 50S. * MONDAY INTO TUESDAY...HIGHER CONFIDENCE. GUIDANCE CONTINUES TO SHOW MID-ATLANTIC TRIPLE POINT LOW DEVELOPING AND MOVING TOWARDS SOUTHERN NEW ENGLAND LATE MONDAY INTO TUESDAY. THIS SYSTEM IS VERY POTENT WITH STRONG 60KT 925MB SOUTHEASTERLY JET AND GOOD MOISTURE FLUX STREAMING INTO THE FLOW. PWAT VALUES REACH AROUND 1.5 INCHES...WHICH IS ABOUT 2 STANDARD DEVIATION`S AWAY. BETTER DYNAMICS OF THIS SYSTEM COME IN AROUND THE MONDAY EVENING COMMUTE...BUT CANNOT RULE OUT LIGHT RAIN AHEAD OF IT DURING THE AFTERNOON HOURS. OVERCAST SKIES DURING THE DAY ON MONDAY WILL LIMIT DIURNAL HEATING SUCH THAT HIGHS WILL STRUGGLE TO GET INTO THE 50S. ALSO ANTICIPATE A FEW GUSTS FROM THE STRONG JET TO MIX DOWN SO WE COULD SEE 20-30 MPH GUSTS IN THE LATE AFTERNOON. THIS WILL MAKE FOR A VERY COOL...WINDY...WET DAY. TEMPS WILL BEGIN TO WARM UP OVERNIGHT AS WARM FRONT ASSOCIATED WITH LOW PRESSURE APPROACHES THE REGION BRINGING A GOOD SLUG OF RAIN. EXPECT QPF VALUES TO RANGE BETWEEN 1-2 INCHES AS RAIN WILL CONTINUE INTO EARLY TUESDAY. THERE IS A LOW PROBABILITY THAT LOCATIONS SOUTH OF THE MASS PIKE MAY SEE SOME ISOLATED THUNDER BY MONDAY EVENING INTO TUESDAY WITHIN THE WARM SECTOR. SHOWALTERS DROP BELOW 0 AND TOTAL TOTALS WILL BE ABOVE 50. KEPT THUNDER OUT OF THE FORECAST FOR NOW AS CONFIDENCE IS LOW. RAIN WILL BEGIN TO END TUESDAY AFTERNOON FROM SOUTHWEST TO NORTHEAST AS COLD FRONT PASSES THROUGH AND LOW MOVES OFFSHORE. * WEDNESDAY INTO FRIDAY...MODERATE CONFIDENCE. STRONG CUT OFF LOW WILL SPIN OVER THE NORTHEAST DURING THIS TIME PERIOD. COULD SEE A FEW WAVES DEVELOP BUT THE INCREASINGLY STACKED UPPER LOW PRESSURES WILL MEAN A DECREASE IN PRECIP INTENSITY. HOWEVER MAY SEE A LOT OF DIURNAL CU AND DIURNAL SHOWERS DEVELOPING AS COLD POOL ALOFT WILL BE OVERHEAD. LASTLY EXPECT TEMPS TO BE ABOUT 5-10 F BELOW AVERAGE FOR THE WEEK THANKS TO THE SLOW-MOVING UPPER-LEVEL LOW AND ITS ASSOCIATED COLD POOL. && .AVIATION /19Z FRIDAY 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/... THROUGH TONIGHT...WIDESPREAD LIFR CONDITIONS IN STRATUS AND FOG HAVE DEVELOPED ALONG THE S COAST AND EXPECT THESE CONDITIONS TO CONTINUE INTO EARLY EVENING. ELSEWHERE...MVFR CIGS WILL GRADUALLY IMPROVE TO VFR FROM N TO S THIS AFTERNOON INTO EARLY EVENING. SW GUSTS TO 25 KT ALONG THE COAST WILL DIMINISH THROUGH THE AFTERNOON. TONIGHT...LIFR STRATUS AND FOG IMPROVES TO VFR AFT 02-03Z FOLLOWING WIND SHIFT TO W. EXACT TIMING UNCERTAIN. MAINLY VFR TONIGHT...BUT PATCHY FOG MAY DEVELOP OVERNIGHT. SATURDAY...HIGH CONFIDENCE. VFR. CHANCE OF AFTERNOON SHOWERS NE MA TO CAPE COD. INCREASING NW WINDS DEVELOPING IN THE INTERIOR IN THE AFTERNOON WITH GUSTS TO 30 KT. SEABREEZES LIKELY ALONG E COASTAL MA INTO THE AFTERNOON...BECOMING NW LATE AFTERNOON. SATURDAY NIGHT...HIGH CONFIDENCE. VFR. KBOS TAF...HIGH CONFIDENCE. SEABREEZE DEVELOPING BY 15Z SAT THEN WINDS SHIFT TO NW AROUND 21Z. KBDL TAF...HIGH CONFIDENCE. OUTLOOK...SUNDAY THROUGH WEDNESDAY... SUN...VFR AND DIMINISHING WINDS. HIGH CONFIDENCE. SEA BREEZE ALONG THE COAST. MON...MVFR/IFR DEVELOPING IN RAIN/FOG BY AFTERNOON. E/SE WIND GUSTING TO 25-30KT NEAR COAST. MODERATE CONFIDENCE. TUE...MVFR POSSIBLE IN SCT SHOWERS. MODERATE CONFIDENCE. WED...MAINLY VFR WITH SCT MVFR IN DIURNAL CU/SHOWERS. MODERATE CONFIDENCE. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SATURDAY NIGHT/...HIGH CONFIDENCE. LIGHT WINDS AND SEAS TONIGHT THROUGH SAT MORNING WITH WEAK HIGH PRES OVER THE WATERS. SEABREEZES LIKELY ACROSS NEARSHORE WATERS DURING SAT AFTERNOON. A PERIOD OF STRONGER NORTHWEST WINDS WILL DEVELOP SAT EVENING BIT SPEEDS MOSTLY BELOW SCA. HOWEVER...A PERIOD OF NORTH WIND GUSTS TO 25 KT POSSIBLE OVER SE WATERS OVERNIGHT. OUTLOOK...SUNDAY THROUGH WEDNESDAY... SUNDAY...HIGH CONFIDENCE. HIGH PRES MOVES ACROSS NEW ENGLAND. LIGHT WINDS AND SUBSIDING SEAS. MONDAY...MODERATE CONFIDENCE. INCREASING E/SE WINDS EXPECTED MON WITH BUILDING SEAS...PROBABLY REQUIRING SCA WITH GUSTS REACHING 25-30KT. OUTSIDE CHANCE OF REACHING MARGINAL GALES /35KT/. SEAS COULD REACH AS HIGH AS 8-11 FT ON OUTER WATERS MON NIGHT. RAIN AND FOG WILL LIMIT VSBY MON AFTERNOON AND AND MON NIGHT. TUESDAY...MODERATE CONFIDENCE. HIGH SEAS WILL CONTINUE THROUGH THE DAY AS LOW PRESSURE SYSTEM EXITS THE REGION. ANTICIPATE SCA TO CONTINUE WELL INTO THE AFTERNOON/EVENING FRO CHOPPY SEAS. WESTERLY WIND GUSTS WILL SLOWLY DIMINISH THROUGHOUT THE DAY. WEDNESDAY...MODERATE CONFIDENCE. SEAS AND WIND WILL SLOWLY SUBSIDE BUT WITH ANOTHER APPROACHING SYSTEM...SEAS MAY REMAIN CHOPPY. SCA MAY BE NEEDED. && .FIRE WEATHER... AFTER COLLABORATION WITH SURROUNDING WFOS AND FIRE WEATHER OFFICIALS...WE HAVE ISSUED A FIRE WEATHER WATCH FOR INTERIOR MA...N CT AND NW RI. RAINFALL THIS MORNING WAS UNDER 0.25" AND VERY DRY CONDITIONS AND GUSTY WINDS WILL DEVELOP SAT AFTERNOON. DEEP MIXING WILL RESULT IN WIND GUSTS TO 35 MPH ACROSS THE INTERIOR WITH RELATIVE HUMIDITIES DROPPING TO NEAR 25 PERCENT LEADING TO CRITICAL FIRE WEATHER CONDITIONS. HIGH PRESSURE MOVES IN ON SUNDAY KEEPING THE WINDS GUSTS AT BAY... BUT ALLOWING FOR RH/S TO DROP NEAR 25 PERCENT AGAIN. CONDITIONS WILL TURN MORE WET BY NEXT WEEK WITH SEVERAL CHANCES OF SHOWERS AND COOLER WEATHER THROUGHOUT THE WORK WEEK. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR CTZ002>004. MA...FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR MAZ002>005-008>012-026. RI...FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR RIZ001. MARINE...NONE. && $$ SYNOPSIS...KJC/DUNTEN NEAR TERM...KJC SHORT TERM...KJC LONG TERM...DUNTEN AVIATION...KJC/DUNTEN MARINE...KJC/DUNTEN FIRE WEATHER...KJC/DUNTEN

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