Area Forecast Discussion
Issued by NWS Boston, MA

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000 FXUS61 KBOX 281812 AFDBOX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 112 PM EST WED JAN 28 2015 .SYNOPSIS... SCATTERED OCEAN EFFECT SNOW SHOWERS WILL LINGER ACROSS PARTS OF CAPE COD AND NANTUCKET THIS AFTERNOON. OTHERWISE...IT WILL BE DRY AND COLD AS THE STORM CLEANUP CONTINUES. AN ALBERTA CLIPPER TYPE SYSTEM WILL MOVE OUT OF THE PLAINS STATES...BRINGING ANOTHER CHANCE FOR SNOW THURSDAY NIGHT INTO FRIDAY NIGHT. DRY...BLUSTERY AND FRIGID CONDITIONS MOVE IN FOR THIS WEEKEND. A THIRD STORM MAY AFFECT THE REGION SUNDAY NIGHT AND MONDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... THE STORM CENTER FOR THE BLIZZARD OF 2015 IS MOVING OFF PAST NOVA SCOTIA. NORTHWEST WINDS ARE NOW DRAWING COLD AIR ACROSS NEW ENGLAND WITH DEWPOINTS MAINLY IN THE SINGLE NUMBERS OR LOWER. THIS COLD AIR FLOWING ACROSS THE EASTERN COASTAL WATERS HAS CAUSED SEVERAL BANDS OF OCEAN EFFECT SNOW SHOWERS ACROSS MID AND OUTER CAPE COD. THIS IS TYPICAL FOR A 330 DEGREE DIRECTION WIND. WITH THE STRONGEST PRESSURE RISES NOW OFFSHORE...EXPECT THE SUSTAINED WIND TO DIMINISH THIS AFTERNOON AND EVENING. AFTERNOON OBSERVED TEMPERATURES IN THE UPPER TEENS AND 20S SHOULD BE AS WARM AS IT GETS AS TEMPS IN THE MIXED LAYER SUPPORT MAX VALUES IN THE UPPER TEENS AND 20S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/... HIGH PRES BUILDS IN FROM THE WEST TONIGHT WITH CLEARING SKIES AND LIGHT WINDS DEVELOPING. WITH DEEP FRESH SNOWPACK...THE STAGE WILL BE SET FOR IDEAL RADIATIONAL COOLING AND A VERY COLD NIGHT. LEANED TOWARD COLDER MOS GUIDANCE AND UNDERCUT BY 2-3F WHICH YIELDS MINS IN THE SINGLE NUMBERS ABOVE AND BELOW ZERO...EXCEPT TEENS CAPE/ISLANDS. COLDEST MINS WILL BE ACROSS W MA. && .LONG TERM /THURSDAY THROUGH TUESDAY/... OVERVIEW... ACTIVE BUT PROGRESSIVE NORTHERN AND SOUTHERN STREAMS ACROSS THE LOWER 48 THROUGH THIS LONG TERM PERIOD. FIRST NORTHERN STREAM SHORT WAVE WORKS OUT OF THE NORTHERN ROCKIES TODAY...CROSSING INTO THE REGION THURSDAY NIGHT AND FRIDAY...POSSIBLY LINGERING ALONG THE E COAST FRIDAY NIGHT. THIS WILL USHER IN ARCTIC AIR FOR THIS WEEKEND ALONG WITH BLUSTERY WINDS AND FRIGID WIND CHILLS. A PAIR OF H5 SHORT WAVES MAY MERGE AS THEY APPROACH THE E COAST SUNDAY NIGHT AND MONDAY. WHILE OPERATIONAL MODELS DID SHOW TIMING AND TRACK DIFFERENCES ESPECIALLY WITH THE POSSIBLE LATE WEEKEND SYSTEM...USED AN OVERALL MODEL BLEND INCLUDING ENSEMBLES. THIS GAVE GOOD CONTINUITY WITH THE PREVIOUS FORECAST. DETAILS... THURSDAY... HIGH PRES RIDGE BUILDS ACROSS IN FAST UPPER FLOW. WILL SEE MOSTLY CLEAR SKIES AND LIGHT WINDS. THE RIDGE WILL PUSH OFFSHORE DURING THE AFTERNOON WITH A LIGHT S-SW WIND FLOW SETTING UP. CLOUDS WILL ALSO INCREASE AHEAD OF NEXT APPROACHING SYSTEM. EXPECT HIGHS MAINLY IN THE UPPER 20S TO MID 30S. THURSDAY NIGHT-FRIDAY NIGHT... PRETTY VIGOROUS H5 SHORT WAVE WITH CLIPPER TYPE SYSTEM WORKING E OUT OF THE EASTERN GREAT LAKES/OHIO VALLEY. LOOKS LIKE THIS SYSTEM WILL REDEVELOP OFF THE NEW ENGLAND COAST AS THE SHORT WAVE BEGINS TO NEGATIVE TILT AND CUTOFF...BUT THIS LOOKS LIKE IT WILL HAPPEN ACROSS CENTRAL NEW ENGLAND. THE LOW DOES NOT DEEPEN UNTIL LATER FRIDAY...WHICH WILL BE INTO THE GULF OF MAINE BY THEN. HOWEVER... THE LOW LOOKS TO SPIN THERE FRI NIGHT AS IT DEEPENS...WHICH MAY KEEP MOISTURE ACROSS EASTERN AREAS. WITH MILDER AIR WORKING INTO THE DEVELOPING LOW FRIDAY...LOOKS LIKE THERE MAY BE A PERIOD OF MIXED RAIN/SNOW OR EVEN A BRIEF CHANGE TO RAIN ALONG THE S COAST...CAPE COD AND THE ISLANDS. OTHERWISE...LOOKS LIKE ANOTHER SHOT OF SNOWFALL FOR THE REGION THOUGH NOT NEARLY AS HIGH AS THE BLIZZARD. TOTAL QPF LOOKS TO BE FROM 0.15 TO 0.25 INCHES ACROSS MOST AREAS...BUT WILL SEE SOME ENHANCEMENT ACROSS E COASTAL AREAS AS THE LOW FORMS WITH QPF POSSIBLY UP TO 0.40 INCHES. WITH THE COLD AIR IN PLACE...WILL LIKELY SEE SNOWFALL TOTALS FROM 2-4 INCHES BUT COULD SEE A BIT MORE ACROSS NE MA CLOSER TO THE DEVELOPING LOW WITH SOME SNOW LINGERING FRI NIGHT. WITH STRONG PRESSURE FALLS AS THE LOW DEVELOPS OFFSHORE...EXPECT TIGHTENING PRES GRADIENT BRINGING INCREASING NW WINDS BEHIND THE STORM LATER FRIDAY NIGHT. WILL LIKELY SEE GUSTS UP TO 25-35 KT AROUND OR AFTER MIDNIGHT...BRINGING IN ARCTIC AIR AS WELL AS LOW WIND CHILL READINGS. LOWS FRIDAY NIGHT PLUNGE TO BELOW ZERO ACROSS THE HIGHER INLAND TERRAIN AS WELL AS THE E SLOPES OF THE BERKSHIRES TO 10-15 ALONG THE S COAST...CAPE COD AND THE ISLANDS. THE COMBINATION OF THE LOW TEMPS AND BLUSTERY WINDS MAY MEAN VERY LOW WIND CHILL READINGS. ADVISORIES MAY BE NEEDED FOR PORTIONS OF THE INTERIOR. SATURDAY-SUNDAY... HIGH PRES BEGINS TO SHIFT E DURING SAT...BUT THE DEPARTING STORM INTO THE MARITIMES WILL CAUSE BLUSTERY CONDITIONS TO CONTINUE. ARCTIC AIRMASS ENTRENCHES ITSELF ACROSS THE REGION WITH H85 TEMPS DROPPING TO -11C TO -16C. THIS TRANSLATES TO TEMPS ONLY RECOVERING TO THE TEENS TO AROUND 20 ON SAT...THOUGH WIND CHILLS WILL MAKE IT FEEL MUCH COLDER. WINDS WILL DIMINISH SAT NIGHT...BUT MAY REMAIN HIGH ENOUGH WITH THE DROPPING TEMPS TO SEE POSSIBLE WIND CHILL ADVISORIES. LOWS WILL BOTTOM OUT FROM ZERO TO 5 BELOW WELL INLAND TO THE MID TEENS ON THE OUTER CAPE AND NANTUCKET. ANOTHER LOW BEGINS TO MOVE NE ACROSS THE MISSISSIPPI VALLEY DURING SUNDAY AS HIGH PRES CRESTS ACROSS THE REGION. NW WINDS DIMINISH AND BEGIN TO BACK TO W LATE IN THE DAY. CLOUDS WILL ALSO INCREASE DURING THE AFTERNOON. SUNDAY NIGHT-MONDAY... PAIR OF UPPER LEVEL SYSTEMS BEGIN TO APPROACH. LOW CONFIDENCE ON THE TIMING AND TRACK OF THESE SYSTEMS...AS WELL AS HOW SURFACE LOW PRES FORMS AS IT APPROACHES. OF CONCERN IS THE TRACK OF THIS LOW ON THE 00Z ECMWF...WHICH TAKES THE LOW S OF THE REGION MEANING ANOTHER SHOT FOR MORE SNOW. THE 00Z GFS AND GGEM MODELS KEEP THE LOW FURTHER INLAND...WITH POSSIBLE MIXTURE OR A CHANGE TO RAIN FOR SOME LOCATIONS. MAY ALSO SEE DECENT RAINFALL WITH SOME INFUSION OF SOUTHERN STREAM MOISTURE WITH THIS LOW. SOMETHING TO KEEP A CLOSE EYE ON...THOUGH AGAIN CONFIDENCE REMAINS LOW. TUESDAY...DEPENDING UPON THE DEPARTURE OF THE LOW...LOOKS LIKE MORE COLD AIR WORKS IN AS ANOTHER HIGH APPROACHES. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM...THROUGH TONIGHT...HIGH CONFIDENCE. THIS AFTERNOON...VFR MOST AREAS. MVFR CIGS/VSBYS POSSIBLE ON MID AND OUTER CAPE COD FROM OCEAN EFFECT SNOW SHOWER BANDS MOVING ASHORE. NORTHWEST WINDS WILL DIMINISH THIS AFTERNOON...BUT GUSTS OF 20 TO 25 KNOTS WILL BE SUPPORTED THROUGH MID AFTERNOON. TONIGHT...VFR. CLEAR SKIES AND LIGHT WIND. THURSDAY...VFR. INCREASING CLOUDS ABOVE 10 THOUSAND FEET. LIGHT WIND. THURSDAY NIGHT AND FRIDAY... CIGS LOWER OVERNIGHT TO MVFR/IFR IN SNOW. SOME RAIN MAY MIX WITH THE SNOW AT ACK AND HYA. PRECIPITATION STARTS AFTER MIDNIGHT AND CONTINUES UNTIL FRIDAY AFTERNOON. WINDS SHIFT TO NORTHWEST MIDDAY OR EARLY AFTERNOON WITH GUSTS OF 20 TO 25 KNOTS POSSIBLE. SKY CONDITIONS IMPROVE TO VFR AFTER THE WIND SHIFT TO NORTHWEST. KBOS TAF...HIGH CONFIDENCE IN TAF. KBDL TAF...HIGH CONFIDENCE IN TAF. OUTLOOK /FRIDAY NIGHT THROUGH SUNDAY/... SATURDAY-SUNDAY...LOW TO MODERATE CONFIDENCE. VFR. GUSTY NORTHWEST WINDS 25-35 KNOTS SATURDAY...LIGHTER WINDS SUNDAY. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM/THIS AFTERNOON THROUGH TONIGHT/... LINGERING NORTHWEST WINDS WILL GUST TO 25 KNOTS THROUGH THE AFTERNOON DIMINISHES THIS EVENING. SEAS OF 5 TO 9 FEET ON THE OUTER WATERS AND ON MASSACHUSETTS BAY WILL LINGER THIS AFTERNOON AND SUBSIDE TONIGHT. SMALL CRAFT ADVISORY CONTINUES ON MOST WATERS THIS AFTERNOON AND DIMINISHES THIS EVENING AND OVERNIGHT. OUTLOOK /FRIDAY THROUGH SUNDAY/...MODERATE CONFIDENCE. FRIDAY... LOW PRES WILL CROSS THE WATERS. EXPECT REDUCED VSBYS IN SNOW. EXPECT WINDS TO SHIFT TO NW BY FRI NIGHT...INCREASING TO 25-35 KT...SO GALES WILL LIKELY BE NEEDED. SEAS ALSO BUILD UP TO 6-8 FT OVER THE OPEN WATERS. FREEZING SPRAY WILL LIKELY DEVELOP FRI NIGHT. SATURDAY...NW GALES EXPECTED WITH POTENTIAL FOR A LIGHT FREEZING SPRAY. SEAS REMAIN HIGH...POSSIBLY UP TO 7-9 FT ON THE EXPOSED WATERS. WINDS WILL BEGIN TO DIMINISH SAT NIGHT. SUNDAY...WINDS AND SEAS AT SMALL CRAFT ADVISORY LEVELS EARLY SUNDAY...BUT WILL DIMINISH THROUGH THE DAY. && .TIDES/COASTAL FLOODING... EARLY MORNING HIGH TIDE CYCLE HAS PASSED. NO REPORTS OF SIGNIFICANT ISSUES WITH SPLASHOVER OR MINOR FLOODING THIS MORNING SO FAR. HAVE ALLOWED THE COASTAL FLOOD ADVISORY TO EXPIRE. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR ANZ232>235-237. SMALL CRAFT ADVISORY UNTIL 4 AM EST THURSDAY FOR ANZ231-251- 255-256. SMALL CRAFT ADVISORY UNTIL 10 AM EST THURSDAY FOR ANZ250-254. && $$ SYNOPSIS...KJC/EVT NEAR TERM...WTB SHORT TERM...KJC LONG TERM...EVT AVIATION...WTB/KJC/EVT MARINE...KJC/EVT TIDES/COASTAL FLOODING...

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