251  
FXUS61 KBOX 270803  
AFDBOX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TAUNTON MA  
403 AM EDT MON MAR 27 2017  
   
SYNOPSIS
 
 
HIGH PRESSURE OVER MARINE WILL RETREAT INTO THE MARITIMES, BUT  
PROVIDE COOL WEATHER ACROSS SOUTHERN NEW ENGLAND TODAY. A WARM  
FRONT WILL APPROACH THE REGION DURING THIS TIME AND RESULT IN  
PERIODS OF RAIN WITH AREAS OF FREEZING RAIN ACROSS THE HIGH  
TERRAIN. WET WEATHER CONTINUES TUE AND TUE NIGHT AS LOW PRESSURE  
TRACKS OVER OR NEAR THE REGION. ALTHOUGH TUE SHOULD BE MILDER  
THAN MONDAY. HIGH PRESSURE BRINGS DRY BUT CHILLY WEATHER WED AND  
THU. MORE UNSETTLED WEATHER IS POSSIBLE LATE FRI INTO SAT.  
 

 
   
NEAR TERM /THROUGH TODAY/
 
 
CONTINUING TO MONITOR PROGRESS OF MAIN AREA OF PRECIPITATION  
TOWARD SOUTHERN NEW ENGLAND. TEMPERATURES AT ELEVATIONS ABOUT  
700 FEET AND HIGHER WERE NEAR FREEZING, SO WILL CONTINUE THE  
FREEZING RAIN ADVISORY THIS MORNING. LOW DEW POINT DEPRESSIONS,  
SO ADDITIONAL COOLING IS POSSIBLE WITH THE MAIN AREA OF  
PRECIPITATION ARRIVES. TEMPERATURES STILL EXPECTED TO RISE ABOVE  
FREEZING BY 8 AM, ENDING THE THREAT OF FREEZING RAIN.  
 
A WARM FRONT WILL TRY TO PUSH NORTH INTO SOUTHERN NEW ENGLAND  
LATER TODAY. A LOW PRESSURE MOVING ALONG THIS FRONT WILL PREVENT  
IT FROM COMPLETELY DOING SO. THIS WILL PROVIDE A FOCUS FOR  
PERIODS OF WIDESPREAD RAIN.  
 
NOT MUCH SUNSHINE TODAY, BUT TEMPERATURES SHOULD BE NEAR NORMAL.  
 

 
   
SHORT TERM /TONIGHT THROUGH 6 PM TUESDAY/
 
 
TONIGHT...  
 
ABUNDANT CLOUDS LINGER. LOTS OF LOW LEVEL MOISTURE IN THE LOWEST  
3,000 FEET ABOVE THE GROUND IN THE WAKE OF A LOW PRESSURE MOVING  
OFFSHORE. AS PREVIOUSLY MENTIONED, CANNOT COMPLETELY RULE OUT  
SOME PATCHY DRIZZLE. STILL NOT EXPECTING TEMPERATURES TO FALL  
MUCH, EVEN WITH A WEAK COLD FRONT MOVING THROUGH.  
 
TUESDAY...  
 
NOT A LOT OF SUNSHINE ANTICIPATED, DESPITE SOUTHERN NEW ENGLAND  
GETTING INTO THE WARM SECTOR OF A LOW PRESSURE IN SOUTHEAST  
CANADA. MAX TEMPERATURES SHOULD BE ABOVE NORMAL, IN THE UPPER  
40S AND 50S. COULD BE WARMER IF CLOUDS AND RAINFALL ARE DELAYED  
UNTIL LATE IN THE DAY. LOW RISK OF A ISOLATED THUNDERSTORM OR  
TWO TOWARD THE SOUTH COAST DUE TO ELEVATED INSTABILITY.  
 

 
   
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/
 
 
HIGHLIGHTS...  
 
* SHOWERS LINGER TUESDAY NIGHT AS COLD FRONT PASSES THROUGH  
* COOLER BUT DRY WEATHER FOR WED AND THURS  
* UNSETTLED WEATHER RETURNS FRIDAY INTO SATURDAY  
 
PATTERN OVERVIEW...  
 
00Z MODEL CONSENSUS CONTINUES TO SHOW AN ACTIVE WEATHER PATTERN  
FOR THE PERIOD. SPLIT FLOW ALOFT WILL CONTINUE THROUGH THE  
PERIOD WITH A FEW SHORTWAVES MOVING THROUGH THE FLOW. PARTIAL  
PHASING OF THE TWO STREAMS WILL OCCUR ACROSS THE GREAT LAKES AND  
NORTHEAST ON TUESDAY. THIS WILL RESULT IN THE DEVELOPMENT OF A  
LOW PRESSURE SYSTEM EAST OF THE REGION LATE TUESDAY INTO  
WEDNESDAY. HIGH PRESSURE AND UPPER LEVEL RIDGE WILL FOLLOW  
THURSDAY INTO EARLY FRIDAY. THE NEXT UPPER LEVEL LOW/TROUGH  
DEAMPLIFIES AS IT MOVES INTO THE MID/UPPER RIDGE AXIS ACROSS THE  
EASTERN U.S. A COASTAL LOW IS FORECAST TO DEVELOP AND QUICKLY  
MOVE EAST IN THE AFOREMENTIONED REGION OF THIS PHASING. THE  
SPREAD HAS DECREASED FOR THIS TIMEFRAME BUT THE STILL QUESTION  
IN STRENGTHEN AND LOCATION OF THIS SYSTEM WILL DETERMINE P-TYPES  
AND QPF AMOUNTS.  
 
DETAILS...  
 
TUESDAY NIGHT...HIGH CONFIDENCE.  
 
WEAK SHORTWAVE WILL MOVE OVER THE REGION ON TUESDAY WITH SURFACE  
LOW PRESSURE OVER NORTHERN NEW ENGLAND. ALONG THE COLD FRONT,  
GUIDANCE DEVELOPS A SECONDARY LOW PRESSURE SYSTEM JUST SOUTH OF  
SOUTHERN NEW ENGLAND BY TUESDAY NIGHT. THIS WAVE OF LOW PRESSURE  
WILL BRING SHOWERY WEATHER TUESDAY EVENING INTO THE OVERNIGHT  
HOURS. CANNOT RULE OUT SOME ISOLATED THUNDER WITH THIS SYSTEM AS  
TT INCREASE ABOVE 50 AND LI'S DROP BELOW 0. THIS IS STRONGEST  
IN THE CONSERVATIVE EC.  
 
PRECIP CHANCE WILL QUICKLY COME TO AN END FROM WEST TO EAST  
DURING THE OVERNIGHT HOURS AS CAA TAKES A HOLD OF THE REGION.  
 
WEDNESDAY INTO FRIDAY...HIGH CONFIDENCE.  
 
TROUGH OVERHEAD AS UPPER LEVEL LOW DEEPENS AS IT MOVES TOWARDS  
THE CANADIAN MARITIMES. THIS PUTS THE REGION IN NORTHWEST FLOW  
THROUGH THE PERIOD RESULTING IN DRY BUT BREEZY CONDITIONS.  
CLOUDS MAY BE STUBBORN ON WED OVER THE CAPE AND ISLANDS GIVEN  
NORTHERLY FLOW ACROSS THE WATERS. IN FACT COULD HAVE SOME OCEAN  
EFFECT RAIN/SNOW SHOWERS OVER THE OUTER CAPE! DESPITE COLD  
ADVECTION, THE ENVIRONMENT SHOULD BE WELL MIXED, SO MAX  
TEMPERATURES WILL BE CLOSE TO NORMAL.  
 
NORTHWEST FLOW CONTINUES ON THURSDAY WITH AN AREA OF HIGH  
PRESSURE BUILDING IN NEW ENGLAND. ANTICIPATE INCREASING  
SUNSHINE AND LIGHTER WINDS. DRY AND SEASONABLE CONDITIONS SHOULD  
PERSIST THROUGH FRIDAY WITH HIGH PRESSURE IN CONTROL.  
 
FRIDAY NIGHT INTO THE WEEKEND...LOW CONFIDENCE.  
 
SPLIT FLOW REMAINS OVER THE REGION WITH THE NEXT SOUTHERN STREAM  
WAVE INTERACTING WITH THE NORTHERN STREAM. STILL SOME MODEL  
SPREAD IN THIS SYSTEM LEADING TO A LOW CONFIDENCE FORECAST. THE  
EC HAS BECOME MORE PROGRESSIVE WITH THIS APPROACHING COASTAL LOW  
DEVELOPING IT OVER 1-95 WHILE THE GFS KEEPS THE SYSTEM  
SUPPRESSED. THE UKMET IS MORE INBETWEEN THE TWO SYSTEMS, BUT THE  
GEFS AND EPS CONTINUE TO SHOW THE SYSTEM SOUTH OF SNE. OVERALL  
A CHILLY RAIN WITH POTENTIAL FOR WET SNOW/SLEET AT TIMES ON THE  
NORTHERN PORTION OF THE PRECIP SHIELD. ALL GUIDANCE SUGGEST  
SYSTEM SHOULD BE OR MOVING OFFSHORE BY SUNDAY, THUS DRYING TREND  
POSSIBLE SECOND HALF OF THE WEEKEND.  
 

 
   
AVIATION /07Z MONDAY THROUGH FRIDAY/
 
 
FORECASTER CONFIDENCE LEVELS...  
 
LOW - LESS THAN 30 PERCENT.  
MODERATE - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
SHORT TERM /THROUGH TUESDAY/...HIGH CONFIDENCE.  
 
TODAY...FZRA RISK DIMINISHES EARLY. OTHERWISE, -RA/RA WITH  
MVFR-LIFR CIGS WITH LIGHT E WINDS INITIALLY TURNING SE AND  
INCREASING.  
 
TONIGHT...RA DIMINISHING, HOWEVER IFR-LIFR CIGS REMAIN. COULD  
SEE AREAS OF -DZ. LIGHT WINDS.  
 
TUESDAY...MVFR CONDITIONS LIKELY IN AREAS OF RAIN AND FOG, WITH  
A TREND LOWERING TO IFR AS FRONTAL BOUNDARY AND SURFACE LOW  
APPROACH. LOW RISK FOR THUNDER TOWARD THE SOUTH COAST.  
 
KBOS TAF...NOT EXPECTING ANY FZRA IMPACTS AT THE TERMINAL WITH  
E ONSHORE FLOW. LOWERING MVFR DOWN TO LIFR THIS MORNING.  
 
KBDL TAF...NOT EXPECTING ANY FZRA IMPACTS AT THE TERMINAL, AS  
TEMPERATURES REMAIN ABOVE FREEZING.  
 
OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/...  
 
TUESDAY NIGHT...HIGH CONFIDENCE. MVFR CONDITIONS WITHIN ANY PASSING  
RAIN SHOWERS WITH IMPROVING CIGS TO VFR BY THE MORNING HOURS. LOW  
RISK FOR THUNDER ACROSS THE SOUTH COAST.  
 
WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE. GUSTY N/W WINDS  
WEDNESDAY WITH VFR CONDITIONS INTO THURSDAY.  
 
FRIDAY...MODERATE CONFIDENCE. VFR AND DRY TO START BUT LIKELY  
LOWERING TO MVFR OR POSSIBLY IFR FRI NIGHT IN RAIN/WINTRY PRECIP.  
 

 
   
MARINE
 
 
FORECASTER CONFIDENCE LEVELS...  
 
LOW - LESS THAN 30 PERCENT.  
MODERATE - 30 TO 60 PERCENT.  
HIGH - GREATER THAN 60 PERCENT.  
 
SHORT TERM /THROUGH TUESDAY/...MODERATE CONFIDENCE.  
 
TODAY...WARM FRONT WILL LIFT ACROSS THE WATERS, RESULTING IN AN  
INCREASING EAST TO SOUTHEAST FLOW. ROUGH SEAS ACROSS THE  
EASTERN OUTER COASTAL WATERS ARE MORE LIKELY THAN THE SOUTHERN  
OUTER WATERS. CONTINUED THE SMALL CRAFT ADVISORIES FOR THOSE  
WATERS. A FEW GUSTS TO 25 KT ARE ALSO POSSIBLE ACROSS CAPE COD  
BAY AND NANTUCKET SOUND. HAVE LESS CONFIDENCE ACROSS THOSE  
WATERS, SO DID NOT EXPAND AN ADVISORY THERE. THAT WILL NEED TO  
BE MONITORED AS THE DAY PROGRESSES.  
 
TONIGHT...A WEAK FRONTAL BOUNDARY SWEEPS THE WATERS, WITH LIGHT  
WEST WINDS DEVELOPING. THIS WILL ALLOW SEAS TO SUBSIDE AND SMALL  
CRAFT ADVISORIES TO CONCLUDE.  
 
TUESDAY...LIGHT SOUTH WINDS WITH FRONTAL BOUNDARY NORTH OF THE  
REGION. VSBY REDUCED AT TIMES IN RAIN AND FOG.  
 
OUTLOOK /TUESDAY NIGHT THROUGH FRIDAY/...  
 
TUESDAY NIGHT...MODERATE CONFIDENCE. WINDS BECOMING NORTHEAST LATE  
TUE NIGHT AS FRONT SLIPS SOUTH AND WAVE OF LOW PRES TRACKS ALONG THE  
FRONT SOUTH OF NEW ENGLAND. VSBY REDUCED AT TIMES IN RAIN AND FOG.  
 
WEDNESDAY INTO THURSDAY...HIGH CONFIDENCE. GUSTY NORTH WINDS NEAR  
WEDNESDAY INTO EARLY THU THEN DIMINISHING AS HIGH PRESSURE BUILDS  
INTO THE AREA LATER THU.  
 
FRIDAY...HIGH CONFIDENCE. QUIET WEATHER WITH HIGH PRESSURE OVER THE  
AREA EARLY FRI. HOWEVER INCREASING EAST-SOUTHEAST WINDS FRI NIGHT AS  
LOW PRES APPROACHES FROM THE WEST. ALSO VSBY LOWERING IN RAIN AND  
FOG FRI NIGHT.  
 

 
   
BOX WATCHES/WARNINGS/ADVISORIES
 
 
CT...NONE.  
MA...FREEZING RAIN ADVISORY UNTIL 8 AM EDT THIS MORNING FOR  
MAZ002>004-008-009-012-026.  
RI...NONE.  
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR ANZ250-254.  
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ255-  
256.  
 

 
 

 
SYNOPSIS...BELK/DUNTEN  
NEAR TERM...BELK  
SHORT TERM...BELK  
LONG TERM...DUNTEN  
AVIATION...BELK/DUNTEN  
MARINE...BELK/DUNTEN  
 
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