Area Forecast Discussion Issued by NWS Boston, MA
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000
FXUS61 KBOX 142311
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
711 PM EDT FRI JUN 14 2013
.SYNOPSIS...
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A SECONDARY TROUGH OF LOW PRESSURE WILL SWING ACROSS SOUTHERN NEW
ENGLAND THIS EVENING. OTHERWISE HIGH PRESSURE AND A DRIER AIRMASS
OVERSPREADS THE REGION TONIGHT INTO SATURDAY NIGHT PROVIDE
SEASONABLE AND DRY WEATHER. BY LATE SUNDAY ANOTHER TROUGH OF LOW
PRESSURE APPROACHES THE AREA BRINGING A RISK OF SHOWERS FROM LATE
SUNDAY THROUGH TUESDAY.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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715 PM UPDATE...A FEW ISOLATED SHOWERS HAVE OCCURRED ACROSS
WESTERN NEW ENGLAND THIS EVENING. THESE HAVE DIMINISHED IN
COVERAGE IN THE LAST 30 MINUTES OR SO. EXPECT THEM TO CONTINUE TO
DIMINISH AS THE SUN SETS AND WE LOSE THE DIURNAL HEATING. WINDS
HAVE DIMINISHED ACROSS THE AREA...PARTICULARLY THE CAPE AND
ISLANDS. HAVE OPTED TO CANCEL THE HIGH SURF ADVISORY AND RIP
CURRENT RISK AN HOUR EARLY AS SEAS HAVE COME DOWN QUITE A BIT AND
WITH COASTAL TEMPERATURES IN THE 60S ITS UNLIKELY THAT BEACHGOERS
ARE STILL OUT.
AFTER 8 PM...
ANY LINGERING SHOWERS/TSTMS ERODE WITH SUNSET/LOSS OF DAYTIME
HEATING. BEHIND SECONDARY TROUGH DRIER AIRMASS OVERSPREADS THE
REGION. SLIGHTLY COOLER THAN NORMAL WITH MIN TEMPS ABOUT 3-5 DEGS
COOLER THAN CLIMO. MODEST NW PGRADIENT WILL PERSIST SO NOT
EXPECTING WINDS TO DECOUPLE ALONG THE COAST/ISLANDS AND THE URBAN
AREAS.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
SATURDAY...
MEAN MID LEVEL TROUGH AXIS EAST OF NEW ENGLAND AND MEAN RIDGE AXIS
ACROSS THE GREAT LAKES. THIS WILL PROVIDE ANTICYCLONE FLOW OVER NEW
ENGLAND WITH DEEP LAYER SUBSIDENCE DRYING THE COLUMN. THUS EXPECTING
ABUNDANCE SUNSHINE WITH TEMPS WARMING TO 75-80! WHILE THESE TEMPS
ARE SEASONABLE FOR JUNE 15TH...IT WILL FEEL MUCH WARMER GIVEN THE
RECENT DAMP/COOL WEATHER. REAL NICE DAY...ENJOY!
JUST AS WARM AT THE BEACHES GIVEN WNW WINDS. BEWARE OF SOME LEFTOVER
ROUGH SURF AND STRONG RIP CURRENTS AT OCEAN BEACHES...BOTH SOUTH AND
EAST COAST GIVEN SE SWELLS. WIND WAVES AND SWELLS APPEAR TO
ERODE/DECAY FAIRLY QUICK GIVEN SOURCE REGION OF SWELLS WAS OVER AND
NEAR NEW ENGLAND /CLOSE TO SHORE VERSUS WELL OFFSHORE/. IF SWELLS
WERE FROM DISTANT OCEAN STORM WAVE ENERGY WOULD BE MORE LONG LIVED.
THUS WHILE SURF MAY BE SOMEWHAT ROUGH TOMORROW ALONG WITH MODEST RIP
CURRENTS...THINK WE WILL FALL SHORT OF HIGH SURF AND/OR HIGH RISK
CRITERIA. LATER SHIFTS WILL HAVE TO MONITOR HOW WAVE ENERGY
DISSIPATES.
SAT NIGHT...
ANTICYCLONIC FLOW LINGERS SO DRY WEATHER PREVAILS. NOT AS COOL AS
AIRMASS MODIFIES ALONG WITH WINDS BECOMING WSW.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...
* MORE ROUNDS OF SHOWERS EXPECTED SUN THRU TUE
* HIGH PRES WILL BRING DRY...SEASONABLE WEATHER WED AND THU
THERE IS FAIRLY GOOD GENERAL AGREEMENT WITHIN THE MODELS THROUGH THE
LONG TERM FOR THE MOST PART. THERE IS UNCERTAINTY WITH THE TIMING
OF VARIOUS FEATURES THROUGHOUT THE FORECAST PERIOD AND SOME
UNCERTAINTY WITH THE TRACK OF SOME OF THE FEATURES. ONE OF THE
BIGGEST DIFFERENCES BETWEEN THE ECMWF AND THE GFS IS THE PATH OF
SEVERAL LOW PRESSURE SYSTEMS IN THE SUNDAY-TUESDAY TIME FRAME. THE
GFS HAS A SYSTEM IN ONTARIO THAT SPLITS WITH ONE LOW MOVING THROUGH
CENTRAL QUEBEC AND THE SECONDARY LOW MOVING OVER SOUTHERN NEW
ENGLAND ABOUT THE SAME TIME SUNDAY AND THEN ANOTHER LOW PRESSURE
SYSTEM MOVING ALONG THE COAST ON TUESDAY. THE ECMWF KEEPS IT TO JUST
ONE LOW PRESSURE SYSTEM SUNDAY MOVING THROUGH QUEBEC...ANOTHER LOW
PRESSURE SYSTEM MOVING ALONG THE U.S./CANADA BORDER ON MONDAY...AND
THEN A COLD FRONT TRAILING THAT LOW ON TUESDAY. SENSIBLE WEATHER
DIFFERENCES WILL MOSTLY BE IN THE TIMING AND PLACEMENT OF RAIN
SHOWERS. IT IS FAIRLY CERTAIN THAT AT LEAST A PORTION OF SOUTHERN
NEW ENGLAND WILL RECEIVE MEASURABLE RAINFALL. QUIET WEATHER
EXPECTED WEDNESDAY AND THURSDAY AS HIGH PRESSURE BUILDS INTO THE
REGION. THEN MORE UNSETTLED WEATHER GOING INTO NEXT WEEKEND. WILL
OPT TO GO WITH THE HPC GUIDANCE WHICH INCORPORATES THE ENSEMBLE
SOLUTIONS FROM BOTH THE ECMWF AND THE GFS. AT THIS POINT IT LOOKS
LIKE WE WILL GET AT LEAST ANOTHER COUPLE OF INCHES OF RAIN BEFORE
THE END OF THE MONTH.
SUNDAY THROUGH TUESDAY...THERE IS SOME UNCERTAINTY HERE WITH THE
TIMING AND TRACK OF A SERIES OF LOW PRESSURE SYSTEMS. SEE ABOVE FOR
MORE DETAIL ON WHICH MODEL IS DOING WHAT. EXPECT PRECIPITATION
CHANCES TO INCREASE SUNDAY NIGHT INTO TUESDAY AS THESE LOWS MOVE
NEAR SOUTHERN NEW ENGLAND...THOUGH ISOLATED SHOWERS ARE POSSIBLE
SUNDAY AFTERNOON AS WELL. THERE IS ENOUGH INSTABILITY MONDAY AND
TUESDAY THAT THUNDERSTORMS ARE POSSIBLE. THE BEST INSTABILITY AND
THUS FOR THUNDERSTORMS LOOKS TO BE TUESDAY RIGHT NOW. SUNDAY AND
MONDAY LOOK TO BE THE WARMEST DAYS OF THE WEEK WITH HIGHS IN THE
UPPER 70S TO LOWER 80S...DEPENDENT ON CLOUD COVER. THEN TUESDAY
EXPECT TEMPS IN THE MID TO UPPER 70S. WILL USE THE HPC GUIDANCE
WHICH INCORPORATES BOTH THE EC AND GFS ENSEMBLES.
WEDNESDAY AND THURSDAY...HIGH PRESSURE STARTS BUILDING INTO THE
REGION...BRINGING A RETURN TO DRIER MORE SEASONABLE WEATHER.
LATE NEXT WEEK...ANOTHER POSSIBILITY FOR SHOWERS WITH A BROAD UPPER
LEVEL TROUGH OVER THE NORTHEAST.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
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FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
OVERVIEW...MODERATE TO HIGH CONFIDENCE THROUGH SAT NIGHT.
TONIGHT...VFR. DISREGARDED LOWER VSBYS FROM MET AND MAV OVERNIGHT
AS DRY NW WINDS SHOULD PROVIDE VFR VSBYS.
SAT...VFR AND DRY WEATHER. WEST WINDS SHOULD PRECLUDE SEABREEZE
DEVELOPMENT...ALTHOUGH WINDS MAY GO SW ALONG THE SOUTH COAST OF
MA AND RI.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF. WEST WINDS SHOULD PRECLUDE
SEABREEZE SAT.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY THROUGH TUESDAY...LOW TO MODERATE CONFIDENCE. MAINLY VFR BUT
MVFR/IFR CONDITIONS LIKELY AT TIMES IN -SHRA/FG.
WEDNESDAY...MODERATE TO HIGH CONFIDENCE. VFR.-- End Changed Discussion --
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH SATURDAY NIGHT...HIGH CONFIDENCE.
TONIGHT...
GALES HAVE DIMINISHED AND WINDS WILL CONTINUE TO RELAX THIS EVENING
AND SHIFT TO WNW BEHIND PASSAGE OF SECONDARY FRONT. ISOLATE SHOWER
POSSIBLE WESTERN/SOUTHERN WATERS. EAST WIND WAVES TRANSITION TO
SWELLS. VSBY REMAINS GOOD.
SAT...
HIGH PRES OVER THE MID ATLC REGION PROVIDES DRY WEATHER AND GOOD
VSBY ACROSS THE SOUTHERN NEW ENGLAND WATERS. WNW WINDS 10-15KT WITH
G20 NEAR SHORE. E SWELLS LINGER ACROSS THE OCEAN WATERS.
SAT NIGHT...
DRY WEATHER AND GOOD VSBY PREVAILS. WINDS SHIFT TO SW AS HIGH PRES
SLIDES OFF MID ATLC REGION.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
MODERATE CONFIDENCE THROUGH THE PERIOD.
WINDS AND SEAS INCREASE TO 5 TO 8 FT SUNDAY AND MONDAY...BRIEFLY
DIMINISH MONDAY NIGHT AND THEN RISE AGAIN TUESDAY AS A SERIES OF
LOW PRESSURE SYSTEMS APPROACH THE WATERS. SEAS WILL DIMINISH ONCE
AGAIN WEDNESDAY AS HIGH PRESSURE BUILDS OVER THE WATERS. WINDS ARE
LIKELY TO REMAIN BELOW 25 KNOTS FOR MUCH OF THIS TIME...BUT SEAS
ON THE OUTER WATERS ESPECIALLY WILL BE ABOVE 5 FEET MUCH OF THE
TIME SO SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED. SHOWERS MAY
LIMIT VISIBILITIES AT TIMES SUNDAY THROUGH TUESDAY.
&&
.HYDROLOGY...
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RIVERS CONTINUE TO RUN HIGH DUE TO THE SIGNIFICANT RAINS THAT HAVE
FALLEN. ACROSS THE WESTERN TWO THIRDS OF THE COUNTY WARNING
AREA...INCLUDING SOUTHERN NH...CENTRAL/WESTERN MA...NORTH CENTRAL
CT...AND RI...MANY OF THE GAGED SMALL STREAMS AND SMALL RIVERS
HAVE ALREADY CRESTED AND ARE RECEDING. HOWEVER LARGER TRIBUTARY
AND MAINSTEM RIVERS ARE GENERALLY STILL RISING. IN THESE
INSTANCES...RIVERS THAT ARE EXPECTED TO GO INTO FLOOD ALREADY HAVE
FLOOD WARNINGS POSTED.
IN EASTERN MA...THE FLOOD WATCH CONTINUES UNTIL MIDNIGHT TONIGHT. A
NUMBER OF SMALL RIVERS AND STREAMS ARE STILL RISING...AND CONTINUE
TO BE MONITORED. A NEW RIVER FLOOD WARNING HAS BEEN ISSUED FOR THE
ASSABET RIVER AT MAYNARD MA. THE WADING RIVER AT NORTON AND MILL
RIVER AT TAUNTON ARE ABOVE ACTION STAGE AND ARE BEING CLOSELY
MONITORED.
RIVER FORECAST POINTS WHERE FLOOD WARNINGS CONTINUED AS OF 415 PM...
IN CT...
FARMINGTON RIVER AT SIMSBURY
CONNECTICUT RIVER AT HARTFORD
CONNECTICUT RIVER AT MIDDLE HADDAM
IN RI...
BLACKSTONE RIVER AT WOONSOCKET
PAWTUXET RIVER AT CRANSTON /FORECAST TO REACH MODERATE FLOOD/
/AREAL FLOOD WARNING ALSO IN EFFECT FOR THE LOWER PAWCATUCK RIVER
NEAR WESTERLY/
IN MA...
ASSABET RIVER AT MAYNARD
SUDBURY RIVER AT SAXONVILLE
CHARLES RIVER AT DOVER
REFER TO THE LATEST FLOOD STATEMENTS FOR SPECIFIC FORECASTS.-- End Changed Discussion --
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR MAZ005>007-013>021.
HIGH SURF ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MAZ022-024.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ231>235-237-250.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT SATURDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...NOCERA/RLG
NEAR TERM...NOCERA/RLG
SHORT TERM...NOCERA
LONG TERM...RLG
AVIATION...NOCERA/RLG
MARINE...NOCERA/RLG
HYDROLOGY...