Area Forecast Discussion Issued by NWS Boston, MA
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000
FXUS61 KBOX 151458
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
1058 AM EDT WED MAY 15 2013
.SYNOPSIS...
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A WARM FRONT WILL BE THE FOCUS FOR SHOWERY WEATHER LATE TODAY INTO
TONIGHT. BEHIND THE FRONT...DRIER AND WARMER WEATHER FOLLOWS
THURSDAY. A DRY COLD FRONT SWEEPS ACROSS THE REGION THU NIGHT
USHERING COOLER BUT SEASONABLE WEATHER INTO THE AREA BEGINNING FRI
AND CONTINUING INTO THE WEEKEND. A WARMING TREND IS LIKELY EARLY
NEXT WEEK AS MARITIME HIGH PRESSURE MOVES OFFSHORE.-- End Changed Discussion --
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
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1040 AM UPDATE...
LEADING EDGE OF HIGH CLOUDS WORKING ACROSS THE REGION THIS
MORNING AS SEEN ON VISIBLE SATELLITE. SHOWERS JUST STARTING TO
APPROACH THE NEW ENGLAND BORDER AS WELL...THOUGH APPEARS THAT
PRECIP NOT REACHING THE GROUND ACROSS THE HUDSON VALLEY AT 14Z.
NOTING REPORTS OF -RA INTO CENTRAL NY/EASTERN PA.
HAVE UPDATED GRIDS TO ADJUST THE ONSET OF PRECIP JUST A BIT INTO
THE REGION...BUT WILL MOVE STEADILY IN DURING THE AFTERNOON. ALSO
ADJUSTED TEMPS/DEWPTS TO BRING CONDITIONS CURRENT. DEWPTS WERE A
BIT LOWER THAN PREVIOUSLY FORECAST THROUGH 14Z...BUT DO EXPECT
THEM TO RISE RATHER QUICKLY AS S-SW WIND PICK UP. ALSO ADJUSTED
CLOUD PROGRESSION JUST A TAD.
PREVIOUS DISCUSSION...
THERE REMAINS UNCERTAINTY CONCERNING OUTCOMES OF POTENTIAL
SHOWERY WEATHER AHEAD OF A WARM FRONT LIFTING THROUGH THE REGION
DURING THE LATTER HALF OF THE DAY. WHILE FORCING IS APPARENT AHEAD
OF LOCALLY ENHANCED W/SW FLOW OF A SIGNIFICANTLY WARMER MID-LEVEL
AIRMASS...THE AVAILABLE MOISTURE IS MORE CONTINENTAL-MARITIME
RATHER THAN TROPICAL-ORIGIN /PWATS AROUND 1 INCH/...AND COUPLED
WITH POTENTIAL LOW-LEVEL DEWPOINT DEPRESSIONS LENDS TO CHANCE POPS
ACROSS THE INTERIOR WITH LIKELY POPS TOWARDS SHORE AND OVER THE
WATERS. OF CERTAINTY...WINDS WILL GUST OUT OF THE SOUTH WITH GUSTS
AROUND 25 TO 30 MPH.-- End Changed Discussion --
&&
.SHORT TERM /7 PM THIS EVENING THROUGH THURSDAY NIGHT/...
TONIGHT...
SHOWERS AND DRIZZLE LINGER NORTH AND EAST...CLEARING OUT BY
MIDNIGHT. MID-HIGH LEVEL CLOUDS WILL LINGER ACROSS THE REGION IN
ASSOCIATION THE BROADER MID-LEVEL LOW OVER THE SAINT LAWRENCE
RIVER VALLEY. WHILE A COLD FRONT WILL SLIDE ACROSS THE REGION
OVERNIGHT THERE IS LITTLE CHANGE IN AIRMASS /AND LITTLE AVAILABLE
MOISTURE...NOT THINKING ANY SHOWERS/. SHOULD SEE SOUTHERLY WINDS
DIMINISH ACROSS THE INTERIOR WITH BOUNDARY LAYER DECOUPLING...BUT
REMAINING BRISK ALONG THE WATERS. LOWS REMAINING MILD AROUND THE
UPPER 40S.
THURSDAY...
DRY CONDITIONS. CONTINUED CYCLONIC FLOW WITH THE DEPARTURE OF THE
MID-LEVEL LOW WILL RESULT IN MID-HIGH LEVEL CLOUDS FILTERING ACROSS
THE REGION. BOUNDARY LAYER MIX-DOWN OF AN ELEVATED MIXED LATER +8-
10C AT H85 WILL RESULT HIGH TEMPERATURES AROUND THE MID-UPPER 70S
WITH A FEW LOCALES REPORTING LOW 80S. WILL SEE WESTERLY WINDS WITH
GUSTS OF 30 TO 35 MPH. RELATIVE HUMIDITIES WILL RANGE AROUND 25 TO
30 PERCENT PRESENTING THE POTENTIAL FOR FIRE WEATHER CONCERNS /SEE
THE FIRE-WEATHER DISCUSSION BELOW/.
THURSDAY NIGHT...
WINDS WILL DIMINISH ACROSS THE INTERIOR BUT REMAIN BRISK ALONG THE
COAST. ANOTHER COLD FRONT WILL SWEEP THROUGH THE REGION WITH LITTLE
FAN-FARE. WESTERLY WINDS WILL BACK OUT OF THE NORTH WITH COLD
FRONTAL PASSAGE. COOLER AIRMASS WILL BUILD ACROSS THE REGION
ALOFT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HIGHLIGHTS...
* NEAR SEASONABLE TEMPS FOLLOWED BY A WARMING TREND EARLY NEXT WEEK
* MAINLY DRY WEATHER PREVAILS THIS PERIOD
SYNOPTIC OVERVIEW/MODEL PREFERENCES AND UNCERTAINTY...
ANOTHER NIGHT OF GOOD MODEL AGREEMENT BETWEEN THE ECMWF/GFS AND ITS
ENSEMBLE COUNTERPARTS REGARDING THE LARGE SCALE FEATURES THIS
PERIOD. THE MAIN FEATURE EARLY IN THIS PERIOD WILL BE A MID LEVEL
TROUGH TRAVERSING SOUTHEAST CANADA. THIS WILL RESULT IN A COOLING
TREND /AFTER THURSDAYS WARMTH/ BEGINNING FRI WITH A DRY COLD FRONTAL
PASSAGE EARLY IN THE DAY. AS THE MID LEVEL TROUGH MOVES FARTHER
EAST...A 1030 MB MARITIME HIGH SLIDES SOUTHWARD TO A POSITION EAST
OF NEW ENGLAND THIS WEEKEND. THIS WILL YIELD DRY BUT COOLER WEATHER
AS MARITIME AIRMASS OVERSPREADS THE REGION. THEN BY EARLY NEXT WEEK
A MID LEVEL RIDGE BUILDS INTO THE EASTERN SEABOARD. HOWEVER FOR THE
SECOND NIGHT IN A ROW THE GFS AND TO A LESSER EXTENT THE GEFS INSIST
ON JET ENERGY UNDERCUTTING INTO THIS RIDGE WHICH YIELDS LOW PRES
TRACKING SOUTH OF NEW ENGLAND EARLY NEXT WEEK. GIVEN THE LACK OF
SUPPORT FROM THE UKMET/EC/ECENS WILL DISCOUNT THE GFS AND FOLLOW THE
WARMER/DRIER MODEL CONSENSUS FOR EARLY NEXT WEEK.
DAILY SENSIBLE WEATHER...
FRIDAY...PLEASANT SPRING WEATHER WITH DRY CONDITIONS AND FAIRLY
LIGHT WINDS. COOLER THAN THU WITH DRY COLD FRONTAL PASSAGE LATE
THU/EARLY FRI. COOLEST TEMPS ALONG WITH COAST WITH AFTN SEABREEZES.
SUNSHINE TO START THE DAY THEN LIKELY GIVING WAY TO SCT-BKN DIURNAL
SC/CU.
SAT/SUN...MILD DAYS AND COOL NIGHTS. FAIRLY LARGE TEMP GRADIENT
ACROSS THE REGION WITH 1030 MB MARITIME HIGH JUST OFFSHORE. HIGHS
WILL RANGE FROM THE L70S WELL INLAND TO THE U50S TO L60S ACROSS CAPE
COD. DRY WEATHER WITH A MIX OF SUN AND CLOUDS EXPECTED. FAIRLY LIGHT
WINDS GIVEN PROXIMITY OF HIGH PRES.
EARLY NEXT WEEK...LIKELY A WARMING TREND WITH MARITIME HIGH MOVING
OUT TO SEA AS MID LEVEL RIDGE AXIS PUSHES EAST INTO THE EASTERN
SEABOARD. BY TUE ECENS ADVECTS A TONGUE OF +12C AIR AT 850 MB ACROSS
SOUTHERN NEW ENGLAND. THUS FULL SUN TEMP POTENTIAL OF NEAR 80
POSSIBLE.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
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FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
1040 AM UPDATE...
FEW CHANGES FROM PREVIOUS FORECAST.
SHORT TERM /THROUGH THURSDAY NIGHT/...MODERATE CONFIDENCE.
THROUGH 00Z...MAINLY VFR AS S-SW WINDS INCREASE. WILL SEE
INCREASING CLOUDS WITH -SHRA MOVING ACROSS. LOW CONFIDENCE -TSRA.
WILL KEEP CIGS AT OR ABOVE LOW-END VFR. SOUTHERLY FLOW WITH GUSTS
25 TO 30 KTS WILL BE POSSIBLE.
TONIGHT-THURSDAY NIGHT...UNCERTAIN WITH MVFR-IFR IMPACTS. BEST
CHANCES WOULD BE ALONG THE IMMEDIATE SOUTH COAST INCLUDING THE
CAPE AND ISLANDS WITH POTENTIAL COASTAL FOG. COULD SEE LLWS
IMPACTS DURING THE EVENING AS A WARM FRONT LIFTS NORTH ACROSS THE
TERMINALS /SW SUSTAINED 50 KTS AT 2 KFT/.
DRIER WEATHER PREVAILS BEGINNING AROUND MIDNIGHT THURSDAY INTO
THURSDAY NIGHT. MAY HAVE TO CONTEND WITH MORNING COASTAL FOG
ALONG THE SOUTH-SOUTHEAST COAST. WINDS WILL BACK MORE
SOUTHWESTERLY...GUSTY DURING THE DAY THURSDAY WITH SPEEDS OF
AROUND 30 KTS...DIMINISHING OVERNIGHT. VFR.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. NOTED BRIEF LIGHT E-SE
WINDS THROUGH 14Z...BUT EXPECT TO SHIFT TO S-SW AS GRADIENT
INCREASES.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.
OUTLOOK...FRIDAY THROUGH SUNDAY...
FRIDAY THROUGH SUNDAY...NOT MUCH CHANGE FROM EARLIER FORECAST...VFR
THROUGH THE PERIOD. LIGHTER WINDS WITH POTENTIAL FOR
MIDDAY/AFTERNOON SEABREEZES EACH DAY.-- End Changed Discussion --
&&
.MARINE...
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FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
1040 AM UPDATE...
NO MAJOR CHANGES TO PREVIOUS FORECAST.
PREVIOUS DISCUSSION...
INCREASING WINDS THIS AFTERNOON ACROSS THE NEAR SHORE WATERS OF
MA AND RI. SCA IN EFFECT FOR ALL WATERS. S WINDS WILL GUSTS TO
25-30 KT FROM 2 PM TO 8 PM. STRONGEST WINDS NEAR SHORE.
SHORT TERM /THROUGH THURSDAY NIGHT/...MODERATE CONFIDENCE.
WITH WINDS INCREASING OUT OF THE S/SW TODAY WITH GUSTS UP TO
AROUND 30 KTS...ANTICIPATE SEAS TO BUILD ACROSS THE OUTER WATERS.
SMALL CRAFT ADVISORIES ARE IN EFFECT ACCORDINGLY. ADVISORIES MAY
NEED TO BE EXTENDED TO THE INNER HARBORS AND BAYS. WILL MONITOR
CLOSELY.
WINDS TO REMAIN BRISK TONIGHT...BACKING OUT OF THE WEST AS A COLD
FRONT SWEEPS THROUGH THE REGION. THURSDAY WILL BE A REPEAT WITH
WESTERLY WINDS GUSTING AROUND 30 KTS. MAY NEED TO BE CONCERNED
ABOUT GALE HEADLINES /ESPECIALLY CLOSER TO SHORE/. ANOTHER COLD
FRONT WILL SWEEP THE WATERS THURSDAY NIGHT RESULTING IN WINDS TO
DIMINISH AS THEY BACK OUT OF THE NORTH.
THROUGHOUT ALL OF THE FORECAST PERIOD...SEAS WILL CONTINUE TO
REMAIN ABOVE 5 FEET ACROSS THE OUTER WATERS.
OUTLOOK...FRIDAY THROUGH SUNDAY...
FRIDAY THROUGH SUNDAY...FINE BOATING WEATHER FOR MID-LATE MAY WITH
FAIRLY LIGHT WINDS AND WAVES. NOT EXPECTING MUCH SWELL FOR THE OCEAN
WATERS. GOOD VSBY AS WELL IN RESPONSE TO DRY WEATHER.-- End Changed Discussion --
&&
.FIRE WEATHER...
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MINIMUM RELATIVE HUMIDITIES THURSDAY AND FRIDAY IS EXPECTED AT 20
TO 30 PERCENT EACH DAY. WEST-NORTHWEST WINDS ON THURSDAY WILL
INCREASE BY MIDDAY WITH AFTERNOON GUSTS TO 30 KNOTS AND POSSIBLY
35 KNOTS. THESE CONDITIONS WILL NEED TO BE WATCHED.-- End Changed Discussion --
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
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CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 2 AM EDT
THURSDAY FOR ANZ232.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 PM EDT THIS
EVENING FOR ANZ230-233-234-236.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 6 AM EDT
THURSDAY FOR ANZ231-251.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 5 AM EDT
FRIDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 AM EDT
FRIDAY FOR ANZ250-254>256.-- End Changed Discussion --
&&
$$
SYNOPSIS...NOCERA/SIPPRELL
NEAR TERM...NOCERA/SIPPRELL/EVT/THOMPSON
SHORT TERM...SIPPRELL
LONG TERM...NOCERA
AVIATION...NOCERA/SIPPRELL/THOMPSON/EVT
MARINE...NOCERA/SIPPRELL/EVT
FIRE WEATHER...STAFF