-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBOX 171055
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
655 AM EDT FRI MAY 17 2013

.SYNOPSIS...
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A DRY NORTH TO NORTHWEST FLOW WILL PREVAIL TODAY BEHIND A COLD
FRONT THAT WILL CONTINUE TO MOVE SOUTH OF NEW ENGLAND TODAY. HIGH
PRESSURE PROVIDES DRY AND SEASONABLE WEATHER FOR MUCH OF THE
WEEKEND. AN APPROACHING WARM FRONT WILL THEN INCREASE THE CHANCE
OF RAIN FROM LATE SUNDAY INTO MONDAY. THE FRONT LIFTS NORTH OF THE
AREA AROUND TUE OF NEXT WEEK YIELDING WARM...MORE HUMID AND
SHOWERY WEATHER MUCH OF NEXT WEEK.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

-- Changed Discussion --
7 AM UPDATE...

VERY PLEASANT WEATHER THIS MORNING ACROSS SOUTHERN NEW ENGLAND.
TEMPS AT 7 AM ALREADY IN THE 50S WITH COMFORTABLE DEW PTS IN THE
U30S AND L40S. ONLY WRINKLE IN THE FORECAST WILL BE WATCHING POST
FRONTAL CLOUDS ACROSS NORTHERN NY-VT AND NH. MODELS KEEP THIS
MOISTURE NORTH OF THE REGION THIS MORNING BUT AS SURFACE HEATING
INCREASES CLOUDS WILL LIFT TO ABOUT 6 KFT AND THEN DRIFT SOUTHWARD
INTO THE AREA THIS AFTERNOON. SO EXPECTING SUN TO MIX WITH
AFTERNOON CLOUDS. STILL A VERY NICE AFTERNOON WITH LIGHT WINDS AND
TEMPS IN THE U60S TO L70S WITH COOLING AFTERNOON SEABREEZES FOR
THE SHORELINE. PREVIOUS FORECAST CAPTURES ALL OF THESE DETAILS SO
NO CHANGES WITH THIS FORECAST UPDATE. EARLIER DISCUSSION BELOW.
-----------------------------------------------------------------

TODAY WILL BE ABOUT 10 DEGREES COOLER THAN YESTERDAY WITH LIGHTER
WINDS. CONSIDERABLE SC AND AC OVER NORTHERN NEW ENGLAND BUT THINK
WE WILL JUST SEE SCT REMNANTS IN SOUTHERN NEW ENGLAND. NAM BUFKIT
DOES SHOW A MOIST LAYER AROUND 6 THSD FT. STILL THINK IT WILL
APPEAR AS MOSTLY SUNNY TO MOST OF THE POPULATION. BIAS CORRECTED
TEMP GRIDS SIMILAR FOR BOTH NAM AND GFS BASED STATISTICAL OUTPUT
AND SEE NO REASON TO STRAY VERY FAR FROM THOSE NUMBERS. GRADIENT
APPEARS TO SLACKEN ENOUGH IN THE AFTERNOON TO SUPPORT A SEA BREEZE
FOR A FEW HOURS NEAR THE IMMEDIATE COAST. THIS IS SHOWN MORE
EXPLICITY BY THE HRR MODEL AND JUST HINTED AT BY MOS GUIDANCE.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
MOSTLY CLEAR SKIES AND LIGHT WINDS SHOULD AID RADIATIONAL COOLING
AND MOST LOCATIONS BACK FROM THE IMMEDIATE COAST SHOULD DIP INTO
THE 40S...PERHAPS UPPER 30S IN COLDER SPOTS OF SW NH AND NW MA.
SATURDAY LOOKS TO BE DRY AS WELL...ALTHOUGH THERE MAY BE ENOUGH OF
A COLD POOL ALOFT N AND E OF WORCESTER FOR POSSIBLY A FEW
SPRINKLES. THINK IT IS TOO DRY FOR ANY MEASURABLE RAFL BUT DID PUT
A SMALL AREA OF SLIGHT CHANCE POPS IN NE MA AND SOUTHERN NH FOR
SATURDAY MID TO LATE AFTERNOON. AIR MASS LOOKS TO BE MODESTLY
MILDER...BRINGING TEMPS INTO THE 70S ACROSS THE INTERIOR. LOOKS
LIKE A LIGHT ENOUGH GRADIENT TO SUPPORT SEA BREEZES NEAR THE
COAST.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGHLIGHTS...

 * CHANCE OF RAIN LATE IN THE WEEKEND
 * TREND TOWARD WARMER/MORE HUMID AND SHOWERY WEATHER NEXT WEEK

LOW CONFIDENCE FORECAST ON THE DETAILS NEXT WEEK AS MODELS ARE NOW
TRENDING TOWARD A MORE AMPLIFIED/BLOCK PATTERN...WITH THE NORTHERN
STREAM BECOMING MORE DOMINANT WITH TIME ACROSS SOUTHEAST CANADA AND
THE NORTHEAST. THE QUESTION THEN BECOMES HOW MUCH DOES THE NORTHERN
STREAM ERODE THE SUBTROPICAL RIDGE ALONG THE EASTERN SEABOARD NEXT
WEEK? THIS WILL DETERMINE THE LOCATION AND SOUTHEAST PROGRESSION OF
A FRONTAL BOUNDARY...WHICH WILL BE CRITICAL IN DETERMINING
TEMPERATURES AND PROBABILITY OF PRECIPITATION. INCREASING FORECAST
UNCERTAINTY HERE IS THE LONG WAVE PATTERN ALSO BECOMES MORE OF A
SPLIT FLOW REGIME...WHICH OFFERS LOW PREDICTABILITY  GIVEN THE
INCREASED FORECAST UNCERTAINTY WILL LEAN/FOLLOW ENSEMBLE GUID
/16-12Z ECENS AND 17-00Z GEFS/ MORE THAN THE DETERMINISTIC
MODELS FROM TUE ONWARD.

SAT NIGHT/SUN BEGINS WITH MID LEVEL CLOSED LOW OVER ATLANTIC CANADA
AND A CORRESPONDING MARITIME HIGH JUST EAST OF NEW ENGLAND. THIS
WILL PROVIDE DRY AND SEASONABLE COOL CONDITIONS SAT NIGHT INTO SUN.
SUN WILL BE COOLER THAN SAT. THEN BY LATE SUN INTO MON THE ATLANTIC
CANADA MID LEVEL LOW MOVES SEAWARD ALLOWING A WARM FRONT SOUTH AND
WEST OF NEW ENGLAND TO APPROACH THE AREA. THIS MAY RESULT IN SOME
WARM ADVECTION PRECIP ACROSS THE REGION FROM LATE SUN /ESP SUN
NIGHT/ INTO MON. A FEW HEAVIER SHOWERS ARE POSSIBLE DURING THIS TIME
AS THE 00Z GEFS INDICATES PWATS OF +2 STD MAY ADVECT INTO SOUTHERN
NEW ENGLAND.

BY TUE AND/OR WED SOUTHERN NEW ENGLAND SHOULD BE IN THE WARM SECTOR
SO A PERIOD OF WARMER MORE HUMID WEATHER IS LIKELY. THEN COMES THE
MORE DIFFICULT PART OF THE FORECAST...HOW FAR SOUTHEAST WILL A
FRONTAL BOUNDARY PROGRESS AS THE LONG WAVE TROUGH OVER SOUTHEAST
CANADA RELOADS WITH YET ANOTHER CLOSED LOW PIVOTING INTO QUEBEC. THE
16/12Z ECENS AND 17/00Z GEFS SUGGEST THE FRONTAL BOUNDARY WILL
REMAIN OVER OR JUST NORTHWEST OF SOUTHERN NEW ENGLAND MUCH OF NEXT
WEEK. THIS SHOULD YIELD WARM AND SOMEWHAT HUMID WEATHER ALONG WITH A
RISK OF MAINLY DIURNAL SHOWERS FROM TUE AND BEYOND.

SO WHILE THE FORECAST FOR NEXT WEEK CONTAINS CHANCE POPS JUST ABOUT
EVERY DAY...NOT EXPECTING A WASHOUT WITH MANY HOURS OF DRY WEATHER
ANTICIPATED ESPECIALLY DURING THE OVERNIGHTS AND INTO THE MORNING
HOURS. AS FOR TEMPS...WARMER THAN NORMAL FROM TUE ONWARD BUT NOT
EXPECTING ANY RECORD HEAT.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
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FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH SATURDAY/...HIGH CONFIDENCE.

7 AM UPDATE...
NO CHANGE TO PREVIOUS FORECAST.

HIGH CONFIDENCE OF VFR CONDITIONS THROUGH SAT. N OR NW WIND GUSTS
TO 20 KT POSSIBLE THIS MORNING IN A FEW LOCATIONS BUT GRADIENT
SLACKENS BY AFTERNOON. LOCAL SEA BREEZES LIKELY NEAR IMMEDIATE
SHORELINES MID AND LATE AFTERNOON.

KBOS TERMINAL...HIGH CONFIDENCE OF VFR CONDITIONS THRU SAT.
MODERATE CONFIDENCE OF A SEA BREEZE DEVELOPING AROUND 18Z AND
LASTING TO 22 OR 23Z.

KBDL TERMINAL...HIGH CONFIDENCE IN TAF.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SAT NIGHT THROUGH SUN...VFR LIKELY ALONG WITH DRY WEATHER AND LIGHT
WINDS. HIGH CONFIDENCE.

SUN NIGHT THROUGH TUE....MVFR-IFR IN PERIODS OF LIGHT RAIN POSSIBLY
IMPROVING TO VFR TUE. MODERATE CONFIDENCE.
-- End Changed Discussion --

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

SHORT TERM /THROUGH SATURDAY/...HIGH CONFIDENCE.
WINDS HAVE DROPPED BELOW SCA THRESHOLDS BUT A RESIDUAL SWELL
REMAINS IN THE OUTER WATERS. WILL DROP SCA FOR BID AND RI
SOUNDS...AND ALLOW SCA TO CONTINUE FOR A WHILE LONGER IN THE OUTER
WATERS TO ALLOW TIME FOR THE SWELL TO SUBSIDE.

OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...

SAT NIGHT AND SUN...HIGH PRES OVER GULF OF ME PROVIDES DRY WEATHER
WITH LIGHT WINDS AND GOOD VSBY. HIGH CONFIDENCE.

SUN NIGHT AND MON...HIGH PRES MOVES OFFSHORE WITH SSW WINDS
INCREASING. PERIODS OF LIGHT RAIN AND FOG POSSIBLE. MODERATE
CONFIDENCE.

TUE...SOME IMPROVEMENT POSSIBLE AS WARM FRONT LIFTS NORTH OF THE
REGION. MODERATE CONFIDENCE.

&&

.FIRE WEATHER...
IT WILL BE DRY AGAIN TODAY WITH REL HUMIDITIES DROPPING MOST
INTERIOR LOCATIONS TO 25 TO 30 PERCENT...BUT NOT AS LOW AS
YESTERDAY WHEN TEMPS WERE ABOUT 10 DEGREES WARMER AND DEWPOINTS
SEVERAL DEGREES LOWER AIDED BY DEEP MIXING. WINDS WILL BE MUCH
LIGHTER TODAY.

OVER THE WEEKEND WINDS BECOME ONSHORE /E TO SE/ AT 10 MPH OR
LESS...WHICH WILL KEEP MINIMUM RELATIVE HUMIDITY NO LOWER THAN 30
TO 40 PERCENT. ASIDE FROM AN ISOLATED SHOWER...DRY WEATHER IS
EXPECTED.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR ANZ250.
     SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ254-
     255.
     SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR ANZ256.

&&

$$
SYNOPSIS...NOCERA/THOMPSON
NEAR TERM...THOMPSON
SHORT TERM...THOMPSON
LONG TERM...NOCERA
AVIATION...NOCERA/THOMPSON
MARINE...NOCERA/THOMPSON
FIRE WEATHER...