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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBOX 160822
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
422 AM EDT THU MAY 16 2013

.SYNOPSIS...

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DRY AND WARM TODAY WITH THE THREAT OF FIRE WEATHER POTENTIAL. A
REINFORCING DRY COLD FRONT TONIGHT WILL PUSH COOLER AIR ACROSS THE
REGION FOR FRIDAY AND INTO THE WEEKEND. A WARMING TREND IS LIKELY
EARLY NEXT WEEK AS MARITIME HIGH PRESSURE MOVES OFFSHORE.
-- End Changed Discussion --

&&

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

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INTO THE MORNING...

FOG ACROSS VALLEY AND COASTAL LOCALES WILL BEGIN TO BURN OFF WITH
SUNRISE. YET IF TRAVELING EARLY THIS MORNING...BE AWARE THAT
VISIBILITES COULD BE LOW AT TIMES MAKING DRIVING HAZARDOUS.
MOTORISTS SHOULD BE AWARE OF THIS THREAT AND EXERCISE CAUTION
TAKING IT SLOW WHERE APPROPRIATE WHEN ENCOUNTERING PATCHY DENSE
FOG.

TODAY...

ANTICIPATING WESTERLY WINDS WITH GUSTS OF AROUND 30 TO 35 MPH AS
BOUNDARY LAYER MIXING UP TO H7-8 WILL ALLOW THE MIX-DOWN OF FASTER
MOMENTUM TO THE SURFACE. SEE THE MARINE SECTION OF THE AFD
CONCERNING THE PLAUSIBILITY OF NEAR-SHORE HAZARDS. WILL ALSO SEE
THE MIX-DOWN OF DRIER AIR RESULTING IN SURFACE MINIMUM RELATIVE
HUMIDITIES AROUND 20 TO 25 PERCENT. HIGHS IN THE UPPER 70S TO LOW
80S WITH MOSTLY CLEAR CONDITIONS...COOLER ALONG THE SOUTH-SHORE
WITH SEA-BREEZES.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...

-- Changed Discussion --
TONIGHT...

WINDS RELAXING. A REINFORCING DRY COLD FRONT WILL SWEEP SOUTH ACROSS
NEW ENGLAND BEHIND WHICH A COOLER AIRMASS SHALL FILTER IN A THE MID-
LEVELS. SURFACE WINDS BACKING OUT OF THE NORTHWEST...AND COUPLED
WITH SCATTERED MID TO HIGH LEVEL CLOUDS...FEEL EFFECTIVE RADIATIONAL
COOLING WILL BE LIMITED. LOWS DOWN TO THE LOW TO MID 40S...WARMER
CLOSER TO SHORE.

FRIDAY...

A MUCH COOLER DAY WITH NORTHWESTERLY FLOW. WILL SEE GUSTS OF 20 TO
25 MPH WITH A WELL-MIXED BOUNDARY LAYER. ANOTHER DAY OF VERY LOW
RELATIVE HUMIDITIES AROUND 25 TO 30 PERCENT. MID TO HIGH LEVEL
CLOUDS FILTERING THROUGH THE REGION. SEA BREEZES LIKELY ALONG THE
IMMEDIATE EASTERN SHORE. WITH A COOLER AIRMASS ALOFT /H85
TEMPERATURES +2-4C/ HIGHS WILL RANGE IN THE UPPER 60S TO LOW 70S.

FRIDAY NIGHT...

HIGH PRESSURE BUILDING INTO NEW ENGLAND. LIGHT NORTHWEST FLOW
COUPLED WITH MOSTLY CLEAR CONDITIONS WILL NET AN EVENING OF
EFFECTIVE RADIATIONAL COOLING. PRESENT FORECASTED LOWS RANGE AROUND
THE UPPER 30S TO LOW 40S /WARMER CLOSER TO SHORES/. WILL NEED TO
CLOSELY EVALUATE TOWARDS THE ISSUANCE OF FROST HEADLINES.
-- End Changed Discussion --

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...

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HIGHLIGHTS...

* TEMPS...SEASONABLE THIS WEEKEND FOLLOWED BY WARMER/HUMID NEXT WEEK

* MAINLY DRY WEATHER PREVAILS WITH PATTERN POSSIBLY BECOMING MORE
  FAVORABLE FOR BENEFICIAL SHOWERS TOWARD THE MIDDLE OF NEXT WEEK

SYNOPTIC OVERVIEW...

MAIN WEATHER FEATURES THIS PERIOD WILL BE A CLOSED LOW/NEGATIVE
HEIGHT ANOMALY OVER ATLANTIC CANADA EARLY THIS PERIOD. THIS WILL
DELIVER MARITIME HIGH PRES TO EASTERN NEW ENGLAND THIS WEEKEND. THE
UPPER AIR PATTERN IS AMPLIFIED BUT PROGRESSIVE WITH MARITIME CLOSED
LOW MOVING SEAWARD BY EARLY NEXT WEEK. THIS ALLOWS DOWNSTREAM RIDGE
TO BUILD INTO THE EASTERN SEABOARD EARLY NEXT WEEK. THIS WILL
TRANSLATE INTO A WARMING TRENDING FOR SOUTHERN NEW ENGLAND EARLY
NEXT WEEK. THE LONG WAVE PATTERN MAY BECOME FAVORABLE FOR BENEFICIAL
SHOWERS HERE MIDDLE OF NEXT WEEK AS MID LEVEL TROUGH SETS UP ACROSS
THE GREAT LAKES. UNTIL THEN MAINLY DRY WEATHER PREVAILS.

MODEL PREFERENCES AND UNCERTAINTY...

GOOD MODEL AGREEMENT THROUGH THE WEEKEND ON THE LARGE SCALE FLOW
ACROSS THE CONUS INTO NEW ENGLAND AMONG DETERMINISTIC RUNS OF THE
GFS/ECMWF AND ENSEMBLES GEFS AND ECENS. THEREFORE THIS PORTION OF
THE FORECAST WAS DERIVED FROM AN EVEN BLEND OF GFS/ECMWF AND THEIR
MOS FIELDS. HOWEVER GIVEN THE PATTERN SUPPORTS MAINLY DRY WEATHER
DECIDED TO UNDERCUT METNAM AND MAVMOS POPS TO SLIGHT CHANCE. THEN
NEXT WEEK MODELS AGREE ON EAST COAST RIDGING BUT THEN DIFFER ON HOW
THIS RIDGE WILL ERODE/DEAMPLIFY BASED ON EVOLUTION OF UPSTREAM
TROUGH OVER THE PLAINS. THUS WILL PLAY IT CONSERVATIVE HERE AND NOT
DEVIATE MUCH FROM GUIDANCE.  TEMPS WERE DERIVED FROM HPC GUID AND IN
HOUSE BIAS CORRECTED MOS.

DAILY SENSIBLE WEATHER DETAILS...

THIS WEEKEND...

COOLER AS MARITIME HIGH PRES DESCENDS UPON EASTERN NEW ENGLAND. SAT
LOOKS WARMER THAN SUN. MAINLY DRY CONDITIONS SHOULD PREVAIL BUT
CAN/T RULE OUT AN ISOLATED DIURNAL SHOWER SAT GIVEN COLD POOL ALOFT
/-20C AT 500MB/ AND STRONG-HIGH MID MAY SUN ANGLE AIDING IN STEEP
LAPSE RATES. ALSO SUNDAY CAN/T RULE OUT SOME SPOTTY WARM ADVECTION
PRECIP ACROSS WESTERN PORTIONS OF CT/MA INTO SOUTHWEST NH IN
RESPONSE TO RETURN FLOW WITH HIGH PRES EAST OF NEW ENGLAND. OVERALL
A MAINLY DRY WEEKEND.

EARLY NEXT WEEK...MID LEVEL RIDGE BUILDS ALONG THE EASTERN SEABOARD
WITH MARITIME HIGH PRES MOVING OFFSHORE AND RETURN FLOW SETTING UP
ACROSS THE NORTHEAST. THUS LOW LEVEL WARM AIR ADVECTION WILL RESULT
IN TEMPS CLIMBING TO NEAR 80 DEGS TUE/WED. WARM DAYS WILL BE
ACCOMPANIED BY MILD NIGHTS IN RESPONSE TO INCREASING DEW PTS.
WEATHER LOOKS DRY MON BUT POSSIBLY BECOMING SHOWERY TUE AND
ESPECIALLY WED AS LONG WAVE TROUGH AND ASSOCIATED FRONTAL BOUNDARY
APPROACHES FROM THE WEST.
-- End Changed Discussion --

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...

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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 FRIDAY NIGHT/...MODERATE CONFIDENCE.

6Z UPDATE...

FOG HAS BEEN A NUISANCE WITH MVFR-VLIFR VARIABILITY. HAVE GREATER
CONFIDENCE THAT SHELTERED VALLEY TERMINALS WITH CALM WINDS...AND
TERMINALS ALONG THE S/SE SHORES...WILL SEE FOG INTO SUNRISE.

THEREAFTER VFR WITH WESTERLY WIND GUSTS AROUND 30 KTS THROUGH THE
DAY. SECONDARY DRY COLD FRONT WILL SHIFT WINDS OUT OF THE N/NW
THURSDAY NIGHT...MOSTLY CLEAR WITH LESSER CONFIDENCE OF FOG
IMPACTS. N/NW WINDS WITH POTENTIAL GUSTS AROUND 20 KTS CONTINUING
INTO FRIDAY BUT DIMINISHING INTO THE EVENING. VFR.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.

OUTLOOK...SATURDAY THROUGH MONDAY...

MODERATE TO HIGH CONFIDENCE FOR VFR AND DRY WEATHER. LOCAL MVFR
AND/OR IFR IN AREAS OF LATE NIGHT/MORNING FOG.
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&&

.MARINE...

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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 FRIDAY NIGHT/...MODERATE CONFIDENCE.

HAVE MODERATE CONFIDENCE THAT WESTERLY WIND GUSTS WILL REACH 25 KTS
ALONG THE NEAR-SHORE. WHILE THE FORECAST MAY NOT PERFECTLY REFLECT
THIS OUTCOME...HAVE GONE AHEAD AND ISSUED SMALL CRAFT ADVISORIES
ACCORDINGLY WITH THE THOUGHT IN MIND OF THE NICE DAY ENCOURAGING
MORE RECREATIONAL BOATING ACTIVITIES OUT ON THE WATERS. MARINERS
SHOULD BE AWARE THAT THE STRONGEST OF WINDS WILL BE RIGHT ALONG THE
IMMEDIATE SHORES. SUCH THREATS SHOULD DIMINISH WITH SUNDOWN.

ELSEWHERE...ALONG THE OUTER WATERS...REMNANT SWELL AND WAVE HEIGHTS
IN EXCESS OF 5 FEET WILL BE OF GREATER CONCERN. HAZARDS AND
ACCOMPANYING SMALL CRAFT ADVISORIES WILL CONTINUE INTO FRIDAY...
DROPPING OFF FRIDAY NIGHT AS HIGH PRESSURE SETTLES INTO THE
REGION.

OUTLOOK...SATURDAY THROUGH MONDAY...

NICE BOATING WEATHER WITH HIGH PRES JUST EAST OF NEW ENGLAND. THUS
DRY WEATHER/LIGHT WINDS/SMALL WIND WAVES AND GOOD VSBY SHOULD
PREVAIL.
-- End Changed Discussion --

&&

.FIRE WEATHER...

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FOR TODAY...WESTERLY WINDS WILL GUST AROUND 30 MPH...POSSIBLY AS
HIGH AS 40 MPH...ACROSS INTERIOR NEW ENGLAND AS RELATIVE HUMIDITIES
DROP TO MINIMUMS BETWEEN 20 TO 30 PERCENT. FIRE WEATHER POTENTIAL
WILL BE SIGNIFICANT AS TEMPERATURES WARM INTO THE UPPER 70S TO LOW
80S.

THOUGH GREEN-UP IS UNDERWAY...FIRE WEATHER POTENTIAL EXISTS AS THERE
IS A RISK OF FIRE SPREAD. IT IS HIGHLY RECOMMENDED TO NOT BURN
TODAY. AFTER COMMUNICATING WITH STATE AGENCIES...IT WAS AGREED UPON
THE ISSUANCE OF A SPECIAL WEATHER STATEMENT /RATHER THAN RED FLAG
WARNINGS/ OUTLINING THE ELEVATED FIRE WEATHER CONDITIONS ACROSS
INTERIOR NEW ENGLAND.

OUTLOOK FOR FRIDAY INTO NEXT WEEK...MINIMUM RELATIVE HUMIDITIES WILL
RANGE AROUND 40 PERCENT WHILE WINDS WILL REMAIN BELOW 20 MPH
THRESHOLD.
-- End Changed Discussion --

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

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CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 10 PM EDT THIS
     EVENING FOR ANZ230>234-236-251.
     SMALL CRAFT ADVISORY UNTIL 5 AM EDT FRIDAY FOR ANZ235-237.
     SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR ANZ250.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT FRIDAY FOR ANZ254-255.
     SMALL CRAFT ADVISORY UNTIL 11 AM EDT FRIDAY FOR ANZ256.
-- End Changed Discussion --

&&

$$

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