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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBOX 030009
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
709 PM EST MON DEC 2 2013

.SYNOPSIS...
AN OCEAN STORM MAY BRUSH THE FAR SOUTHEAST NEW ENGLAND COAST WITH
A PERIOD OF RAIN SHOWERS LATE TONIGHT INTO TUESDAY...BUT THE REST
OF THE REGION SHOULD REMAIN DRY. HIGH PRESSURE AND RELATIVELY MILD
WEATHER WILL PUSH INTO THE REGION WED AND THU. A WARM FRONT...
FOLLOWED BY A STRONG COLD FRONT...SHOULD APPROACH LATE THURSDAY
INTO FRIDAY...BRINGING A CHANCE FOR PRECIPITATION. PROGRESSIVELY
COLDER AIR IS EXPECTED FOR THIS WEEKEND INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
-- Changed Discussion --
700 PM UPDATE...LOW CLOUDS CONTINUE TO HOLD TOUGH ACROSS EASTERN
MA AND THE MERRIMACK VALLEY IN NH. THINKING THESE LOW CLOUDS
SHOULD SLOW THEIR RATE OF DISSIPATION AS WE ARE NOW PAST SUNSET
AND LOW LEVEL RELATIVE HUMIDITY NATURALLY INCREASES. LATEST LAMP
GUIDANCE APPEARS TO HAVE A GOOD HANDLE ON THIS TREND. EVENTUALLY
THE LIGHT NORTH TO NORTHWEST WINDS WILL ERODE THESE CLOUDS...BUT
IT MAY BE JUST AFTER DAYBREAK TUESDAY FOR THIS TO HAPPEN.

MADE MINOR TWEAKS TO NEAR-TERM CONDITIONS TO REFLECT THE LATEST
OBSERVED TRENDS.

PREVIOUS DISCUSSION...

TONIGHT...LOW PRESSURE INTENSIFIES AS IT MOVES NORTHEAST FROM THE
COAST OF NORTH CAROLINA.  THIS LOW IS ON A TRACK TO PASS SOUTHERN
NEW ENGLAND WELL OUTSIDE OF THE 40/70 BENCHMARK.  WHILE THERE IS
STILL SOME DISPARITY IN THE MODELS ON THE EXACT TRACK...ALL MODELS
HAVE IT PASSING SOUTHERN NEW ENGLAND WELL OUTSIDE THE BENCHMARK.
THIS WILL LIMIT ITS IMPACT ON THE REGION...WITH RAIN SHOWERS LIKELY
ONLY ON THE OUTER CAPE AND NANTUCKET LATE TONIGHT INTO TUESDAY
MORNING.  THERE IS A LOW PROBABILITY THAT SHOWERS WILL EXTEND INTO
THE SOUTHEASTERN MASSACHUSETTS COASTAL PLAIN...BUT AT THIS TIME THAT
SEEMS UNLIKELY.  LOW TEMPERATURES ON THE CAPE AND ISLANDS WILL BE IN
THE UPPER 30S TO AROUND 40.  TEMPERATURES ELSEWHERE AROUND THE
REGION WILL BE IN THE UPPER 20S TO LOWER 30S.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
TUESDAY...ABOVE MENTIONED LOW PRESSURE SYSTEM PASSES WELL OUTSIDE
THE 40/70 BENCHMARK ON ITS WAY TO THE MARITIMES.  RAIN SHOWERS ARE
POSSIBLE ON THE OUTER CAPE AND NANTUCKET...THOUGH IF THE LOW PASSES
FARTHER TO THE EAST...EVEN THESE LOCATIONS COULD BE DRY.  THIS COULD
GO THE OTHER WAY AS WELL AND IF IT PASSES FARTHER WEST...SHOWERS
COULD EXTEND INTO THE COASTAL PLAIN.  THAT SAID...MODELS ARE
CONSISTENT WITH AN OFFSHORE TRACK.  HAVE SLIGHT CHANCE TO CHANCE
POPS FROM HYANNIS EAST ON THE CAPE AND ON NANTUCKET...CONSISTENT
WITH LATEST MODEL CONSENSUS.

WITH SOME CLEARING EXPECTED...HAVE FORECAST HIGH TEMPERATURES IN THE
MID 40S.  HOWEVER...IF SKIES ARE OVERCAST FOR MUCH OF THE DAY...THE
TEMPERATURES MAY END UP BEING COOLER.

TUESDAY NIGHT...HIGH PRESSURE STARTS BUILDING IN AS THE LOW PRESSURE
MOVES OFF TO THE MARITIMES.  COUPLED WITH CLEAR SKIES AND LIGHT
WINDS...EXPECT GOOD RADIATIONAL COOLING CONDITIONS.  LOW
TEMPERATURES WERE A BLEND OF GUIDANCE...RESULTING IN VALUES IN THE
MID 20S ACROSS THE INTERIOR TO LOW 30S ALONG THE COAST.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HIGHLIGHTS...

* SPOTTY SHOWERS WEDNESDAY NIGHT INTO THURSDAY WITH ABOVE AVERAGE
  TEMPERATURES
* COLD FRONTAL PASSAGE FRIDAY INTO FRIDAY NIGHT WILL BRING A
  PERIOD OF PRECIPITATION
* BELOW NORMAL TEMPERATURES RETURN SATURDAY INTO MONDAY

CONFIDENCE LEVEL/MODEL GUIDANCE...

02/12Z GUIDANCE HAS NOT IMPROVED CONSISTENCY MUCH FROM PRIOR RUNS.
THERE ARE STILL TWO CAMPS IN THE DETAILS...BUT AGREEMENT IN AN
OVERALL THEME TOWARD THE END OF THIS WEEK. GOOD AGREEMENT A LOW
PRESSURE WILL MOVE THROUGH THE GREAT LAKES REGION WEDNESDAY INTO
THURSDAY. THE PRIMARY DISAGREEMENT IS THE TIMING. SLIGHTLY BETTER
AGREEMENT ON THE TIMING A OF WARM AND COLD FRONT THROUGH SOUTHERN
NEW ENGLAND LATE THIS WEEK. MODERATE OVERALL CONFIDENCE IN THE
PATTERN...WITH NOT AS MUCH CONFIDENCE IN THE TIMING. DECIDED TO GO
WITH HIGHER POPS AHEAD OF A COLD FRONT THURSDAY NIGHT INTO
FRIDAY...BUT THE TIMING MAY CHANGE.

MODELS STILL INDICATE A LARGE TROUGH AMPLIFYING OVER THE WESTERN
CONUS...INDUCING WEAK RIDGING OVER THE EAST COAST. A STRONG LOW
PRESSURE NEAR TO JUST NORTH OF THE GREAT LAKES THURSDAY/FRIDAY
WILL FORCE A FULL BLOWN ARCTIC OUTBREAK ACROSS MUCH OF THE LOWER
CONUS. THIS COLD SHOULD MAINLY IMPACT OUR REGION THIS WEEKEND
INTO EARLY NEXT WEEK.

DETAILS...

WEDNESDAY...

OCEAN STORM WILL MOVE INTO THE MARITIMES BY WEDNESDAY. UPPER LEVEL
RIDGE WILL MOVE INTO THE AREA ALLOWING A SOME DRY WEATHER AND NEAR
AVERAGE TEMPERATURES. CLOUD COVER WILL START TO INCREASE ON
WEDNESDAY AS WARM FRONT WILL APPROACH THE REGION.

WEDNESDAY NIGHT INTO SATURDAY...

A WARM FRONT WILL PASS OVER THE REGION WEDNESDAY NIGHT INTO
THURSDAY. A FEW SPOTTY SHOWERS ARE POSSIBLE. BECAUSE TEMPERATURES
WILL BE CLOSE TO FREEZING...ESPECIALLY ACROSS THE HIGHER TERRAIN
OF SOUTHERN NH...AND A WARM NOSE WILL INTRUDE...STILL THINKING
THERE IS A POSSIBILITY FOR SOME FREEZING RAIN WEDNESDAY NIGHT
INTO THURSDAY MORNING. WILL NEED TO MONITOR THIS POTENTIAL OVER
THE NEXT FEW DAYS DUE TO THE TIMING DIFFERENCES.

A COLD FRONT WILL DRAG ACROSS NEW ENGLAND LATE THURSDAY NIGHT INTO
FRIDAY. SEVERAL IMPULSES COULD DEVELOP ALONG THE FRONT...SLOWING
ITS EASTWARD PROGRESS. WITH PRECIPITABLE WATER VALUES NEARING 1
TO 1.5 INCHES...THE POTENTIAL FOR HEAVY RAINFALL INCREASES.
HOWEVER MODELS ARE STRUGGLING ON WHERE THIS STALLED FRONT WILL SET
UP. THERE MAY BE SOME FLAKES ON THE BACK SIDE OF THE FRONT AS
THERE IS STRONG ARCTIC AIR BEHIND.

SUNDAY AND BEYOND...

TEMPERATURES ON SUNDAY AND MONDAY WILL BE BELOW AVERAGE. THERE IS
A POSSIBILITY FOR A COASTAL STORM TO PASS BY LATE SUNDAY INTO
MONDAY. THE PRECISE TRACK AND TIMING WILL NEED TO BE RESOLVED OVER
THE COURSE OF THIS WEEK.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TUESDAY NIGHT/...MODERATE CONFIDENCE
TONIGHT...MAINLY DUE TO TIMING ISSUES. HIGH CONFIDENCE TUESDAY
AND TUESDAY NIGHT.

TONIGHT...SLOW IMPROVEMENT TO MVFR AND THEN VFR CONDITIONS. SOME
LOCALIZED MVFR-IFR VISIBILITIES MAY DEVELOP IN PATCHY FOG. RAIN
SHOWERS MAY AFFECT THE OUTER CAPE AND NANTUCKET LATE.

TUESDAY...MAINLY VFR ACROSS THE INTERIOR.  MVFR CONDITIONS ARE
POSSIBLE ALONG THE COASTAL PLAIN AND ESPECIALLY THE OUTER CAPE AND
NANTUCKET...WHERE SOME RAIN SHOWERS MAY AFFECT THE REGION.

TUESDAY NIGHT...CONDITIONS IMPROVE TO VFR AS HIGH PRESSURE BUILDS
INTO THE REGION.

KBOS TAF...HIGH CONFIDENCE IN TRENDS. LOW CONFIDENCE IN TIMING
IMPROVEMENT TO VFR.

KBDL TAF...HIGH CONFIDENCE.

OUTLOOK...WEDNESDAY THROUGH SATURDAY...MODERATE OVERALL CONFIDENCE.

WEDNESDAY...HIGH CONFIDENCE VFR.

WEDNESDAY NIGHT INTO THURSDAY...LOW END VFR CONDITIONS WITH PERIODS
OF MVFR-IFR IN SCT SHOWERS. MAY SEE BRIEF PERIOD OF -FZRA LATE WED
NIGHT ACROSS HIGHER TERRAIN OF S NH POSSIBLY INTO N CENTRAL AND NW
MA.

THURSDAY NIGHT INTO FRIDAY...MVFR CIGS/VSBYS IN SHOWERS DURING THE
DAY. LOW CONFIDENCE ON IFR CONDITIONS IN HEAVY RAIN.

SATURDAY...MODERATE CONFIDENCE VFR.
-- End Changed Discussion --

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /TODAY THROUGH TUESDAY/...HIGH CONFIDENCE.

TONIGHT...NORTHERLY WINDS AND SEAS GRADUALLY INCREASE THROUGH THE
NIGHT...THOUGH THEY REMAIN BELOW SCA CRITERIA.  RAIN SHOWERS WILL
AFFECT THE SOUTHEASTERN COASTAL WATERS LATE AS AN OCEAN STORM
APPROACHES FROM THE CAROLINAS.

TUESDAY...SEAS INCREASE TO 4 TO 6 FEET AND NORTHERLY WINDS TO NEAR
25 KTS AS THE OCEAN STORM PASSES TO THE EAST OF THE COASTAL WATERS.
SMALL CRAFT ADVISORIES CONTINUE FOR THE OUTER WATERS DURING THIS
TIME FRAME.  RAIN SHOWERS WILL CONTINUE TO EFFECT THE EASTERN WATERS.

TUESDAY NIGHT...WINDS SHIFT TO THE NORTHWEST AND VERY SLOWLY
DIMINISH.  SEAS START TO DIMINISH AS WELL.  SMALL CRAFT ADVISORIES
MAY HAVE TO BE EXTENDED BUT GIVEN THE MARGINAL NATURE OF THE
ADVISORY HAVE OPTED NOT TO EXTEND AT THIS TIME.

OUTLOOK...WEDNESDAY THROUGH SATURDAY...

TUESDAY NIGHT INTO WEDNESDAY...AN OCEAN STORM WILL MOVE INTO THE
MARITIMES...ALLOWING FOR PRESSURE GRADIENT TO SLACKEN. SEAS AND
WINDS WILL DIMINISH AS WELL. EXPECT LINGERING SMALL CRAFT
ADVISORIES THROUGH THE DAY WEDNESDAY FOR SEAS...MAINLY ACROSS THE
OUTER COASTAL WATERS.

THURSDAY-FRIDAY...EXPECT WINDS BELOW SMALL CRAFT ADVISORY
CRITERIA. SEAS MAY LINGER AROUND 5 FT ACROSS THE OUTER WATERS.
VSBYS MAY BE REDUCED ON FRIDAY FROM HEAVY RAINFALL.

SATURDAY...RELATIVELY MORE TRANQUIL CONDITIONS ANTICIPATED.

&&

.TIDES/COASTAL FLOODING...
ASTRONOMICAL TIDES ARE QUITE HIGH LATE TUESDAY MORNING...WITH AN
11.9 HIGH TIDE IN BOSTON. THE WIND FIELD ABOUT THE OCEAN STORM
SHOULD BE ENOUGH TO PRODUCE A MODEST SURGE OF GENERALLY .5 TO
POSSIBLY .7 FEET ALONG THE MA E COAST. A WORST CASE SCENARIO COULD
RESULT IN A STORM SURGE NEAR 1 FT SANDWICH AND NANTUCKET HARBOR.
WAVES WILL PROBABLY NOT BUILD ANY HIGHER THAN 4 TO 7 FT A FEW
MILES OFFSHORE. WE ISSUED A COASTAL FLOOD ADVISORY FOR THE REACH
OF COASTLINE FROM BOSTON TO SANDWICH AND NANTUCKET HARBOR BUT
ANTICIPATE MINIMAL IMPACT. THE MAIN IMPACT IS LIKELY TO BE
ISOLATED BRIEF LANE OR ROAD CLOSURES IN THE MOST VULNERABLE
LOCATIONS. MINOR BEACH EROSION IS ALSO A POSSIBILITY ALONG THE
EAST SHORE OF NANTUCKET...BUT WAVES ARE NOT EXPECTED TO BE HIGH
ENOUGH TO CAUSE ANY SERIOUS PROBLEMS.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...COASTAL FLOOD ADVISORY FROM 9 AM TO 1 PM EST TUESDAY FOR
     MAZ015-016-019-022-024.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 AM TO 7 PM EST TUESDAY FOR
     ANZ231>234.
     SMALL CRAFT ADVISORY FROM 6 AM TO 7 PM EST TUESDAY FOR ANZ250-
     251-254>256.

&&

$$
SYNOPSIS...RLG/BELK
NEAR TERM...BELK/RLG
SHORT TERM...RLG
LONG TERM...BELK
AVIATION...RLG/BELK
MARINE...RLG/BELK
TIDES/COASTAL FLOODING...THOMPSON