-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBOX 272111
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
411 PM EST TUE JAN 27 2015

.SYNOPSIS...
-- Changed Discussion --
A CRIPPLING AND HISTORIC WINTER STORM/BLIZZARD WILL GRADUALLY LOOSEN
ITS GRIP ON EASTERN NEW ENGLAND THIS EVENING. DRIER WEATHER FOLLOWS
WEDNESDAY AFTERNOON INTO THURSDAY. PLAINS LOW PRESSURE WILL BRING
ANOTHER CHANCE FOR SNOW THURSDAY NIGHT AND FRIDAY. DRY BUT VERY
COLD AIR LOOKS TO FOLLOW FOR THE WEEKEND. A THIRD STORM MAY
AFFECT THE REGION SUNDAY NIGHT AND MONDAY.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
HIGHLIGHTS...

* BLIZZARD CONTINUES ACROSS EASTERN MA/RI THIS AFTERNOON WITH
  GRADUAL IMPROVEMENT TONIGHT

* SNOW DIMINISHING ACROSS WESTERN MA/NORTHERN CT THIS AFTERNOON BUT
  SOME BLOWING AND DRIFTING SNOW CONTINUES

* DESTRUCTIVE WINDS CONTINUE ON THE CAPE/NANTUCKET THROUGH THE
  AFTERNOON WITH WINDS GRADUALLY DIMINISHING TONIGHT

1235 PM UPDATE...

JUST LIGHTER SNOWFALL REMAINED ACROSS NORTHERN CT AND WESTERN MA AT
AROUND NOON.  THEREFORE...HAVE DOWNGRADED NORTHERN CT TO A WINTER
STORM WARNING.  ANY ADDITIONAL SNOW ACCUMULATIONS IN THIS REGION
SHOULD BE LIGHT WITH IT ALL PRETTY MUCH OVER BY EARLY THIS EVENING.
HOWEVER...GUSTS BETWEEN 25 AND 35 MPH WILL RESULT IN BLOWING AND
DRIFTING SNOW AND POOR VISIBILITIES AT TIMES.

MEANWHILE...1 TO 2 INCH PER HOUR SNOWFALL RATES CONTINUE ACROSS
EASTERN MA/RI.  THIS A RESULT OF WELL DEVELOPED STORM AND A GOOD MID
LEVEL DEFORMATION ZONE.  MODERATE TO HEAVY SNOW WILL CONTINUE IN
THIS REGION FOR ANOTHER FEW HOURS...BEFORE TAPERING TO LIGHTER
SNOWFALL BY EARLY EVENING.  BLOWING AND DRIFTING SNOW WILL CONTINUE
TO RESULT IN BLIZZARD CONDITIONS AND NEAR ZERO VISIBILITY THROUGH THE
AFTERNOON.  GRADUAL IMPROVEMENT OCCURS THIS EVENING AND ESPECIALLY
TONIGHT.

CONDITIONS ACROSS THE CAPE AND ISLANDS ARE LIFE THREATENING.
NORTHERLY WIND GUSTS BETWEEN 55 AND 70 MPH WITH HEAVY SNOW AND
NEAR ZERO VISIBILITY CONTINUE TO AFFECT THE REGION.  SNOW WILL
DIMINISH SOME IN INTENSITY BY LATE AFTERNOON/EARLY EVENING...BUT
BLOWING AND DRIFTING SNOW WILL CONTINUE RIGHT THROUGH TONIGHT.
WINDS WILL REMAIN POWERFUL WITH STRONG NORTHERLY LOW LEVEL JET
THROUGH THE AFTERNOON...SO IT WILL TAKE UNTIL THIS EVENING TO
DIMINISH SOME ALTHOUGH THEY WILL REMAIN STRONG.

TONIGHT...
AS MID LEVEL LOW LIFTS NORTH FROM EAST OF CAPE COD...EXPECT SNOW
TO GRADUALLY WIND DOWN AND END FROM WEST TO EAST. SOME MINOR
ADDITIONAL ACCUM POSSIBLE. OTHERWISE VERY COLD WITH LOWS DOWN
INTO THE SINGLE NUMBERS...EXCEPT TEENS IMMEDIATE COAST. EXPECT
SUBZERO WIND CHILLS DEVELOPING AND APPROACHING WIND CHILL
THRESHOLD OF -15 OVER THE HIGHER TERRAIN IN WESTERN AND NORTHERN
MA.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
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WEDNESDAY...
EXPECT COASTAL STORM TO DRIFT NE THROUGH THE GULF OF MAINE ACROSS
NOVA SCOTIA DURING THE DAY. LAST OF LIGHT SNOW WILL PUSH OFF THE
COAST WED MORNING...WITH IMPROVING CONDITIONS. HOWEVER...WILL
STILL SEE BLUSTERY NW WINDS BEHIND THE DEPARTING LOW ALONG THE
COAST AS TIGHT PRES GRADIENT LINGERS THROUGH MIDDAY BEFORE
DIMINISHING. BRIEF SHOT OF COLD AIR MOVES ACROSS WITH H85 TEMPS
DOWN TO -10C TO -12C. THIS WILL TRANSLATE TO HIGH TEMPS ONLY IN
THE 20S ACROSS THE REGION...POSSIBLY ONLY IN THE UPPER TEENS
ACROSS THE INTERIOR HIGHER TERRAIN.
-- End Changed Discussion --

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...

-- Changed Discussion --
BIG PICTURE...
NORTHERN AND SOUTHERN STREAMS WILL PUSH SHORTWAVES ACROSS THE USA.
ONE NORTHERN STREAM SHORTWAVE ENTERED THE PACIFIC NORTHWEST TODAY
AND WILL REACH NEW ENGLAND THURSDAY NIGHT/FRIDAY. A SOUTHERN
STREAM SHORTWAVE FROM CALIFORNIA MAY MERGE WITH IT WEDNESDAY OR
THURSDAY. ANOTHER PAIR OF SHORTWAVES DIG OVER THE PLAINS OVER THE
WEEKEND AND APPROACH THE EAST COAST SUNDAY NIGHT/MONDAY.

THE VARIOUS MODELS ARE SIMILAR IN THE BROAD PORTRAIT OF WEATHER
SYSTEMS THESE NEXT SEVEN DAYS BUT DIFFER ON DETAILS SUCH AS
TIMING. WE OPTED FOR A BLEND OF MODEL DATA FOR THIS FORECAST.

THE DAILIES...

WEDNESDAY NIGHT-THURSDAY...HIGH CONFIDENCE
HIGH PRESSURE MOVES ACROSS THE REGION AND SHOULD PROVIDE A PERIOD
OF CLEAR SKIES AND LIGHT WINDS. DEW POINTS WILL BE IN THE SINGLE
NUMBERS BELOW ZERO WHICH SHOULD ALLOW THE COLDER LOCATIONS TO A
SIMILAR RANGE OVERNIGHT. IF THERE ARE POTENTIAL PROBLEMS IN THE
FORECAST...IT WOULD BE THAT MINS MAY BE 2-4F TOO WARM IN THE
NORMAL COLD SPOTS OF THE EAST IF THEY RADIATE MORE EFFECTIVELY.

THE HIGH WILL SHIFT OFFSHORE THURSDAY BUT STILL PROVIDE PLENTY OF
DRY AIR FOR NEW ENGLAND. AS IT SHIFTS OFFSHORE...A SOUTHWEST FLOW
ALOFT WILL BRING IN INCREASING MOISTURE ALOFT AND THUS INCREASING
MID AND HIGH CLOUDS. ANY PCPN SHOULD HOLD OFF UNTIL AFTER DARK.

THURSDAY NIGHT-FRIDAY...LOW-MODERATE CONFIDENCE
CLIPPER AND SUPPORTING SHORTWAVE RACE EAST TO THE GREAT LAKES
THURSDAY AND THEN REDEVELOP ALONG THE NEW ENGLAND COAST. THE GFS
HAS THE REDEVELOPMENT IN THE GULF OF MAINE WHILE THE ECMWF AND
GGEM SHOW THIS CLOSER TO 40N/70W. THE SOUTHERN SOLUTION IS CLOSER
TO THE DYNAMICALLY FAVORED LEFT EXIT REGION OF THE UPPER JET...AND
MAY RESULT IN MORE PCPN IF IT OCCURS. TEMPERATURE PROFILES FAVOR
SNOW ALTHOUGH SOME WARM INTRUSION MAY WARM THE CAPE/ISLANDS INTO
THE UPPER 30S AND PROVIDE A BRIEF CHANGE TO RAIN. THIS WILL NEED
TO BE MONITORED. THE DIFFERENCES IN MODEL PLACEMENT OF THE SURFACE
LOW LEAD TO THE REDUCED CONFIDENCE IN THIS PART OF THE FORECAST.

SURFACE PRESSURE FALLS AS THE STORM DEEPENS OFFSHORE. THIS WILL
TIGHTEN THE PRESSURE GRADIENT AND BRING INCREASING NORTHWEST WINDS
ON THE TRAILING SIDE OF THE STORM. COLD AIR THEN GETS DRAWN IN
ACROSS NEW ENGLAND FRIDAY. TEMPS ALOFT WILL SUPPORT MAX TEMPS IN
THE 30S DURING THE MORNING-MIDDAY AND 20S BY SUNSET.

FRIDAY NIGHT-SATURDAY-SUNDAY...
STRONG WINDS TRAILING THE STORM BRING INCOMING COLD AIR WITH
AIRMASS TEMPS REACHING THE SINGLE NUMBERS. THIS WILL BRING WIND
CHILLS BELOW ZERO. NORTHERN AND WESTERN WIND CHILLS SHOULD GO
BELOW 10 BELOW ZERO AND MAY REQUIRE A WIND CHILL ADVISORY.

HIGH PRESSURE BUILDS OVER THE REGION ON SATURDAY WITH DRY WEATHER
AND GUSTY NORTHWEST WINDS. TEMPS AT 925 MB WILL BE -13C TO
-17C...SO MAX TEMPS SATURDAY WILL BE CHALLENGED TO REACH THE 20S
MOST PLACES...BEST CHANCE WILL BE IN RI AND SOUTHEAST MASS.

THE HIGH MOVES OFFSHORE ON SUNDAY...AGAIN CREATING INCREASING
MOISTURE ALOFT WHILE DRY NEAR THE SURFACE. THIS WILL MEAN
INCREASING CLOUDS DURING THE DAY WITH TEMPS A LITTLE LESS COLD
THAN ON SATURDAY.

SUNDAY NIGHT-MONDAY...
NEXT PAIR OF SHORTWAVES APPROACH. THE SOUTHERN STREAM SHORTWAVE
GENERATES AN INVERTED TROUGH IN THE WESTERN GULF/MISSISSIPPI
VALLEY REGION. THE NORTHERN SHORTWAVE HELPS GENERATE LOW PRESSURE
IN THIS TROUGH AND SWINGS IT NORTHEAST TOWARD NEW ENGLAND. ALL
MOVE PCPN INTO NEW ENGLAND AND CONSENSUS KEEPS TEMPS COLD ENOUGH
FOR SNOW. BUT DIFFERENCES IN TRACK RANGING FROM ACROSS THE
BERKSHIRES /ECMWF/ TO ACROSS THE 40N/70W BENCHMARK /GGEM/. AND
THIS IS A DAY 5 FORECAST. SO CONFIDENCE REMAINS LOW.

TUESDAY...
HIGH PRESSURE BUILDS OVER THE REGION WITH 925 MB TEMPS AGAIN
FALLING TO AROUND -15 TO -17C. ANOTHER CHILLY DRY WEATHER DAY.
-- End Changed Discussion --

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
-- 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...

THIS AFTERNOON AND TONIGHT...

RADAR SHOWS MOST OF THE SNOW IS NOW EAST OF THE CT VALLEY. THE
HEAVIEST SNOW IS CONCENTRATED IN EASTERN MASS AND TO A LESSER
EXTENT IN RHODE ISLAND. MOST CIGS AND VSBYS WITHIN THIS SNOW BAND
SHOULD BE AT OR BELOW 1000 FEET AND BELOW 1 MILE. BASED ON THE
LOCATION OF THE STORM CENTER EAST OF NANTUCKET...EXPECT THE SNOW
BAND WILL LINGER OVER EASTERN MASS/RI THROUGH THE AFTERNOON WITH
AN IMPROVING TREND AFTER 22Z. STRONG WIND GUSTS CONTINUE IN THE
EAST WITH 50-60 KNOT GUSTS CAPE COD AND ISLANDS. LOW LEVEL WIND
SHEAR CONTINUES THIS AFTERNOON ON THE CAPE AND ISLANDS BEFORE
SHIFTING OFFSHORE.

EXPECT CIGS AND VSBYS TO IMPROVE WEST TO EAST THE FIRST PART OF
TONIGHT. WESTERN AREAS REMAIN VFR THROUGH THE NIGHT WHILE EASTERN
AREAS BECOME VFR AFTER MIDNIGHT. MVFR CIGS MAY LINGER ON CAPE COD
AND NANTUCKET. NORTHWEST WINDS WILL DIMINISH WITH ALL AREAS UNDER
30 KNOTS AFTER MIDNIGHT.

WEDNESDAY...VFR MOST AREAS. SOME LINGERING MVFR CIGS OUTER CAPE
COD AND NANTUCKET. NORTHWEST WINDS CONTINUE TO DIMINISH UNDER 20
KNOTS.

KBOS TAF...HIGH CONFIDENCE IN TAF TRENDS...LOWER CONFIDENCE IN
EXACT TIMING.

KBDL TAF...HIGH CONFIDENCE IN TAF.

OUTLOOK /WEDNESDAY NIGHT THROUGH SUNDAY/...LOW TO MODERATE
CONFIDENCE.

WEDNESDAY NIGHT-THURSDAY...VFR WITH LIGHT NORTHWEST WIND BECOMING
LIGHT SOUTH ON THURSDAY.

THURSDAY NIGHT-FRIDAY...CIGS LOWER TO MVFR WITH MVFR-IFR VSBYS IN
SNOW. CONDITIONS IMPROVE TO VFR FRIDAY AFTERNOON. WINDS ALSO SHIFT
TO NORTHWEST WITH GUSTS OF AT LEAST 25 KNOTS.

SATURDAY-SUNDAY...VFR. GUSTY NORTHWEST WINDS 25-30 KNOTS
SATURDAY...LIGHTER WINDS SUNDAY.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM /THROUGH TONIGHT/...HIGH CONFIDENCE.

*** POWERFUL STORM PRODUCE LIFE THREATENING CONDITIONS ***

WE STILL HAVE NORTHERLY WIND GUSTS OF 45-60 KT WITH SEAS NEAR 30 FEET
STILL AFFECTING OUR EASTERN WATERS.  WE DID CONVERT HURRICANE WIND
WARNINGS OVER TO STORM FORCE WIND WARNINGS AS WINDS HAVE DIMINISHED
JUST ENOUGH...BUT DANGEROUS AND LIFE THREATENING CONDITIONS WILL
CONTINUE ACROSS THE WATERS INTO THE EVENING.

OUTLOOK /WEDNESDAY NIGHT THROUGH SUNDAY/...MODERATE CONFIDENCE.

WEDNESDAY NIGHT-THURSDAY...

DIMINISHING NORTHWEST WINDS THROUGH THE NIGHT. COULD BE SOME 25
KNOT GUSTS IN THE EVENING BUT OTHERWISE WINDS SHOULD BE LESS THAN
THAT THRESHOLD. LINGERING 5 TO 7 FOOT SEAS ON MASSACHUSETTS BAY
AND THE OUTER WATERS WILL DIMINISH OVERNIGHT. CONDITIONS REMAIN
BELOW SMALL CRAFT THRESHOLDS ON THURSDAY.

FRIDAY...
COLD FRONT MOVES THROUGH WITH AREAS OF REDUCED VISIBILITY IN SNOW.
ONCE THE FRONT MOVES ACROSS THE WATERS...WINDS SHIFT TO NORTHWEST
AND INCREASE TO 30-35 KNOTS. THIS IS CLOSE ENOUGH TO THE GALE
THRESHOLD SO THAT LOW-END GALES ARE A POSSIBILITY. THIS WILL BE
MONITORED.

SEAS WILL ALSO INCREASE TO 5 TO 8 FEET ON THE EXPOSED WATERS. THE
NORTHWEST WINDS WILL BRING IN PLENTY OF COLD AIR. THIS WILL CAUSE
OCEAN EFFECT SNOW SHOWERS OFF OUTER CAPE COD...AND FREEZING SPRAY
WILL AGAIN DEVELOP FRIDAY NIGHT.

SATURDAY...NW GALES EXPECTED WITH POTENTIAL FOR A LIGHT FREEZING
SPRAY. SEAS REMAIN HIGH...POSSIBLY UP TO 7-9 FT ON THE EXPOSED
WATERS.

SUNDAY...WINDS AND SEAS AT SMALL CRAFT ADVISORY LEVELS BUT
DIMINISHING THROUGH THE DAY.
-- End Changed Discussion --

&&

.TIDES/COASTAL FLOODING...
*** LATE AFTERNOON HIGH TIDE WILL LIKELY PRODUCE COMPARABLE
 IMPACTS TO EARLY MORNING HIGH TIDE IN MANY AREAS EXCEPT PROBABLY
 HIGHER IMPACTS NORTH SIDE OF CAPE COD AND NANTUCKET ***

FORECAST FOR LATE AFTERNOON HIGH TIDE IS TRICKY WHEN IT COMES TO
THE  DETAILS. THE SURGE SHOULD BE SUBSIDING BUT NOT FAST ENOUGH
TO PRECLUDE PROBLEMS. THE ISSUE IS HOW FAST THE SURGE SUBSIDES.
BELIEVE WAVES WILL BE HIGHER THAN AT THE TIME OF THE EARLY MORNING
HIGH TIDE BUT ALSO STARTING TO SUBSIDE. THERE ARE A COUPLE OF
OTHER FACTORS TO CONSIDER. SOME SHORELINE DEFENSES MAY HAVE BEEN
COMPROMISED WITH THE EARLY MORNING HIGH TIDE AND THUS INCREASING
VULNERABILITY FOR AT LEAST A FEW SPOTS. ALSO...WAVE PERIODS HAVE
INCREASED TO THE 13 TO 15 SECOND RANGE AND SUGGEST GREATER ENERGY
IN THE BREAKING SURF THIS AFTERNOON COMPARED WITH EARLY THIS
MORNING. AND THERE ARE SOME AREAS WHICH REMAIN INUNDATED FROM THE
EARLY MORNING HIGH TIDE WITH THE WATER UNABLE TO DRAIN...AN
UNSETTLING SITUATION FOR SURE.

GREATEST CONCERN IS THE POTENTIAL IMPACT FOR CAPE COD AND
NANTUCKET. VERY STRONG ONSHORE WINDS WILL JUST BE STARTING TO
DIMINISH AS WE APPROACH THE TIME OF HIGH TIDE AND SO THINK THE
SURGE WILL REMAIN NEAR 4.5 FEET ALONG THE NORTH SIDE OF CAPE COD
AND NEAR 4 FEET IN NANTUCKET HARBOR. THESE VALUES ARE WELL ABOVE
THOSE FROM BOTH THE ETSS AND ESTOFS GUIDANCE. EXPECT A WORSE
IMPACT FOR THE NORTH SIDE OF CAPE COD AND PROBABLY AT LEAST A
LITTLE WORSE FOR NANTUCKET. BEACH EROSION IS EXPECTED TO BE SEVERE
IN THESE SAME AREAS AS WELL AS THE OCEAN SIDE OF CAPE COD FROM
TRURO TO CHATHAM.

ELSEWHERE ALONG THE MASSACHUSETTS EAST COAST...ANTICIPATE
COMPARABLE COASTAL FLOOD IMPACT FOR THE SHORELINE FROM HULL TO
PLYMOUTH WITH RUNUP AND OVERWASH AS BIG OR PERHAPS EVEN BIGGER
FACTOR DUE TO THE LARGE WAVES. WE ARE ALSO THINKING A COMPARABLE
IMPACT FOR THE SHORELINE FROM SALISBURY TO ROCKPORT WITH LARGE
WAVES AND EROSION PLAYING A ROLE THERE AS WELL. IN CONTRAST...THE
SHIFT IN THE WIND TO BE FROM THE N OR NNW IS EXPECTED TO RESULT IN
LESS IMPACT ALONG THE NORTH SHORE FROM BOSTON TO GLOUCESTER.

LOOKING AHEAD TO THE EARLY WEDNESDAY MORNING HIGH TIDE
CYCLE...GENERALLY BETWEEN 530 AM AND 630 AM...ANTICIPATE POCKETS
OF MINOR COASTAL FLOODING ALONG NORTH AND NORTHEAST FACING
SHORELINES AS WELL AS SOME ADDITIONAL EROSION. IMPACTS FOR THE
EARLY WEDNESDAY HIGH TIDE WILL BE MUCH LESS THAN WHAT WE HAVE
EXPERIENCED OR WILL HAVE EXPERIENCED DURING THE HIGH TIDES TODAY.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WARNING UNTIL 8 PM EST THIS EVENING FOR
     CTZ002>004.
MA...BLIZZARD WARNING UNTIL 8 PM EST THIS EVENING FOR MAZ005>007-
     012>023.
     COASTAL FLOOD WARNING UNTIL 8 PM EST THIS EVENING FOR MAZ007-
     015-016-019-022-024.
     WINTER STORM WARNING UNTIL 8 PM EST THIS EVENING FOR
     MAZ002>004-008>011-026.
     HIGH WIND WARNING UNTIL 1 AM EST WEDNESDAY FOR MAZ024.
     WINTER STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR MAZ024.
RI...BLIZZARD WARNING UNTIL 8 PM EST THIS EVENING FOR RIZ001>008.
MARINE...STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR ANZ232-255-256.
     FREEZING SPRAY ADVISORY UNTIL 8 AM EST WEDNESDAY FOR
     ANZ231>235-237-251.
     STORM WARNING UNTIL 10 PM EST THIS EVENING FOR ANZ231-233-234.
     GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ230-235>237.
     STORM WARNING UNTIL 9 PM EST THIS EVENING FOR ANZ250-254.
     STORM WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ251.

&&

$$
SYNOPSIS...WTB/KJC
NEAR TERM...KJC/FRANK
SHORT TERM...EVT
LONG TERM...WTB
AVIATION...WTB/EVT
MARINE...WTB/FRANK
TIDES/COASTAL FLOODING...