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Area Forecast Discussion
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000
FXUS61 KBOX 271334
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
834 AM EST TUE JAN 27 2015

.SYNOPSIS...
A CRIPPLING AND HISTORIC WINTER STORM / BLIZZARD WILL IMPACT THE
REGION INTO TONIGHT. DRIER WEATHER FOLLOWS WEDNESDAY AFTERNOON
INTO EARLY THURSDAY. LOW PRESSURE WILL BRING ANOTHER CHANCE FOR
SNOW THURSDAY NIGHT AND FRIDAY. DRY BUT VERY COLD AIR LOOKS TO
FOLLOW FOR NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
HIGHLIGHTS...

* CRIPPLING AND POTENTIALLY HISTORIC BLIZZARD WITH 1 TO 2 FT OF
  SNOW...LOCALLY HIGHER AMOUNTS
* STRONG TO DAMAGING WINDS / HURRICANE FORCE ACROSS SE NEW ENGLAND 
* MODERATE TO MAJOR COASTAL FLOODING / SEVERE BEACH EROSION

7 AM UPDATE...

WV LOOP SHOWS DEEPENING MID LEVEL LOW NEAR THE BENCHMARK WITH
CONVECTION AND LIGHTNING STRIKES NOTED AT THE ED GE OF THE DRY
SLOT EAST OF NEW ENGLAND. DRY SLOT WILL REMAIN EAST OF NEW ENG.
SFC LOW DOWN TO NEAR 980 MB ALSO NEAR THE BENCHMARK AS SYSTEM IS
BECOMING VERTICALLY STACKED. ONLY SLOW MOVEMENT NORTH EXPECTED
DURING TODAY AS THE LOW GETS CAPTURED BY THE UPPER LEVEL SYSTEM
WHICH WILL PROLONG OCCASIONAL HEAVY SNOW THROUGH TODAY.

SNOWFALL / BANDING / BLIZZARD...

CLASSIC DEFORMATION/FRONTOGENESIS BAND ACROSS CENTRAL/NE MA
EXTENDING INTO NE CT AND N RI. VERY HEAVY SNOW UNDER THIS BAND
WITH SNOWFALL RATES LIKELY 2-3"/HOUR. NAM MID LEVEL FGEN FIELDS
DOING A VERY GOOD JOB SIGNALING THIS BAND AND SHOW A SLOW
WEAKENING DURING THE DAY AS IT GRADUALLY MOVES EAST. SO WHILE THE
INTENSITY IS EXPECTED TO DIMINISH A BIT...STILL EXPECT OCCASIONAL
HEAVY SNOW TODAY ACROSS E HALF NEW ENG. MEANWHILE...PULSES OF
HEAVIER SNOW BANDS WHICH ARE CONVECTIVE IN NATURE CONTINUE TO MOVE
FROM THE OCEAN ACROSS SE MA. IN FACT...RECEIVING REPORTS OF
THUNDER SNOW ACROSS THE CAPE AS MID LEVEL LAPSE RATES OVER 6 C/KM
ACROSS SE NEW ENG SUGGESTING POTENTIAL FOR UPRIGHT CONVECTION.

HEAVIEST SNOW WILL REMAIN EAST OF WESTERN NEW ENGLAND BUT STILL
EXPECT WIDESPREAD LIGHT TO MODERATE NOW.

ADDITIONAL SNOWFALL TODAY INTO THIS EVENING WILL LIKELY RANGE
FROM 6-10 INCHES WITH LESSER AMOUNTS IN WESTERN NEW ENGLAND.

MADE SOME MODIFICATIONS TO THE SNOW ACCUM MAP...WITH MAX ACCUM
AROUND 2 FT AND LOCALLY SLIGHTLY HIGHER AMOUNTS FROM NE CT
THROUGH CENTRAL/NE MA AND EXTENDING S ALONG E COASTAL MA TO THE
UPPER CAPE. LOWERED AMOUNTS ACROSS FAR WESTERN NEW ENG AND
ACROSS RI AND ADJACENT INTERIOR SE MA WHICH WILL LARGELY REMAIN
OUTSIDE OF THE HEAVIEST BANDING. 

COMBINATION OF HEAVY SNOW AND STRONG WIND WILL RESULT IN BLIZZARD
CONDITIONS...ESPECIALLY ACROSS EASTERN HALF NEW ENG WITH
CONSIDERABLE BLOWING AND DRIFTING. IN ADDITION...WIND CHILLS WILL
BE DOWN INTO THE SINGLE NUMBERS ABOVE AND BELOW ZERO ADDING TO THE
SEVERITY AND LIFE THREATENING ASPECT OF THE STORM. TRAVEL WILL BE
NEARLY IMPOSSIBLE.

WIND... 
CORE OF STRONGEST WINDS WILL BE OCCURRING THROUGH ABOUT 18Z FOR
THE CAPE/ISLANDS TO COASTAL SE MA AS LOW PRES DEEPENS NEAR THE
BENCHMARK. LOW LEVEL JET AROUND 75 KTS PERSISTS IN THIS REGION.
SOUNDINGS SHOW POTENTIAL FOR NEAR HURRICANE FORCE GUSTS TO 75 MPH
IN THIS REGION...WITH GUSTS TO 50-60 BACK TO THE I-95 CORRIDOR AND
30-40 FURTHER IN THE INTERIOR. EXPECT WIND DAMAGE AND WIDESPREAD
POWER OUTAGES ACROSS PORTIONS OF SE MA AND ESPECIALLY THE
CAPE/ISLANDS WHERE HEAVY WET SNOW WILL ADD TO LOAD.

TEMPS...
COASTAL FRONT CURRENTLY ACROSS SE MA WITH TEMPS IN THE TEENS WEST
OF THE FRONT AND 20S TO LOWER 30S TO THE EAST. EXPECT TEMPS TO
REMAIN IN THE TEENS TO NEAR 20 TODAY FOR MOST OF THE REGION...AND
EVENTUALLY FALLING INTO THE TEENS AND LOWER 20S SE COASTAL MA THIS
AFTERNOON AS THE COASTAL FRONT MOVES THROUGH.

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 /WEDNESDAY THROUGH THURSDAY/...
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.

WEDNESDAY NIGHT...
WEAK H5 RIDGE BUILDS ACROSS ALONG WITH ASSOCIATED N-S ELONGATED
HIGH PRES. AS RIDGE AXIS MOVES ACROSS AFTER MIDNIGHT...WINDS WILL
DROP OFF TO LIGHT/VRBL OR CALM. THIS...ALONG WITH MOSTLY CLEAR
SKIES AWAY FROM THE COAST AND THE NEW SNOW PACK...EXPECT OVERNIGHT
LOWS INLAND TO DROP TO BETWEEN ZERO AND -5 ACROSS THE COLDER
INLAND VALLEYS...RANGING TO 5 TO 10 DEGREES FOR MOST OTHER AREAS
EXCEPT HOLDING AROUND 20 ACROSS THE OUTER CAPE AND NANTUCKET.

THURSDAY...
PROGRESSIVE UPPER PATTERN BRINGS ANOTHER H5 SHORT WAVE/CLIPPER
SURFACE LOW IN THIS W-NW FLOW. RIDGE EARLY THU MORNING WILL PUSH
E AS LOW SHIFTS OUT OF THE GREAT LAKES AND OHIO VALLEY. WILL SEE
INCREASING CLOUDS DURING THE AFTERNOON. SOME LIGHT SNOW MAY SNEAK
INTO THE E SLOPES OF THE BERKSHIRES LATE IN THE DAY. WINDS BACK TO
SW...SO WILL BRING SOMEWHAT MILDER AIR TO THE REGION. EXPECT HIGHS
TO RECOVER TO THE UPPER 20S TO MID 30S...MILDEST ALONG THE S
COAST.

&&

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

* CLIPPER LOW MAY BRING MORE MEASURABLE SNOW THU NIGHT AND FRI
* MUCH COLDER EARLY NEXT WEEK

OVERVIEW...

NOTING RATHER GOOD AGREEMENT ON SYNOPTIC FEATURES ON THE 00Z
MODEL SUITE INTO THE UPCOMING WEEKEND...THOUGH SOME QUESTIONS LIE
IN THE DETAILS. CONTINUE TO SEE SIGNAL FOR POSSIBLE LOW PRES
MOVING OUT OF THE LOWER MISSISSIPPI VALLEY TOWARD THE REGION LATE
NEXT WEEKEND OR EARLY NEXT WEEK...BUT TIMING IS IN QUESTION. USED
A BLEND OF AVAILABLE GUIDANCE ALONG WITH ENSEMBLES FOR A CONSENSUS
FORECAST.

DETAILS...
 
THURSDAY NIGHT AND FRIDAY...
EXPECT CLIPPER LOW TO CROSS THE REGION DURING THIS TIMEFRAME.
NOTING A COUPLE OF WEAK H5 SHORT WAVES WHICH ARE NOT WELL
ORGANIZED AND SURFACE SYSTEM REMAINS ON THE WEAK SIDE. HOWEVER...
FAIRLY GOOD QPF ASSOCIATED WITH THE SYSTEM SO COULD SEE A PLOWABLE
SNOWFALL. 

FRIDAY NIGHT THROUGH MONDAY...
LOW PRES AND SHORT WAVE EXIT THE REGION DURING FRI NIGHT...THOUGH
TIMING THE EXIT OF THE PRECIP ACROSS EASTERN AREAS IS STILL
SOMEWHAT IN QUESTION. HOWEVER...NOTING ANOTHER SHOT OF VERY COLD
AIR WORKING IN AS H85 TEMPS DIVE TO -18C TO -22C BY 12Z SAT.
SHOULD BE DRY BY MIDDAY SAT BUT VERY COLD. 

HIGH PRES LOOKS TO CROSS DURING SUNDAY...THEN TIMING ISSUES COME
INTO PLAY WITH ANOTHER POSSIBLE SYSTEM OUT OF THE LOWER
MISSISSIPPI VALLEY FOR SUN NIGHT AND/OR MON. LOW CONFIDENCE AS
UNCERTAINTY ON TIMING AND TRACK CONTINUE.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...

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

SHORT TERM...THROUGH TUESDAY NIGHT...

TODAY AND TONIGHT...

SIGNIFICANT SNOWSTORM CONTINUES THROUGH THE PERIOD WITH SNOWFALL
RATES OF 1-3 INCHES PER HOUR. ISOLATED THUNDER POSSIBLE. MOST
AIRPORTS ARE EXPECTED TO BE AT OR BELOW MINIMUMS DURING THIS
PERIOD WITH CONDITIONS RANGING FROM IFR TO VLIFR. VERY STRONG
WIND CONTINUE WITH GUSTS 70-80 KNOTS CAPE AND ISLANDS AND PARTS OF
SOUTHEAST MASS. LOW LEVEL WIND SHEAR CONTINUES TODAY AND DIMINISHES
TONIGHT.

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

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

OUTLOOK /WEDNESDAY THROUGH SATURDAY/...

WEDNESDAY...HIGH CONFIDENCE IN TRENDS...MODERATE CONFIDENCE IN 
TIMING. CONDITIONS IMPROVE TO VFR FROM WEST TO EAST...ALTHOUGH MVFR 
CIGS MAY LINGER ACROSS CAPE COD AND THE ISLANDS THROUGH MIDDAY OR
EARLY AFTERNOON. NORTHWEST WIND GUSTS TO 20-25 KNOTS THROUGH
MIDDAY ALONG THE COAST.

THURSDAY THROUGH FRIDAY NIGHT...MODERATE CONFIDENCE. VFR THROUGH
MOST OF THU. ANOTHER ROUND OF MVFR-IFR CONDITIONS IN -SN AND
PATCHY FOG THU NIGHT INTO FRI NIGHT...THEN IMPROVING FROM W-E
AFTER MIDNIGHT. NW WINDS BECOMING GUSTY AFTER MIDNIGHT FRIDAY.

SATURDAY...MODERATE CONFIDENCE. VFR. LEFTOVER MVFR CIGS/VSBYS
ACROSS E MA EARLY. NW WINDS WITH GUSTS UP TO 25-35 KT POSSIBLE.

&&

.MARINE...
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 ***

EXPECT NE WIND GUSTS OF 55-65 KT WITH SEAS 30-35 FT OVER THE E
WATERS AS WELL. HURRICANE FORCE WIND WARNINGS CONTINUE FOR THE
OPEN WATERS...WITH STORM WARNINGS CLOSER TO THE SHORE. 

CONDITIONS IMPROVE SOMEWHAT LATER TODAY INTO TONIGHT...ALTHOUGH A
PERIOD OF GALES ARE POSSIBLE UNTIL CONDITIONS DROP DOWN TO SMALL
CRAFT ADVISORY THRESHOLDS.
 
OUTLOOK /WEDNESDAY THROUGH SATURDAY/...

WEDNESDAY...HIGH CONFIDENCE. ANY LEFTOVER GALE FORCE NORTHWEST WIND 
GUSTS EARLY IN THE MORNING WILL QUICKLY DIMINISH TO SMALL CRAFT 
ADVISORY LEVELS...THEN SHOULD SUBSIDE BELOW SMALL CRAFT WED NIGHT.
SEAS WILL CONTINUE TO SUBSIDE...BUT WILL REMAIN WELL ABOVE SMALL
CRAFT THRESHOLDS ACROSS THE OUTER WATERS.

THURSDAY AND FRIDAY...MODERATE CONFIDENCE. EXPECT WINDS AND SEAS
BELOW SMALL CRAFT THU INTO THU NIGHT. W-NW WINDS INCREASE DURING
FRIDAY. LOW END GALE GUSTS POSSIBLE FRI NIGHT. SEAS BUILDING.
LIGHT FREEZING SPRAY LIKELY.

SATURDAY...NW GALE GUSTS REMAIN POSSIBLE ON THE OUTER WATERS ALONG
WITH LIGHT FREEZING SPRAY. SEAS REMAIN HIGH...POSSIBLY UP TO 7-9
FT ON THE OUTER WATERS.

&&

.TIDES/COASTAL FLOODING...
*** MODERATE TO MAJOR COASTAL FLOODING TODAY ALONG THE EASTERN MA 
  COAST FOR BOTH THIS MORNING AND LATE AFTERNOON HIGH TIDE CYCLES ***

POWERFUL WINTER STORM DEVELOPING NEAR THE 40N/70W BENCHMARK AND 
COMBINING WITH ARCTIC HIGH PRESSURE OVER SOUTHEAST QUEBEC TO YIELD 
HURRICANE FORCE WIND GUSTS THIS MORNING AND INTO MIDDAY ACROSS 
NANTUCKET...CAPE COD AND COASTAL PLYMOUTH COUNTY. TIDE GAUGES ALONG 
THE EASTERN MA COASTLINE AT 3 AM INDICATING STORM SURGE VALUES 
ALREADY 2.5 TO 3.0 FT! THIS WILL YIELD MODERATE TO MAJOR COASTAL 
FLOODING WITH THIS MORNING/S HIGH TIDE CYCLE. THE HIGHEST IMPACT 
AREAS WILL LIKELY BE NANTUCKET/CAPE COD BAY COMMUNITIES AND 
NORTHWARD ALONG THE COAST INTO PLYMOUTH COUNTY INCLUDING THE 
COMMUNITIES OF HULL/MARSHFIELD AND SCITUATE. 

COASTAL FLOODING WILL OCCUR FARTHER NORTHWARD INTO CAPE ANN HOWEVER 
THE MAGNITUDE OF THE FLOODING SHOULD BE SLIGHTLY LESS THAN THE SOUTH 
SHORE. 

THESE HIGH WATER LEVELS WILL RESULT IN SIGNIFICANT INUNDATION OF SEA 
WATER. STRUCTURAL DAMAGE IS LIKELY AS WELL GIVEN SEAS OFFSHORE HAVE 
ALREADY CLIMBED TO 18 TO 22 FT AND WILL ONLY CONTINUE TO INCREASE. 
COULD SEE OFFSHORE SEAS 25 TO 35 FT THIS AFTERNOON! THIS WILL RESULT 
LARGE WAVES BATTERING SEAWALLS AND OTHER SHORELINE STRUCTURES. IN 
ADDITION THE HIGH WATER LEVELS WILL COMBINE WITH THE LARGE WAVE 
ACTION TO YIELD SEVERE BEACH EROSION.

AS FOR THE LATE AFTERNOON HIGH TIDE...WATER LEVELS MAY BE ABOUT A 
HALF A FOOT LOWER HOWEVER SEAS WILL BE AT LEAST AS LARGE AS THIS 
MORNING OR POSSIBLE A FEW FEET HIGHER. THUS IMPACTS WILL BE SIMILAR 
HOWEVER THE FOCUS WILL SHIFT TO COASTAL PLYMOUTH COUNTY SOUTHWARD TO 
CAPE COD BAY COMMUNITIES SUCH AS SANDWICH HARBOR. THUS LESS IMPACT 
FOR NANTUCKET THAN THIS MORNING. NEVERTHELESS AT LEAST MODERATE 
COASTAL FLOODING EXPECTED FOR NANTUCKET. 

SO IN A NUTSHELL...NO CHANGES TO ANY HEADLINES WITH COASTAL FLOOD 
WARNINGS REMAINING IN PLACE FOR THE NEXT TWO TIDE CYCLES.

AS FOR RI...THE RISK FOR MINOR COASTAL FLOODING HAS COMMENCED WITH 
HIGH TIDE ALREADY OCCURRING. THEREFORE THE RISK HAS DIMINISHED AND 
THE ADVISORY WILL BE ALLOWED TO EXPIRE.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...BLIZZARD WARNING UNTIL 1 AM EST WEDNESDAY FOR CTZ002>004.
MA...BLIZZARD WARNING UNTIL 1 AM EST WEDNESDAY FOR MAZ005>007-
     012>021.
     COASTAL FLOOD WARNING FROM 3 PM THIS AFTERNOON TO 7 PM EST 
     THIS EVENING FOR MAZ007-015-016-019-022-024.
     WINTER STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR MAZ002>004-
     008>011-024-026.
     HIGH WIND WARNING UNTIL 1 AM EST WEDNESDAY FOR MAZ024.
     BLIZZARD WARNING UNTIL NOON EST TODAY FOR MAZ022-023.
RI...BLIZZARD WARNING UNTIL 1 AM EST WEDNESDAY FOR RIZ001>008.
MARINE...HURRICANE FORCE WIND WARNING UNTIL 7 PM EST THIS EVENING FOR 
     ANZ231>235.
     FREEZING SPRAY ADVISORY UNTIL 8 AM EST WEDNESDAY FOR 
     ANZ231>235-237-251.
     STORM WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ230-236-237-
     251.
     HURRICANE FORCE WIND WARNING UNTIL NOON EST TODAY FOR ANZ250-
     254>256.

&&

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



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