-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBOX 090918
AFDBOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
418 AM EST MON DEC 9 2013

.SYNOPSIS...
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LOW PRESSURE LIFTING NORTH FROM THE MID ATLANTIC WILL BRING MIXED
PRECIP TODAY. ANOTHER DISTURBANCE MAY BRING ACCUMULATING SNOW
TUESDAY...MAINLY SOUTH OF THE MASSACHUSETTS TURNPIKE. MAINLY
DRY...BUT UNSEASONABLY COLD AND BLUSTERY WEATHER IS EXPECTED FOR
THE REST OF THE WEEK.
-- End Changed Discussion --

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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VERY LIGHT SNOW OCCURRING IN SNE EARLY THIS MORNING WITH NORTHERN
EXTENT OF WARMER AIR ALOFT AND CHANGEOVER TO FZRA LIFTING N/NE
FROM THE SOUTHERN CT. PRECIP ON RADAR IS QUITE DISORGANIZED AS THE
COLUMN IS NOT SATURATED THROUGH A DEEP LAYER AND MUCH OF THE SNOW
GROWTH REGION ABOVE 700 MB IS DRY. ICE IN THE CLOUD LAYER ACTUALLY
BEING INTRODUCED BELOW 850 MB.

HEAVIER PRECIP SOUTH OF NEW ENG IS ASSOCD WITH DEEPER MOISTURE
AND OMEGA INTO THE SNOW GROWTH REGION...BUT GUIDANCE INDICATES
THE NORTHERN EXTENT OF THIS MOISTURE AND LIFT WILL JUST CLIP THE S
COAST THIS MORNING. FURTHER INTO THE INTERIOR...THE MID LEVELS
NEVER SATURATE AND ACTUALLY DRY DURING THE DAY. THIS COMBINED WITH
WEAK OMEGA WILL RESULT IN A LIGHT QPF EVENT TODAY. SNOW ACCUM
WILL BE LIMITED TO A COATING TO AN INCH FOR MOST OF THE
REGION...WITH LOCALLY UP TO 2 INCHES POSSIBLE ACROSS NORTHERN
HIGHER TERRAIN. BUT THERE REMAINS A CONCERN FOR LIGHT ICING
ACROSS MUCH OF THE REGION...ESPECIALLY INTERIOR.

SNOW WILL CHANGE TO FREEZING RAIN/DRIZZLE THROUGH 12Z SOUTH OF
THE MASS PIKE...WITH CHANGEOVER OCCURRING TO THE NORTH LATER THIS
MORNING THROUGH MIDDAY. CURRENT TEMPS REMAIN BELOW FREEZING ACROSS
MOST OF THE REGION SO EVEN PORTIONS OF THE COAST WILL LIKELY SEE A
BRIEF PERIOD OF FZRA. A CHANGE TO PLAIN RAIN/DRIZZLE WILL OCCUR IN
THE COASTAL PLAIN DURING THE MORNING AS EASTERLY WINDS WARM THE
BOUNDARY LAYER WITH HIGH TEMPS REACHING THE LOW TO MID 40S S/E OF
I95 CORRIDOR IN RI AND SE MA.

HOWEVER...LOW LEVEL COLD AIR WILL BE SLOW TO ERODE IN THE
INTERIOR AS GUIDANCE SIGNALING GOOD COLD AIR DAMMING SIGNATURE.
WITH OPEN WAVE LIFTING ACROSS SE NEW ENG...LIGHT N WINDS IN THE
INTERIOR AND CT VALLEY WILL HELP TO LOCK IN THE COLD AIR WITH
PARTS OF THE DISTANT INTERIOR STRUGGLING TO REACH 32 DEGREES
WHICH WILL RESULT IN AN EXTENDED PERIOD OF FREEZING RAIN/DRIZZLE.

DURING THE AFTERNOON PRECIP WILL LIKELY TAPER OFF AND BECOME
DRIZZLE/FREEZING DRIZZLE AS SOUNDINGS SHOW NO ICE IN THE CLOUD
LAYER.
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&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
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WAVE LIFTS TO THE NORTH THIS EVENING WITH DRIER WESTERLY FLOW
DEVELOPING. EXPECT MAINLY DRY CONDITIONS WITH LOW CLOUDS
ERODING...ALTHOUGH MID/HIGH CLOUDS WILL BE MOVING IN OVERNIGHT.
LOW TEMPS WILL BE MOSTLY IN THE 20S...EXCEPT LOWER 30S NEAR THE
COAST.
-- End Changed Discussion --

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGHLIGHTS...

* PERIOD OF LIGHT SNOW POSSIBLE SOUTH OF MA PIKE ON TUE
* MAINLY DRY AND UNSEASONABLY COLD WED THROUGH FRI
* LOW CONFIDENCE FORECAST NEXT WEEKEND

DETAILS...

MONDAY NIGHT...

OTHER THAN PERHAPS A LEFT OVER SPOT SHOWER IN THE EARLY EVENING...
DRY WEATHER EXPECTED. A COLD FRONT SWINGS THROUGH THE REGION EARLY
IN THE EVENING. TEMPS WILL ACTUALLY RISE ABOVE FREEZING ACROSS
PORTIONS OF THE INTERIOR THAT HAVE BEEN JAMMED IN SHALLOW COLD AIR
DURING THE DAY MONDAY. THE REASON FOR THIS IS THAT WARMER MID
LEVEL AIR WILL BE TEMPORARILY MIXED DOWN...AS WINDS SHIFT TO THE
WEST. THIS SHOULD ALLOW ANY LEFTOVER ICY CONDITIONS ON ROADWAYS TO
MELT. COLDER AIR WILL FINALLY BEGIN WORKING BACK INTO THE REGION
OVERNIGHT...WITH LOWS BY DAYBREAK BACK INTO THE 20S ACROSS THE
INTERIOR. THE COASTAL PLAIN SHOULD ONLY SEE LOWS REACH THE LOWER
TO MIDDLE 30S.

TUESDAY...

THE MAIN CONCERN IS THE CHANCES FOR A PERIOD OF LIGHT SNOW ON
TUESDAY...MAINLY SOUTH OF THE MA TURNPIKE. A WEAK WAVE OF LOW
PRESSURE WILL BE PASSING WELL TO OUR SOUTH...BUT AN APPROACHING
SHORTWAVE BACKS THE UPPER LEVEL FLOW. IT PLACES US UNDERNEATH A
POTENT JET STREAK WHICH RESULTS IN A PERIOD OF DECENT MID LEVEL
LIFT. WILL BE FIGHTING LOW LEVEL DRY AIR SO NOT EXPECTING A LOT OF
PRECIP...BUT A PERIOD OF LIGHT SNOW IS STILL POSSIBLE SOUTH OF MA
TURNPIKE ESPECIALLY NEAR THE SOUTH COAST. PERHAPS ITS MILD ENOUGH
FOR MIXED PRECIP AT THE ONSET ACROSS CAPE/ISLANDS...BUT SHOULD
TURN OVER TO ALL LIGHT SNOW. A COATING TO PERHAPS 1 INCH OF SNOW IS
POSSIBLE IN A FEW LOCATIONS. THERE ALSO IS A LOW PROBABILITY OF A BIT
MORE SNOW THAN THAT NEAR THE SOUTH COAST...BUT MOST GUIDANCE DOES NOT
SUPPORT THAT AT THIS TIME.

WEDNESDAY THROUGH FRIDAY...

NORTHWEST FLOW ALOFT WILL RESULT IN UNSEASONABLY COLD WEATHER FOR
SOUTHERN NEW ENGLAND. THERE ARE SOME MODEL DISCREPANCIES ON THE
TIMING OF REINFORCING SHOTS OF COLD AIR...HENCE UNCERTAINTIES ON
WHICH DAY WILL BE THE COLDEST. MAINLY DRY WEATHER DOMINATES OVER
THIS TIME PERIOD...BUT CAN/T RULE OUT A BRIEF PASSING FLURRY/SNOW
SHOWER WITH SOME MOISTURE STARVED NORTHERN STREAM ENERGY/FRONTAL
PASSAGES. IT ALSO WILL BE WINDY AT TIMES...SO IT CERTAINLY WILL
FEEL WINTERLIKE.

SATURDAY AND SUNDAY...

FORECAST CONFIDENCE IS VERY LOW OVER THIS TIME. THE ONE THING WILL
HAVE TO WATCH NEXT WEEKEND IS THE TRACK A WAVE OF LOW PRESSURE TO
OUR SOUTH. MOST MODELS SUGGEST THAT THE SYSTEM WILL PASS FAR
ENOUGH SOUTH TO SPARE OUR REGION OF SIGNIFICANT PRECIP.
HOWEVER...SOME MODELS SUGGEST THE LARGE HIGH TO OUR NORTH MAY
EVENTUALLY RESULT IN ONSHORE FLOW...BRINGING THE POTENTIAL FOR
SOME LIGHT WINTRY PRECIPITATION. OTHER GUIDANCE SUGGESTS SOUTHWEST
FLOW ALOFT MAY RESULT IN SOME OVER RUNNING PRECIPITATION. ALL IN
ALL...VERY LOW CONFIDENT FORECAST FOR NEXT WEEKEND.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...

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

NEAR-TERM /THROUGH TONIGHT/...

HIGH CONFIDENCE IN WIDESPREAD IFR CONDITIONS DEVELOPING AS PRECIP
MOVES ACROSS THE REGION. LOWER CONFIDENCE IN TIMING OF PTYPE
TRANSITIONS. EXPECT SNOW CHANGING TO SLEET/FZRA FROM SOUTH TO
NORTH THIS MORNING AND EVENTUALLY TO PLAIN RAIN IN THE COASTAL
PLAIN. INTERIOR TERMINALS WILL LIKELY HAVE TO DEAL WITH AN
EXTENDED PERIOD OF FREEZING RAIN/DRIZZLE INTO THE AFTERNOON.
MINOR SNOW ACCUM UP TO 2 INCHES POSSIBLE. CONDITIONS EXPECTED TO
IMPROVE TO VFR LATER TONIGHT.

KBOS TAF...HIGH CONFIDENCE IN MVFR/IFR DEVELOPING. LOW CONFIDENCE
IN TIMING OF PTYPE TRANSITIONS.

KBDL TAF...HIGH CONFIDENCE IN MVFR/IFR DEVELOPING. LOW CONFIDENCE
IN TIMING OF PTYPE TRANSITIONS.

OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...

MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. LEFT OVER MVFR-IFR
CONDITIONS EARLY IN THE EVENING IMPROVE TO VFR BEHIND A COLD FRONT.

TUESDAY...LOW CONFIDENCE.  A PERIOD OF MVFR-IFR CONDITIONS POSSIBLE
SOUTH OF THE MA TURNPIKE IN A ROUND OF LIGHT SNOW. OTHERWISE...VFR
CONDITIONS FOR THE REST OF THE TIME.

WEDNESDAY THROUGH FRIDAY...MODERATE TO HIGH CONFIDENCE. VFR
CONDITIONS DOMINATE WITH GUSTY WNW WINDS AT TIMES.

&&

.MARINE...
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FORECASTER CONFIDENCE LEVELS...

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

NEAR-TERM /THROUGH TONIGHT/...HIGH CONFIDENCE.

A PERIOD OF EASTERLY WIND GUSTS TO 25-30 KT EXPECTED OVER THE
OPEN WATERS THROUGH THE MORNING...ESPECIALLY SOUTH OF THE COAST.
WINDS DIMINISH AND VEER TO THE S AND SE LATER TODAY.

ANOTHER PULSE OF G25 KT POSSIBLE THIS EVENING OVER THE OUTER
WATERS AS WINDS SHIFT TO THE WEST.

SMALL CRAFT ADVISORIES CONTINUE. AREAS OF RAIN/DRIZZLE AND FOG
WILL LIMIT VSBYS AT TIMES TODAY.

OUTLOOK...TUESDAY THROUGH FRIDAY...HIGH CONFIDENCE.

THE GENERAL IDEA IS THAT THE PASSAGE OF A COUPLE OF STRONG COLD
FRONTS WILL RESULT IN PERSISTENT WEST TO NORTHWEST WINDS OVER THIS
TIME.  GIVEN THE STRONG COLD ADVECTION OVER THE WATERS...SCA WIND
GUSTS ARE EXPECTED OVER MUCH OF THIS TIME PERIOD OVER THE OPEN
WATERS.  WE MAY EVEN SEE A BRIEF GALE FOR A TIME ON WEDNESDAY. THERE
ALSO WILL BE LULLS IN THE WIND...BUT TIMING THAT THIS FAR OUT IS
IMPOSSIBLE.
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&&

.BOX WATCHES/WARNINGS/ADVISORIES...
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CT...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR CTZ002.
     WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
     CTZ003-004.
MA...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR
     MAZ002>004-008>011-026.
     WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     MAZ017-018-020-021.
     WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
     MAZ005-006-012>014.
NH...WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR NHZ011-
     012-015.
RI...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     RIZ002>007.
     WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
     RIZ001.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
     ANZ231>234.
     SMALL CRAFT ADVISORY UNTIL 7 AM EST TUESDAY FOR ANZ235-237-
     254>256.
     SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 7 AM EST
     TUESDAY FOR ANZ250.
     SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 1 AM EST
     TUESDAY FOR ANZ251.
-- End Changed Discussion --

&&

$$
SYNOPSIS...KJC
NEAR TERM...KJC
SHORT TERM...KJC
LONG TERM...FRANK
AVIATION...KJC/FRANK
MARINE...KJC/FRANK