

956 

FXUS61 KBOX 270001

AFDBOX



AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE TAUNTON MA

701 PM EST MON NOV 26 2012



.SYNOPSIS...



DRY WEATHER CONTINUES ACROSS THE AREA TONIGHT. AS FOR THE POTENTIAL

STORM FOR TOMORROW...LATEST TRENDS CONTINUE TO SUPPORT ONLY A

MINOR IMPACT TO THE AREA AS LOW PRESSURE IS EXPECTED TO TRACK WELL

SOUTH OF THE REGION. MUCH COLDER WEATHER IS EXPECTED BEHIND THE

STORM DURING THE END OF THE WEEK FOLLOWED BY MILDER WEATHER OVER

THE WEEKEND ALONG WITH THE RISK OF SCATTERED RAIN SHOWERS.



&&



.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...



7 PM UPDATE...

DRY AIR WILL DOMINATE INITIALLY AS A QUICK MOVING HIGH WILL MOVE

ACROSS SOUTHERN NEW ENGLAND. THIS WILL HELP BOTTOM OUT LOW TEMPS

MAKING IT ANOTHER CHILLY NIGHT. EXPECT LOW TEMPS TO REACH IN THE

LOW 20S IN THE NW WITH UPPER 20S ACROSS THE COAST. A FEW TEENS

MAKE SNEAK OUT ACROSS HIGHER TERRAIN IN NH. OTHERWISE CLOUD COVER

WILL BEGIN TO INCREASE AS LOW PRESSURE BEGINS TO APPROACH THE

AREA. THIS CLOUD COVER MAY HELP REGULATE/INCREASE TEMPS SLIGHTLY

BY THE EXTREME EARLY MORNING HOURS. THE LOW AND ATTENDANT SHORTWAVE

IS QUICK MOVING...SO EXPECT SOME PRECIP TO SPREAD ACROSS CT AND

WESTERN MASS BY MORNING HOURS. PRECIP WILL START AS SNOW DURING

THIS TIME PERIOD AS TEMPS AND THE COLUMN IS WELL BELOW FREEZING.



&&



.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...



TUESDAY/TUESDAY NIGHT...



SYNOPSIS/GUIDANCE... 

12Z GUIDANCE IS IN GOOD AGREEMENT WITH THE DEVELOPMENT AND

PASSAGE OF A LOW PRESSURE SYSTEM ACROSS SOUTHERN NEW ENGLAND.

EXPECT THIS SYSTEM TO BE QUICK MOVING AND WITH THE LOW BEYOND THE

BENCHMARK EXPECT CT/RI AND SOUTHERN MASS TO SEE THE GREATEST

AMOUNT OF PRECIP. AS THE SHORTWAVE CONTINUES TO MOVE ACROSS

SOUTHERN NEW ENGLAND...ATTENDANT SURFACE LOW PRESSURE WILL BEGIN

TO DEEPEN OVERNIGHT AND CONTINUE TO MOVE TOWARDS THE NORTH

ATLANTIC BY EARLY WED MORNING.



SPECIFICS... 

AS THE LOW PASSES TO THE SOUTH OF THE REGION EXPECT QPF VALUES TO

BE LIGHT ACROSS THE AREA WITH THE SOUTH COASTAL REGION SEEING THE

HEAVIEST AMOUNT OF PRECIP...UP TO 0.15 INCHES. THERMAL PROFILES

ARE QUITE COLD AS BEING ON THE NORTH SIDE OF THE LOW WILL DRAW IN

COOLER AIR. WITH THIS BEING SAID...PRECIPITATION WILL START OUT AS

SNOW FROM WEST TO EAST BY EARLY TUESDAY MORNING LASTING THROUGH

THE OVERNIGHT HOURS AND MAINLY DIMINISHING BY EARLY WED MORNING.

AREAS CLOSER TO THE COAST WILL HAVE THE MARINE INFLUENCE...SO

TEMPS WILL BE SLIGHTLY WARMER. THEREFORE BELIEVE A MIX OF

RAIN/SNOW WILL OCCUR ACROSS THE SOUTH AND EAST COASTS. BY THE

OVERNIGHT HOURS WHEN SURFACE TEMPS DROP...EXPECT ALL SNOW TO OCCUR

ACROSS THE REGION. SNOWFALL AMOUNTS WILL RANGE FROM A TRACE TO UP

TO AN INCH WITH THE HIGHEST AMOUNTS ACROSS INTERIOR CT AND RI

WHERE THE COLDEST TEMPS...HIGHER QPF...AND BETTER LIFT IS LOCATED.

AGAIN THIS IS A QUICK MOVING LOW SO HIGH SNOW ACCUMULATIONS SEEMS

TO BE LOW.



HAZARDS...

COMMUTE MAY BE SLOW GOING TUESDAY NIGHT ACROSS THE AREA WHETHER

IT IS RAIN OR SNOW FALLING. BLACK ICE IS ALSO A POTENTIAL FOR THE

OVERNIGHT HOURS ON TUES INTO WED.



&&



.LONG TERM /WEDNESDAY THROUGH MONDAY/...



HIGHLIGHTS...



* SHOWERS POSSIBLY LINGERING ACROSS E NEW ENGLAND INTO LATE WEDNESDAY

* HIGH PRES AND BELOW-NORMAL TEMPS EXPECTED INTO FRIDAY

* A WEAK WX DISTURBANCE AND WARMER CONDITIONS FOR THE WEEKEND

* UNCERTAINTY WITH THE FCST INTO NEXT WEEK...



DISCUSSION... 



A PROGRESSIVE FLOW REGIME IS EVIDENT FROM TELECONNECTIONS WITHIN THE 

NORTHERN HEMISPHERE RESULTING IN A SERIES OF WEAK DISTURBANCES 

FOLLOWED BY REINFORCED COLD AIR. NOTED BY PREVIOUS FORECASTERS... 

THE STRONGER -AO INDICATES A WEAKER POLAR JET ALOFT SUBSEQUENT OF 

COLDER STRATOSPHERIC AIR BUILDING S INTO THE MID-LATITUDES...WHILE A 

NEAR-NEUTRAL NAO COUPLED WITH A -PNA KEEPS A PROGRESSIVE...LOWER 

AMPLITUDE FLOW PATTERN ACROSS THE REGION. THERE IS SOME DISTINCT 

POSSIBILITY IN A SHIFT IN THIS PATTERN FOR THE EARLY HALF OF

DECEMBER BUT FOR THE LONG-TERM FORECAST AS IT STANDS NOW...THE

MAJORITY OF IT WILL BE COLD AND QUIET WITH A BRIEF WEAK

DISTURBANCE HERE AND THERE COUPLED WITH SLIGHTLY WARMER AIR.



WEDNESDAY INTO FRIDAY...



AS TUESDAY/S LOW PRES QUICKLY DEPARTS E...AN ELONGATED PIECE OF 

POLAR VORTEX ENERGY INVIGORATES AN INVERTED TROUGH TO THE REAR OF 

THE DEPARTING LOW ALONG THE E COAST OF THE NERN CONUS WITHIN THE 

BETTER BAROCLINIC REGION. WHILE SOLNS DIVERGE ON THE INVERTED TROUGH 

SETUP IN TERMS OF PLACEMENT...THERE STILL REMAINS A PLAUSIBILITY 

THAT RAIN SHOWERS COULD IMPACT THE CAPE AND ADJACENT COASTAL PLAIN 

/POSSIBLY FALLING AS SNOW SHOWERS OVER INTERIOR E NEW ENGLAND/. THE 

26/12Z NAM REMAINS THE OUTLIER...WITH THE 26/09Z SREF EXHIBITING 

SOME SUPPORT...BUT THE MAJORITY OF REMAINING GUIDANCE CONTAINS THE 

INVERTED TROUGH NW-SE THROUGH MAINE INTO THE ADJACENT GULF. WITH 

THAT BEING SAID...WILL CONTINUE WITH SLGT CHC POPS FOR E/SE NEW 

ENGLAND INTO LATE WED...MONITORING THE FETCH OFF THE WATERS /THERE 

ALSO IS THE PLAUSIBILITY OF SEEING WINDS GUSTING AROUND 15-20 MPH/. 



OTHERWISE...A SERIES OF REINFORCING COLD FRNTS WILL ANCHOR HIGH PRES 

AND COLDER AIR ACROSS THE NERN CONUS. ANTICIPATING WELL-MIXED LOW-

LVLS UP TO H85 WHERE TEMPS WILL AVERAGE AROUND -8C /MAX TEMPS AROUND 

THE LOW 40S WEDNESDAY TRANSITIONING TO VALUES AROUND THE UPPER 30S 

FOR FRIDAY/. IN ADDITION...THERE IS THE LIKELIHOOD FOR MIX-DOWN OF 

FASTER MOMENTUM AND DRIER AIR...ESPECIALLY THURSDAY AND FRIDAY... 

WITH WIND GUSTS AROUND 20 MPH /AROUND 30 MPH OVER THE WATERS/ 

RESULTING IN WIND CHILLS AROUND THE FREEZING MARK DURING THE DAY... 

FALLING AS LOW INTO THE SINGLE DIGITS OVERNIGHT. EXPECTING THE 

MAJORITY OF THE PERIOD AVERAGING OUT WITH PARTLY CLOUDY CONDITIONS 

CONSEQUENTIAL OF REMNANT MOISTURE FRONTOGENTICALLY LIFTED BY THE 

SERIES OF COLD FRNTS. YET WITH SUCH A COLD AIRMASS...THE AMOUNT OF 

CLOUD COVER SHOULD EFFECTIVELY IMPACT SFC TEMPS THRU THE PERIOD. 



WEEKEND...



HIGH PRES ELONGATES SW-NE ACROSS THE WRN ATLANTIC RESULTING IN 

RETURN SLY FLOW AHEAD OF A WEAK SYNOPTIC DISTURBANCE ANTICIPATED FOR 

LATE SUNDAY INTO MONDAY. ANTICIPATE AN INCREASE IN LOW-LVL FLOW 

USHERING MUCH WARMER AIR ACROSS THE REGION /H925 TEMPS AROUND -2C 

FOR SATURDAY WARMING TO AROUND +6-8C SUNDAY PRIOR TO THE ONSET OF 

THE COLD FRNT INTO MONDAY MORNING/. SATURDAY LOOKS TO BE THE BEST 

BOTH DAYS /MAX TEMPS AROUND THE LOW 40S/...WITH INCREASING CLOUDS 

LATE INTO SUNDAY /MAX TEMPS POSSIBLY AS WARM AS THE MID-UPR 50S/. A 

BROAD SWATH OF FRONTOGENETICALLY FORCED SHOWERS IS EXPECTED SUNDAY 

CONTINUING INTO MONDAY MORNING. AT PRESENT IT LOOKS LIKE THE 

MAJORITY OF THE PRECIP WILL BE IN THE FORM OF LIQUID...BUT IT IS 

POSSIBLE TO SEE A WINTRY MIX DURING THE EVENING PERIOD FOR WESTERN 

AND CENTRAL PORTIONS OF NEW ENGLAND /INCLUDING W AND CENTRAL MA INTO 

S NH/. 

 

EARLY NEXT WEEK...



HIGH PRES WITH COOLER AND DRIER CONDITIONS RETURNS TO THE NERN CONUS 

IN WAKE OF THE WEEKEND DISTURBANCE. THIS MAY BE BRIEF AS THERE ARE 

SUBTLE HINTS OF ANOTHER WEAK DISTURBANCE BY MIDWEEK WITH RETURN SLY 

FLOW...WARMER CONDITIONS...AND SHOWERY WX.



&&



.AVIATION /00Z TUESDAY THROUGH SATURDAY/...



FORECASTER CONFIDENCE LEVELS...

  LOW...LESS THAN 30 PERCENT 

  MODERATE...30 PERCENT TO 60 PERCENT 

  HIGH...GREATER THAN 60 PERCENT



OVERVIEW...MODERATE TO HIGH CONFIDENCE.



VFR DOMINATES INTO THE MORNING HRS. THEREAFTER WILL SEE THE ONSET

OF LOWERING CIGS TO MVFR WITH -RA/-SN WEST TO EAST. STILL SOME

UNCERTAINTY AS TO THE TIMING AND STRENGTH OF THE EXPECTANT BROAD

SWATH OF PRECIPITATION FOR THE TUESDAY INTO TUESDAY NIGHT

TIMEFRAME...HAVE PREVAILED WITH A CONSERVATIVE FORECAST. IT IS

LIKELY THAT WITH -SN VSBYS MAY FALL TO IFR-VLIFR. LOWEST CIGS

WILL BE ALONG S COAST TERMINALS /MVFR-IFR/ RISING AS YOU CONTINUE

NORTH.



A FINAL NOTE...THERE ARE SOME POSSIBILITIES WORTH NOTING BASED ON

THE LATEST FORECAST GUIDANCE. ITS POSSIBLE TO SEE A BROAD INITIAL

SWATH OF SNOW WITH ACCUMULATIONS UP TO AN INCH ALONG A LINE FROM

BDL-OWD DURING THE DAY TUES...WITH A SECOND BURST POSSIBLE

OVERNIGHT ACROSS THE SE COASTAL PLAIN FROM PVD-TAN-PYM AND

ANOTHER INCH OF ACCUMULATION. TAF/S WILL BE UPDATED AND MONITORED

ACCORDINGLY SHOULD THIS POTENTIAL COME TO FRUITION. AGAIN...THE

LATEST TAF/S MAINTAIN A CONSERVATIVE BASIS AS THE STORM BEGINS TO

EVOLVE. WITH SNOWS...IFR- VLIFR VSBYS WILL BE POSSIBLE.



KBOS TAF...MODERATE TO HIGH CONFIDENCE. 

A CONSERVATIVE FCST. WILL SEE CONDITIONS DETERIORATE INTO MIDDAY

AND OVERNIGHT WITH INITIAL -SHSN BECOMING A -RASN MIX. VSBYS

RESTRICTIONS PSBL. 



KBDL TAF...MODERATE TO HIGH CONFIDENCE.

A CONSERVATIVE FCST. CONDITIONS DETERIORATING INTO THE MORNING AS

-SN BUILDS ACROSS THE TERMINAL. EXPECTING THE WORST CONDITIONS TO

CENTER AROUND MIDDAY INTO EVNG. MAY SEE -SHSN LINGER INTO THE

EVNG. 



OUTLOOK...WEDNESDAY THROUGH FRIDAY...



WEDNESDAY...MODERATE TO HIGH CONFIDENCE. 



MVFR CIGS AND SCT -SHRA/-SHSN WILL LINGER ALONG EASTERN NEW ENGLAND 

INITIALLY...GRADUALLY LIFTING AND IMPROVING INTO THE EVENING PD. 

STRONGEST W/NW FLOW WITH GUSTS UP TO 20 KTS WILL BE ALONG THE 

IMMEDIATE COASTLINE.



THURSDAY THROUGH FRIDAY...MODERATE TO HIGH CONFIDENCE.



VFR. GUSTY W/NW WINDS ESPECIALLY FOR SHORELINE TERMINALS. STRONGEST 

OF WINDS WITH GUSTS UP TO 30 KTS POSSIBLE IS ANTICIPATED THURSDAY.



&&



.MARINE...



HAVE LET SEVERAL SCA GO AS WINDS HAVE DIMINISHED BELOW 25 KTS.

OUTER WATERS CONTINUE WITH SCA AS SEAS WILL BE SLOW TO RESPOND

AND DIMINISH BELOW 5FT. BELIEVE BY THE OVERNIGHT HOURS ALL SCA CAN

BE LET GO. HIGH PRESSURE WILL QUICKLY MOVE THROUGH BY THE

OVERNIGHT HOURS. LOW PRESSURE SYSTEM WILL MOVE ACROSS THE SOUTHERN

WATERS BY TUESDAY. THIS WILL INCREASE SEAS AND WINDS BY LATE

TUESDAY NIGHT INTO EARLY WINDS. HOWEVER STILL SLIGHTLY BELOW

SCA...WILL NEED TO MONITOR CLOSELY. LOW PRESSURE SYSTEM BRING

RAIN/SNOW TO THE WATERS REDUCING VSBYS.



OUTLOOK...WEDNESDAY THROUGH FRIDAY...



WEDNESDAY...MODERATE TO HIGH CONFIDENCE.



SHOWERS ARE EXPECTED TO IMPACT THE WATERS INTO THE EVENING HOURS 

WITH W/NW WINDS GUSTING UP TO 20 KTS AS TUESDAY/S LOW EXITS EAST. 

ANTICIPATING MAINLY RAIN SHOWERS. NOT EXPECTING MUCH IN THE WAY OF 

VISIBILITY IMPACTS...JUST LOW CLOUDS. SEAS UP TO 5 FT WILL BE 

POSSIBLE ACROSS THE OUTER WATERS WITH STRONG W/NW FLOW. SMALL CRAFT 

ADVISORIES MAY BE NEEDED...ESPECIALLY FOR THE OUTER WATERS. 



THURSDAY INTO FRIDAY...MODERATE TO HIGH CONFIDENCE.



CONTINUED W/NW FLOW WILL INTENSIFY...ESPECIALLY ON THURSDAY WHEN 

GALE FORCE GUSTS WILL BE POSSIBLE /LOW CONFIDENCE AT THIS TIME/. 

SEAS ACROSS THE OUTER WATERS ARE LIKELY TO SWELL TO 6 TO 8 FEET. 

WHILE A GALE WARNING IS SPECULATIVE...SMALL CRAFT ADVISORIES ARE 

LIKELY TO BE NECESSARY.



&&



.BOX WATCHES/WARNINGS/ADVISORIES...

CT...NONE.

MA...NONE.

NH...NONE.

RI...NONE.

MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR ANZ254-

     255.

     SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ256.



&&



$$



SYNOPSIS...DUNTEN/SIPPRELL

NEAR TERM...DUNTEN/SIPPRELL

SHORT TERM...DUNTEN

LONG TERM...SIPPRELL

AVIATION...DUNTEN/SIPPRELL

MARINE...DUNTEN/SIPPRELL




