359 
FXUS61 KCAR 152000
AFDCAR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
300 PM EST SAT DEC 15 2012

.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE REGION TONIGHT INTO SUNDAY...
THEN SLOWLY MOVE EAST SUNDAY NIGHT AND MONDAY. WEAK LOW PRESSURE
WILL TRACK SOUTH OF REGION MONDAY WHILE A STRONGER LOW WILL 
DEVELOP OFF THE NEW ENGLAND COAST TUESDAY AND MOVE SLOWLY NORTHEAST
INTO WEDNESDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
CLEAR AND COLD CONDITIONS EXPECTED TONIGHT AS HIGH PRESSURE BUILDS 
OVER THE STATE. WE'LL SEE GOOD RADIATIONAL COOLING TONIGHT, AIDED BY 
LIGHT WINDS AND A BIT OF FRESH SNOW ON THE GROUND. LOWS WILL BE
IN THE SINGLE DIGITS BELOW ZERO IN THE NORTHERN HALF OF THE
FORECAST AREA, WHILE THE SOUTHERN HALF WILL BE ON THE POSITIVE
SIDE OF ZERO.

THE HIGH WILL PEAK OVER MAINE TOMORROW MORNING AND THEN BEGIN TO
SLIDE EASTWARD THROUGH THE DAY. WE'LL SEE LOTS OF SUNSHINE, THOUGH
HIGH CLOUDS WILL BEGIN TO SPREAD OVER THE AREA FROM THE SOUTHWEST
DURING THE AFTERNOON. HIGHS WILL BE VERY SIMILAR TO THOSE TODAY,
RANGING FROM THE MID TEENS IN THE SAINT JOHN VALLEY TO THE MID 20S
ALONG THE COAST.


&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
UPPER LVL BLOCKING OVR NERN CAN AND THE FAR NW ATLC MAKE THIS
SHORT TERM UPDATE FULL OF UNCERTAINTY...SPCLY IN REGARD TO THE
ONSET TMG OF MORE SIG PRECIP AMOUNTS INTO OUR FA FROM THE SW MON
AND TUE.

POPS FOR THE ENTIRE SHORT TERM WERE GENERATED FROM THE POP FROM
QPF TOOL AFT WE BLENDED 50 PERCENT OF THE COMBINED 12Z CMC AND
ECMWF DTMNSTC MODELS WITH A EVEN BLEND OF 12Z GFS/NAM MODEL DATA
AND 12Z/09Z HPC/SREF GUIDANCE. THIS RESULTED IN A SLOW
PROGRESSION OF THE LEADING EDGE OF QPF FROM WSW TO ENE ACROSS
OUR FA FROM ERLY MON MORN THRU TUE...AND DELAYS SIG 6 HRLY QPF
AMOUNTS INTO OUR FA TO MSLY LATER MON NGT SW PTNS OF THE FA INTO
TUE FOR THE NE. THE BASIS FOR THIS IS TO TRY TO EVEN OUT MODEL
PRECIP ONSET DIFFERENCES BETWEEN THE MUCH SLOWER ECMWF AND CMC
MODELS COMPARED TO THE MUCH FASTER GFS...AND TO A SOMEWHAT LESSER
EXTENT THE 12Z GFS ENS MEAN.

SO THIS MEANS IF THE GFS IS CORRECT WITH ITS GREATER QPF OVR WRN
PTNS OF THE FA ON MON...WE WILL NEED TO BEEF-UP EQUIV QPF AND SNFL
THERE DURING THIS PD IN SUBSEQUENT UPDATES. IF THE ECMWF...IN
PARTICULAR...IS CORRECT...WE MAY NEED TO HOLD OFF ON SNFL FOR THE
FA UNTIL LATE MON NGT OR TUE. OUR QPF AND DERIVED SNFL IS BETWEEN
THESE ONSET EXTREMES FOR MON. AT LEAST THERE IS A LITTLE MORE QPF
AGREEMENT FOR TUE...ALLOWING MORE DEFINITIVE CATEGORICAL POPS FOR
ALL OF THE FA BY TUE AFTN.

SFC TEMPS AND ABV GROUND LOW TO MID LAYER WARMING DIFFERS AS WELL
WITH THE GFS SHOWING SIG INROADS OF ABV FZG TEMPS WELL N INTO OUR
FA BY TUE AFTN WHILE THE ECMWF KEEPS THIS TO DOWNEAST AREAS BY
THIS TM. AGAIN...WE TAKE A BLEND OF THESE MODELS...PERHAPS LEANING
A TAD MORE ON THE ECMWF SOLUTION. THIS KEEPS MOST OF THE N ALL SN
THRU TUE WITH DOWNEAST AND E CNTRL AREAS TRANSITIONING TO MIX AND
POTENTIALLY ALL RN FOR COASTAL DOWNEAST AREAS BY LATE TUE AFTN...
WITH SIG UNCERTAINTY OF THE FINAL PSN OF THE PRECIP TRANSITION
ZONE BASED ON THE VARIETY OF MODEL SOLUTIONS OUT THERE.

TEMPS WILL BE COLDEST SUN EVE SPCLY NERN PTNS OF THE FA AHEAD OF
THICKER CLD CVR...PRECIP AND INCREASING LLVL ERLY GRAD WINDS...
FOLLOWED BY MSLY SLOWLY RISING TEMPS FROM LATE SUN NGT THRU TUE
ACROSS THE FA.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE EXTENDED MODELS CONTINUE TO BE IN GOOD AGREEMENT AT THE START
OF THE LONG TERM. A LOW IN SW QUEBEC A SECOND LOW PRESSURE SYSTEM
IN THE SW GULF OF MAINE NEAR CAPE COD WITH AN ASSOCIATED FRONT
EXTENDING FROM SW QUEBEC THROUGH MAINE INTO THE NORTH ATLANTIC. A
HIGH PRESSURE RIDGE BUILT INTO THE CENTRAL PORTIONS OF THE US AND
CANADA. WEDNESDAY MORNING THE LOW IN THE GULF OF MAINE REMAIN
QUASI-STATIONARY IN THE SW PORTIONS OF THE GULF OF MAINE AS IT
BECOMES COLD CORE. THE OCCLUDED FRONT REMAINS EXTENDED ACROSS
MAINE THROUGH THE GULF OF MAINE TO A NEW LOW AT THE TRIPLE POINT
SW OF NOVA SCOTIA. THE COLD CORE LOW WILL DRIFT ACROSS THE NRN
PORTIONS OF THE GULF OF MAINE THROUGH THURSDAY MORNING...KEEPING
ERN AND NRN ME UNDER WRAP AROUND PRECIPITATION THROUGH THE
PERIOD...HIGHER PRESSURE WILL BEGIN TO RIDGE ACROSS THE REGION
EARLY THURSDAY MORNING. A NEW LOW PRESSURE SYSTEM WILL BEGIN
DEEPENING IN THE MID-WEST. THE GFS HAS THE LOW CENTERED OVER
CHICAGO...THE ECMWF HAS THE LOW OVER CNTRL MISSOURI. THE HIGH
PRESSURE WILL DOMINATE THE WEATHER THROUGH EARLY FRIDAY MORNING.
THE GFS DEEPENS THE LOW AND MOVES IT NE TO LAKE HURON...ITS FRONT
WRAPPED AROUND IT EXTENDING FROM HUDSON BAY THROUGH NH...SOUTH
ALONG THE ERN SEABOARD TO THE SE FL COAST. THE GFS SHOWS A NEW LOW
DEVELOPING ON THE FRONT AROUND LONG ISLAND NY. THE ECMWF DEEPENS
THE LOW MOVES IT NE TO CNTRL IN...THE FRONT WRAPPED AROUND THE LOW
EXTENDING FROM LAKE MICHIGAN THROUGH WV...SOUTH THE FL PANHANDLE.
THE ECMWF SHOWS A NEW LOW DEVELOPING OVER SW NC. BY EARLY FRIDAY
AFTERNOON THE GFS MOVES THE LOW INTO SW QUEBEC...THE FRONT THROUGH
CNTRL ME...SOUTH INTO THE N ATLANTIC. THE ECMWF SHIFTS THE ENERGY
TO LOW OVR NC...MOVES IT N TO DELMARVA. BY SATURDAY MORNING THE
THE GFS MOVES THE FRONT THROUGH MAINE...THE LOW NOW MATURE AND
BECOMING COLD CORE IS LOCATED IN NE QUEBEC...WITH MAINE REMAINING
IN WRAP AROUND PCPN. THE ECMWF DEEPENS THE LOW MOVES IT NW INTO
ERN LAKE ONTARIO...THE FRONT WRAPPED AROUND THE LOW EXTENDING EAST
ACROSS CENTRAL MAINE...SOUTH INTO THE GULF OF MAINE TO A SECONDARY
LOW SW OF NOVA SCOTIA. FROM SATURDAY MORNING THROUGH END OF THE
PERIOD THE GFS AND ECMWF ARE IN PRETTY GOOD AGREEMENT. MAINE WILL
REMAIN IN WRAP AROUND PCPN AS A COLD CORE LOW SLOWLY DRIFT EAST
ACROSS THE GULF OF ST LAWRENCE.

STARTED WITH A BASE OF THE GMOS...MODIFIED IT WITH A BLEND OF
GFS/ECMWF TUES NIGHT THRU EARLY THURS. THE GFS AND ECMWF CONTINUE
TO INDICATE THAT THE MIDDLE THROUGH THE END OF THE PERIOD WILL BE
ACTIVE...HOWEVER THERE SOLUTION CONTINUE TO DIFFER ON ORIGIN OF
THE PRIMARY LOW...AS WELL AS HOW IT WILL TRACK ONCE DEVELOPED.
LOADED NAWAVE 4 FOR SEAS IN THE COASTAL WATERS. ADJUST WND GUSTS
WITH WNDS PLUS 25 PERCENT OVER WATER AND 15 PERCENT OVER LAND FOR
GUSTS.



&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
NEAR TERM: OCCASIONAL MVFR AT THE NORTHERN TERMINALS THROUGH THIS
AFTERNOON. OTHERWISE, CLEARING SKIES WITH VFR EXPECTED TONIGHT
AND TOMORROW.


SHORT TO LONG TERM: XPCT VFR CONDITIONS TO SLOWLY TRANSITION TO
MVFR IN SN SUN NGT INTO MON SW TO NE ACROSS THE TAF SITES AND
THEN TO IFR IN SN/MIXED PRECIP SW TO NE ACROSS TAF SITES MON NGT
INTO TUE. IFR CONDITIONS IN SN N...MIXED PRECIP CNTRL AND MSLY RN
DOWNEAST WILL CONT TUE NGT THRU WED MORN...BEFORE IMPROVING TO
MVFR SW TO NE ACROSS THE TAF SITES WED AFTN AND WED NGT AND THEN
TO VFR ALL SITES BY THU.

&&

.MARINE...
NEAR TERM: ALTHOUGH A FEW GUSTS TO 25 KT WILL BE POSSIBLE THIS
AFTERNOON, WINDS WILL CONTINUE TO SUBSIDE THIS EVENING AND
OVERNIGHT. THEREFORE, WILL LET THE SCA EXPIRE WITH THIS PACKAGE.
NO ADDITIONAL HEADLINES WILL BE NEEDED THROUGH TOMORROW.

SHORT TERM: INITIALLY NO HDLNS FOR SUN NGT...WITH WINDS AND WVS
INCREASING TO AT LEAST THE SCA RANGE MON AND MON NGT AND
POTENTIALLY TO GALES ON TUE AS THE SFC PRES GRAD SLOWLY INCREASES
BETWEEN SLOWLY RETREATING HIGH PRES OVR ERN CAN AND A SECOND...
STRONGER LOW PRES APCHG FROM THE N MID ATLC STATES ON TUE.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.

&&

$$
NEAR TERM...HASTINGS
SHORT TERM...VJN
LONG TERM...NORTON
AVIATION...HASTINGS
MARINE...HASTINGS/VJN