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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCAR 091600
AFDCAR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
1100 AM EST MON DEC 9 2013

.SYNOPSIS...
LOW PRESSURE WILL APPROACH FROM THE SOUTHWEST TODAY AND CROSS THE
REGION TONIGHT. WEAK HIGH PRESSURE WILL RIDGE ACROSS THE REGION
TUESDAY AND TUESDAY NIGHT. AN ARCTIC COLD FRONT FROM CENTRAL CANADA
WILL APPROACH WEDNESDAY MORNING AND CROSS THE REGION BY WEDNESDAY
EVENING...WITH HIGH PRESSURE FROM NORTHERN CANADA RIDGING TOWARD
THE REGION FOR THE LATE WEEK.
&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
11:00 AM UPDATE...SNOW IS BEGINNING TO SPREAD INTO CENTRAL AREAS.
THE AIR IS DRY SO THE SNOW IS TAKING SOME TIME TO REACH THE
GROUND. FORECAST REMAINS ON TRACK.

PREVIOUS DISCUSSION...THE CHALLENGE FOR THE NEAR TERM WILL BE SNOW
AMOUNTS AND PRECIPITATION TYPE. THE WINTER WEATHER ADVISORY HAS
BEEN EXTENDED TO INCLUDE ALL OF NORTHERN AND EASTERN MAINE EXCEPT
THE COAST. READ BELOW FOR DETAILS.

LOW PRESSURE CURRENTLY PIVOTING INTO THE GREAT LAKES EARLY THIS
MORNING WILL CONTINUE TO TREK NORTHEAST ACROSS ONTARIO INTO QUEBEC
TODAY AND TONIGHT. MEANWHILE, A SECONDARY LOW WILL DEVELOP OFF LONG
ISLAND THIS AFTERNOON AND SLIDE EAST TO JUST SOUTH OF NOVA SCOTIA BY
MIDNIGHT TONIGHT. SNOW ASSOCIATED WITH THE PRIMARY LOW WILL SPREAD
INTO THE FORECAST AREA FROM WEST TO EAST LATER THIS MORNING INTO
EARLY AFTERNOON. HOWEVER, AS THE SECONDARY LOW MOVES SOUTH OF THE
GULF OF MAINE, WARM AIR WILL LIFT NORTHWARD INTO DOWNEAST AREAS.
THIS WARMER AIR WILL LIFT OVER THE COLD AIR ALREADY EXISTING AT THE
SURFACE, ALLOWING FOR A WINTRY MIX OF SNOW, SLEET, AND FREEZING RAIN
TO DEVELOP. THOSE AREAS ALONG THE COAST WILL WARM ENOUGH FOR THE
PRECIPITATION TO CHANGE TO ALL RAIN, BUT INTERIOR AREAS OF DOWNEAST
MAINE WILL REMAIN AT OR BELOW FREEZING FOR MUCH OF THE EVENT,
ALLOWING FOR A FEW HOURS OF THE WINTRY MIX. LIGHT SNOW ACCUMULATIONS
AROUND AN INCH ARE POSSIBLE BEFORE THE CHANGEOVER STARTS. THE WINTRY
MIX WILL START ALONG THE COAST LATE THIS AFTERNOON AND LIFT NORTH
THROUGH THIS EVENING, WITH THE TRANSITION ZONE MAKING IT TO ROUGHLY
A DEXTER-LINCOLN-TOPSFIELD LINE. MOST AREAS WILL ONLY SEE A TRACE OF
ICE ACCUMULATION, THOUGH UP TO 0.05 INCH IS POSSIBLE IN SOME AREAS.
TEMPERATURES WILL ACTUALLY RISE IN THESE AREAS THROUGH THE FIRST
PART OF THE EVENING, BUT COLDER AIR WILL MOVE IN AFTER MIDNIGHT AS
THE SECONDARY LOW MOVES EAST OF NOVA SCOTIA. THE PRECIPITATION WILL
COME AN END AFTER MIDNIGHT. GIVEN THE POTENTIAL FOR ICE
ACCUMULATION, HAVE OPTED TO EXTEND THE WINTER WEATHER ADVISORY TO
INCLUDE ALL OF EASTERN AND DOWNEAST MAINE AWAY FROM THE COAST.
LITTLE TO NO ICE ACCUMULATION IS EXPECTED ALONG THE COAST.

FOR NORTHERN AND WESTERN MAINE...THE PRECIPITATION WILL REMAIN SNOW.
THE LATEST MODEL GUIDANCE HAS LESSENED QPF AMOUNTS A BIT, BUT STILL
FEEL SNOW ACCUMULATIONS OF 3 TO 4 INCHES WITH ISOLATED AMOUNTS
NEARING 5 INCHES ARE REASONABLE. THE STEADIEST SNOW WILL BE THIS
AFTERNOON INTO EARLY EVENING. THE SNOW WILL TAPER OFF TO SHOWERS
AFTER MIDNIGHT TONIGHT AS DRIER AIR WORKS INTO THE AREA BEHIND THE
DEPARTING SECONDARY LOW.
-- End Changed Discussion --

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AN INTERIM MODIFIED ARCTIC AIRMASS WILL MOVE INTO THE FA ON TUE
BEHIND THE OCCLUSION...WITH ONLY LMTD RISE IN TEMPS FROM TUE MORN
LOW TEMPS. BOTH THE 00Z GFS AND ECMWF SHOW A FLAT S/WV MOVG E S OF
THE GULF OF ME WITH LGT OVRRNG LGT PRECIP TRACKING S OF OUR FA...
PERHAPS GRAZING SRN PTNS OF OUR COASTAL WATERS...SO THE BIGGEST
IMPACT WILL LIKELY BE A HI/MID CLD DECK PERSISTING OVR DOWNEAST
AREAS TUE. A DECENT NW MSL PRES GRAD AND FAIRLY STRONG WINDS ALF
WILL ALLOW WIND GUSTS OF 25 TO 30 MPH LATE MORN INTO MID AFTN.

AFT A BREAK TUE NGT...ALL MODELS SHOW AN ARCTIC COLD FRONT
SUPPORTED BY A COUPLE OF WEAK S/WVS CROSSING W TO E ACROSS QB
AND NRN PTNS OF OUR FA ON WED. THE TMG OF THIS FRONT WILL BE
ERLY AFTN ACROSS THE FAR NW TO ERLY EVE PAST EASTPORT ME...
WITH FRONT ACCOMPANIED BY FLURRIES AND SCT SN SHWRS SPCLY
ACROSS THE N...WITH PERHAPS LCLZD SN ACCUMULATIONS UP TO AN
INCH. GIVEN THE TMG OF THE FRONT...HI TEMPS WILL LIKELY BE A
LITTLE EARLY ACROSS THE NW....WITH MDT LLVL COLD ADVCN PERHAPS
REVERSING THE NORMAL DIURNAL TREND OF RISING TEMPS IN THE AFTN
OVR THIS PTN OF THE FA.

OTHERWISE...VERY COLD TEMPS AND BRISK NW WINDS LATE WED NGT INTO
THU MAY RESULT IN NEAR ADV WIND CHILLS DURING THIS TM. HI TEMPS
THU WILL STRUGGLE TO REACH MID SINGLE DIGITS ACROSS THE FAR N
TO MID TEENS OVR DOWNEAST AREAS.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
WELL...WE ARE PRETTY CERTAIN THAT TEMPS WILL CONT SIG BLO NORMAL
IN THE LONG RANGE. LOTS OF UNCERTAINTY ATTM...HOWEVER...REGARDING
S/WVS AND ASSOCIATED TRACKS OF SFC LOWS THAT COULD IMPACT OUR FA
DURING THIS PD. SUFFICE IT TO SAY...THE FCST WAS GUIDED MORE TOWARD
DRIER...WITH LOWER POPS THAN WHAT MIGHT BE IMPLIED BY THE 00Z OPNL
GFS...MORE IN LN WITH THE 00Z ECMWF AND HPC`S MANUAL GRAPHICS FOR
DAYS 4 THRU 7. GIVEN UNCERTAINTY OF MODEL SCENARIOS...SPCLY
REGARDING CLD CVR AT NGT... WE COULD NOT GAMBLE WITH GOING WITH
COLDER OVRNGT LOW TEMPS THAN THE SUPERBLEND MODEL GUIDANCE...WHICH
WOULD BE TOO MILD IN ARCTIC AIRMASSES...SPCLY OVR OUR NW VLY
REGIONS UNDER CLR SKIES. SO... IT WOULD NOT BE SURPRISING IF
OVRNGT LOW TEMPS ON ONE OR TWO NGTS IN THE LONG TERM END UP SIG
COLDER THAN WE CURRENTLY SHOW IN THIS FCST UPDATE. WE BELIEVE THE
IDEA OF INCREASING POPS ALG THE S PTNS OF THE FA LATER SUN INTO
SUN NGT AS PER THE ECMWF SOLUTION MAY BE THE CORRECT TREND...BUT
WITH LITTLE COLLABORATING SOLUTIONS FROM OTHER MODELS...WE KEEP
POPS IN THE SLGT CHC TO LOW CHC CATEGORY ATTM.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR CONDITIONS THIS MORNING WILL GIVE WAY TO IFR AS
SNOW SPREADS FROM WEST TO EAST. WHILE THE NORTHERN TERMINALS WILL
REMAIN ALL SNOW, A WINTRY MIX OF SNOW, SLEET, AND FREEZING RAIN IS
LIKELY AT KBGR AND KBHB 20Z-03Z. KBHB WILL LIKELY CHANGE TO ALL
RAIN BY 01-03Z. THE PRECIPATION WILL COME TO AN END FROM SOUTH TO
NORTH AFTER 04Z, BUT IFR CONDITIONS WILL CONTINUE TO PREVAIL
THROUGH THE REMAINDER OF THE PERIOD.


SHORT TO LONG TERM: VFR XPCTD OVR DOWNEAST TAF SITES EACH DAY WITH
SCT-BKN SC ATTMS. MSLY LOW VFR XPCTD ACROSS NRN TAF SITES IN BKN-
OVC SC WITH MVFR CLGS AND LOWERED VSBYS WITH FLURRIES ATTMS...SPCLY
KFVE AND KCAR.

&&

.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY REMAINS IN EFFECT FROM 9 AM
THROUGH TONIGHT. WINDS AND WAVES ARE EXPECTED TO INCREASE BY MID MORNING
AS LOW PRESSURE APPROACHES FROM THE WEST. A SECOND LOW WILL
DEVELOP OFF LONG ISLAND THIS AFTERNOON AND MOVE TO NOVA SCOTIA
THIS EVENING, KEEPING WINDS AND SEAS ABOVE SMALL CRAFT LEVELS
THROUGH THE PERIOD.

SHORT TO LONG TERM: MSLY SCA CONDITIONS WITH NW GRADIENT FLOW AND
LLVL COLD ADVCN XPCTD TUE THRU FRI ACROSS OUR WATERS...WITH ONLY
BRIEF PDS OF LESS THAN SCA CONDITIONS. VERY COLD AIR OVER
RELATIVELY WARM SSTS WILL LIKELY RESULT IN OCNL SN SHWRS OVR OUTER
MZS THU INTO FRI WITH VSBYS BRIEFLY BLO 3 NM ATTMS.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MEZ001>006-010-011-015>017-031-032.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST TUESDAY FOR ANZ050>052.

&&

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