Potential Historic Three Day New Years' Snowstorm Update 5

000
FXUS61 KCAR 012128
AFDCAR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
428 PM EST FRI JAN 1 2010

.SYNOPSIS...
-- Changed Discussion --LOW PRESSURE WILL INTENSIFY SOUTHEAST OF THE GULF OF MAINE TONIGHT
THROUGH SATURDAY...THEN MOVE BACK TOWARD THE MAINE COAST SATURDAY
NIGHT THROUGH SUNDAY. THIS LOW WILL THEN WEAKEN AND DRIFT
NORTHEAST INTO THE CANADIAN MARITIMES THROUGH EARLY NEXT WEEK.-- End Changed Discussion --
&&

.NEAR TERM /THROUGH SATURDAY/...
-- Changed Discussion --THE FIRST OF TWO SYSTEMS TO AFFECT THE AREA...AND THE WEAKER OF
THE TWO...CURRENTLY S OF NOVA SCOTIA AND IS WEAKENING AS
ANTICIPATED. THIS SYSTEM HAS SPREAD A MAINLY LGT SNOW ACROSS MUCH
OF THE REGION DURING THE PAST 12-24 HRS W/ AROUND AN INCH FAR N TO
5 INCHES FAR SRN AND SWRN AREAS. AREA OF LGT SNOW HAS BEEN DCRSG
LAST FEW HRS W/ MANY RPTG STNS YIELDING IMPRVG VSBYS LAST FEW HRS
AS WELL. ALL MODELS SUPPORT THESE TRENDS SO WILL CANX THE CURRENT
WNTR WX ADV. ANY REMAINING LGT SNOW ACROSS THE FA SHOULD RESULT IN
LESS THAN AN INCH OF NEW SNOW THRU TNGT.

OTHRWS...ALL ATTENTION TURNS TO THE SECOND AND MUCH STRONGER
SYSTEM XPCTD TO AFFECT THE AREA FROM SAT AM THRU SUN AM. CURRENT
12Z MODEL SUITE DEVELOPS AN AREA OF LOW PRES WELL S OF NS LATER
TNGT THEN LIFT THIS LOW NWRD TOWARD THE SWRN COAST OF NS BY LATE
SAT WHILE RAPIDLY INTENSIFYING IT. XPCT THIS STORM TO SPREAD SNOW OF
INCRSG INTENSITY FROM SE-NW SAT AM ACROSS SRN/SERN SECTIONS AND
INTO FAR NWRN SECTIONS BY LATE SAT. IN ADDITION TO THE SNOW...XPCT
STRONG NRLY WNDS TO DEVELOP N AND W OF THIS APPROACHING STORM
SYSTEM W/ SIGNIFICANT BLOWING AND DRIFTING SNOW AND NEAR BLIZZARD
CONDS PSBL BY SAT EVE. ATTM...WILL ISSUE WNTR STORM WRNGS ALL ZNS
BUT WILL HIT THE WNDS AND VSBY ISSUES HARD IN THE WSW STATEMENT.
WNDS ARE A REAL CONCERN W/ THIS UPCOMING EVENT AND MAY NEED TO
UPGRADE TO BLIZZARD WRNGS AT SOME POINT IF LATER DATA CONTS TO
SUPPORT THESE CONCERNS.-- End Changed Discussion --
&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
-- Changed Discussion --VERY INTENSE LOW PRESSURE EXPECTED TO BE LOCATED NEAR SOUTHERN
PORTION OF NOVA SCOTIA AT THE BEGINNING OF THIS FORECAST PERIOD.
AT THE SAME TIME A 500MB LOW PRESSURE CENTER WILL BE PIVOTING
AROUND THE SOUTH SIDE OF THE SURFACE LOW. EXPECT THE SURFACE LOW
ALSO TO BE CAPTURED BY THE UPPER LEVEL SYSTEM AT THIS TIME. DURING
THE REMAINDER OF SATURDAY NIGHT THE SURFACE LOW WILL ROTATE AROUND
THE UPPER LOW...DRIFTING TO THE WEST THEN TO THE SOUTHWEST LATER
SATURDAY NIGHT AND DURING THE DAY SUNDAY. ALL OF THIS BASED ON A
COMPRISE OF MOST OPERATIONAL MODELS AND THE SREF. THE LOW CENTER
EVENTUALLY RETREATS BACK TO THE EAST IN CONJUNCTION WITH THE UPPER
LEVEL SYSTEM LATER SUNDAY NIGHT AND DURING THE DAY MONDAY. MARITME
AIR WILL MOVE AROUND THE NORTH OF THE LOW CENTER LATER SATURDAY
INTO SATURDAY NIGHT RESULTING IN A BAROCLINIC ZONE MOVING ACROSS
NEW BRUNSWICK INTO NORTHERN MAINE. EXPECT SOME BANDING TO DEVELOP
ALONG THIS FRONTAL ZONE LATE SATURDAY INTO SATURDAY EVENING WITH
HEAVIEST PRECIPITATION OCCURRING IN CONJUNCTION WITH THIS AS MOIST
MARITIME AIR IS TRANSPORTED AND THEN LIFTED OVER THE FRONT.

ANOTHER ISSUE IS PRECIPITATION TYPE. HAVE USED BUFKIT THICKNESS
BASED TOOL. THIS INDICATES ALL PRECIPITATION IN NORTH IN FORM OF
SNOW HOWEVER EASTERN AREAS DO COME VERY CLOSE TO TRANSITION ZONE.
ALONG COAST WASHINGTON COUNTY COASTAL FRONT MOVES INLAND BETWEEN
03Z AND 09Z RESULTING IN A CHANGE TO RAIN THUS REDUCING SNOW
ACCUMULATION.

ALSO EXPECT STRONG SURFACE WINDS WITH THIS SYSTEM. HAVE OVERLAYED
MIXING LAYER IN BUFKIT TIME/HEIGHT CROSS SECTION. THIS FOR THE
MOST PART SHOWS GOOD TRANSPORT OF WIND TO SURFACE. HAVE INITIALIZED
WINDS WITH NAM12 AND THEN DID SOME HAND EDITING. WILL INCLUDE
AREAS OF BLOWING SNOW IN ALL BUT SOUTHEAST WHERE SNOW IS EXPECTED
TOO MIX.

FOR QPF HAVE INITIALIZED GRIDS WITH SREF THEN DID SOME HAND
EDITING TO INCREASE AMOUNTS SLIGHTLY IN VICINITY OF EXPECT FRONTAL
POSITION. FOR SNOW AMOUNTS HAVE INITIALIZED GRIDS WITH OFFICE SNOW
FROM THICKNESS TOOL. THIS TECHNIQUE HIGHLIGHTS SOUTHEAST WHERE
MIXED PRECIPITATION TYPE OCCURS. SNOW GRIDS WHERE THEN SMOOTHED
MANUALLY.-- End Changed Discussion --
&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
-- Changed Discussion --MONDAY NIGHT INTO TUESDAY THE LOW PRESSURE SYSTEM SHOULD STILL BE IN
THE AREA. CLOUDS WILL STILL BE AROUND THROUGHOUT THE ENTIRE CWA AND
STILL CARRY CHANCE POPS FOR A SNOW SHOWER ESPECIALLY IN THE NORTHERN
PART OF THE CWA FOR MONDAY NIGHT THROUGH TUESDAY. TUESDAY NIGHT
THINGS SHOULD CALM DOWN FOR THE REST OF THE FORECAST PERIOD THROUGH
THURSDAY. THE LOW WILL SLOWLY MOVE OUT AND EXPECT MOSTLY CLOUDY
TO CLOUDY SKIES FOR TUESDAY NIGHT THROUGH FRIDAY AND WITH THAT THE
SLOW MOVEMENT OF THE LOW STILL CANNOT RULE OUT A STRAY SNOW SHOWER
ESPECIALLY IN THE NORTHERN PART OF THE CWA. AREAS DOWNEAST COULD
SEE SOME CLEARING WEDNESDAY AND THURSDAY. AT THE MOMENT NO MAJOR
STORMS ARE ON THE TABLE WITHIN THE PERIOD. AS FOR TEMPS USED GMOS AND
ADJUSTED AS NEEDED.-- End Changed Discussion --

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --PTCHY LGT SNOW ACROSS THE AREA RESULTING IN WDLY VARYING CONDS
ACROSS OUR TAF SITES... XPCT THIS TREND TO CONT THRU THE NGT W/
CONDS LOWERING TO WDSPRD IFR AT ALL TAF SITES DURING SAT AS
INTENSE LOW PRES APPROACHES FROM THE SE.

SHORT TERM: EXPECT IFR CONDITIONS SATURDAY NIGHT INTO SUNDAY
MORNING. THEN GRADUAL IMPROVMENT TO MVFR/VFR AS PRECIPITATION
INTENSITY DECREASES SUNDAY. VFR CONDITIONS EXPECTED MONDAY INTO
WEDNESDAY.-- End Changed Discussion --
&&

.MARINE...
-- Changed Discussion --NEAR TERM: STRONG SCA CONDS ATTM ACROSS THE WATERS... WNDS/SEAS
XPCTD TO INCRS ON SAT AS DEEP LOW PRES APPROACHES FROM SSE OF THE WATERS.

SHORT TERM: HAVE INITIALZIED WIND GRIDS WITH NAM/DNG5. VERY
STRONG GRADIENT IN PLACE...ESPECIALLY IF NAM PRESSURE FIELD IS
CORRECT. BUFKIT INDICATES GOOD MIXING WITH POTENTIAL FOR 50 KNOTS
GETTING MIXED TO SURFACE...SO WILL GO WITH STORM WARNING FOR
PERIOD OF STRONGEST JET. FOR WAVES: WILL INITIALIZE GRIDS WITH
NAM/SWAN SINCE NAM WINDS LOOK MOST REASONABLE.-- End Changed Discussion --
&&

.TIDES/COASTAL FLOODING...
-- Changed Discussion --ASTRONOMICAL TIDE VERY HIGH WITH SATURDAY MORNING TIDE AROUND
11:25 AM AND AGAIN SUNDAY AFTERNOON AROUND 12:17 PM. WINDS SPEEDS
AROUND 25 KNOTS SATURDAY MORNING. EXPECT THIS WILL RESULT IN 1 TO
1.5 FOOT SURGE WHICH WOULD BRING TIDE LEVEL TO AROUND 14.5 FEET AT
BAR HARBOR TIDE STATION SATURDAY MORNING SO WILL KEEP COASTAL
FLOOD WATCH IN PLACE AND REVIEW FORECAST WIND SPEED AGAIN TONIGHT.-- End Changed Discussion --
&&

.CAR WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --ME...WINTER STORM WARNING FROM NOON SATURDAY TO 1 PM EST SUNDAY FOR
MEZ001>006-010.
WINTER STORM WARNING FROM 7 AM SATURDAY TO 1 PM EST SUNDAY FOR
MEZ011-015>017-029>032.
COASTAL FLOOD WATCH FROM SATURDAY MORNING THROUGH SATURDAY
AFTERNOON FOR MEZ029-030.
MARINE...STORM WARNING FROM 7 PM SATURDAY TO 1 PM EST SUNDAY FOR
ANZ050>052.-- End Changed Discussion --

&&

$$
NEAR TERM...KHW
SHORT TERM...MIGNONE
LONG TERM...HILL
AVIATION...KHW
MARINE...KHW/MIGNONE
TIDES/COASTAL FLOODING...