FXUS61 KCAR 052252
AFDCAR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
552 PM EST SAT DEC 5 2009

.SYNOPSIS...
STRONG LOW PRESSURE TRACKING EAST-NORTHEAST THROUGH THE GULF OF
MAINE WILL BRING SIGNIFICANT SNOWFALL TO MOSTLY DOWNEAST AREAS
OVERNIGHT AND LESSER OR NO SNOWFALL ELSEWHERE ACROSS THE REGION.
SNOW WILL END ACROSS SOUTHEAST MAINE BY LATE SUNDAY MORNING AS THE
LOW MOVES AWAY SOUTH OF THE MARITIMES AND A RIDGE OF HIGH PRESSURE
FROM THE WEST BUILDS TOWARD THE AREA SUNDAY AFTERNOON. COLDER
CONDITIONS WITH SCATTERED SNOW SHOWERS IS EXPECTED MONDAY AND
TUESDAY. THE NEXT SIGNIFICANT STORM SYSTEM MAY BRING SNOW OR MIXED
PRECIPITATION TO THE REGION LATER WEDNESDAY AND INTO THURSDAY.
&&

.NEAR TERM /THROUGH SUNDAY/...
DECIDED TO BRING THE 1 INCH SNOW LINE AS FAR NORTH AS PQI AS THE
LATEST NAM40 AND SREF SUPPORT FORCING AND QPF SHIELD EDGING JUST A
BIT FURTHER NORTH THAN THE PREVIOUS RUNS. WE ARE MONITORING MEZ032 
AND MEZ011 AS LATEST RADAR SHOWS ENHANCEMENT CREEPING INTO THESE
AREAS. THIS COULD LEAD TO HIGHER SNOWFALL TOTALS. NO CHGS TO THE HEADLINES
ATTM.

ALL MODELS WERE ON BOARD IN BRINGING DOWNEAST AREAS...SPCLY THE
COAST AND CNTRL WASHINGTON COUNTY...SIGNIFICANT SNFL OVRNGT.
MARGINAL SFC-BL TEMPS MAY RESULT IN PRECIP BRIEFLY BEGINNING AS A
MIX OF RN AND SN ALG THE COAST THE REMAINDER OF THE AFT BEFORE
EVAPORATIONAL/DYNAMIC/AND ADVECTIVE PROCESSES RESULT IN IN FAIRLY
QUICK CHGOVR TO ALL SN ERLY THIS EVE. MOST MODELS INDICATE ABOUT
3/4 OF AN INCH LIQ EQIV IN THE WARNING AREA...MOST OF WHICH OCCURS
AFT THE CHGOVR TO SN. MOST OF THE FORCING OVRNGT FOR THE QPF IS
TIED UP WITH A DEVELOPING 700 MB LOW JUST S OF THE MAINE COAST...
OTHERWISE THE TRACK OF THE SFC LOW THIS FAR S WOULD LIKELY NOT
RESULT IN SIGNIFICANT TO HVY SNFL EVEN ALG THE COAST. GIVEN THE
XPCTN OF DEFORMATION BANDING OVRNGT...THERE COULD BE A LARGE
GRADIENT OF SNFL OVR THE WRNG AREA. GIVEN SOMEWHAT HIGHER WIND
SPEEDS XPCTD ALG THE COAST...WE MENTION SOME BLOWING AND DRIFTING
OF SNFL LATE TNGT OVR THE WRNG AREA.

OTHERWISE...SNFL AMOUNTS WILL STEADILY DROP OFF NWRD FROM THE
WRNG AREA TO 3 TO 6 INCHES IN THE ADV AREA AND CORRESPONDING
LESSER AMOUNTS FURTHER N. ATTM...IT APPEARS THAT THE NRN MOST
PROGRESSION OF THE SN CANOPY WILL REACH ACROSS NRN ZONE 4 AND
CENTRAL ZONE 2 BEFORE MOVING EAST OF THE AREA THRU NEW BRUNSWICK
BY ERLY SUN MORN. ANY STEADY SNFL LEFT ACROSS SE PTNS OF THE FA
SHOULD TAPER TO SN SHWRS BY LATE SUN MORN AS THE DEEP LAYER
FORCING MOVES E OF THE FA...WITH MUCH OF THE FA POTENTIALLY
EXPERIENCING PARTIAL SUNSHINE BY SUN AFT. LOW TEMPS TNGT WILL BE
MILD RELATIVE TO CLIMO SPCLY ACROSS THE N...WITH AT OR JUST ABV
NORMAL HI TEMPS XPCTD ON SUN WITH A FAIRLY BRISK NW WIND.
&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
STRONG LOW PRESSURE WILL HAVE MOVED WELL OUT TO SEA BY SUNDAY
NIGHT LEAVING STRONG CAA IN ITS WAKE. H10 TO H5 THICKNESSES LOOK
TO BE ABOUT 510 DAM ACROSS THE NORTHERN TIER. HOWEVER...STRONG
NORTHWEST FLOW WILL PERSIST AS RIDGING BUILDS IN FROM THE
SOUTHEAST AND A WEAK UPPER WAVE PASSES NORTH OF THE STATE
OVERNIGHT. THE WINDS ASSOCIATED WITH THE GRADIENT COMBINED WITH
THE POTENTIAL FOR CLOUD DEV ELOPEMENT WITH THE WAVE SHOULD HELP
MODERATE TEMPERATURES...WHICH WILL STILL BE COLD COMPARATIVELY SPEAKING.
THE SAME AFOREMENTIONED WEAK WAVE IS EMBEDDED IN CP AIR AND WILL
BE DRY FOR THE MOST PART SO WILL KEEP ONLY SLIGHT CHANCE POPS
ACROSS THE VERY CROWN OF MAINE.

A SECOND WEAK WAVE WILL MOVE SWIFTLY ACROSS THE STATE LATE DAY
MONDAY. LATEST GFS AND NAM MOVE THIS LOW AND ITS BEST FORCING WELL
OVER THE SOUTHERN HALF OF THE STATE. USED THESE MODELS AS A BLEND
FOR PRECIP AND CLOUDS AS WELL AS A MODERATED BLEND OF MOS GUIDANCE
FROM EACH OF THESE FOR TEMPS AND DEWPOINTS. THIS YIELDED GOOD
RESULTS AS BEST WEAK UPPER LEVEL INSTABILITY WITH THIS OPEN WAVE
WILL BE OVER THE SOUTHERN PORTION OF THE STATE. MAX OMEGA IS WELL
OUT OF THE GROWTH ZONE SO SNOWFALL SHOULD BE KEPT LOW. WENT WITH
ONLY CHANCE POPS FOR A MENTION OF SNOW SHOWERS ACROSS SOUTHERN
ZONES. STRONG HIGH PRESSURE ASSOCIATED WITH A COLD AIRMASS BUILDING
INTO THE CENTRAL STATES WILL BEGIN TO RIDGE OVER DURING THE DAY ON
TUESDAY.
&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
STILL APPEARS AS IF A SIGNIFICANT WEATHER MAKER WILL AFFECT THE
REGION LATER WEDNESDAY AND WEDNESDAY NIGHT. FELT ENOUGH JUSTIFICATION
TO WARRANT INCREASING POPS TO LOW END CATEGORICAL SINCE MODELS
CONTINUE TO BE RATHER CONSISTENT WITH REGARD TO TIMING. WHATS
STILL UNCERTAIN IS PTYPE. CERTAINLY LOOKS LIKE ENOUGH LOW LEVEL
COLD WILL BE IN PLACE FOR PRECIPITATION TO BEGIN AS ALL SNOW.
HOWEVER...WARMER AIR COULD EVENTUALLY BE DRAWN UP ACROSS THE
REGION FOR A SNOW TO MIX TO POSSIBLY ALL LIQUID DOWNEAST. SINCE
TRACK OF THE LOW WILL BE CRITICAL WITH REGARD TO PRECIPITATION
TYPE HAVE USED THE WX FROM SFC TEMP TO GO STRAIGHT SNOW/RAIN AT
TIME. THIS SYSTEM WILL MOVE AWAY FROM THE REGION THURSDAY WITH
LINGERING SNOW SHOWERS ACROSS THE NORTH AND MTNS. DRIER BUT COLDER
WEATHER IS ANTICIPATED FOR THE LATTER PART OF NEXT WEEK.
&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: WE XPCT IFR CONDITIONS IN SN TO OVERSPREAD DOWNEAST
SITES THIS EVENING AND EVEN TO KHUL BY LATE TNGT. NRN TAF SITES
WILL REMAIN VFR/MVFR IN SC/NS CLD DECK AND IN ANY LGTR SNFL. ALL
SITES SHOULD RECOVER TO VFR BY LATE SUN MORN.

SHORT TERM: VFR CONDITIONS WILL PERSIST ACROSS ALL TAF SITES
THROUGH LATE MONDAY. MVFR AND LOCAL IFR CONDITIONS WILL OCCUR WITH
THE PASSING OF A WEAK LOW PRESSURE SYSTEM OVER THE SOUTHERN TAF
SITES MONDAY NIGHT INTO EARLY TUESDAY. CONDITIONS WILL THEN REMAIN
VFR THROUGH LATE WEDNESDAY. IFR/LIFR CONDITIONS ARE POSSIBLE IN
PRECIPITATION LATE WEDNESDAY INTO THURSDAY.
&&

.MARINE...
NEAR TERM: WE WILL CONT WITH THE GALE WRNG OVR THE OUTER COASTAL
WATER ZONES AND AN SCA FOR THE INNER HARBOR ZONE LATE THIS EVE
INTO SUN MORN. THE GALE WILL LIKELY NEED TO BE TRANSITIONED TO AN
INTERMEDIARY SCA OVER THE OUTER WATERS BY THE LATE MORNING CWF
UPDATE. 

SHORT TERM: SEAS WILL SLACKEN AS GRADIENT WEAKENS WITH LOW
PRESSURE MOVING OUT TO SEA LATE SUNDAY. OFFSHORE FLOW WILL PERSIST
AND ALLOW SEAS TO SLACKEN FURTHER STILL THROUGH LATE MONDAY. WEAK LOW
PRESSURE WILL MOVE QUICKLY OVER THE WATERS AND BRING THE POTENTIAL
FOR DETERIORATING VISIBILITIES IN LIGHT SNOW SHOWERS MONDAY NIGHT INTO
TUESDAY MORNING. HIGH PRESSURE WILL BUILD OVER THE WATERS THROUGH
WEDNESDAY.
&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 8 AM EST SUNDAY FOR MEZ011-015-
     016-032.
     WINTER STORM WARNING UNTIL 8 AM EST SUNDAY FOR MEZ017-029-030.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST SUNDAY 
     FOR ANZ052.
     GALE WARNING FROM 9 PM THIS EVENING TO NOON EST SUNDAY FOR 
     ANZ050-051.

&&

$$
NEAR TERM...HEWITT/VJN
SHORT TERM...DOODY
LONG TERM...DUDA
AVIATION...HEWITT/VJN
MARINE...HEWITT/VJN/DOODY