FXUS61 KCAR 222112
AFDCAR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
412 PM EST TUE DEC 22 2009

.SYNOPSIS...
A TROUGH OF SURFACE LOW PRESSURE EXTENDING NORTHWEST FROM LOW
PRESSURE WELL EAST OF NOVA SCOTIA WILL SLOWLY BACK WESTWARD INTO
THE REGION THROUGH WEDNESDAY AS AN UPPER LEVEL LOW FROM VERMONT SLIDES
SOUTHEAST INTO THE GULF OF MAINE. THE TROUGH WILL WEAKEN WEDNESDAY
NIGHT WITH HIGH PRESSURE BUILDING OVER THE REGION THURSDAY. 
&&

.NEAR TERM /THROUGH WEDNESDAY/...
THE OVERRUNNING TROUGH IN NEW BRUNSWICK IS BACKING INTO NORTHERN
MAINE WHILE A COLD UPPER LOW IS MOVING INTO NEW ENGLAND. THIS IS
CAUSING SNOWFALL TO INTENSIFY IN NORTHERN AND CENTRAL MAINE. THE
TROUGH WILL CREEP SLOWLY SOUTHWARD TOWARD CENTRAL MAINE BY
WEDNESDAY AFTERNOON. THIS SLOW MOVEMENT WILL ALLOW SUBSTANTIAL
SNOWFALL IN A BAND FROM NEAR HOULTON TOWARDS THE ALLAGASH ALONG
THE FRONTAL BOUNDARY. SNOW RATIOS WILL BE HIGHER ON THE SOUTH OF
THE BOUNDARY WHERE THE COLDER AIR RESIDES. THE NORTHERN EDGE OF
THE SNOW WILL BE CLOSE TO THE ST JOHN VALLEY AROUND VAN BUREN WHILE
THE SOUTHERN EDGE WILL RUN IN A LINE FROM CALAIS TOWARDS
GREENVILLE. HEAVIEST SNOW WILL FALL TONIGHT INTO EARLY WEDNESDAY
MORNING AND GRADUALLY TAPER OFF DURING THE AFTERNOON. UNCERTAINTY
CONTINUES TO EXIST WITH THESE NORTHERN AND SOUTHERN CUT-OFFS.  
&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
THINGS WILL BE WINDING DOWN BY WEDNESDAY EVENING AS THE UPPER LOW
PULLS FURTHER SE AND SFC TROUGH WEAKENS AND PULLS AWAY.

THEREFORE...KEPT HIGHEST CHCS STARTING OFF WEDNESDAY EVENING
ACROSS THE EASTERN 3RD OF THE CWA AND THEN DROP OFF THE POPS TO
CHC BY MIDNIGHT. WE ARE NOT EXPECTING MUCH MORE ACCUMULATION AND
MAYBE AN INCH AND THAT SHOULD DO IT.

HIGH PRES IS EXPECTED TO BUILD IN FROM CANADA ON THURSDAY AND
REMAIN OVER THE CWA THROUGH CHRISTMAS NIGHT. GENERALLY FOLLOWED
THE ECMWF AND GFS W/THE PLACEMENT OF THE HIGH AND FOLLOWED CLOSELY
W/THE GMOS NUMBERS W/TEMPS ABOVE NORMAL FOR THIS TIME OF YEAR.
&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
BIGGER CHALLENGE THIS TERM COMES LATER IN THE WEEKEND W/THE APCH
OF THE NEXT STORM. LATEST RUNS FROM BOTH THE GFS AND ECMWF POINT
TO THE LOW MOVING INTO NYS AND THEN RE-DEVELOPING ON THE SOUTHERN
NEW ENGLAND COAST AND MOVING NE. 

1000-850 AND 850-700MB THICKNESSES POINT TO THE POTENTIAL OF A
START OF SNOW OR MIXED PRECIPITATION AND THEN THINGS WARM UP TO
ALL PRECIP TO GO TO RAIN ACROSS THE INTERIOR DOWNEAST AND COAST
BY LATER SUNDAY. FURTHER NORTH...DECIDED ATTM TO KEEP MIXED SNOW
AND SLEET GIVEN THAT THE TREND HAS BEEN FOR THE SFC LOW TO BE A
JOG FURTHER SOUTH WHICH COULD FAVOR A COLDER SOLUTION. ADJUSTED
THE GMOS POPS FOR SUNDAY TO LIKELY AND RAISED TEMPERATURES FOR
INTERIOR DOWNEAST AND THE COAST TO MID AND UPPER 30S BY SUNDAY 
AFTERNOON. STILL PLENTY OF TIME TO ASSESS THIS UPCOMING EVENT.

THINGS ARE EXPECTED TO TURN COLDER MONDAY INTO TUESDAY W/A RETURN
TO NORMAL CONDITIONS.
&&

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
NEAR TERM: IFR PRETTY MUCH INTO WEDNESDAY. 

SHORT TERM: MVFR STARTING THINGS OUT WEDNESDAY NIGHT AND THEN AS HIGH
PRES SETTLES IN ON THURSDAY AND REMAINS OVER THE CWA THROUGH
SATURDAY WE SHOULD SEE A RETURN TO VFR CONDITIONS. 
&&

.MARINE...
NEAR TERM: SCA CONDITIONS LIKELY TO RETURN WEDNESDAY NIGHT AS
WINDS INCREASE ON THE BACKSIDE OF THE LOW PRESSURE IN THE MARITIMES.

SHORT TERM: WE ARE EXPECTING WINDS TO PICK BACK UP TO SCA LEVELS
WEDNESDAY NIGHT INTO THURSDAY ON THE BACKSIDE OF LOW. BACKED OFF
ON THE GFS/GMOS WINDS WHICH WERE SHOWING GALE POTENTIAL. DECIDED
TO BACK THEM DOWN 5 TO 10 KTS WHICH PUT THINGS IN SCA CATEGORY.
WVAWAVE GUIDANCE LOOKED GOOD AND RAN W/IT FOR WAVE HEIGHTS WHICH
BRINGS SEAS TO 4-6 FT WEDNESDAY NIGHT INTO EARLY THURSDAY. THING
ARE EXPECTED TO COME DOWN THURSDAY AND CONTINUE THROUGH SATURDAY.
&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR MEZ001>006-
     010-011-031-032.
     WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST 
     WEDNESDAY FOR MEZ017.
     WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST 
     WEDNESDAY FOR MEZ030.
MARINE...NONE.

&&

$$
NEAR TERM...MWALKER
SHORT TERM...TURNER/HEWITT
LONG TERM...TURNER/HEWITT 
AVIATION...HEWITT 
MARINE...MWALKER/HEWITT