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Area Forecast Discussion
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000
FXUS61 KGYX 312219
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
619 PM EDT FRI OCT 31 2014

.SYNOPSIS...
LOW PRESSURE OVER THE GREAT LAKES WILL REDEVELOP OFF THE MID
ATLANTIC COAST THIS EVENING AND WILL TRACK NORTHEAST THROUGH
SATURDAY. LOW PRESSURE WILL RAPIDLY INTENSIFY OFF THE NEW ENGLAND
COAST SATURDAY NIGHT AND EARLY SUNDAY. LOW PRESSURE WILL LIFT
NORTHEAST INTO THE MARITIMES SUNDAY AFTERNOON THROUGH SUNDAY
EVENING. A STRONG NORTHWEST FLOW WILL PERSIST OVER THE REGION
SUNDAY NIGHT. A RIDGE OF HIGH PRESSURE WILL BUILD IN FROM THE WEST
ON MONDAY AND WILL SHIFT OFFSHORE MONDAY NIGHT. HIGH PRESSURE WILL
HOLD OFF THE EAST COAST ON TUESDAY AS A COLD FRONT APPROACHES FROM
THE WEST. THE COLD FRONT WILL CROSS THE AREA ON WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...

615 PM...MINOR ESTF UPDATE TO 1ST PERIOD GRIDS TO INGEST THE 22Z
MESONET. 

PREV DISC...
THE HALLOWEEN FORECAST IS THE LEAST FRIGHTFUL PART OF THE NEXT
SEVERAL DAYS. TONIGHT WILL SEE GRADUALLY INCREASING CLOUD COVER
FROM THE S...WHICH WILL KEEP OVERNIGHT TEMPS ABOVE NORMAL. TRICK
OR TREATERS CAN EXPECT LOW 30S IN THE FAR N...AND UPPER 30S TO
NEAR 40 NEAR THE COAST. WINDS WILL BE MAINLY LIGHT AND VARIABLE
INLAND...GRADUALLY INCREASING FROM THE NE IN THE MORNING.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
THE REAL TRICK OR TREAT COMES WITH A DEVELOPING COASTAL LOW PRES
SYSTEM THAT MODEL GUIDANCE IS STRUGGLING WITH. A POTENT S/WV IS
DIVING THRU THE WRN GREAT LAKES...COMPLETE WITH SOME LIGHTNING
DESPITE SFC TEMPS IN THE 30S. THIS WILL HELP CARVE OUT AN
ANOMALOUSLY DEEP TROF OVER THE ERN CONUS. H5 HEIGHTS WILL BE SOME
-5 STANDARD DEVIATIONS ACROSS PARTS OF THE CAROLINAS. NORMALLY
THIS WOULD BE A SLAM DUNK STORM SYSTEM FOR THE NORTHEAST.
HOWEVER...COMPLICATING THINGS ARE MAXIMA OF FRONT RUNNING
VORTICITY WHICH WILL EJECT OUT OF THE ERN TROF AND FEED OFF THE
STRONG BAROCLINIC ZONE JUST OFF THE COAST. ON SAT CYCLOGENESIS
OCCURS WELL S OF CAPE COD AND MOVES NEWD. THIS WILL SPREAD PCPN
ACROSS NH AND WRN ME DURING THE DAY. THE COMBINATION OF NELY
WINDS...CLOUD COVER...AND PCPN FALLING WILL KEEP TEMPS BELOW
GUIDANCE DURING THE DAY. IT WILL BE A NASTY...COLD RAIN...WITH
INCREASINGLY GUSTY NE WINDS.

SAT NIGHT...COLD AIR STARTS TO POUR IN FROM THE N AS MAIN S/WV
TROF EXITS THE COAST AND BEGINS TO DEVELOP A SECONDARY SFC LOW
PRES. THE MTNS SHOULD SEE PCPN TRANSITION TO SNFL. WHILE THIS
SECOND AREA OF LOW PRES BECOMES DOMINATE...IT APPEARS WE MAY LOSE
SATURATION FOR A TIME LATE SAT AND EARLY SUN. THIS COULD CHANGE
PCPN TO DZ OR FZDZ BRIEFLY DEPENDING ON SFC TEMPS. THE
SECOND...TRAILING LOW PRES IS THE MAIN PLAYER IN QUESTION. AS IT
MAKES ITS CLOSEST APPROACH TO THE COAST...TEMPS WILL BE COLD
ENOUGH FOR SNFL. HOWEVER...ITS CLOSEST APPROACH MAY BE TOO FAR OUT
TO SEA FOR ANY LOCATION TO SEE APPRECIABLE PCPN. THE LEAD WAVE
SHIFTS BAROCLINICITY OFFSHORE...AND LEAVES LITTLE ROOM FOR THE
TRAILING WAVE TO TRACK MORE WWD. THE GREATEST CONCERN ATTM IS FOR
THE MIDCOAST...WHERE EVEN THE DRIEST SCENARIO WOULD PRODUCE AN
INCH OR TWO OF SNOW. IF A SOLUTION LIKE THE 31/12Z GFS PLAYED
OUT...IT WOULD BE CLOSE TO WINTER STORM WARNING CRITERIA. FOR NOW
THE FORECAST USES AN EVEN BLEND OF THE RFC...NAM...GFS...AND ECMWF
QPF. THE RESULT IS 4 TO 6 INCHES OF SNOW FOR WALDO AND KNOX
COUNTIES...BUT CONFIDENCE REMAINS TOO LOW FOR A WATCH ATTM. DURING
THIS TIME PERIOD WE WILL ALSO HAVE TO MONITOR WINDS. ESPECIALLY
THE GFS DEVELOPS A POWERFUL NLY LLJ OVER COASTAL ME. WITH STRONG
WIND SITTING ONLY 1000 FT OFF THE DECK...A SIGNIFICANT PORTION OF
THAT LLJ COULD MIX DOWN...ESPECIALLY AS CAA COMMENCES. SO THERE IS
A NARROW WINDOW FOR 50 TO 60 MPH WIND GUSTS OVER THE COAST AND
WATERS. HOWEVER...THE GFS IS THE ONLY MODEL SHOWING THAT
AGGRESSIVE OF A SCENARIO. THE REMAINING GUIDANCE IS A MORE MODEST
40-45 MPH FOR COASTAL ZONES.

EVENTUALLY SUN WINDS TURN MORE NWLY AS LOW PRES PULLS TOWARDS THE
MARITIMES. THIS WILL BEGIN TO DOWNSLOPE OFF THE HIGH TERRAIN...AND
PCPN WILL COME TO AN END FROM W TO E.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
STRONG SYSTEM WILL BE SLOWLY EXITING NEW ENGLAND SUNDAY
NIGHT. WITH PRECIP TO OUR EAST...WILL THEN BE DEALING WITH GUSTY
WINDS ALBEIT THEY WILL DIMINISH WITH TIME.  

A RIDGE OF HIGH PRESSURE WILL ALLOW FOR DRY CONDITIONS FOR THE
BEGINNING OF THE WORK WEEK. HOWEVER...IT WILL BE CHILLY WITH HIGHS
ONLY IN THE LOWER 40S.

CLOUDS WILL BE ON THE INCREASE ON TUESDAY AS A WARM FRONT CROSSES
THE REGION. THERE MAY BE A CHANCE FOR A SHOWER TUESDAY
NIGHT...ALTHOUGH ANY PRECIP WILL BE LIGHT.  

THERE WILL BE A CONTINUATION OF SCATTERED SHOWERS DURING THE MID
TO LATE WEEK PERIOD. A COLD FRONT WILL CROSS NEW ENGLAND ON
WEDNESDAY...QUICKLY FOLLOWED BY AN APPROACHING COLD FRONT ON
THURSDAY. AN UPPER LEVEL LOW WILL REMAIN OVER THE REGION ON
FRIDAY...KEEPING UNSETTLED WEATHER CONDITIONS IN OUR AREA. A FEW
SNOW SHOWERS CAN BE EXPECTED UP NORTH AS CHILLY CONDITIONS
CONTINUE.

&&

.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR CONDITIONS WILL LINGER INTO TONIGHT...BEFORE MVFR
CIGS BEGIN WORKING NWD INTO THE AREA. SAT GENERALLY EXPECT -RA AND
MVFR CONDITIONS AS LOW PRES WORKS UP THE COAST. NE WINDS WILL ALSO
BEGIN TO INCREASE...BECOMING GUSTY SAT NIGHT AND SUN ESPECIALLY
ALONG THE COAST. AT TIMES 40 KT GUSTS WILL BE POSSIBLE FROM THE
NNE. EARLY SUN PCPN WILL BEGIN TO CHANGE OVER TO SN AT ALL
TERMINALS. HOWEVER...PCPN WILL BE LIGHT FOR MOST AREAS...EXCEPT
FOR KAUG AND KRKD. HERE SOME MINOR ACCUMS ARE POSSIBLE...AND IFR
CONDITIONS ARE LIKELY FOR A TIME SUN. WINDS WILL GRADUALLY TURN
MORE NWLY SUN...AND REMAIN GUSTY.

LONG TERM...MAINLY VFR CONDITIONS THROUGH THE PERIOD.

&&

.MARINE...
SHORT TERM...GALE WARNINGS IN EFFECT FOR ALL WATERS STARTING SAT
AND LASTING THRU THE PERIOD. LATE SAT AND EARLY SUN A BRIEF PERIOD
OF STORM FORCE GUSTS IS POSSIBLE...BUT CONFIDENCE ATTM IS TOO LOW
FOR ANY HEADLINE. WENT WELL ABOVE WAVE HEIGHT GUIDANCE...AS 45 KT
GUSTS WILL ALMOST CERTAINLY PRODUCE NEAR 20 FT SEAS ON THE OUTER
WATERS.

LONG TERM...GALE FORCE WIND CONDITIONS AND LARGE WAVES WILL BE
SUBSIDING EARLY IN THE LONG TERM PORTION OF THE FORECAST.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...GALE WARNING FROM 11 AM EDT SATURDAY TO 4 AM EST MONDAY FOR 
     ANZ150>154.

&&

$$
ES



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