FXUS61 KGYX 072045
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
345 PM EST MON DEC 7 2009

.SYNOPSIS...
WEAK LOW PRESSURE OVER THE NORTHERN PLAINS WILL RACE EASTWARD
TONIGHT PRODUCING A FEW SNOW SHOWERS WITH SOME LIGHT ACCUMULATION
POSSIBLE FOR MOUNTAIN SECTIONS. HIGH PRESSURE WILL BUILD OVER THE
AREA TUESDAY AND TUESDAY NIGHT. A WARM FRONT EXTENDING FROM LOW
PRESSURE OVER THE GREAT LAKES WILL APPROACH THE REGION LATE
TUESDAY NIGHT AND WEDNESDAY. THIS WILL BRING SNOW...RAIN...SLEET AND
GUSTY WINDS NEAR THE COAST. AS THE FRONT PASSES WEDNESDAY
EVENING...THE PRECIPITATION WILL TAPER OFF LATER AT NIGHT. HIGH
PRESSURE BUILDING IN BEHIND THE SYSTEM THURSDAY AND FRIDAY WILL
BRING BLUSTERY AND COLDER CONDITIONS TO NORTHERN NEW ENGLAND.

&&

.NEAR TERM /TONIGHT/...LIGHT SNOW SHOWERS WERE OVERSPREADING THE
AREA THIS AFTERNOON AS THE ASSOCIATED SHORTWAVE CONTINUED TO SHEAR
EASTWARD ACROSS UPSTATE NEW YORK. THE MAIN SNOWFALL WILL TARGET
UPSLOPE AREAS OF THE HIGHER TERRAIN. SNOWFALL AMOUNTS WILL BE IN
THE 1 TO 3 INCH RANGE AT THEIR GREATEST IN NORTHERN NEW HAMPSHIRE.

THE LOW-LEVEL REFLECTION OF THIS WAVE WILL RESULT IN INTENSIFYING
LOW PRESSURE IN THE COASTAL WATERS TONIGHT WITH SOME LIGHT
PRECIPITATION WHICH SHOULD NOT CAUSE ANY PROBLEMS ON LAND.

OTHERWISE WINDS SHOULD BE LIGHT WITH TEMPERATURES STEADY IN THE
20S TO LOWER 30S.

&&

.SHORT TERM /TUESDAY/...WEAK HIGH PRESSURE CRESTS ACROSS NEW
ENGLAND TUESDAY AFTERNOON WITH CLEARING SKIES THROUGH THE
AFTERNOON. TEMPERATURES SHOULD BE SOME 5-8F WARMER THAN TODAY'S READINGS. 

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
THE MAIN EVENT WILL BE WEDNESDAY AND WEDNESDAY NIGHT...WITH THE
POTENTIAL FOR A HIGH IMPACT EVENT WITH REGARD TO SNOW INLAND AND
WIND CLOSER TO THE COAST. AFTER THAT...COLD AND BLUSTERY CONDITIONS
INTO THE UPCOMING WEEKEND WITH THE COLDEST AIR SO FAR THIS SEASON.

MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE MASS FIELDS FOR
TUESDAY NIGHT INTO WEDNESDAY NIGHT...AND THERE IS BETTER CONFIDENCE
IN THE OVERALL SYNOPTIC SETUP. THE COLUMN STARTS COLD AND DRY AND
MOISTENS IN THE INCREASING WARM AIR ADVECTION. 12Z MODELS RUNS
SEEM TO BRING THE PRECIP IN SLIGHTLY FASTER THAN PREV RUNS...AND
HAVE INTRODUCED SOME CHC POPS AFTER MIDNIGHT WED FOR SRN TIER OF NH
ZONES.

WARM AIR ADVECTION BECOMES VERY IMPRESSIVE WEDNESDAY MORNING
AHEAD OF A WARM FRONTAL OCCLUSION EXTENDING FROM DEEP LOW PRESSURE
OVER THE GREAT LAKES. THE FRONTOGENETIC FORCING BETWEEN 850-700 MB
PEAKS ACROSS NEW HAMPSHIRE AND SOUTHWEST MAINE LATE WEDNESDAY
MORNING AND EARLY WEDNESDAY AFTERNOON. WOULD EXPECT TO SEE A
FRONTOGENETICALLY FORCED BAND OF MODERATE TO HEAVY PRECIPITATION
TO DEVELOP SOMEWHERE IN THE SRN 2/3 OF THE CWA.

AS MENTIONED EARLIER...THE COLUMN STARTS COLD...AND THIS SHOULD RESULT
IN THE PRECIPITATION STARTING AS SNOW IN ALL AREAS. HOWEVER...WITH
THE SURFACE FRONT TO THE SOUTH...THE BOUNDARY LAYER WILL BECOME
THE PROBLEM FOR PRECIPITATION TYPE NEAR THE COAST. THE BANDED SNOW
MAY PRODUCE ADVISORY LEVELS SNOWS NEAR THE COAST BEFORE THE
BOUNDARY WARMS. FURTHER INLAND...ACROSS THE FOOTHILLS AND
MOUNTAINS...THIS PROCESS WILL BE DELAYED...OR PERHAPS NOT EVEN
OCCUR AT ALL...AS MODELS HINT AS SOME WEAK COLD AIR DAMMING...THIS
COULD LEAD TO SIGNIFICANT SNOWFALL IN THESE AREAS. 

WIND FORECASTS SEEM TO MORE PROBLEMATIC...AS THEY WILL HINGE ON
WHEN AND WHERE TRIPLE POINT...OR PERHAPS WEAK COASTAL
LOW...DEVELOPS...AND WHETHER THIS WILL INTERRUPT THE STRONG
GRADIENT THAT DEVELOPS BETWEEN HIGH TO THE NE AND LOW TO THE WEST.
FOR NOW...HAVE TAKEN A MID-POINT BETWEEN THE STRONGER WINDS OF THE
GFS...AND THE LESSER WINDS OF THE NAM. THE AFTERNOON TIDE
WEDNESDAY WOULD BE A TIDE THAT WOULD NEED TO BE WATCHED. WHILE THE
ASTRONOMICAL TIDE IS RELATIVELY LOW (9.5 FT AT PORTLAND)...A STORM
SURGE PRODUCED BY STRONG WINDS AND PRESSURE FALLS...COMBINED WITH
BUILDING SEAS...COULD RESULT IN SPLASHOVER.

THE HEAVIEST PRECIPITATION SHOULD END WITH THE PASSAGE OF THE OCCLUSION
WEDNESDAY NIGHT FROM SOUTHWEST TO NORTHEAST. AFTER THIS...THE MAIN
SYNOPTIC LIFT MOVES THROUGH BEFORE 0600 UTC THURSDAY. MAINTAINED A
MENTION OF PRECIPITATION FOR ALL AREAS...WITH SOUTHERN ZONES
HAVING THE LOWEST CHANCE OF RAIN. WEST WINDS COULD BECOME GUSTY AS
THE MIXED LAYER INCREASES BEHIND THE FRONT AND 40 KNOTS WOULD BE
AVAILABLE AT THE TOP OF THE INVERSION.

CYCLONIC FLOW WILL RESULT IN CLOUDS WITH UPSLOPE SNOW SHOWERS
LATER WEDNESDAY NIGHT AND THURSDAY. AFTER THIS...BLUSTERY AND
COLDER FOR THE WEEKEND.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 23Z TUESDAY/...VFR. AREAS OF MVFR CEILINGS AND
VSBYS EXPECTED MAINLY IN THE HIGHER TERRAIN WITH SNOW SHOWERS
THROUGH EARLY TUESDAY MORNING.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...VFR CONDITIONS
TUESDAY NIGHT WILL DETERIORATE DURING WED MORNING AS SNOW WORKS
IN FROM SOUTHWEST TO NORTHEAST. ALL TERMINALS SHOULD BE LIFR WITH
PRECIPITATION AND LOW CEILINGS BEFORE MIDDAY. LOW LEVEL WIND SHEAR
IS POSSIBLE WEDNESDAY...WITH WINDS GUSTING NEAR 35 KNOTS AT KPWM
AND KPSM INTO WEDNESDAY EVENING.

AFTER THE WARM FRONT OR OCCLUSION PASSES WEDNESDAY EVENING...THE
PRECIPITATION WILL START TO TAPER OFF...BUT LOW CEILINGS ARE EXPECTED
THROUGH 1200 UTC THURSDAY. BEHIND THE FRONT...SOUTHWEST WINDS MAY
GUST TO 25 KNOTS WEDNESDAY NIGHT AT KPWM...KPSM AND KAUG.

AS LOW PRESSURE MOVES INTO THE MARITIMES AND HIGH PRESSURE BUILDS
EAST FROM THE OHIO VALLEY...VFR CONDITIONS SHOULD RETURN TO ALL
TERMINALS THURSDAY. THE EXCEPTION COULD BE KLEB...WHERE THE UPSLOPE
FLOW COULD KEEP MVFR CONDITIONS IN PLACE MUCH OF THE DAY. WEST
WINDS WILL GUST TO 25 TO 30 KNOTS THURSDAY AT ALL TERMINALS...AND
THE GUSTINESS MAY PERSIST INTO FRIDAY.

&&

.MARINE...

SHORT TERM /TONIGHT AND TUESDAY/...NO HEADLINES THROUGH TUESDAY.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...AS LOW PRESSURE SPINS
ACROSS THE GREAT LAKES...THE GRADIENT TIGHTENS QUICKLY AHEAD OF
THE WARM FRONT OR OCCLUSION ACROSS CENTRAL NEW ENGLAND WEDNESDAY
MORNING. THE TIGHTEST GRADIENT SHOULD OCCUR BETWEEN 18Z WEDNESDAY
AND 00Z THURSDAY...JUST AHEAD OF THE OCCLUSION. 12 GFS AND NAM
HAVE FLIP-FLOPPED AND NOW THE GFS SHOWS THE STRONGEST
WINDS...WITH THE NAM LESS IMPRESSIVE. EITHER WAY GALES LOOK LIKE A
GOOD BET...WITH THE POSSIBILITY OF STORM FORCE GUSTS.

AS THE OCCLUSION PASSES...THERE WILL BE A LULL IN THE WINDS AS THE
GRADIENT BECOMES BAGGY...BUT THE DEPTH OF THE MIXED LAYER
INCREASES DRAMATICALLY BEHIND THE FRONT...AND GALE FORCE WINDS
LOOK LIKELY FOR LATER WEDNESDAY NIGHT INTO THURSDAY. AS THE LOW
TRACKS INTO THE MARITIMES AND HIGH PRESSURE APPROACHES FROM THE
OHIO VALLEY...GALE FORCE WINDS COULD CONTINUE INTO FRIDAY.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...GALE WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY MORNING FOR 
     ANZ150>154.

&&

$$
SYNOPSIS...CEMPA
NEAR TERM...STJEAN
SHORT TERM...STJEAN
LONG TERM...CEMPA
AVIATION...STJEAN/CEMPA
MARINE...STJEAN/CEMPA