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Area Forecast Discussion
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000
FXUS61 KGYX 210000
AFDGYX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
700 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE BUILDS OVER NORTHERN MAINE SUNDAY...ALLOWING THE
FLOW TO TURN ONSHORE. A WEAK WEATHER DISTURBANCE MAY TRIGGER SOME
FLURRIES OR LIGHT SNOW OVER SOUTHERN REGIONS RIGHT THROUGH MONDAY.
A WEAK AREA OF LOW PRESSURE WILL MOVE UP THE COAST TUESDAY...WITH
A MORE SIGNIFICANT SYSTEM GRADUALLY ORGANIZING WEDNESDAY...BEFORE
MOVING OVER THE GREAT LAKES. THIS COULD BRING WINDY CONDITIONS AND
THE POTENTIAL FOR HEAVY RAIN AROUND CHRISTMAS EVE INTO EARLY
CHRISTMAS MORNING.

&&

.NEAR TERM /TONIGHT/... 
7PM UPDATE...
HAVE UPDATED THE FORECAST TO BRING HOURLY TEMPERATURE TRENDS IN
LINE WITH LATEST OBSERVATIONS. HAVE ALSO MADE SOME MINOR
ADJUSTMENTS TO SKY COVER AND POP. TWO AREAS OF CLOUDS ARE
IMPACTING PARTS OF THE FORECAST AREA THIS EVENING AS SURFACE HIGH
PRESSURE SITS OVER NORTHERN NEW ENGLAND AND SOUTHERN QUEBEC. SOME
LOW CLOUDS HAVE MOVED SOUTHWEST ACROSS MUCH OF MAINE AND ARE NOW
IMPACTING AUGUSTA AND LEWISTON AND POINTS EAST. ANOTHER AREA OF
CLOUDS HAS PUSHED WESTWARD OFF THE WATER OVER SOUTHERN NEW ENGLAND
AND INTO THE SOUTHERN HALF OF NEW HAMPSHIRE. SOME LIGHT SNOW
SHOWERS ALSO ARE DRIFTING IN ON THE ONSHORE FLOW OVER
MASSACHUSETTS AND SOME OF THESE SNOW SHOWERS ARE EXPECTED TO MOVE
NORTH INTO SOUTHERN NEW HAMPSHIRE OVERNIGHT. THESE SNOW SHOWERS
ARE PRIMARILY BEING GENERATED FROM THE ONSHORE FLOW OFF THE OCEAN.
ONLY LIGHT ACCUMULATIONS ARE EXPECTED... UP TO ABOUT AN INCH.

ORIGINAL DISCUSSION...
STRATOCUMULUS CONTINUES TO POUR IN OFF THE GULF OF MAINE LATE
THIS AFTERNOON. SCATTERED SNOW SHOWERS WILL REMAIN OFFSHORE FOR A
FEW MORE HOURS PER LATEST RADAR TRENDS. HOWEVER...SOME
PRECIPITATION WILL BEGIN TO ENTER THE SEACOAST OF NH THIS
EVENING. 12Z MESOSCALE MODEL SUITE CONTINUES TO SHOW THESE SNOW
SHOWERS BECOMING PERSISTENT ENOUGH TO DROP A LIGHT COATING OF SNOW
IN THE MANCHESTER THROUGH PORTSMOUTH CORRIDOR.

WITH MAINLY CLEAR SKIES UP NORTH...EXPECT ANOTHER COLD NIGHT WITH
LOWS IN THE SINGLE NUMBERS. SOME AREAS IN THE NORTH WERE BELOW
ZERO THIS MORNING.

&&

.SHORT TERM /SUNDAY AND SUNDAY NIGHT/... 
SNOW SHOWERS MAY BE PERSISTENT OVER SOUTHERN NEW HAMPSHIRE EARLY
SUNDAY DUE TO OCEAN EFFECT...WITH DRYING OCCURRING DURING THE
AFTERNOON. THE PASSAGE OF A WEAK UPPER LEVEL LOW OVER EASTERN
AREAS MAY BRING A SNOW SHOWER OR TWO TO THE MIDCOAST AREA OF
MAINE.

SOME CLEARING WILL OCCUR SUNDAY NIGHT AS THE WEAK SYSTEM SHIFTS TO
THE EAST. HOWEVER...A LOW LEVEL NORTHEAST FLOW WILL CONTINUE...WHICH
WILL ALLOW FOR THE POSSIBILITY OF A LIGHT SNOW SHOWER ALONG THE
COAST AND SOME LOW CLOUDINESS. THIS WILL KEEP MINIMUM TEMPERATURES
ALONG THE COAST IN THE MID TO UPPER 20S...WHILE THE MOUNTAINS DROP
OFF INTO THE LOWER TO MIDDLE TEENS.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
THE WEAK ONSHORE FLOW CONTINUES MONDAY INTO TUESDAY WITH LOW
LEVEL MOISTURE DEEPEST ALONG THE COAST. SOME PERIODS OF LIGHT SNOW
OR DRIZZLE OR EVEN SOME FREEZING DRIZZLE ARE POSSIBLE MONDAY AND
MONDAY NIGHT. ON TUESDAY THE WARMER ONSHORE FLOW DEEPENS AS THE
HIGH MOVES FURTHER OFFSHORE ALLOWING A SOUTHEAST FLOW TO
INCREASE...SO CANNOT RULE OUT SOME LIGHT INTERMITTENT
PRECIPITATION. THE MAIN EVENT WILL BE THE ONSET OF THE HEAVIER
PRECIPITATION LATE CHRISTMAS EVE AND ESPECIALLY CHRISTMAS DAY AND
NIGHT WHERE THE RAIN WILL BECOME HEAVY AT TIMES AS A STRONG WARM
ADVECTION PATTERN DEVELOPS BEING ACCOMPANIED BY A STRONG LOW/MID
LEVEL JET. THE MAIN UPPER LOW PASSES WELL TO OUR WEST AS IT MOVES
THROUGH THE GREAT LAKES. QPF TOTALS FOR LATE TUESDAY INTO THURSDAY
COULD BE IN THE 2-4 INCH RANGE. DUE TO VERY WARM AIR THIS WILL BE
IN THE FORM OF RAIN EVEN IN THE MOUNTAINS. SOME FLOODING PROBLEMS
MAY ARISE IN THE HEADWATERS BY WEDNESDAY NIGHT OR THURSDAY DUE TO
THE COMBINATION OF SNOWMELT AND THE HEAVY RAINS. ALL MODELS AGREE
ON MILD TEMPERATURES...USED A BLEND OF THE MODELS.

SYSTEM FINALLY WINDS DOWN BY THURSDAY AFTERNOON AS A DRY SLOT
MOVES ACROSS THE AREA. 

ANOTHER SYSTEM WHICH WILL BE WEAKER APPROACHES FOR THE WEEKEND
WHICH ALSO LOOKS WARM AND WET.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...IFR CLOUD DECK IS ADVANCING SOUTHWEST ACROSS MUCH OF
MAINE THIS EVENING. THIS WILL PRIMARILY IMPACT AUGUSTA AND
ROCKLAND BUT COULD IMPACT PORTLAND AS WELL. ANOTHER AREA OF
MVFR/VFR CLOUDS ARE IMPACTING SOUTHERN NEW HAMPSHIRE AND MAY LOWER
A BIT INTO THE MVFR TO IFR RANGE OVERNIGHT. SOME LIGHT SNOW
SHOWERS ARE ALSO POSSIBLE ACROSS SOUTHERN NEW HAMPSHIRE INCLUDING
AT PORTSMOUTH AND MANCHESTER OVERNIGHT INTO SUNDAY MORNING.

LONG TERM...POSSIBLE PERIODS OF MVFR TO IFR AT COASTAL TERMINALS
MONDAY AS INVERTED TROUGH DEVELOPS ACROSS THE GULF OF MAINE. MVFR
LIKELY TO HOLD TUESDAY INTO TUESDAY NIGHT...LOWERING TO IFR LATE
TUESDAY NIGHT INTO THURSDAY IN RAIN...WITH INCREASING E-SE WINDS
WEDNESDAY.

&&

.MARINE...
SHORT TERM...A FEW WIND GUSTS CONTINUE JUST BELOW 25 KTS THIS
AFTERNOON...WITH WAVES 4' OR LOWER...THEREFORE NO FLAGS IN THE
NEAR TERM. WINDS SHOULD CONTINUE TO SLOWLY DECREASE TONIGHT INTO
TOMORROW FROM THE NORTHEAST.

LONG TERM...STRONG LOW PRESSURE WILL MOVE WELL TO THE WEST AND
WILL CAUSE WINDS TO INCREASE TO GALES TUESDAY NIGHT THROUGH
WEDNESDAY WITH BORDERLINE STORM FORCE WINDS POSSIBLE WEDNESDAY
NIGHT. SEAS COULD BUILD IN EXCESS OF 15 FT OVER THE OUTER WATERS
BY WEDNESDAY NIGHT. GUIDANCE LOOKS LOW ON BOTH WINDS AND SEAS
WHICH IS TYPICAL FOR THESE TYPE OF EVENTS.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$

NEAR TERM UPDATE... KIMBLE



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