FXUS61 KGYX 250756
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
256 AM EST FRI DEC 25 2009
.SYNOPSIS...
HIGH PRESSURE WILL CREST OVER THE REGION TODAY AND WILL SHIFT EAST
OF THE REGION TONIGHT. AN OCCLUDED FRONT WILL APPROACH FROM THE
SOUTHWEST SATURDAY AND WILL CROSS THE AREA ON SUNDAY. A WEAK RIDGE
OF HIGH PRESSURE WILL BUILD OVER THE AREA SUNDAY NIGHT. AN ARCTIC
FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND WILL CROSS THE
REGION MONDAY NIGHT. A STRONG NORTHWEST FLOW WILL PERSIST BEHIND
THE FRONT TUESDAY THROUGH WEDNESDAY AS HIGH PRESSURE SLOWLY BUILDS
IN FROM THE WEST. HIGH PRESSURE WILL CREST OVER THE REGION ON
THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
HIGH PRESSURE CRESTS OVER THE REGION TODAY BUT LOW LEVEL MOISTURE
WILL COMPLICATE THE FORECAST. SHARP INVERSION BETWEEN 1 AND 2 KFT
TRAPPING MOIST NORTHERLY FLOW BENEATH IT. MUCH OF THIS CLOUDINESS
HOLDING OVER THE MOUNTAINS AND CONNECTICUT VALLEY BUT LATEST SAT
PICS SHOWING LOW CLOUDS DEVELOPING OVER SOUTHERN MAINE AND CENTRAL
NEW HAMPSHIRE AND EXPECT THIS TREND TO CONTINUE THROUGH THE EARLY
MORNING HOURS. BIG QUESTION IS HOW MUCH OF THIS SHALLOW MOIST
LAYER BURNS OFF DURING THE DAY. NOT READY TO ACCEPT THE TOTAL
CLOUD COVER ADVERTISED BY THE NAM AND WILL BE TRENDING THE
FORECAST AFTER THE MORE OPTIMISTIC GFS. EXPECT THE BULK OF THIS
MOISTURE TO REMAIN BANKED WEST OF THE MOUNTAINS TODAY WITH PATCHES
OF MORNING CLOUDS THINNING IN DOWNWIND LOCATIONS. LOOKING FOR
ANOTHER MILD DAY WITH READINGS IN THE 30S TO NEAR 40.
&&
.SHORT TERM /TONIGHT/...
EXPECT LOW CLOUDS TO REFORM THIS EVENING ALONG WITH INCREASING MID
AND HIGH LEVEL MOISTURE AS OCCLUSION APPROACHES FROM THE
SOUTHWEST. SOME WEAK MID LEVEL OVER-RUNNING PUSHES INTO SOUTHWEST
ZONES AFTER MIDNIGHT BUT NOT LOOKING FOR MUCH IF ANYTHING IN THE
WAY OF PRECIPITATION CONSIDERING VERY DRY AIRMASS IN PLACE ABOVE
THE INVERSION. GENERALLY SATISFIED WITH SLIGHT CHANCE POPS OFFERED
BY THE GFS FOR LATE TONIGHT.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
A LARGE SURFACE CYCLONE WILL BE IN THE PROCESS OF FILLING OVER
THE UPPER MIDWEST ON SATURDAY AS A POTENT 5H CLOSED LOW MOVES ENE.
AS THIS OCCURS...SECONDARY CYCLOGENESIS WILL OCCUR ALONG THE
ATLANTIC COAST. THIS DEEPENING COASTAL LOW WILL ENCOURAGE ONSHORE
FLOW...WITH PW VALUES JUST OVER 2 STANDARD DEVIATIONS ABOVE NORMAL
BY SUN MORNING. THE STRONGEST ISENTROPIC LIFT WILL OCCUR OVER THE
COASTAL ZONES AS AN OCCLUDED FRONT MOVES NORTH.
THE ATMOSPHERE AT THE ONSET OF THE EVENT ON SATURDAY NIGHT LOOKS
COLD ENOUGH FOR SNOW. HOWEVER...AS THE LOW LEVEL WARM ADVECTION
OVERSPREADS THE REGION...A MIX OF RAIN...SNOW...SLEET...AND
FREEZING RAIN WILL BE POSSIBLE. DURING THE DAY SUN THE MIXED
PRECIP WILL BE CONFINED TO THE MOUNTAINS WHERE THE COLDER AIR WILL
BE TRAPPED. ALTHOUGH THE MODELS ARE SHOWING BIG DIFFERENCES AS FAR
AS THE AMOUNT AND PLACEMENT OF THE QPF...AT THIS POINT IT LOOKS
LIKE A HALF INCH TO AN INCH OF PRECIP IS POSSIBLE FOR MUCH OF
THE AREA ON SUNDAY. PRECIP WILL CHANGE OVER TO ALL SNOW ONCE AGAIN
SUNDAY NIGHT WITH ONLY CHANCE POPS IN PLACE.
BY MONDAY NIGHT...ANOTHER SHORTWAVE MOVING THRU THE UPPER TROUGH
WILL PUSH A STRONG ARCTIC COLD FRONT THRU NEW ENGLAND. MOISTURE
WILL BE MORE LIMITED WITH THIS BOUNDARY...SO NOT EXPECTING AS MUCH
QPF AS SUNDAY'S SYSTEM. TEMPERATURES FOR TUE THRU THU WILL BE
COLD...WITH TEENS AND 20S FOR HIGHS AND NEGATIVE SINGLE DIGITS TO
SINGLE DIGITS FOR LOWS. HIGH PRESSURE WILL BUILD IN FOR THE END OF
THE WEEK HELPING TO MODERATE TEMPERATURES.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...IFR/MVFR CEILINGS MAINLY IN THE CONNECTICUT VALLEY
AND NORTH THIS MORNING BECOMING VFR. IFR/MVFR CEILINGS REFORM
THROUGHOUT THE REGION TONIGHT.
LONG TERM...MVFR TO IFR CONDITIONS LATE SAT INTO SUN FOR ALL SITES
IN SN AND RA...WITH LEB AND CON POSSIBLE SEEING OTHER TYPES OF
FROZEN PRECIP. CONDITIONS WILL IMPROVE SOME LATE SUNDAY WITH
LINGERING PRECIP POSSIBLE.
&&
.MARINE...
SHORT TERM...DROPPING SCA FOR SEAS.
LONG TERM...SCA MAY BE NEEDED LATE SAT THRU SUN IN HIGH SEAS AND
INCREASING ESE WINDS. SCA OR EVEN GALE POSSIBLE FOR MON NIGHT INTO
TUE FOR STRONG W WINDS BEHIND AN ARCTIC FRONT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
SINSABAUGH/HANES
