799
FXUS61 KGYX 200327
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1027 PM EST THU DEC 19 2024
SYNOPSIS
COOLER AIR COMES IN BEHIND EXITING LOW PRESSURE WITH UPSLOPE
SNOW SHOWERS IN THE MOUNTAINS TONIGHT. A WEAK CLIPPER PASSES
THROUGH FRIDAY NIGHT, WITH VERY COLD AIR MOVING INTO NEW ENGLAND
FOR THE WEEKEND. ALTHOUGH IT WILL GRADUALLY MODERATE TO NEAR
NORMAL BY THE MIDDLE OF NEXT WEEK, AS STRONG HIGH PRESSURE
SETTLES OVER THE REGION.
NEAR TERM /UNTIL 6 AM FRIDAY MORNING/
1015 PM UPDATE...NO CHANGES TO THE GOING FORECAST FOR THE REST
OF THE OVERNIGHT. WILL HAVE TO CONTINUE TO WATCH FOR WEAK
FORCING FOR ASCENT COMBINED WITH HIGH S/LIQ RATIOS ON FRIDAY
AFTERNOON AND EVENING THAT COULD MAKE FOR SOME LOCALLY SLICK
CONDITIONS IN LIGHT SNOW.
610 PM UPDATE...LITTLE CHANGE TO THE GOING FORECAST THIS EVENING
WITH VARIABLY CLOUDY SKIES AND DRY WEATHER EXPECTED. DID RAISE
POPS TO LIKELY FOR SOUTHWESTERN AND WESTERN NH FOR FRIDAY
AFTERNOON AS A MULTI-MODEL CONSENSUS INDICATES WIDESPREAD
MEASURABLE SNOW, EVEN IF VERY LIGHT.
PREVIOUSLY...
A NORTHWEST GRADIENT OVER THE AREA WILL SLACKEN THROUGH THIS EVENING
AS HIGH PRESSURE SLIDES EAST ACROSS QUEBEC. THIS WILL ALLOW FOR
NW WINDS TO SUBSIDE AND UPSLOPE SNOW SHOWERS IN THE MOUNTAINS
GRADUALLY DIMINISHING OVERNIGHT. SKIES TONIGHT WILL BE PARTLY
CLOUDY TURNING MOSTLY CLOUDY SW TO NE AS A SYSTEM APPROACHES
FROM THE GREAT LAKES.
SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/
LATEST WATER VAPOR IMAGERY SHOWS A PAIR OF SHORT WAVES TRACKING ESE
ACROSS THE UPPER MIDWEST AND GREAT LAKES. THE 12Z MODEL SUITE IS IN
DECENT AGREEMENT THAT THESE SHORT WAVES WILL TAKE ON A MORE
SOUTHEASTERLY TRAJECTORY TOMORROW AND WILL INTERACT WITH A
STALLED FRONTAL SYSTEM OFF THE CAROLINA COASTLINE. THE MAJORITY
OF MODEL SOLUTIONS INDICATE THIS INTERACTION WILL RESULT IN A
DEEPENING LOW PRESSURE SYSTEM TRACKING SE OF THE 40N/70W
BENCHMARK FRIDAY NIGHT. ALL THE WHILE, ADDITIONAL SHORT WAVE
ENERGY WILL BE DIVING SOUTHEAST OUT OF ONTARIO SPREADING MODEST
DPVA ACROSS THE FORECAST AREA. WHILE THE DEEPENING LOW PRESSURE
SYSTEM IS FORECAST TO TRACK TOO FAR OFFSHORE THE SPREAD MUCH IN
THE WAY OF SNOW INTO THE REGION THERE WILL BE MODEST VERTICAL
VELOCITIES OVER THE AREA FROM THE DPVA TO BRING AREAS OF LIGHT
SNOW. MESOSCALE MODELS HAVE ALSO SHOWN A SIGNAL FOR SOME OCEAN
ENHANCEMENT ALONG COASTAL SW MAINE AND NH SEACOAST FRIDAY
EVENING. HAVE GENERALLY GONE WITH CHANCE POPS ACROSS MUCH OF THE
AREA BY FRIDAY AFTERNOON AND CONTINUING CHANCE POPS THROUGH
FRIDAY NIGHT. QPF IS GENERALLY LIGHT ENOUGH FOR THE SNOWFALL
FORECAST TO REMAIN AROUND AN INCH OR LESS ACROSS MUCH OF THE
AREA WITH AMOUNTS CLOSER TO 2 INCHES ALONG THE NH SEACOAST.
OTHERWISE, IT WILL BE A MOSTLY CLOUDY DAY WITH INCREASING
NORTHEAST WINDS AND HIGHS IN THE 20S TO LOW 30S.
CHANCES FOR LIGHT SNOW WILL CONTINUE THROUGH FRIDAY NIGHT. AS
THE OFFSHORE SYSTEM CONTINUES TO DEEPEN THE WILL BE AN INCREASE
IN NORTHERLY WINDS WITH GUSTS AROUND 20 MPH ALONG THE COASTAL
PLAIN. LOWS FRIDAY NIGHT WILL RANGE FROM THE TEENS NORTH TO 20S
SOUTH.
LONG TERM /SATURDAY THROUGH THURSDAY/
STRONG COLD AIR ADVECTION WILL BE IN FULL MODE DURING THE DAY
ON SATURDAY. NEVERTHELESS, WE DO NOT START OUT THE DAY ALL THAT
COLD ALLOWING TEMPERATURES TO REMAIN MOSTLY IN THE 20S NORTH TO
THE LOWER 30S SOUTH. HIGH PRESSURE BUILDS TOWARDS THE REGION
SATURDAY NIGHT WITH BREEZY CONDITIONS ALLOWING FOR A WELL MIXED
LAYER. TEMPERATURES WILL STILL FALL TO NEAR ZERO IN THE NORTH
WITH SINGLE DIGITS IN THE SOUTH. WIND CHILL VALUES WILL BE BELOW
ZERO IN ALL AREAS BY MORNING.
DESPITE LOW PRESSURE INTENSIFYING AND PASSING WELL TO OUR EAST, SNOW
SHOWERS WILL CROSS THE REGION ON SATURDAY. THIS WILL MAINLY BE
DUE TO FORCING FROM AN UPPER LEVEL TROUGH CROSSING THE REGION.
THE HIGHEST CHANCE FOR PRECIPITATION WILL BE IN THE NORTHERN,
HIGHER TERRAIN.
BY SUNDAY AND SUNDAY NIGHT, THE CORE OF THE COLDEST AIR OF THE
SEASON WILL BE OVER THE REGION. SOME AREAS WILL UNDERGO RADIATIONAL
COOLING SUNDAY NIGHT, ALLOWING FOR TEMPERATURES TO DROP TO ZERO TO
10 BELOW IN THE NORTH AND SINGLE DIGITS IN THE SOUTH.
12Z MODELS AND LATEST ENSEMBLE SOLUTIONS SUGGEST THE DRY PATTERN
CONTINUES EARLY NEXT WEEK WITH HIGH PRESSURE IN CONTROL OVER THE
NORTHEAST. THIS WILL ALLOW FOR WEAK WEATHER SYSTEMS TO PASS BY TO
OUR SOUTH.
AVIATION /04Z FRIDAY THROUGH TUESDAY/
SHORT TERM...MAINLY VFR TONIGHT INTO FRIDAY WITH NW WINDS
RELAXING OVERNIGHT. CLOUDS WILL THICKEN AND LOWER THROUGH THE
DAY FRIDAY WITH AREAS OF LIGHT SNOW OVERSPREADING THE AREA BY
FRIDAY AFTERNOON. THIS WILL LIKELY BRING PERIODS OF MVFR THROUGH
FRIDAY NIGHT.
LONG TERM...MVFR AND IFR CONDITIONS EXPECTED IN SNOW SHOWERS MAINLY
IN THE NORTH ON SATURDAY. OTHERWISE, HIGH PRESSURE GRADUALLY BUILDS
INTO THE REGION DURING THE PERIOD WITH VFR CONDITIONS AND DOWNSLOPE
WINDS OVER MUCH OF THE AREA
MARINE
SHORT TERM...NW WINDS WILL CONTINUE TO BRING SCA CONDITIONS
THROUGH THIS EVENING WITH WINDS AND SEAS DROPPING BELOW SCA
THRESHOLDS TONIGHT THROUGH FRIDAY MORNING. LOW PRESSURE PASSING
SOUTHEAST OF THE GULF OF MAINE LATE FRIDAY INTO SATURDAY MORNING
WILL BRING INCREASING NE WINDS WITH SCA CONDITIONS LIKELY.
LONG TERM...WINDS AND SEAS WILL ONCE AGAIN EXCEED SCA THRESHOLDS
OVER THE WEEKEND. WINDS WILL BACK OUT OF THE NORTH BEFORE
BECOMING NORTHWESTERLY.
GYX WATCHES/WARNINGS/ADVISORIES
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON FRIDAY TO 3 PM EST SUNDAY FOR
ANZ150-152-154.
SMALL CRAFT ADVISORY FROM 5 PM FRIDAY TO 3 AM EST SUNDAY FOR
ANZ151-153.
SYNOPSIS...
NEAR TERM...EKSTER/SCHROETER
SHORT TERM...SCHROETER
LONG TERM...CANNON
AVIATION...
MARINE...
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