534
FXUS61 KGYX 201549
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
1049 AM EST FRI DEC 20 2024
SYNOPSIS
A WEAK CLIPPER PASSES NORTH OF THE AREA TODAY AND TONIGHT,
WHILE ANOTHER LOW PASSES WELL OFFSHORE TONIGHT, BRING SOME SNOW
SHOWERS OR LIGHT SNOW. VERY COLD AIR MOVES INTO NEW ENGLAND
SATURDAY NIGHT AND SUNDAY. 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 PM THIS EVENING/
1045AM...PRIMARY FOCUS WITH THIS UPDATE IS ON POPS/QPF/SNOW
AMOUNTS THIS AFTERNOON, ESPECIALLY ACROSS SE NH AND SW MAINE. TO
OUR SOUTH, THERE IS A STEADY STREAM OF SNOW SHOWERS ALREADY
MOVING ONSHORE OVER PORTIONS OF COASTAL MA ASSOCIATED WITH AN
INVERTED TROUGH, AND RADAR TRENDS WILL HAVE TO BE WATCHED
CLOSELY AS THE INVERTED TROUGH IS EXPECTED TO LIFT NORTHWARD
LATER TODAY. THE NAMNEST SEEMS TO HAVE A FAIRLY GOOD HANDLE ON
THE CURRENT SITUATION AS WELL AS THE RAP, AND I HAVE TRENDED THE
FORECAST IN THAT DIRECTION. THIS BRINGS HIGHER POPS/SNOW
AMOUNTS INTO PORTIONS OF THE SEACOAST AND COASTAL YORK WITH 1-3"
AND SLIPPER TRAVEL POSSIBLE DURING THE AFTERNOON AND EVENING
COMMUTE. IF THE NAMNEST IS REALLY ON TO SOMETHING, THE
ADDITIONAL QPF AND HIGH SNOW RATIOS COULD ADDED A COUPLE MORE
INCHES ON TOP OF THIS EVEN...BUT AGAIN WILL HAVE TO FOLLOW THE
TRENDS CLOSELY.
PREVIOUS...
640 AM...NO CHANGES TO THE OVERALL FORECAST FOR TODAY, JUST
SOME MINOR CHANGES THIS MORNING BASED ON OBS. STILL SOME
POSSIBILITY OF LOCALIZED HIGHER ACCUMS SOMEWHERE ON THE COAST IF
INVERTED TROUGH DEVELOPS GIVEN THE HIGH FLUFF FACTOR, BUT NO
CLEAR SIGNALS SHOWING UP YET.
PREVIOUSLY...500MB TROUGH EXTENDING FROM JAMES BAY SOUTHWARD
TOWARD THE GREAT LAKES THIS MORNING, AND SRN STREAM WAVE DIVING
OUT OF THE LOWER OHIO VALLEY TOWARD THE CAROLINA COAST ARE OUR
TWO SYSTEMS OF INTEREST TODAY AND TONIGHT, ALTHOUGH THEY NEVER
QUITE GET TOGETHER TO PHASE, THERE WILL BE SOME INTERACTION
BETWEEN THAT WILL BRING LIGHT SNOW OR SHSN TO THE REGION THIS
AFTERNOON INTO TONIGHT. THE SRN STREAM WILL SEE A DEVELOPING
COASTAL LOW OFF THE MID-ATLANTIC COAST, THAT TRACKS WELL
OFFSHORE TO A POINT S OF NOVA SCOTIA BY SATURDAY MORNING. THIS
SHOULD BRING SOME LIGHT SN OR SNOW SHOWERS INTO S NH AND ALONG
THE ME COAST DURING THE AFTERNOON. MEANWHILE THE BROADER TROUGH
TO OUR W WILL BRING SOME SHSN INTO THE MTNS, AND THE CT VLY THIS
AFTERNOON AS WELL. NONE OF THIS WILL BE SIGNIFICANT BUT IT WILL
IMPACT THE EVENING COMMUTE. COULD SEE UP TO AN INCH OF SNOW IN
SE NH AND ALONG THE ME COAST S OF PORTLAND BY SUNSET, WITH SOME
LOCALIZED COATINGS OF SNOW IN MOST OTHER SPOTS, ALTHOUGH EASTERN
ZONES MAY BOT SEE MUCH SNOW UNTIL SUNSET. IT’LL GENERALLY BE
CLOUDY ALL DAY, AND HIGHS WILL RANGE FROM THE LOW TO MID 20S IN
THE N TO AROUND 30 IN THE S.
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/
THE OFFSHORE LOW DEEPENS THOUGH TONIGHT, BUT ALSO TRACK NE AND
FURTHER AWAY FROM THE CWA OVERNIGHT. THIS SHOULD BRING ANY SNOW
TO AN END ACROSS ALL BIT THE MID COAST AND CAPITAL DISTRICT
BEFORE MIDNIGHT, BUT IN THAT AREA, COULD SEE A PERIOD OF LIGHT
SNOW DEVELOP LATER THIS EVENING AND OVERNIGHT CLOSER TO THE LOW.
HERE COULD GET AN INCH OR TWO IN SOME SPOTS TONIGHT. OTHERWISE
WINDS SHIFT FROM NE TO NW IN THE NH AND W ME, WHICH WILL SEE
UPSLOPE SHSN REDEVELOP IN THE MTNS AND END THE SNOW IN THE
DOWNSLOPE AREAS. LOW DROP TO 10-15 IN THE MTNS, TO AROUND 20 IN
THE S, ALTHOUGH SOME LOW TO MID 20S ALONG MID COAST WITH THE
SNOW AND CLOUDS IN PLACE. HIGHS WILL MAINLY BE IN THE IN THE 20S
TO AROUND 30 IN SE NH AND ON THE COAST, WITH PARTLY SUNNY
SKIES.
ON SATURDAY SHOULD SEE SNOW END EVERYWHERE BUT THE MOUNTAINS
WHERE THE UPSLOPE SHSN WILL CONTINUE WITH SOME LIGHT ACCUMS IN
THE FAVORED AREAS. HIGHS WILL MAINLY BE IN THE 20S, TO AROUND 30
NEAR THE COAST.
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/
UPDATE...LITTLE CHANGE TO THE EXTENDED FORECAST WITH THE ARRIVAL
OF THE 01Z NBM. CHANCES FOR LIGHT SNOW CURRENTLY REMAINS IN THE CARDS
FOR CHRISTMAS EVE.
PREVIOUSLY...
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 /16Z FRIDAY THROUGH TUESDAY/
SHORT TERM...A PERIOD OF MVFR CIGS IS EXPECTED THIS AFTERNOON
INTO TONIGHT, WITH SOME BRIEF PERIODS OF IFR IN -SN THIS
AFTERNOON AND EVENING, ALTHOUGH KRKD COULD SEE MORE IFR
OVERNIGHT THAN OTHER LOCATIONS. A RETURN VFR IS EXPECTED ON
SATURDAY AT ALL BUT KHIE WHICH WILL BE MAINLY MVFR IN UPSLOPE
CLOUDS/SHSN.
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...NE FLOW INCREASES THIS MORNING WITH SCA WINDS
EXPECTED THOUGH THE DAY INTO THIS EVENING BEFORE WINDS SWITCH N
LATER TONIGHT AND EVENTUALLY NW ON SAT. AS COASTAL LOW DEEPENS
WELL OFFSHORE COULD SEE A VERY BRIEF PERIOD OF GALES IN THE
WATERS S OF PEN BAY LATE TONIGHT EARLY SAT. OTHERWISE SCA WINDS
CONTINUE THROUGH AT LEAST SAT NIGHT.
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 UNTIL 3 PM EST SUNDAY FOR ANZ150-152-154.
SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 3 AM EST
SUNDAY FOR ANZ151-153.
NEAR TERM...CEMPA/COMBS
SHORT TERM...CEMPA
LONG TERM...CANNON/EKSTER
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