193
FXUS61 KGYX 241012
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
612 AM EDT THU SEP 24 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES NEEDED TO THE FORECAST WITH THIS EARLY
MORNING UPDATE. TEMPERATURES THIS MORNING HAVE DROPPED INTO THE
UPPER 30S AND LOW 40S THIS MORNING WITH THE BETTER RADIATING
LOCATIONS DROPPING NEAR OR BELOW FREEZING. TEMPERATURES WILL
REBOUND QUICKLY AFTER SUNRISE SO THE FROST ADVISORY WILL BE
ALLOWED TO EXPIRE ON TIME AT 7 AM. ALSO, UPDATED THE AVIATION
DISCUSSION FOR THE 12Z TAFS.
KEY MESSAGES
1. HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER PATTERN INTO
FRIDAY.
2. A STRONG COASTAL STORM WILL TRACK NEAR SOUTHERN NEW ENGLAND
TO END THE WEEK. SOAKING RAIN, GUSTY WINDS, HIGH SURF, AND
COASTAL FLOODING ARE POSSIBLE THROUGH THE WEEKEND.
DISCUSSION
KEY MESSAGE 1 DESCRIPTION...
WE WILL REMAIN UNDER THE INFLUENCE OF COOL HIGH PRESSURE AT THE
SURFACE THROUGH AT LEAST EARLY ON FRIDAY. THE AIRMASS OVERHEAD
IS VERY DRY AS SAMPLED BY THE 00Z GYX UPPER AIR SOUNDING. THE
SAMPLED PWATS WERE AT 0.31 INCHES WHICH IS CLOSE TO THE MINIMUM
FOR THIS TIME OF YEAR. THUS, WITH CLEAR SKIES AND LIGHT WINDS,
CONDITIONS WILL BE FAVORABLE FOR RADIATIONAL COOLING AND FROST
FORMATION IN THE SHELTERED VALLEYS THIS MORNING. WINDS WILL BE A
BIT BREEZIER ON THE HILLTOPS AND AREAS ALONG AND SOUTH OF THE
COASTAL PLAIN WHICH MAY LIMIT THE FROST POTENTIAL HERE. LOWS ARE
FORECAST TO MAINLY BE IN THE 40S BUT SOME MID TO UPPER 30S ARE
LIKELY IN THE NORTHERN VALLEYS AND PORTIONS OF THE INTERIOR.
FROST ADVISORY REMAINS IN EFFECT FOR PORTIONS OF THE INTERIOR
AND MIDCOAST UNTIL 11Z.
WHILE THE HIGH BRINGS COOL AND FAIR WEATHER TO NORTHERN NEW
ENGLAND, A DEVELOPING STORM SYSTEM OFF THE CAROLINA COAST
CONTINUES TO ORGANIZE TO OUR SOUTH. THE SURF CONTINUES TO BUILD
OVER THE NEXT FEW DAYS AS A LONG EASTERLY FETCH STRENGTHENS
ACROSS THE NORTH ATLANTIC BETWEEN THE HIGH OVERHEAD AND THE
DEVELOPING STORM SYSTEM. THESE WAVES BRING INCREASINGLY LARGE
BREAKING SURF AND RIP CURRENTS THROUGH THE END OF THE WEEK.
KEY MESSAGE 2 DESCRIPTION...
IT WOULD NOT BE A COASTAL PARTY WITHOUT SOME UNCERTAINTY
BRINGING CONFIDENCE DOWN IN THE MEDIUM RANGE. WHILE ALL NWP
SYSTEMS AGREE ON A STRONG EARLY SEASON COASTAL STORM DEVELOPING
OFF THE MID ATLANTIC AND DRIFTING NORTH BEFORE DOING A LOOP,
WHAT THEY DO NOT AGREE ON IS WHERE THAT STALL AND CAPTURE TAKES
PLACE. FOR INSTANCE THE DETERMINISTIC GFS FAVORS CAPE COD WHILE
THE ECMWF TUCKS INTO NYC. EVEN THEIR RESPECTIVE ENSEMBLE SYSTEMS
HAVE LITTLE OVERLAP BETWEEN LOW LOCATIONS. THE ENSEMBLES ARE
FAIRLY AGNOSTIC ON STRENGTH HOWEVER, ALL FEATURING SIMILAR
SPREAD. SO GIVEN HOW SIMILAR THE DIFFERENT MODEL SUITES WITH THE
UPPER AIR PATTERN, THAT LEADS TO SOMEWHAT LOWER CONFIDENCE ON
THE OUTCOMES LOCALLY. A FARTHER NORTHEAST STORM WILL BRING
GREATER IMPACTS VS. ONE HANGING OFF THE JERSEY SHORE. MUCH LIKE
YESTERDAY THE IMPACTS IN ORDER OF CONFIDENCE ARE AS FOLLOWS:
HIGH SURF...IT WILL BE SEVERAL DAYS OF NORTHEAST WINDS ALONG
THE LONGEST POSSIBLE FETCH. SEAS WILL BUILD THRU SAT BEFORE THE
WEAKENING ALLOWS WAVES TO DIMINISH SLOWLY THRU THE BEGINNING OF
NEXT WEEK. SEAS BUILDING TO AROUND 10 FT REMAINS LIKELY, BUT
SIGNIFICANT WAVE HEIGHTS UP TO 15 FT ARE NOT OUT OF THE QUESTION
IF THE CLOSER/STRONGER TRACKS ARE REALIZED. THIS WILL
ESPECIALLY BE TRUE TOWARDS JEFFREY'S LEDGE WHERE THE FETCH WILL
BE THE LONGEST.
WINDS...THIS MAY BE A 2/2A WITH COASTAL FLOODING BELOW. A
STRONG PRESSURE GRADIENT FORECAST TO SET UP BETWEEN THE COASTAL
STORM AND RETREATING HIGH PRESSURE. BOTH PRESSURE SYSTEMS ARE
ANOMALOUS FOR THIS TIME OF YEAR. NORTHEAST WINDS ALSO TEND TO
KEEP A FAIRLY WELL MIXED BOUNDARY LAYER THANKS TO COLD
ADVECTION. AS A RESULT THOSE WINDS SHOULD BE FAIRLY CONSISTENTLY
GUSTY BEGINNING AS EARLY AS FRI. IT COULD BE A GREATER THAN 48
HOUR PERIOD WITH WIND GUSTS FREQUENTLY IN EXCESS OF 35 MPH ALONG
THE COAST. THE GREATEST AREA OF CONCERN WILL BE CASCO BAY SOUTH
TO THE SEACOAST. THIS IS WHERE STRONGEST WINDS ALOFT ARE
FORECAST AS WELL AS THE GREATEST ONSHORE COMPONENT OF THOSE
WINDS. THE MORE EXTREME WIND FORECASTS APPROACHING 60 MPH ARE
BECOMING MORE UNLIKELY. HOWEVER A LOW END WIND ADVISORY REMAINS
POSSIBLE, ESPECIALLY WITH LEAVES STILL ON THE TREES FOR NOW. THE
WINDOW FOR THE BEST POSSIBLE MIXING AND GUSTS PUSHING 45 MPH
WILL BE DURING THE CLOSEST APPROACH SUN.
COASTAL FLOODING...WITH SUSTAINED NORTHEAST WINDS AND BUILDING
SEAS OVER SEVERAL DAYS WE ARE PRIMED TO MAXIMIZE THE POTENTIAL
STORM SURGE BY THE WEEKEND. THANKFULLY ASTRONOMICAL TIDES ARE
NOT PEAKING UNTIL NEXT WEEK, BUT THEY WILL BE INCREASING THRU
THE WEEKEND. BECAUSE THE ASTRONOMICAL TIDES ARE NOT SUPER HIGH
THERE IS LOWER CONFIDENCE THAT WE REACH FLOOD STAGE, BUT THE
COMBINATION OF HIGH WATER AND POUNDING SURF SHOULD LEAD TO
SIGNIFICANT SPLASHOVER AT THE VERY LEAST. THE STEVENS INST FLOOD
ADVISORY SYSTEM IS BELOW FLOOD STAGE AT PORTLAND AT THIS TIME
SAT INTO SUN, BUT SURGE FORECASTS ALSO REMAIN LESS THAN 2 FT.
GIVEN THE VERY FAVORABLE MULTI-CYCLE SET UP I TEND TO THINK WE
WILL COME IN CLOSER TO THAT NUMBER THAN 1 FT. THIS SHOULD BE
ENOUGH FOR WATER LEVELS TO GET RIGHT UP TO FLOOD STAGE.
RAINFALL...THIS REMAINS THE LOWEST CONFIDENCE IMPACT OF THE
BUNCH BECAUSE IT WILL BE SO DEPENDENT ON STORM TRACK AND THERE
IS SUCH A WIDE RANGE OF POSSIBILITIES AT THIS POINT IN TIME. THE
FORECAST STALL AND CAPTURE, WITH A LOOPING SURFACE LOW, IS A
FAVORABLE SET UP FOR FAIRLY WIDESPREAD SOAKING RAINS, EVEN THE
FARTHER SOUTHWEST ECMWF CASES. THE LATE WARM SEASON MOISTURE
CONTENT AND STRONG SYNOPTIC FORCING DOES MEAN THAT SOME
SIGNIFICANT RAINFALL REMAINS POSSIBLE, AND THE ECMWF ENS
ESPECIALLY CONTINUES TO PUT A 20 TO 30 PERCENT CHANCE OF 4
INCHES OR MORE RAINFALL ACROSS PARTS OF SOUTHWESTERN MAINE AND
THE SEACOAST. HOWEVER WHEN YOU DRILL DOWN TO 24 HOUR QPF, THE
PROBABILITIES OF MORE THAN 2 INCHES IN THAT PERIOD IS 10 PERCENT
OR LESS. SO THIS REALLY LOOKS LIKE A LONG DURATION LIGHT TO
MODERATE RAIN. I WOULD LIKE TO SEE THE CAM GUIDANCE AS THE EVENT
GETS CLOSER, AS THERE COULD DEFINITELY BE CONVECTIVE ELEMENTS
THAT TRAIN AND LEAD TO SOME LOCALLY HIGHER RAINFALL AMOUNTS. NOW
THAT MODELS HAVE SETTLED INTO SOME AGREEMENT ON TIMING, THE NBM
BUMPING UP TO CATEGORICAL POP AND LINGERING THAT THRU MON
MORNING SEEMS REASONABLE FROM A MESSAGING STANDPOINT.
AVIATION /12Z THURSDAY THROUGH MONDAY/
THROUGH 12Z FRIDAY...AFTER VALLEY FOG CLEARS EARLY THIS MORNING,
VFR PREVAILS THROUGH THE DAY WITH LIGHTER WINDS. COASTAL
TERMINALS MAY ONCE AGAIN SEE NORTHEASTERLY GUSTS 15-20 KTS.
VALLEY FOG IS POSSIBLE AGAIN TONIGHT IMPACTING AT LEAST LEB,
BUT OTHER TERMINALS LIKE HIE AND CON WHO WERE IMPACTED THIS PAST
EVENING MAY SEE IT AGAIN AS WELL.
OUTLOOK:
FRIDAY: AREAS OF MVFR DEVELOPING AS RAIN MOVES TOWARDS THE
AREA. NORTHEAST SURFACE GUSTS OF 25 KT OR MORE POSSIBLE NEAR THE
COAST.
SATURDAY-SUNDAY: WIDESPREAD MVFR LIKELY, AREAS OF IFR OR LOWER
POSSIBLE NEAR THE COAST IN RAIN. COASTAL TERMINALS MAY SEE
NORTHEAST SURFACE GUSTS OF 30 KT OR MORE.
MONDAY: AREAS OF MVFR OR LOWER DURING THE FIRST HALF OF THE DAY
AS RAIN ENDS. NORTH NORTHEAST SURFACE GUSTS OF 25 KT OR MORE
POSSIBLE.
TUESDAY: VFR CONDITIONS EXPECTED.
MARINE
SCA CONDITIONS CONTINUE TO SPREAD NORTH TODAY, AND CONTINUE TO
BUILD TONIGHT AS A STORM ORGANIZES OFF THE CAROLINA COAST.
STEADILY INCREASING NORTHEAST WINDS ARE EXPECTED THRU THE
WEEKEND. BUILDING SEAS IN EXCESS OF 10 FT ARE LIKELY BY FRI
AFTERNOON. EARLY SAT SEAS MAY REACH AT LEAST 15 FT IN THE
VICINITY OF JEFFREY'S LEDGE. NORTHEAST GALES MAY DEVELOP AS SOON
AS FRI, AND STORM CONDITIONS ARE NOT OUT OF THE QUESTION IF THE
STORM TRACKS CLOSER TO THE GULF OF MAINE. MODERATE TO LOCALLY
HEAVY RAINFALL OVER THE WATERS WILL ALSO REDUCE VISIBILITY TO
BELOW 3 MILES AT TIMES THRU MON MORNING. WINDS AND SEAS WILL BE
SLOW TO DIMINISH BY EARLY NEXT WEEK.
GYX WATCHES/WARNINGS/ADVISORIES
ME...FROST ADVISORY UNTIL 7 AM EDT THIS MORNING FOR MEZ012>014-022-
028-033.
HIGH SURF ADVISORY FROM 8 AM FRIDAY TO 8 PM EDT SUNDAY FOR
MEZ023>027.
NH...FROST ADVISORY UNTIL 7 AM EDT THIS MORNING FOR NHZ003>006.
HIGH SURF ADVISORY FROM 8 AM FRIDAY TO 8 PM EDT SUNDAY FOR
NHZ014.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 AM EDT
FRIDAY FOR ANZ150-152.
GALE WARNING FROM 2 AM SATURDAY TO 8 PM EDT SUNDAY FOR ANZ150-
152.
SMALL CRAFT ADVISORY FROM 2 AM SATURDAY TO 8 PM EDT SUNDAY FOR
ANZ151-153.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 8 AM EDT FRIDAY
FOR ANZ153.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR ANZ154.
GALE WARNING FROM 8 PM FRIDAY TO 8 PM EDT SUNDAY FOR ANZ154.
GALE WARNING FROM 11 AM FRIDAY TO 8 PM EDT SUNDAY FOR ANZ180-
182-184.
UPDATE...BARON
DISCUSSION...CLAIR/HARGROVE/LEGRO
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