763
FXUS61 KGYX 091821
AFDGYX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAY ME
221 PM EDT FRI OCT 9 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE.
KEY MESSAGES
1. HIGH PRESSURE BUILDS IN WITH FAIR WEATHER EXPECTED THROUGH
SUNDAY. OVERNIGHT FROST WILL BE POSSIBLE TO THE COAST,
ESPECIALLY SATURDAY NIGHT.
2. RAIN CHANCES INCREASE LATE SUNDAY AND PERSIST INTO MONDAY AS
THE REMNANTS OF ISAIAS CROSS THE NORTHEAST AND A FRONT
APPROACHES FROM THE NORTH. MORE SHOWERS ARE LIKELY WITH A COLD
FRONT ON TUESDAY THAT MAY LAST INTO PART OF WEDNESDAY.
DISCUSSION
KEY MESSAGE 1 DESCRIPTION...
SECONDARY COLD FRONT WILL CROSS THE REGION THIS EVENING. ANOTHER
ROUND OR BAND OF SHOWERS WILL CROSS THE FORECAST AREA, THEN
TRANSITIONING TO UPSLOPE SHOWERS. HAD TO BLEND IN A LITTLE CAM
GUIDANCE TO GET SHOWER COVERAGE THIS EVENING. OVERNIGHT SOME
LIGHT SNOW ACCUMULATION WILL BE POSSIBLE FOR THE HIGHEST
ELEVATIONS. SO THERE COULD BE SOME SNOWLIAGE IN THE MORNING. IT
WILL ALSO BE A RACE TO SEE HOW QUICKLY WE CAN DECOUPLE THE COLD
ADVECTION WINDS. NBM GUIDANCE IS QUITE COLD OVERNIGHT, WITH MOS
GUIDANCE WARMER. I THINK THE NBM IS PROBABLY LEANING A BIT TOO
HARD ON BIAS CORRECTION FROM PAST NIGHTS, SO I BROUGHT LOWS UP A
BIT. THIS KEEPS FROST MOSTLY OUT OF THE ACTIVE ZONES. SO NO
HEADLINES CURRENTLY, BUT IF WE DO DECOUPLE EARLY IT MAY BE
SOMETHING TO CONSIDER FOR THE EVENING SHIFT.
SAT WILL BRING SHALLOW MIXING AND FAIR WEATHER AS THE STRONG
HIGH SETTLES OVERHEAD. THIS WILL SET UP SAT NIGHT TO LIKELY BE
THE COLDER OF THE TWO NIGHTS. DESPITE HIGH CENTER DRIFTING EAST
AND RETURN FLOW DEVELOPING ALOFT, THE BOUNDARY LAYER SHOULD
DECOUPLE QUICKLY AROUND SUNSET. I BLENDED IN MOS GUIDANCE WHICH
WAS COOLER THAN NBM, SO THAT AREAS OF FROST MAKE IT TO THE COAST
FROM PORTLAND NORTH. HEADLINES WILL LIKELY BE NEEDED FOR THE
FINAL NIGHT OF THE FROST/FREEZE PROGRAM.
KEY MESSAGE 2 DESCRIPTION...
TODAY'S MODEL GUIDANCE REMAINS IN GOOD AGREEMENT IN CONTINUING
TO LIFT HIGHER MOISTURE ASSOCIATED WITH THE REMNANTS OF ISAIAS
TOWARD THE MID-ATLANTIC AND NORTHEAST AND A WEAK LOW DEVELOPING
NEAR OR JUST SOUTH OF SOUTHERN NEW ENGLAND. THIS WILL BRINGING
INCREASING RAIN CHANCES SUNDAY EVENING INTO AT LEAST THE FIRST
PART OF MONDAY, BUT THERE'S STILL UNCERTAINTY IN THE NORTHWARD
EXTENT OF MEASURABLE RAIN. SOUTHERNMOST NH REMAINS ON TRACK TO
SEE THE HIGHER RAIN TOTALS LOCALLY WITH BOX AND WHISKER PLOTS
FROM ENSEMBLES FAVORING AROUND 0.50" OF RAIN POSSIBLE, ALTHOUGH
THERE ARE STILL SOME JUICIER ENSEMBLE MEMBERS SUGGESTING UPWARDS
OF AN INCH. EITHER WAY, HYDRO ISSUES ARE NOT ANTICIPATED.
RAINFALL AMOUNTS DIMINISH WITH NORTHWARD EXTENT, AND THEN A
DRYING TREND SHOULD OCCUR BY MONDAY AFTERNOON AS THE SYSTEM
PULLS AWAY TO THE EAST. A COLD FRONT APPROACHING FROM THE NORTH
COULD ALSO BRING SOME SHOWERS TO THE MOUNTAINS LATE IN THE DAY
OR MONDAY NIGHT.
TURNING TO TUESDAY, A LOW PRESSURE AND COLD FRONT IS FORECAST
TO APPROACH NEW ENGLAND FROM THE GREAT LAKES, BRINGING MORE
SHOWERS TUESDAY INTO AT LEAST TUESDAY NIGHT. NBM POP IS ALREADY
60-80% NH AND WESTERN ME, WHICH IS SUPPORTED BY THE ENSEMBLES,
BUT TIMING IS THE MORE UNCERTAIN ASPECT. THE GFS IS MUCH FASTER
IN CLEARING THE FRONT, WHICH WOULD MAKE WEDNESDAY GENERALLY DRY,
COOLER, AND BREEZY WHILE ON THE OTHER HAND THE ECMWF CAMP IS
SLOWER AND KEEPS SOME RAIN INTO WEDNESDAY. REGARDLESS OF THE
SPEED OF THE SYSTEM, COOLER AIR WILL BE DRAWN IN BEHIND THIS
SYSTEM, WHICH COULD BRING IN SOME HIGHER ELEVATION SNOW SHOWERS
EITHER WEDNESDAY OR WEDNESDAY NIGHT.
HIGH PRESSURE IS FAVORED FOR THURSDAY TO BRING A DRY DAY, AND
THEN GLOBAL MODELS ARE ALREADY IN GOOD AGREEMENT FOR THIS FAR
OUT SHOWING A LOW MOVING ACROSS QUEBEC AND SENDING A COLD FRONT
OUR WAY TO BRING THE NEXT CHANCE OF SHOWERS ON FRIDAY.
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
LOCAL MVFR OR LOWER POSSIBLE WITH SHOWERS LATE THIS AFTERNOON
AND EARLY THIS EVENING, THEN WIDESPREAD VFR CONDITIONS EXPECTED
THRU SUN. GUSTY NORTHWEST WINDS WILL DIMINISH AROUND SUNSET
TONIGHT ALONG WITH SHOWERS, BUT A BREEZE OVERNIGHT SHOULD BE
ENOUGH TO STIR THE BOUNDARY LAYER AND PRECLUDE ANY FOG
FORMATION. LOCAL IFR POSSIBLE IN VALLEY FOG SAT NIGHT.
OUTLOOK:
SUNDAY NIGHT-MONDAY...IFR CEILINGS ARE LOOKING INCREASING
LIKELY, ESPECIALLY SOUTH OF A PWM-LEB LINE. THIS AREA IS ALSO
MOST LIKELY TO SEE RAIN. TO THE NORTH, MVFR CEILINGS AND RAIN
ARE POSSIBLE BUT LESS CERTAIN. SOME IMPROVEMENT IS POSSIBLE
LATER IN THE DAY.
TUESDAY-WEDNESDAY: RAIN SHOWERS AND IFR TO MVFR POSSIBLE AS A
FRONT/LOW PRESSURE CROSS THROUGH ON TUESDAY AND TUESDAY NIGHT.
DEPENDING ON HOW QUICKLY THE FRONT MOVES THROUGH, WEDNESDAY
COULD BE BREEZY AND MAINLY VFR, BUT IT'S POSSIBLE RAIN AND SOME
DEGREE OF RESTRICTIONS LINGER INTO WEDNESDAY.
MARINE
GUSTY NORTHWEST WINDS ARE EXPECTED TO STAY BELOW SCA THRESHOLDS
THIS EVENING, THEN HIGH PRESSURE SETTLES OVERHEAD AND WINDS AND
SEAS DIMINISH THRU THE WEEKEND. SUNDAY NIGHT-FRIDAY...LOW
PRESSURE LIKELY PASSES SOUTH OF THE WATERS SUNDAY NIGHT INTO
MONDAY WITH WINDS TURNING EAST TO NORTHEAST BUT CURRENTLY
EXPECTED TO REMAIN BELOW SCA LEVELS. HOWEVER, RAIN IS LIKELY
WITH FOG ALSO POSSIBLE. SCA CONDITIONS ARE THEN POSSIBLE TUESDAY
INTO WEDNESDAY AS LOW PRESSURE AND A FRONTAL BOUNDARY APPROACH
FROM THE WEST, ALTHOUGH THERE IS UNCERTAINTY IF THE LOW WILL BE
A NORTHERN OR SOUTHERN TRACK OR SOMEWHERE IN BETWEEN. HIGH
PRESSURE SHOULD BUILD IN AROUND THURSDAY, AND THEN ANOTHER COLD
FRONT APPROACHES LATE IN THE WEEK, POTENTIALLY BRINGING
ADDITIONAL SCA CONDITIONS.
GYX WATCHES/WARNINGS/ADVISORIES
ME...NONE.
NH...NONE.
MARINE...NONE.
DISCUSSION...LEGRO/COMBS
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