124
FXUS61 KBOX 021130
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
730 AM EDT FRI OCT 2 2026
WHAT HAS CHANGED
A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE SOUTHERN
WATERS THROUGH THIS EVENING FOR GUSTY WINDS AND ELEVATED SEAS.
OTHERWISE, THE FORECAST REMAINS ON TRACK.
KEY MESSAGES
- ONE LAST WARM DAY ON TAP TODAY BEFORE SHOWERS, POSSIBLY A FEW
THUNDERSTORMS, RETURN THIS AFTERNOON AND EVENING. EXPECTING
TEMPERATURES TO DROP FOR SATURDAY BEHIND THE COLD FRONT.
- LOW POTENTIAL FOR A FEW SCATTERED SHOWERS SUNDAY NIGHT SOUTH
OF I- 95. A SECONDARY, SHARP TEMPERATURE DROP IS THEN EXPECTED
FOR THE START OF NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...ONE LAST WARM DAY ON TAP TODAY BEFORE SHOWERS,
POSSIBLY A FEW THUNDERSTORMS, RETURN THIS AFTERNOON AND EVENING.
EXPECTING TEMPERATURES TO DROP FOR SATURDAY BEHIND THE COLD
FRONT.
ALREADY SEEING QUITE A BIT OF CLEARING SKIES ON THE SATELLITE
THIS MORNING; HOWEVER, DEWPOINTS REMAIN IN THE 62 TO 65 DEGREE
RANGE, ONLY 1 OR 2 DEGREES LOWER THAN THE ACTUAL TEMPERATURES
AROUND SOUTHERN NEW ENGLAND, AND COMBINED WITH MOSTLY CALM
WINDS... WOULDN'T BE SURPRISED TO SEE A LITTLE BIT OF PATCHY,
SHALLOW FOG TO DEVELOP IN SOME AREAS.
EXPECTING SKIES TO STAY MOSTLY CLEAR THROUGH THE NOON HOUR
TODAY, PERHAPS INTO THE EARLY AFTERNOON, BEFORE THE COLD FRONT
STARTS TO PUSH INTO NW MA. ONCE THE SUN COMES UP, EXPECTING TO
SEE THE SURFACE TEMPERATURES RISING RAPIDLY, TO NEAR OR JUST
ABOVE 80F, DUE TO THOSE 925MB TEMPERATURES HOVERING IN THE +20C
TO +22C RANGE.
THE LATEST HI-RES GUIDANCE IS IN GOOD AGREEMENT THAT THE COLD
FRONT, AND THE SUBSEQUENT SHOWERS, SHOULD START TO ARRIVE AROUND
3 TO 4 PM AND EXIT OFFSHORE AROUND 10 PM TO MIDNIGHT TONIGHT.
GIVEN THE HIGH DEWPOINTS, PWATS ARE ALSO EXPECTED TO SURGE TO
NEAR 2.0" (ALTHOUGH THE NAM IS MUCH MORE ROBUST, IN THE
2.0"-2.25" RANGE ALONG THE IMMEDIATE FRONTAL BOUNDARY), AND THE
LOW-LEVEL LAPSE RATES REMAIN ON THE STEEPER SIDE, NEAR 7C/KM.
THIS LEADS TO THE POTENTIAL FOR SOME LOCALIZED HEAVY DOWNPOURS
AS THE LINE OF SHOWERS PASSES. WHILE INSTABILITY IS ON THE LOWER
END WITH ONLY A FEW HUNDRED J/KG OF CAPE, IT DOESN'T TAKE MUCH
THIS TIME OF YEAR TO SPARK A FEW RUMBLES OF THUNDER.
BEHIND THE COLD FRONT, A RATHER STRONG CONTINENTAL HIGH
PRESSURE SYSTEM WILL BUILD OVER THE GREAT LAKES AND SOUTHERN
ONTARIO, SINKING THOSE +4C TO +6C 850MB TEMPERATURES DOWN INTO
NEW ENGLAND AND SHARPLY DROPPING SURFACE TEMPERATURES THROUGH
THE WEEKEND. SATURDAY'S HIGHS ARE LIKELY TO BE ON THE ORDER OF
10-15 DEGREES LESS THAN TODAY'S WITH OVERNIGHT TEMPS DROPPING
INTO THE LOW 40S (LOW 50S ON THE CAPE AND ISLANDS).
KEY MESSAGE 2...LOW POTENTIAL FOR A FEW SCATTERED SHOWERS
SUNDAY NIGHT SOUTH OF I-95. A SECONDARY, SHARP TEMPERATURE DROP
IS THEN EXPECTED FOR THE START OF NEXT WEEK.
STILL QUITE A BIT OF UNCERTAINTY ON IF SHOWERS WILL PUSH FAR
ENOUGH NORTH INTO SOUTHERN NEW ENGLAND SUNDAY EVENING. THE
LATEST ECMWF AND CANADIAN RUNS INDICATE SOME SCATTERED SHOWERS
BRUSHING ACROSS THE CAPE/ISLANDS AND IMMEDIATE SOUTH COAST WHILE
THE GFS SHOWS WIDESPREAD SHOWERS REACHING ALL THE WAY INTO
SOUTHERN NH. OPTED TO KEEP LOW-END POPS SOUTH OF I-95 FOR NOW.
REGARDLESS OF THE SHOWERS, A STRONG HIGH PRESSURE SYSTEM IS
EXPECTED TO BUILD IN RIGHT ON THE HEELS OF A DEEP CANADIAN LOW,
BRINGING A SECONDARY SHOT OF EVEN COLDER AIR TO NEW ENGLAND FOR
THE START OF NEXT WORK WEEK. LATEST GUIDANCE INDICATES THE 530MB
LINE SINKING POSSIBLY AS FAR SOUTH AS THE HARTFORD-PROVIDENCE-
PLYMOUTH CORRIDOR, MEANING 850MB TEMPERATURES COULD DROP TO NEAR
OR JUST BELOW 0C BY TUESDAY MORNING. THIS WOULD SUPPORT SURFACE
HIGHS IN MID 50S WITH NIGHTTIME LOWS POSSIBLY FALLING INTO THE
30S THROUGH WEDNESDAY.
THE HIGH THEN PUSHES EAST BY THURSDAY, MARKING THE RETURN OF
PREDOMINANTLY SOUTHWEST FLOW AND SEASONABLE TEMPERATURE TO
SOUTHERN NEW ENGLAND FOR THE END OF THE WEEK.
AVIATION /12Z FRIDAY THROUGH TUESDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
12Z TAF UPDATE:
TODAY: HIGH CONFIDENCE IN TAF/TRENDS BUT MODERATE ON TIMING.
MAINLY VFR, WITH SW WINDS AROUND 8-12 KT WITH OCCASIONAL SUB-20
KT GUSTS THROUGH AT LEAST 20Z. THEREAFTER COLD FRONTAL
LIGHT -SHRA APPROACHES TAFS DURING THE APPROX 19-03Z FROM WEST
TO EAST WITH PROB30 FOR MVFR VISBY SHRA. WHILE NOT ZERO, THE
RISK FOR TS IS MINIMAL AND PREDOMINANTLY SHOULD BE SHRA. POST-
FRONTAL WINDSHIFT FROM SW TO W/WNW AND DECREASING TO 5-10 KT.
TONIGHT: HIGH CONFIDENCE.
COLD FRONTAL SHRA MOVES OFFSHORE THE CAPE AND ISLANDS BY 03Z
SAT, WITH DECREASING VFR CLOUDINESS. NW TO N WINDS INCREASE TO
AROUND 10 KT, ESPECIALLY AROUND/AFTER MIDNIGHT.
SATURDAY AND SATURDAY NIGHT: HIGH CONFIDENCE.
VFR THROUGH THE PERIOD. N WINDS AROUND 10 KT TO START SATURDAY,
THOUGH DECREASE TO AROUND 5-10 KT BY AFTERNOON, WITH ENE/E
WINDS FOR THE EASTERN MA COAST. THESE WIND CONDITIONS SHOULD
STAY STEADY THROUGH THE OVERNIGHT HOURS AS WELL.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF/TRENDS BUT MODERATE ON
TIMING. THINKING SHRA BEGINS AROUND 20Z, WITH EMBEDDED HEAVIER
SHRA AND MVFR VISBY BETWEEN 21-23Z.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF. THINKING SHRA BEGINS
AROUND 19Z, WITH EMBEDDED HEAVIER SHRA AND MVFR VISBY BETWEEN
20-22Z.
OUTLOOK /SUNDAY THROUGH TUESDAY/...
SUNDAY: VFR.
SUNDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. SLIGHT
CHANCE SHRA.
MONDAY THROUGH TUESDAY: VFR. BREEZY.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
THROUGH SUNDAY...HIGH CONFIDENCE.
A COLD FRONT APPROACHES THE SOUTHERN NEW ENGLAND COASTAL WATERS
THIS EVENING. AHEAD OF THE FRONT, SOUTHWEST FLOW WILL BRING
GUSTS OF 20-25 KNOTS ACROSS THE SOUTHERN NEARSHORE WATERS,
INCLUDING CAPE COD BAY, WITH MARGINAL SEAS OF 5-6 FEET ACROSS
THE SOUTHERN OUTER WATERS. A FEW SHOWERS AND AN ISOLATED
THUNDERSTORM ARE POSSIBLE WITH THE FRONTAL PASSAGE THIS EVENING.
HIGH PRESSURE BRIEFLY RETURNS SATURDAY WITH TRANQUIL BOATING
CONDITIONS.
OUTLOOK /SUNDAY THROUGH TUESDAY/...
SUNDAY: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING 5 FT.
CHANCE OF RAIN SHOWERS.
SUNDAY NIGHT: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. CHANCE OF
RAIN SHOWERS, SLIGHT CHANCE OF THUNDERSTORMS.
MONDAY: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. SLIGHT CHANCE
OF RAIN SHOWERS.
MONDAY NIGHT: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 30 KT. AREAS OF ROUGH SEAS.
TUESDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS UP
TO 25 KT. LOCAL ROUGH SEAS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS
EVENING FOR ANZ231>235-237.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 2 AM EDT
SATURDAY FOR ANZ254>256.
DISCUSSION...MCMINN
AVIATION...LOCONTO/MCMINN
MARINE...MCMINN
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