174
FXUS61 KBOX 021826
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
226 PM 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 /18Z FRIDAY THROUGH WEDNESDAY/
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 GUSTS
TO 20 KTS AND UP TO 25 KTS FOR EAST COAST AND CAPE TERMINALS.
-SHRA APPROACHES TAF SITES BETWEEN 19-03Z FROM WEST TO EAST WITH
BRIEF PERIOD OF MVFR VISBY/CIGS WITHIN ANY SHRA. WHILE NOT
ZERO, THE RISK FOR TS IS LOW (< 20%) AND PREDOMINANTLY SHOULD
BE SHRA. WINDS SHIFT BEHIND THE FRONT FROM SW TO W/WNW THIS
EVENING. COULD SEE A BRIEF GUST 20 KTS WITH THE FRONTAL
PASSAGE.
TONIGHT: HIGH CONFIDENCE.
VFR FOR MOST, WITH PATCHY MVFR POSSIBLE FOR CAPE COD AND ISLANDS
OVERNIGHT. ANOTHER "WAVE" OF -SHRA IS POSSIBLE FOR PORTIONS OF
EASTERN SOUTHERN NEW ENGLAND TONIGHT. THIS IS MORE LIKELY TO
IMPACT PVD AND CAPE/ISLAND TERMINALS, BUT COULD PUSH AS NORTH AS
BOS 00 TO APPROX 04Z. -SHRA MOVE OFFSHORE THE CAPE AND ISLANDS
BY 10Z SAT. NW TO N WINDS INCREASE TO AROUND 10 KT, ESPECIALLY
AROUND/AFTER MIDNIGHT. CEILINGS GRADUALLY INCREASE 06-12Z.
SATURDAY AND SATURDAY NIGHT: HIGH CONFIDENCE.
VFR. 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. SCT MID-LEVEL DECKS POSSIBLE. N/NNE WINDS CONTINUE
OVERNIGHT.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF/TRENDS BUT MODERATE ON
TIMING. THINKING SHRA BEGINS AROUND 20-22Z, WITH EMBEDDED
HEAVIER SHRA AND MVFR VISBY BETWEEN 21-23Z. ADDED IN A PROB30
FOR -SHRA 00-04Z AS SOME ADDITIONAL SHOWERS MAY PUSH NEAR BOS IN
THAT TIMEFRAME. WINDS SHIFT TO THE NW 22-00Z WITH THE FRONTAL
PASSAGE THIS EVENING.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF. THINKING SHRA BEGINS
AROUND 19Z, WITH EMBEDDED HEAVIER SHRA AND MVFR VISBY BETWEEN
20-22Z.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUNDAY: VFR.
SUNDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. SLIGHT
CHANCE SHRA.
MONDAY THROUGH TUESDAY: VFR. BREEZY.
TUESDAY NIGHT THROUGH WEDNESDAY: VFR.
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 WEDNESDAY/...
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.
TUESDAY NIGHT: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT.
WEDNESDAY: WINDS LESS THAN 25 KT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR
ANZ230>237-251.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ254>256.
DISCUSSION...MCMINN
AVIATION...MENSCH
MARINE...MCMINN
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