266
FXUS61 KBOX 091744
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
144 PM EDT FRI OCT 9 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES TO THE FORECAST.
KEY MESSAGES
- COOL, QUIET, AND DRY WEATHER PREVAILS THROUGH THE FIRST HALF
OF SUNDAY. EXPECT HIGHS IN THE 60S WITH A CHILLY START TO
SATURDAY MORNING, ESPECIALLY IN THE TYPICAL COLD SPOTS.
- THE NEXT QUICK MOVING ROUND OF RAIN COMES SUNDAY AFTERNOON AND
EVENING, CONTINUING OVERNIGHT AND EXITING BY MONDAY MORNING.
- QUICK ROUND OF RAIN AROUND MID WEEK, THEN DRY WEATHER RETURNS BY
THURSDAY.
DISCUSSION
KEY MESSAGE 1...COOL, QUIET, AND DRY WEATHER PREVAILS THROUGH THE
FIRST HALF OF SUNDAY. EXPECT HIGHS IN THE 60S WITH A CHILLY START TO
SATURDAY MORNING, ESPECIALLY IN THE TYPICAL COLD SPOTS.
A BROAD MID LEVEL TROUGH SLOWLY TRAVERSES OVERHEAD FRIDAY AS HIGH
PRESSURE RIDGING APPROACHES FROM THE WEST. THIS PLACES SNE BENEATH A
NW 30-35 KT LLJ; WITH GOOD MIXING (BUFKIT SHOWING TO NEAR 850MB)
EXPECTING A GUSTY DAY TODAY, MUCH LIKE THURSDAY. OTHERWISE,
BEAUTIFUL, MOSTLY SUNNY WEATHER EXPECTED WITH HIGHS IN THE MID 60S
AND A MIX OF DIURNAL CLOUDS. HIGH PRESSURE CONTINUES TO EXPAND AND
MOVE EAST, DIRECTLY OVERHEAD BY SATURDAY AFTERNOON GIVING A VERY
NICE START TO THE HOLIDAY WEEKEND WITH SUN, LIGHT WINDS, AND HIGHS
IN THE 60S. SOMETHING TO WATCH WILL BE HOW QUICKLY THAT PRESSURE
GRADIENT WEAKENS BECAUSE LIGHT/CALM WINDS OVERNIGHT WOULD ALLOW FOR
EFFICIENT RADIATIONAL COOLING. THUS, LEANED ON MOS GUIDANCE FOR
SATURDAY MORNING LOW TEMPERATURES.
KEY MESSAGE 2...THE NEXT QUICK MOVING ROUND OF RAIN COMES SUNDAY
AFTERNOON AND EVENING, CONTINUING OVERNIGHT AND EXITING BY MONDAY
MORNING.
THE MAIN CHANGE FROM 24 HOURS AGO IS BOTH A SLIGHTLY QUICKER ARRIVAL
AND EXIT OF THE RAIN. GUIDANCE IS IN AGREEMENT THAT THE MOISTURE
LEFT OVER FROM WHAT USED TO BE HURRICANE ISAIAS WILL BE PULLED EAST
BY A NORTHERN STREAM TROUGH AND QUICKLY USHERED THROUGH THE MID
ATLANTIC AND OFFSHORE. THERE IS LESS AGREEMENT AS TO EXACTLY HOW FAR
NORTH THE PRECIP SHIELD IS, BUT CONTINUING TO EXPECT SOUTHERN NEW
ENGLAND TO BE WELL WITHIN THE AREA THAT WILL SEE RAIN. ONE ONE HAND,
PARTS OF THE AREA (ESPECIALLY WEST) LIKELY HAVE TO DEAL WITH RAIN
SHOWERS SUNDAY AFTERNOON/EVENING. 8PM SUNDAY ENSEMBLE GUIDANCE
INDICATES A 80-90% CHANCE OF AT LEAST 0.01" RAIN FOR WESTERN MA/CT,
BUT ONLY 40-50% FOR FAR EASTERN MA. ON THE OTHER HAND, BY MONDAY
MORNING THERE'S A GOOD AGREEMENT THE RAIN HAS EXITED EAST SO IT
SHOULD BE A MOSTLY OVERNIGHT EVENT. ON THE WHOLE THIS LOOKS TO BE A
FAIRLY TYPICAL RAINFALL PRODUCING SYSTEM FOR THE REGION WITHOUT
HAZARDS FROM FLOODING OR DAMAGING WINDS. GUIDANCE GENERALLY PAINTS A
PICTURE OF A HALF INCH FOR NORTHERN MA TO 1+" ALONG THE SOUTH SHORE
IN CLOSER PROXIMITY TO THE BETTER FORCING AND MOISTURE. WHILE EPS
ENSEMBLE PROBABILITIES OF >1" OF RAIN HAVE INCREASED TO MAX 40-50%
ALONG THE IMMEDIATE SOUTH COAST, GEFS PROBS PUT THE ODDS AT
ESSENTIALLY NIL; NEEDLESS TO SAY, UNCERTAINTY REMAINS ON WHO WILL
SEE THE MOST RAIN AND HOW MUCH.
KEY MESSAGE 3...QUICK ROUND OF RAIN AROUND MID WEEK, THEN DRY
WEATHER RETURNS BY THURSDAY.
A BREAK IN THE RAIN COMES MONDAY INTO TUESDAY UNDER BRIEF HIGH
PRESSURE RIDGING BEFORE ANOTHER FRONTAL SYSTEM MOVES THROUGH
BRINGING A ROUND OF WET WEATHER. CONFIDENCE IN ANY TIMING OR
PLACEMENT DETAILS IS LOW AND WILL DEPEND ON HOW THIS HOLIDAY
WEEKEND'S SYSTEM PLAYS OUT BUT UNSETTLED WEATHER LOOKS POSSIBLE
AROUND LATE TUESDAY OR WEDNESDAY.
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE:
THROUGH 00Z SATURDAY: HIGH CONFIDENCE.
VFR. WESTERLY WIND GUSTS 25-30 KT CONTINUE THROUGH SUNDOWN
(22-23Z).
TONIGHT THROUGH SATURDAY NIGHT: HIGH CONFIDENCE.
VFR. NW WINDS AROUND 5-10 KT, BECOMING LIGHT N TO NE BY LATE-
AFTERNOON, THEN TURNING EASTERLY SATURDAY NIGHT INTO OVERNIGHT
SUNDAY.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /SATURDAY NIGHT THROUGH WEDNESDAY/...
SATURDAY NIGHT: VFR.
SUNDAY: VFR. CHANCE SHRA.
SUNDAY NIGHT: MVFR/IFR CONDITIONS POSSIBLE. BREEZY. SHRA.
COLUMBUS DAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. SLIGHT
CHANCE SHRA.
MONDAY NIGHT: VFR.
TUESDAY: VFR. CHANCE SHRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
THROUGH SATURDAY: HIGH CONFIDENCE.
W WINDS WILL INCREASE THROUGH THE MORNING, PEAKING IN THE AFTERNOON.
EXPECTING SUSTAINED WINDS 10-15 KTS WITH GUSTS 20-25KTS THOUGH SOME
GUSTS 25-30 KT ARE POSSIBLE. SEAS AROUND 4 FT OR LESS FRIDAY FOR ALL
WATERS, WITH GOOD VISIBILITY EXPECTED. HIGH PRESSURE OVERHEAD
SATURDAY LEADS TO SEAS 2 FT OR LESS WITH N WINDS 5-10 KTS.
OUTLOOK /SATURDAY NIGHT THROUGH WEDNESDAY/...
SATURDAY NIGHT: WINDS LESS THAN 25 KT.
SUNDAY: WINDS LESS THAN 25 KT. CHANCE OF RAIN SHOWERS.
SUNDAY NIGHT: WINDS LESS THAN 25 KT. LOCAL ROUGH SEAS. RAIN
SHOWERS, SLIGHT CHANCE OF THUNDERSTORMS.
COLUMBUS DAY: WINDS LESS THAN 25 KT. ROUGH SEAS UP TO 9 FT.
CHANCE OF RAIN SHOWERS.
MONDAY NIGHT: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT.
TUESDAY: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. SLIGHT CHANCE
OF RAIN SHOWERS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
ANZ230>237-250-251-254>256.
DISCUSSION...BW
AVIATION...LOCONTO/BW/MENSCH
MARINE...BW
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page