821
FXUS61 KBOX 270725
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
325 AM EDT SAT JUN 27 2026
WHAT HAS CHANGED
NO MAJOR CHANGES TO THE FORECAST. TRENDS REMAIN RELATIVELY
CONSISTENT.
KEY MESSAGES
- SPOT SHOWERS TOWARDS THE SOUTH COAST TODAY.
- SCATTERED SHOWERS POSSIBLE SUNDAY, THEN THE START OF A
WARMING TREND.
- WARM AND HUMID MIDWEEK, ALONG WITH A RISK OF SHOWERS TOWARDS
THE SECOND HALF OF NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...SPOT SHOWERS TOWARDS THE SOUTH COAST TODAY.
GENERALLY DRY ACROSS THE REGION TODAY ASIDE FROM SOME SPOT SHOWERS
TOWARDS THE SOUTH COAST. GUIDANCE HAS CONTINUED TO KEEP THESE
SHOWERS THERE, REACHING SOMEWHAT INTO RI AND SE MA. ANY SHOWERS THAT
POP UP ARE NOT EXPECTED TO BE VERY IMPACTFUL, LET ALONG SEVERE.
HIGHS TODAY IN THE MIDST OF LIGHT WINDS WITH SOME SUNSHINE WILL
REACH THE LOW 80S AND UPPER 70S. GIVEN LOCALIZED SEABREEZES, SPOTS
ALONG THE IMMEDIATE COASTLINES MAY BE COOLER THAN SURROUNDING AREAS.
KEY MESSAGE 2...SCATTERED SHOWERS POSSIBLE SUNDAY, THEN THE START OF
A WARMING TREND.
AHEAD OF THE RIDGE BUILDING IN FROM THE WEST, WE FIND OURSELVES
UNDER SOME TROUGHING SUNDAY WITH SURFACE HIGH PRESSURE EXTENDING
INTO NEW ENGLAND AND A SOMEWHAT STATIONARY FRONT JUST TO THE SOUTH
OF SOUTHERN NEW ENGLAND. WITH THIS MESSIER SETUP, THE CHANCE FOR
SOME AFTERNOON SHOWERS RETURNS; THE LATEST CAMS ALL SEEM TO HAVE A
SIGNAL FOR THESE SHOWERS POPPING UP ACROSS SOUTHERN NEW ENGLAND.
SOME OF THE LATEST GLOBAL GUIDANCE PLUS THE NAM DOES ALSO HINT AT
THE CHANCE OF THESE SHOWERS EXTENDING INTO THE NIGHTTIME HOURS. NO
SPECIFIC AREA WITHIN OUR REGION SEEMS TO BE MORE LIKELY THAN THE
OTHERS AT THIS TIME. AS FOR THE RISK OF ANY OF THESE BECOMING
THUNDERSTORMS, THE CHANCE IS QUITE LOW AT THIS TIME GIVEN THE LACK
OF FORCING AND MLCAPE GENERALLY ONLY MAXING OUT AROUND 500 J/KG.
DRIER WEATHER IS EXPECTED TO RETURN (AT LEAST BRIEFLY) AS HIGH
PRESSURE ASSOCIATED WITH AN AMPLIFIED UPPER LEVEL RIDGE MOVES INTO
SOUTHERN NEW ENGLAND. THIS RIDGE WILL BE A KEY FEATURE TO MONITOR
FOR NEXT WEEK, AS IT IS THE ANTICIPATED HEAT DOME THAT WILL IMPACT
MUCH OF THE EASTERN US. A WARMING TREND ALSO KICKS OFF, CONTINUING
AND INTENSIFYING INTO MIDWEEK.
KEY MESSAGE 3...WARM AND HUMID MIDWEEK, ALONG WITH A RISK OF SHOWERS
TOWARDS THE SECOND HALF OF NEXT WEEK.
THE INCREASED WARMTH LOOKS TO PEAK SOMETIME MID- TO LATE-WEEK AS WE
SIT JUST ON THE EDGE OF THE ANTICIPATED HEAT DOME BUILDING OVER MUCH
OF THE EASTERN US. ENSEMBLES HAVE INDICATED MEAN HIGH TEMPERATURES
WEDNESDAY AND THURSDAY CLIMBING INTO THE 90S WITH EVEN A SHOT AT
100F, SUPPORTED BY 850 MB TEMPERATURES AT 20-22C AND 925 MB
TEMPERATURES IN THE DETERMINISTIC GUIDANCE APPROACHING 30C.
PROBABILITIES FOR TEMPERATURES AT 100F OR HIGHER ARE AROUND 20-40
PERCENT ACROSS A NUMBER OF THE ENSEMBLES, WITH THE GEFS MORE BULLISH
WITH PROBABILITIES TO 60 PERCENT THURSDAY AFTERNOON. FOR WEDNESDAY
AFTERNOON, PROBABILITIES ARE MOSTLY BETWEEN 20-40 PERCENT. THE
HIGHEST PROBABILITIES BOTH DAYS LIE MOSTLY IN EASTERN MA BUT DO
REACH INTO CT BOTH DAYS. IT'S WORTH NOTING, TOO, THAT THIS IS BEFORE
FACTORING IN ANY HUMIDITY, WHICH WILL ALSO BE INCREASING IN THIS
PATTERN. A SHORTWAVE OR TWO MAY "ROLL" ALONG THE EASTERN EDGE OF THE
UPPER LEVEL RIDGE, WHICH MAY BRING SOME UNSETTLED WEATHER FOR
MIDWEEK. LOCATION-SPECIFIC AND REFINED TIMING DETAILS ARE NOT YET
KNOWN, THOUGH LATEST GUIDANCE IS POINTING TOWARDS SOMETIME BETWEEN
TUESDAY EVENING AND THURSDAY.
AVIATION /07Z SATURDAY THROUGH WEDNESDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
06Z UPDATE
THROUGH 12Z...MODERATE CONFIDENCE.
VFR FOR MOST. PATCHY FOG LEADING TO AREAS OF MVFR/IFR MAY
DEVELOP OVERNIGHT ACROSS MUCH OF SE MA AND CAPE COD; THESE HAVE
ALREADY DEVELOPED OVER THE ISLANDS. WINDS SHIFT MORE W AND GO
LIGHT TO CALM OVERNIGHT.
TODAY...MODERATE CONFIDENCE.
MOSTLY LOWER-END VFR WITH AREAS OF MVFR. SHOWERS MOSTLY SCRAPING
ALONG THE SOUTH COAST ARE FAVORED; LOWER CONFIDENCE IN THOSE
GOING MUCH FURTHER NORTH THAN THAT. THESE MAY ALSO APPROACH
LATER IN THE DAY THAN ORIGINALLY EXPECTED. LIGHT WINDS, WITH
SEA BREEZES DEVELOPING BY 14Z.
TONIGHT...MODERATE CONFIDENCE.
VFR FOR MOST. AREAS MVFR/IFR TOWARDS SOUTHEASTERN MA AND
SOUTHERN RI.
SUNDAY...MODERATE CONFIDENCE.
MOSTLY VFR WITH THE CHANCE FOR SCATTERED SHOWERS MOSTLY IN THE
AFTERNOON. ONSHORE FLOW PREVAILS WITH LIGHT WINDS.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...
SUNDAY NIGHT THROUGH MONDAY NIGHT: VFR.
TUESDAY: VFR. BREEZY. CHANCE SHRA, CHANCE TSRA.
TUESDAY NIGHT: VFR. BREEZY. SLIGHT CHANCE SHRA, SLIGHT CHANCE
TSRA.
WEDNESDAY: 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 WEAK PRESSURE GRADIENT WILL KEEP WINDS/SEAS BELOW SMALL CRAFT
ADVISORY THRESHOLDS THROUGH TONIGHT. WITH EARLIER SHOWERS AND
STORMS HAVING LONG SINCE MOVED OUT OF OUR WATERS, AREAS OF FOG
MAY IMPACT THE WATERS AT TIMES THROUGH EARLY THIS MORNING.
SOME FOG MAY LINGER THROUGH TODAY AND EVEN TONIGHT IN THE
EASTERN WATERS WHILE SHOWERS MAY IMPACT THE SOUTHERN OUTER AND
OCEAN WATERS TODAY. FOG MAY ALSO REDEVELOP TONIGHT IN AREAS
OVER THE SOUTHERN WATERS THAT SEE SOME CLEARING TODAY. HOWEVER,
WINDS REMAIN VERY LIGHT (BELOW 10 KT!) INTO SUNDAY AND SEAS ALSO
REMAIN GENERALLY BETWEEN 2-3 FT. FOG SHOULD DIMINISH GREATLY FOR
SUNDAY.
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...
SUNDAY NIGHT THROUGH MONDAY NIGHT: WINDS LESS THAN 25 KT.
TUESDAY: WINDS LESS THAN 25 KT. SLIGHT CHANCE OF RAIN SHOWERS.
TUESDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. CHANCE OF RAIN SHOWERS, SLIGHT CHANCE OF
THUNDERSTORMS.
WEDNESDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. SEAS LOCALLY APPROACHING 5 FT. SLIGHT CHANCE
OF RAIN SHOWERS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
DISCUSSION...HRENCECIN
AVIATION...HRENCECIN
MARINE...HRENCECIN
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