012
FXUS61 KBOX 151913
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
313 PM EDT FRI MAY 15 2026
WHAT HAS CHANGED
CHANCES FOR SOME SHOWERS LATE SATURDAY NIGHT INTO SUNDAY
MORNING. CONFIDENCE INCREASING IN NEAR RECORD HIGH TEMPERATURES
POSSIBLE BY TUESDAY AND/OR WEDNESDAY ALONG WITH THE POTENTIAL
FOR A ROUND OF STRONG TO SEVERE THUNDERSTORMS.
KEY MESSAGES
- DREARY CONDITIONS CONTINUE TODAY WITH FOG POSSIBLE OVERNIGHT
BEFORE WARM-UP KICKS OFF SATURDAY.
- UNSEASONABLY WARM TEMPS SUN THROUGH WED WITH NEAR RECORD HIGH
TEMPS INTO THE 90S POSSIBLE TUE AND/OR WED.
- STRONG TO SEVERE THUNDERSTORMS POSSIBLE BY TUE WITH PERHAPS A
BETTER POTENTIAL BY WED BUT A LOT NEEDS TO BE SORTED OUT.
- SEASONABLE TEMPERATURES RETURN BY NEXT THU AND FRI.
DISCUSSION
KEY MESSAGE 1...DREARY CONDITIONS CONTINUE TODAY WITH FOG POSSIBLE
OVERNIGHT BEFORE WARM-UP KICKS OFF SATURDAY.
THE CLOSED LOW ALOFT WILL CONTINUE SHIFTING OFFSHORE THROUGH
TONIGHT, BEING REPLACED BY MORE ZONAL FLOW TO KICK OFF THE WEEKEND.
THE ASSOCIATED SURFACE LOW CURRENTLY LOCATED OFF TO OUR EAST THAT IS
PROVIDING THE MOISTURE PLUME AROUND NE MA WILL ALSO PROGRESS EAST
THROUGH TONIGHT AND PULL AWAY FROM THE REGION. LATEST MESOANALYSIS
INDICATES SOME SURFACE-BASED CAPE ALONG THE SOUTH COAST THAT'S
HELPING FUEL SOME POP-UP SHOWERS. THESE WILL LIKELY CONTINUE THROUGH
THIS EVENING, ENDING AROUND SUNSET. CLOUD COVER WILL LINGER BEFORE
WINDS START TO SHIFT MORE NW THEN SW, AND WITH THE MOIST GROUND
CONDITIONS, PATCHES OF FOG MAY DEVELOP ACROSS SOUTHERN NEW
ENGLAND, EXTENDING BEYOND THE USUAL AREAS IN THE RIVER VALLEYS
AND OTHER FREQUENTLY FOGGY AREAS. LOWS WILL ONCE AGAIN BE
MOSTLY IN THE 40S WITH DEW POINTS NOT FAR BEHIND THEM.
SOUTHWEST FLOW CLOSER TO THE SURFACE REALLY KICKS UP SATURDAY
MORNING AS THE QUASI-ZONAL FLOW ALOFT TAKES HOLD. SKIES CLEAR
OUT AND WITH THE FULL SUN ALONG WITH WARMER AIR ALOFT, HIGHS
WILL RISE INTO THE 70S ACROSS SOUTHERN NEW ENGLAND. SPOTS IN THE
CT VALLEY MAY ALSO APPROACH 80. WINDS MAY GUST BETWEEN 20-25
MPH IN THE AFTERNOON. A WEAK SHORTWAVE PASSING JUST TO OUR NORTH
OVERNIGHT MAY ALSO BRING THE CHANCE FOR SOME LIGHT SHOWERS LATE
SATURDAY NIGHT INTO SUNDAY, BUT NOT MUCH ELSE EXPECTED IN THE
WAY OF PRECIPITATION TOMORROW. WITH WARMER AIR REMAINING ALOFT
AND SW FLOW STARTING TO SHIFT MORE W, LOWS OVERNIGHT SATURDAY
WILL LIKELY ONLY FALL INTO THE MID TO UPPER 50S.
KEY MESSAGE 2...UNSEASONABLY WARM TEMPS SUN THROUGH WED WITH NEAR
RECORD HIGH TEMPS INTO THE 90S POSSIBLE TUE AND/OR WED.
HIGH CONFIDENCE CONTINUES IN A PATTERN CHANGE TO UNSEASONABLE WARM
TEMPERATURES FOR THE FIRST HALF OF NEXT WEEK AND POTENTIALLY
FLIRTING WITH RECORD HIGHS ON TUE/WED. GEFS/EPS GUIDANCE CONTINUE TO
SHOW A BUILDING BERMUDA HIGH PRESSURE SYSTEM RESULTING IN ABOVE TO
WELL ABOVE NORMAL HEIGHT FIELDS.
W-SW FLOW SHOULD PUSH HIGH TEMPS INTO THE 80S ON SUN AWAY FROM THE
CAPE AND ISLANDS. A WEAK BACKDOOR COLD FRONT MAY BRING BRIEFLY
COOLER TEMPS MON...MAINLY ON THE IMMEDIATE COAST. HIGHS MON ON THE
IMMEDIATE COAST PROBABLY IN THE UPPER 60S AND 70S WHILE 80+ RISK
WILL BE CONFINED TO THE INTERIOR. THE HOTTEST DAYS LOOK TO BE TUE
AND/OR WED DEPENDING ON THE TIMING OF A COLD FRONT. 925T NEAR +24C
SHOULD RESULT IN THE POTENTIAL FOR HIGH TEMPERATURES TO CLIMB INTO
THE 90S AWAY FROM ANY MODIFIED MARINE INFLUENCES. THIS MAY RESULT IN
RECORD HIGH TEMPERATURES BEING CHALLENGED AT LEAST IN AREAS AWAY
FROM THE SOUTH COAST.
KEY MESSAGE 3...STRONG TO SEVERE THUNDERSTORMS POSSIBLE BY TUE WITH
PERHAPS A BETTER POTENTIAL BY WED BUT A LOT NEEDS TO BE SORTED OUT.
QUITE THE WAYS OUT THERE...ESPECIALLY FOR A CONVECTIVE FORECAST.
THAT BEING SAID...THERE ARE SOME SIGNALS FOR POTENTIALLY STRONG TO
SEVERE THUNDERSTORMS LATER TUE AND PERHAPS A BETTER CHANCE BY WED.
THIS WILL BE DEPENDENT UPON THE TIMING OF A COLD FRONT...BUT GIVEN
ANOMALOUS/NEAR RECORD WARMTH THE POTENTIAL IS THERE. IN FACT...MUCH
OF OUR MACHINE LEARNING GUIDANCE INDICATES SOME MODEST SEVERE
WEATHER PROBABILITIES FOR A DAY 4-5 FORECAST...SO THIS IS CERTAINLY
SOMETHING TO WATCH.
KEY MESSAGE 4...SEASONABLE TEMPERATURES RETURN BY NEXT THU AND FRI.
THE LONG RANGE GUIDANCE IS IN GOOD AGREEMENT IN THE RETURN OF
SEASONABLE TEMPERATURES BY THU AND FRI BEHIND THE MID-WEEK COLD
FRONT.
AVIATION /19Z FRIDAY THROUGH WEDNESDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE:
REST OF TODAY...MODERATE CONFIDENCE.
GENERALLY MVFR AND LOW END VFR THIS AFTERNOON, WITH THE
EXCEPTION OF BOS AND NORTH WHERE IFR/LIFR IS ONGOING.
UNCERTAINTY REMAINS REGARDING ANY SHOWERS MAKING IT TO BOS
AND NOT MUCH EXPECTED AT BED FOR THE REST OF THE DAY. AT MOST,
SOME DRIZZLE POSSIBLE THROUGH 20Z. VFR OUT WEST AND IN GENERAL
WILL LIKELY BE ON THE LOWER END OF THE SCALE WITH CEILINGS
CLOSER TO 30 KFT. WINDS NW THROUGH THIS AFTERNOON, BECOMING MORE
N CLOSER TO 00Z.
TONIGHT...HIGH CONFIDENCE IN TRENDS, MODERATE IN FOG
DEVELOPMENT.
LINGERING MVFR/IFR CEILINGS THROUGH AROUND 02-04Z, THOUGH COULD
BE LONGER TOWARDS THE CAPE AND ISLANDS. MVFR/IFR PATCHY FOG
COULD DEVELOP UPON ANY CLEARING, GIVEN RECENT DAMP GROUND, LIGHT
WINDS AND A LIKELIHOOD OF NARROW TEMPERATURE/DEWPOINT SPREADS.
IT IS UNCERTAIN IF FOG DEVELOPS AND ITS AREAL COVERAGE, BUT MOST
TAFS SEEM PRONE TO FOG DEVELOPMENT BESIDES THE USUAL FOG
TROUBLE SPOTS. LIGHT NORTHERLY WINDS, WHICH SHIFT TO SW 5 KT OR
LESS BY DAYBREAK. WIND SHIFT SW SHOULD ALSO AID IN IMPROVEMENT
TO VFR HEADING INTO SAT MORNING.
SATURDAY...HIGH CONFIDENCE.
ANY MIST OR FOG FROM OVERNIGHT DISSIPATES RAPIDLY AFTER SUNRISE
TO VFR CONDITIONS. SW WINDS INCREASE TO AROUND 10-13 KT WITH
GUSTS IN THE 20-25 KT RANGE.
KBOS...MODERATE CONFIDENCE IN TAF. PERIODS OF 1/2SM VISBYS
EXPECTED THROUGH AT LEAST 20Z, THOUGH UNCERTAINTY REMAINS
REGARDING EXACT TIMING FOR IMPROVEMENT. IFR THROUGH MUCH OF THE
EVENING BEFORE WINDS SHIFT SW AND HELP CLEAR OUT THE LOWER
CEILINGS.
KBDL...MODERATE CONFIDENCE IN TAF. VFR WITH PERIODS OF MVFR AS
CEILINGS REMAIN BORDERLINE. CLEARING LATER TONIGHT COULD BRING
A RISK FOR POSSIBLE MIST/FOG. CONFIDENCE TOO LOW AT THIS TIME
TO INCLUDE IN TAF.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUNDAY: VFR. BREEZY.
SUNDAY NIGHT: VFR.
MONDAY: VFR. BREEZY.
MONDAY NIGHT: VFR.
TUESDAY THROUGH TUESDAY NIGHT: VFR. BREEZY.
WEDNESDAY: MAINLY VFR, WITH LOCAL IFR POSSIBLE. BREEZY.
SCATTERED SHRA, SCATTERED TSRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
SCAS REMAIN IN EFFECT ON MOST WATERS AS EASTERLY SWELL BRINGS
ELEVATED SEAS IN THE 4-7 FT RANGE TONIGHT. WINDS SHIFT MORE SW
TONIGHT INTO SATURDAY, GETTING UP TO AROUND 15 KT SUSTAINED
SATURDAY AFTERNOON. GUSTS TO 25 KT POSSIBLE THEN AS WELL. FOG
POSSIBLE AGAIN TONIGHT OVER THE WATERS.
GIVEN THE CONTINUED ELEVATED SEAS AND INCREASE IN WINDS
TOMORROW, SCAS HAVE BEEN EXTENDED THROUGH SATURDAY INTO PART OF
SATURDAY NIGHT. WINDS AND SEAS ARE EXPECTED TO REMAIN ELEVATED
THEN, AND POSSIBLY INTO SUNDAY MORNING.
OUTLOOK /SUNDAY THROUGH WEDNESDAY/...
SUNDAY THROUGH MONDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF
SEAS APPROACHING 5 FT.
TUESDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS UP
TO 25 KT. AREAS OF SEAS APPROACHING 5 FT.
TUESDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT.
WEDNESDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS
UP TO 25 KT. AREAS OF SEAS APPROACHING 5 FT. SCATTERED RAIN
SHOWERS, ISOLATED THUNDERSTORMS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SUNDAY FOR ANZ235-237-251.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT SUNDAY FOR ANZ250-254>256.
DISCUSSION...FRANK/HRENCECIN
AVIATION...FRANK/HRENCECIN
MARINE...FRANK/HRENCECIN
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