258
FXUS61 KBOX 161109
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
709 AM EDT SAT MAY 16 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES IN THIS FORECAST PACKAGE.
KEY MESSAGES
- AREAS OF PATCHY FOG THIS MORNING FOLLOWED BY A QUICK WARM UP
- 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...AREAS OF PATCHY FOG THIS MORNING FOLLOWED BY A
QUICK WARM UP
A MID-LEVEL RIDGE ALOFT HAS SLOWLY BUILT OVER SOUTHERN NEW
ENGLAND THIS EVENING. MOSTLY CLEAR SKIES HAS ALLOWED NEAR-
SURFACE TEMPERATURES TO COOL ENOUGH TO MATCH DEW POINT
TEMPERATURES IN THE LOW TO MID 40S. WITH A SHALLOW INVERSION IN
PLACE, THE BOUNDARY LAYER HAS SLOWLY SATURATED WITH FOG
DEVELOPMENT AT A FEW LOCATIONS IN SOUTHERN NEW ENGLAND, MAINLY
IN THE RADIATOR AREAS. EXPECT PATCHY FOG DEVELOPMENT TO CONTINUE
THROUGH SUNRISE. THEREAFTER, ANY AREAS OF FOG WILL LIFT AFTER
SUN RISE. WEST/SOUTHWEST FLOW WILL BEGIN TO ADVECT A WARMER AIR
MASS OVER THE REGION, BEGINNING A PERIOD OF ABOVE NORMAL
TEMPERATURES THAT WILL PERSIST THROUGH THE MIDDLE OF NEXT WEEK.
WITH DIURNAL MIXING AND 925 HPA TEMPS RISING TO 18-20C, WE CAN
EXPECT HIGH TEMPERATURES IN THE MID TO UPPER 70S FOR MOST
LOCATIONS IN SOUTHERN NEW ENGLAND THIS AFTERNOON WITH NEAR 80
POSSIBLE IN THE CT RIVER VALLEY. THE CAPE AND ISLANDS WILL BE
COOLER GIVEN THE PROXIMITY TO THE OCEAN WITH HIGHS IN THE UPPER
60S/LOW 70S. OVERALL A VERY PLEASANT SPRING DAY TO START THE
WEEKEND.
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 /12Z SATURDAY THROUGH WEDNESDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
12Z TAF UPDATE...HIGH CONFIDENCE
TODAY THROUGH TOMORROW...HIGH CONFIDENCE
VFR CONDITIONS THROUGH TOMORROW, EXCEPT LIFR AT ACK THROUGH 13Z
TODAY WHEN FG LIFTS OUT. STEADY SOUTHWEST WINDS AROUND 10 KNOTS
TODAY WITH SOME GUSTS OF 20+ KNOTS POSSIBLE DURING THE MID-
AFTERNOON HOURS. SOUTHWEST WINDS SHOULD BE STRONG ENOUGH TO FEND
OFF A SEA- BREEZE. STEADY WEST WINDS CONTINUE OVERNIGHT AND
BECOME MORE WEST/NORTHWEST ON SUNDAY.
KBOS...HIGH CONFIDENCE IN TAF
KBDL...HIGH CONFIDENCE IN TAF.
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...
SUNDAY NIGHT THROUGH MONDAY NIGHT: VFR.
TUESDAY: VFR. BREEZY. SLIGHT CHANCE SHRA, SLIGHT CHANCE TSRA.
TUESDAY NIGHT: VFR. BREEZY.
WEDNESDAY: VFR. BREEZY. CHANCE SHRA, SLIGHT CHANCE 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 NIGHT THROUGH WEDNESDAY/...
SUNDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT.
MONDAY THROUGH MONDAY NIGHT: WINDS LESS THAN 25 KT.
TUESDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS UP
TO 25 KT. AREAS OF SEAS APPROACHING 5 FT.
TUESDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. SEAS UP TO 5 FT.
WEDNESDAY: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS
UP TO 25 KT. AREAS OF SEAS APPROACHING 5 FT. SLIGHT CHANCE OF
RAIN SHOWERS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING
FOR ANZ231>234.
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...RM
AVIATION...MCMINN
MARINE...RM
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