244
FXUS61 KBOX 090518
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
118 AM EDT TUE JUN 9 2026
WHAT HAS CHANGED
NO SIGNIFICANT FORECAST CHANGES.
KEY MESSAGES
- PLEASANT WEATHER CONTINUES ON TUESDAY WITH MOSTLY SUNNY SKIES
BUT WARMER HIGH TEMPERATURES WELL INTO THE 80S.
- SUMMER LIKE HEAT REMAINS IN PLACE THROUGH THE WEEKEND WITH
CHANGES FOR DIURNAL THUNDERSTORMS WEDNESDAY THROUGH FRIDAY.
DISCUSSION
KEY MESSAGE 1...PLEASANT WEATHER CONTINUES ON TUESDAY WITH MOSTLY
SUNNY SKIES BUT WARMER HIGH TEMPERATURES WELL INTO THE 80S.
HIGH PRESSURE JUST OFF THE MID-ATLANTIC COAST WILL CONTINUE TO
SLOWLY SINK FURTHER SOUTH THROUGH TUESDAY NIGHT. THIS WILL RESULT IN
THE CONTINUATION OF DRY AND PLEASANT WEATHER ON TUESDAY...BUT WITH
WARMER TEMPERATURES.
MAINLY CLEAR SKIES WITH LIGHT/CALM WINDS TONIGHT WILL RESULT IN GOOD
RADIATIONAL COOLING CONDITIONS AND COMFORTABLE TEMPERATURES. LOW
TEMPS TONIGHT WILL RANGE FROM THE UPPER 40S IN THE NORMALLY COOLEST
OUTLYING LOCATIONS...TO THE LOWER TO MIDDLE 50S IN MOST OTHER
LOCATIONS. THE MILD SPOT WILL BE THE URBAN HEAT ISLAND OF BOSTON
WITH LOWS ONLY DROPPING TO NEAR 60 AS SOUTHWEST WINDS BEGIN TO MIX
MILDER TEMPS ALOFT.
PLENTY OF SUNSHINE ON TUESDAY WITH A WARMER SOUTHWEST FLOW OF AIR
WORKING INTO THE REGION. THIS SHOULD PUSH HIGH TEMPS WELL INTO THE
80S IN MOST LOCATIONS...EXCEPT 70S NEAR THE IMMEDIATE SOUTH COAST
WITH A MODIFIED MARINE AIRMASS GIVEN GUSTY SW WINDS.
OTHERWISE...DEWPOINTS WILL BE LOW ON TUESDAY SO HUMIDITY LEVELS WILL
REMAIN QUITE COMFORTABLE DESPITE THE WARM TEMPERATURES.
DRY AND PLEASANT WEATHER CONTINUES TUESDAY NIGHT WITH LOW TEMPS
MAINLY IN THE MIDDLE 50S TO THE LOWER 60S.
KEY MESSAGE 2...SUMMER LIKE HEAT REMAINS IN PLACE THROUGH THE
WEEKEND WITH CHANGES FOR DIURNAL THUNDERSTORMS WEDNESDAY THROUGH
FRIDAY.
HIGH PRESSURE POSITIONED OFF THE EAST COAST WILL CONTINUE TO SUPPORT
A STRETCH OF WARM, SUMMER-LIKE WEATHER ACROSS SOUTHERN NEW ENGLAND
FROM WEDNESDAY THROUGH THE WEEKEND. TEMPERATURES SEVERAL THOUSAND
FEET ABOVE THE SURFACE WILL REMAIN QUITE WARM, FAVORING AFTERNOON
HIGHS RANGING FROM THE MID 80S TO LOWER 90S EACH DAY. COASTAL
LOCATIONS WILL BE COOLER GIVEN THE PROXIMITY TO THE OCEAN.
IN ADDITION TO THE WARMTH, A HUMID AIR MASS WILL REMAIN IN PLACE
FROM WEDNESDAY THROUGH FRIDAY, WITH DEW POINTS GENERALLY IN THE MID
TO UPPER 60S AND LOCALLY NEAR 70 DEGREES. THIS COMBINATION OF HEAT
AND HUMIDITY WILL CREATE ENOUGH INSTABILITY FOR SCATTERED AFTERNOON
SHOWERS AND THUNDERSTORMS TO DEVELOP. SEVERAL WEAK DISTURBANCES
MOVING THROUGH THE FLOW ALOFT MAY HELP TRIGGER THIS ACTIVITY,
PARTICULARLY DURING THE AFTERNOON AND EVENING HOURS.
AT THIS TIME, THERE ARE NO STRONG INDICATIONS OF A WIDESPREAD SEVERE
WEATHER EVENT. THE INGREDIENTS TYPICALLY ASSOCIATED WITH ORGANIZED
SEVERE THUNDERSTORMS—INCLUDING STRONG FORCING, ABUNDANT INSTABILITY,
AND STRONGER WIND SHEAR APPEAR SOMEWHAT LIMITED. THAT SAID, A FEW
STRONGER STORMS CANNOT BE RULED OUT. CURRENT CSU MACHINE-LEARNING
GUIDANCE INDICATES A 5 TO 15 PERCENT PROBABILITY OF SEVERE WEATHER
THURSDAY INTO FRIDAY, WITH SLIGHTLY HIGHER PROBABILITIES OF 15 TO 30
PERCENT ACROSS PORTIONS OF CONNECTICUT. FORECAST CONFIDENCE
REGARDING THUNDERSTORM COVERAGE AND INTENSITY SHOULD IMPROVE AS
HIGHER-RESOLUTION GUIDANCE BECOMES AVAILABLE OVER THE NEXT COUPLE OF
DAYS.
HEAT AND HUMIDITY WILL ALSO POSE A RISK, ESPECIALLY ON THURSDAY WHEN
HEAT INDEX VALUES MAY APPROACH 100 DEGREES IN PARTS OF THE
CONNECTICUT RIVER VALLEY. THESE VALUES ARE ASSOCIATED WITH MODERATE
TO MAJOR HEAT IMPACTS, INCREASING THE RISK OF HEAT-RELATED ILLNESS
FOR ANYONE SPENDING EXTENDED TIME OUTDOORS WITHOUT ADEQUATE
HYDRATION OR ACCESS TO COOLING. CONFIDENCE REMAINS TOO LOW AT THIS
TIME TO DETERMINE WHETHER HEAT HEADLINES WILL BE NEEDED, BUT THEY
MAY BECOME NECESSARY IF CONFIDENCE INCREASES IN HEAT INDEX VALUES
EXCEEDING 100 DEGREES.
BY THE WEEKEND, A MID-LEVEL RIDGE IS EXPECTED TO STRENGTHEN OVER
SOUTHERN NEW ENGLAND, PROMOTING RISING HEIGHTS ALOFT AND A SOMEWHAT
DRIER AIR MASS. WHILE TEMPERATURES WILL REMAIN QUITE WARM, DEW
POINTS SHOULD FALL BACK INTO THE 50S, RESULTING IN NOTICEABLY MORE
COMFORTABLE CONDITIONS AND A REDUCED RISK OF AFTERNOON
THUNDERSTORMS.
AVIATION /06Z TUESDAY THROUGH SATURDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
06Z TAF UPDATE...
THROUGH WEDNESDAY MORNING...HIGH CONFIDENCE.
VFR CONDITIONS CONTINUE THROUGH WED MORNING. SW-LY WINDS WITH
SOME 20-25 KNOT GUSTS DURING THE DAY TUESDAY, THE STRONGEST OF
WHICH WILL BE FOCUSED NEAR THE SOUTH COAST AND UPPER CAPE. CIGS
START TO LOWER WEDNESDAY FROM WEST TO EAST AS A WARM FRONT LIFTS
THROUGH SOUTHERN NEW ENGLAND, BUT SHOULD REMAIN VFR THROUGH AT
LEAST WED MORNING.
KBOS TERMINAL...HIGH CONFIDENCE.
KBDL TERMINAL...HIGH CONFIDENCE.
OUTLOOK /WEDNESDAY NIGHT THROUGH SATURDAY/...
WEDNESDAY NIGHT: MAINLY VFR, WITH AREAS IFR POSSIBLE. BREEZY.
CHANCE SHRA, SLIGHT CHANCE TSRA.
THURSDAY: VFR. CHANCE SHRA, CHANCE TSRA.
THURSDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. CHANCE
SHRA.
FRIDAY: VFR. SLIGHT CHANCE SHRA, SLIGHT CHANCE TSRA.
FRIDAY NIGHT: VFR. CHANCE SHRA, SLIGHT CHANCE TSRA.
SATURDAY: VFR. SLIGHT CHANCE SHRA.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
THROUGH WEDNESDAY MORNING...HIGH CONFIDENCE.
HIGH PRESSURE CENTERED ACROSS THE MID-ATLANTIC STATES WILL
CONTINUE TO SLOWLY SINK SOUTHWARD THROUGH TUESDAY NIGHT, WITH
WINDS ALREADY SHIFTING SW. GOOD MIXING OVER THE LAND SHOULD
YIELD SW WIND GUSTS AROUND 25 KNOTS ACROSS OUR NEARSHORE
SOUTHERN WATERS TUESDAY AFTERNOON, PROMPTING THE CONTINUATION OF
SMALL CRAFT ADVISORIES. THE REST OF THE REGION SHOULD GENERALLY
REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH WEDNESDAY
MORNING.
OUTLOOK /WEDNESDAY NIGHT THROUGH SATURDAY/...
WEDNESDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. SEAS UP TO 5 FT. RAIN SHOWERS, SLIGHT CHANCE
OF THUNDERSTORMS.
THURSDAY: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS. CHANCE OF
RAIN SHOWERS.
THURSDAY NIGHT: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. CHANCE
OF RAIN SHOWERS.
FRIDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
FRIDAY NIGHT THROUGH SATURDAY: WINDS LESS THAN 25 KT. SLIGHT
CHANCE OF RAIN SHOWERS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 7 PM EDT THIS
EVENING FOR ANZ231>236.
DISCUSSION...FRANK/RM
AVIATION...MCMINN
MARINE...MCMINN
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