362
FXUS61 KBOX 050849
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
449 AM EDT SUN JUL 5 2026
WHAT HAS CHANGED
A FLOOD WATCH HAS BEEN ISSUED FOR CONNECTICUT.
KEY MESSAGES
- COOLER/SEASONABLE TEMPS RETURN TODAY WITH HIGHS MAINLY IN THE
UPPER 70S TO THE MIDDLE 80S. MAINLY DRY TODAY OUTSIDE A FEW
SHOWERS ACROSS WESTERN MA/CT AND NEAR THE SOUTH COAST.
- CONFIDENCE GROWING IN THE POTENTIAL FOR BANDS OF HEAVY RAINFALL
& EVEN THE RISK FOR LOCALIZED FLASH FLOODING LATE TONIGHT INTO TUE.
GREATEST RISK FOR THIS RIGHT NOW IS IN NORTHERN CT...WHERE A
FLOOD WATCH HAS BEEN ISSUED.
- SUMMER WARMTH & HUMIDITY RETURN FOR THE LATTER HALF OF THE WEEK.
A FEW SHOWERS AND THUNDERSTORMS POSSIBLE BY FRI-SAT.
DISCUSSION
KEY MESSAGE 1...COOLER/SEASONABLE TEMPS RETURN TODAY WITH HIGHS
MAINLY IN THE UPPER 70S TO THE MIDDLE 80S. MAINLY DRY TODAY OUTSIDE
A FEW SHOWERS ACROSS WESTERN MA/CT AND NEAR THE SOUTH COAST.
THE UPPER LEVEL RIDGE HAS FINALLY BROKEN DOWN ACROSS THE
REGION...WHICH WILL BRING A RETURN TO COOLER/SEASONABLE TEMPERATURES
TODAY. WE DO EXPECT A SCATTERED TO BROKEN DECK OF MID-LEVEL
CLOUDINESS ACROSS THE REGION AS A WEAK SURFACE BOUNDARY SLOWLY LIFTS
NORTH ACROSS THE REGION. DRY WEATHER WILL DOMINATE TODAY...EXCEPT
FOR A FEW SHOWERS ACROSS WESTERN MA/CT AND NEAR THE SOUTH COAST
GIVEN THEIR PROXIMITY TO DEEPER MOISTURE AND FORCING.
KEY MESSAGE 2...CONFIDENCE GROWING IN THE POTENTIAL FOR BANDS OF
HEAVY RAINFALL & EVEN THE RISK FOR LOCALIZED FLASH FLOODING LATE
TONIGHT INTO TUE. GREATEST RISK FOR THIS RIGHT NOW IS IN NORTHERN
CT...WHERE A FLOOD WATCH HAS BEEN ISSUED.
CONFIDENCE IS GROWING IN THE POTENTIAL FOR BANDS OF HEAVY RAINFALL
AND EVEN THE RISK FOR LOCALIZED FLASH FLOODING LATE TONIGHT INTO
TUE. THIS IS A RATHER COMPLEX FORECAST IN TRYING TO DETERMINE THE
LOCATION AND GREATEST RISK FOR TORRENTIAL RAINFALL/LOCALIZED FLASH
FLOODING WHICH WE WILL DISCUSS MORE BELOW.
WEAK HIGH PRESSURE OVER EASTERN CANADA WILL HELP TO FOCUS A SHALLOW
BOUNDARY AT THE SURFACE. JUST ABOVE THAT A MODEST ESE LOW LEVEL OF 25
TO 35 KNOTS AT 925 MB WILL IMPINGE ON THIS SURFACE BOUNDARY. THIS
WILL COMBINED WITH PWATS OF 1.5 TO 2+ INCHES AND SET THE STAGE FOR
BANDS OF HEAVY RAINFALL LATE TONIGHT INTO TUE WITH SOME EMBEDDED
THUNDER POSSIBLE. WE ARE ESSENTIALLY COMBINING SYNOPTIC SCALE
FORCING WITH SUMMERTIME MOISTURE AND INSTABILITY...WHICH IS A GOOD
SETUP OF FOR BANDS OF TORRENTIAL RAINFALL AND POTENTIAL FOR
LOCALIZED FLASH FLOODING. THE MODELS DO QUITE A GOOD JOB THESE DAYS
IN INDICATING THE POTENTIAL FOR TORRENTIAL RAINFALL/LOCALIZED FLASH
FLOODING. HOWEVER...THEY OFTEN STRUGGLE TO DEPICT THE LOCATION GIVEN
VARIOUS MESOSCALE PARAMETERS IN PLAY. CURRENTLY, THE MODELS SEEM TO
BE FAVORING OUR SOUTHWEST ZONES WHERE THE BEST MOISTURE AND PWAT
PLUME ARE LOCATED.
GIVEN THE ABOVE...WE HAVE GONE AHEAD AND ISSUED A FLOOD WATCH FOR
OUR CT ZONES. THIS IS FOR A WIDESPREAD 1-3 INCHES OF RAINFALL...BUT
THE POTENTIAL FOR LOCALIZED NARROW BANDS OF 4-6 INCHES OF RAIN
INSIDE 6 HOURS. IF THIS WERE TO OCCUR...THE POTENTIAL WOULD EXIST
FOR BOTH URBAN AND SMALL STREAM FLASH FLOODING LATE TONIGHT INTO
TUE. LATER SHIFTS MAY NEED TO EXPAND THE FLOOD WATCH FURTHER NORTH
AND EAST...BUT WE FELT THIS WAS A GOOD STARTING POINT FOR NOW. IT IS
ALSO POSSIBLE THAT THE HEAVY RAIN/FLOOD THREAT REMAINS TO OUR
SOUTHWEST...BUT EITHER WAY FELT A FLOOD WATCH FOR CT WAS REASONABLE
TO JUST HIGHLIGHT THE POTENTIAL.
KEY MESSAGE 3...SUMMER WARMTH & HUMIDITY RETURN FOR THE LATTER HALF
OF THE WEEK.
DRIER WEATHER WORKS INTO THE REGION BY WED AS THE SHORTWAVE TROUGH
DEPARTS. WESTERLY FLOW WILL DEVELOP BY LATE IN THE WEEK BRINGING
TYPICAL SUMMERTIME WARMTH AND HUMIDITY BACK INTO THE REGION...BUT
FORTUNATELY NOT THE EXTREME HEAT WE HAVE DEALT WITH THE LAST FEW
DAYS. THERE WILL ALSO BE THE RISK FOR A FEW SHOWERS AND
THUNDERSTORMS BY FRI-SAT AS THE NEXT SHORTWAVE WORKS INTO THE
REGION.
AVIATION /08Z SUNDAY THROUGH THURSDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
06Z TAF UPDATE...
TODAY THROUGH MONDAY...MODERATE CONFIDENCE.
MAINLY VFR TODAY BUT SOME LOWER MVFR CONDITIONS POSSIBLE AT TIMES
TODAY IN A FEW SHOWERS ACROSS WESTERN MA/CT AND NEAR THE SOUTH
COAST. MVFR CONDITIONS BECOME MORE WIDESPREAD ACROSS WESTERN MA/CT
LATER TONIGHT AND MON ALONG WITH PERIODS OF SHOWERS WITH LOCALLY
HEAVY RAINFALL.
LIGHT ESE WINDS TODAY AND TONIGHT BECOMING E AT 6 TO 13 KNOTS ON
MON.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT: MAINLY MVFR, WITH AREAS IFR POSSIBLE. BREEZY.
SHRA, SLIGHT CHANCE TSRA, PATCHY BR.
TUESDAY: MVFR/IFR CONDITIONS POSSIBLE. WINDY WITH LOCAL GUSTS
UP TO 30 KT. CHANCE SHRA, SLIGHT CHANCE TSRA, PATCHY BR.
TUESDAY NIGHT: MAINLY VFR, WITH AREAS MVFR POSSIBLE. BREEZY.
CHANCE SHRA.
WEDNESDAY THROUGH WEDNESDAY NIGHT: VFR.
THURSDAY: VFR. BREEZY.
MARINE
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
TODAY AND TONIGHT...HIGH CONFIDENCE.
HIGH PRESSURE OVER EASTERN CANADA COMBINED WITH A WAVE OF LOW
PRESSURE PASSING TO OUR SOUTH WILL RESULT IN ESE WINDS TODAY AND
TONIGHT...BUT THE WINDS/SEAS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY THRESHOLDS.
MONDAY...MODERATE CONFIDENCE.
WAVE OF LOW PRESSURE PASSING TO OUR SOUTH SHOULD RESULT IN E WIND
GUSTS INCREASING TO AROUND 25+ KNOTS ACROSS OUR SOUTHERN WATERS.
LATER SHIFTS WILL LIKELY NEED TO ISSUE SMALL CRAFT ADVISORIES FOR
OUR SOUTHERN WATERS AND WE MAY NEED TO EXPAND THEM FURTHER NORTH
MONDAY NIGHT.
OUTLOOK /MONDAY NIGHT THROUGH THURSDAY/...
MONDAY NIGHT: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 30 KT. LOCAL ROUGH SEAS. RAIN SHOWERS, SLIGHT
CHANCE OF THUNDERSTORMS, PATCHY FOG.
TUESDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH
LOCAL GUSTS UP TO 30 KT. ROUGH SEAS UP TO 10 FT. RAIN SHOWERS
LIKELY, SLIGHT CHANCE OF THUNDERSTORMS, PATCHY FOG.
TUESDAY NIGHT: WINDS LESS THAN 25 KT. ROUGH SEAS UP TO 10 FT.
CHANCE OF RAIN SHOWERS, SLIGHT CHANCE OF THUNDERSTORMS.
WEDNESDAY: WINDS LESS THAN 25 KT. ROUGH SEAS UP TO 9 FT. SLIGHT
CHANCE OF RAIN SHOWERS.
WEDNESDAY NIGHT THROUGH THURSDAY: WINDS LESS THAN 25 KT. SEAS
UP TO 5 FT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...FLOOD WATCH FROM LATE TONIGHT THROUGH TUESDAY AFTERNOON FOR
CTZ002>004.
MA...NONE.
RI...NONE.
MARINE...NONE.
DISCUSSION...FRANK
AVIATION...FRANK
MARINE...FRANK
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page