743
FXUS61 KBOX 011758
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
158 PM EDT SAT AUG 1 2026
WHAT HAS CHANGED
INTRODUCED A SLIGHT CHANCE OF SHOWERS/T-STORMS THIS AFTERNOON THOUGH
MOST WILL STAY DRY.
KEY MESSAGES
- MOSTLY DRY SATURDAY WITH A MIX OF CLOUDS AND SUN, BUT THERE
REMAINS A CHANCE FOR SOME WIDELY SCATTERED SHOWERS OR T-STORMS.
- A COLD FRONT BRINGS THE RETURN OF HEAVY RAIN AND GUSTY WINDS
SUNDAY NIGHT AND MONDAY, PERHAPS LINGERING INTO TUESDAY.
- PERIODIC RAIN CHANCES WILL BE WITH US FOR MUCH OF NEXT WEEK.
DISCUSSION
KEY MESSAGE 1...MOSTLY DRY SATURDAY WITH A MIX OF CLOUDS AND SUN,
BUT THERE REMAINS A CHANCE FOR SOME WIDELY SCATTERED SHOWERS OR T-
STORMS.
A WARMER AIRMASS REMAINS OVERHEAD THANKS TO BRIEF MID LEVEL RIDGING.
THIS WILL CONTINUE TO DELIVER HIGHS IN THE MID TO UPPER 80S SATURDAY
AND SUNDAY. THE RIDGE AXIS CROSSES SNE THIS MORNING THEN BEGINS TO
BREAK DOWN SLOWLY OVER THE NEXT 24-36 HOURS. FOR THIS REASON,
DESPITE THE SURFACE HIGH PRESSURE NEARBY, INTRODUCED A SLIGHT CHANCE
OF RAIN SHOWERS OR A THUNDERSTORM THIS AFTERNOON, MAINLY OVER THE
INTERIOR. THAT BEING SAID, THE FORECAST FOR A MOSTLY DRY DAY
PERSISTS, WITH JUST SOME WIDELY SCATTERED SHOWERS OR THUNDERSTORMS
GIVEN A FEW 1000 J/KG OF CAPE. ANY CONVECTION THAT DOES FIRE UP HAS
THE POTENTIAL TO INDUCE A QUICK DOWNPOUR GIVEN PWATS STILL OVER 1".
FOR MOST LOCATIONS WE'LL SEE A MIX OF SUN AND DIURNAL LOW LEVEL
CLOUDS. HIGH CLOUDS WILL BE THICKENING AND LOWERING THROUGH THE DAY
AHEAD OF THE APPROACHING SYSTEM.
KEY MESSAGE 2...A COLD FRONT BRINGS THE RETURN OF HEAVY RAIN AND
GUSTY WINDS SUNDAY NIGHT AND MONDAY, PERHAPS LINGERING INTO TUESDAY.
THE MID LEVEL RIDGE CONTINUES TO BREAK DOWN ON SUNDAY AS AN
ANOMOLOUS MID-LEVEL LOW DIGS INTO THE OHIO VALLEY INDUCING A
DEEPENING SURFACE LOW WHICH ITSELF VERY SLOWLY TRACKS NORTHEAST.
THIS WAVE MOVES INTO NEW ENGLAND BY MONDAY, ACCOMPANIED BY AND
PRECEDED BY AN ANOMALOUS SUBTROPICAL MOISTURE PLUME WITH PWATS OVER
2" (2+SD ABOVE NORMAL). ISENTROPICALLY FORCED RAIN ARRIVES BY LATE
SUNDAY EVENING (WEST) OR SUNDAY NIGHT (EAST) AS WARM ADVECTION TAKES
HOLD. THE HEAVIEST RAINFALL RATES LIKELY OCCUR ON MONDAY AS THE COLD
FRONT ADVANCES AT THE SURFACE. THIS, COMBINED WITH FORCING FOR
ASCENT FROM A 35-45KT LLJ AND PLACEMENT UNDER THE RRQ OF A 120KT
300MB JET WILL LEAD TO MODERATE TO HEAVY RAINFALL ACROSS SNE. STILL
TOO SOON TO SAY WHERE THE HEAVIEST AMOUNTS WILL BE OR HOW MUCH, BUT
ENSEMBLE GUIDANCE IS NOT EXCITED ABOUT POTENTIAL FOR 2+ INCHES
THROUGH TUESDAY MORNING DESPITE SOME DETERMINISTIC GUIDANCE
SUGGESTING IT. THIS WILL COME INTO FOCUS AS WE GET INTO RANGE OF
MORE HIGH RESOLUTION GUIDANCE. THE PREVIOUSLY MENTIONED LLJ
WILL BRING GUSTY WINDS ON MONDAY, ESPECIALLY OVER THE
CAPE/ISLANDS AND OVER THE WATERS.
KEY MESSAGE 3...PERIODIC RAIN CHANCES WILL BE WITH US FOR MUCH OF
NEXT WEEK.
LOW CONFIDENCE FORECAST WHEN IT COMES TO HOW MUCH, IF ANY, OF A
BREAK WE SEE IN WET WEATHER BETWEEN THE EXITING SHORTWAVE MONDAY
NIGHT/EARLY TUESDAY AND THE NEXT. THAT BEING SAID, NO SPRAWLING OR
PERSISTENT HIGH PRESSURE RIDGE IS IN THE CARDS SO PERIODIC RAIN
CHANCES LIKELY PERSIST.
AVIATION /18Z SATURDAY THROUGH THURSDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE:
THIS AFTERNOON: HIGH CONFIDENCE.
VFR. SW WINDS AROUND 5-10 KT AND SEA BREEZE AROUND 10 KTS AT
BOS. LOW CHANCE FOR AN ISOLATED SHOWER OR WEAK STORM THROUGH
00Z. SEA BREEZE KICKS OUT OF BOS 23-00Z RETURNING TO SSW FLOW.
TONIGHT: MODERATE CONFIDENCE.
VFR TO START. MAIN CHALLENGE FOR TONIGHT WILL BE CEILINGS. THERE
IS POTENTIAL FOR RE-DEVELOPMENT OF A STRATUS DECK ACROSS THE
CAPE/ISLANDS POTENTIALLY EXTENDING TO THE SOUTH COAST CLOSER TO
03Z. THIS COULD BRING A RANGE OF LIFR TO IFR CEILINGS WITH FG
POSSIBLE FOR THE CAPE/ISLANDS. THERE IS CONSIDERABLE
UNCERTAINTY IN THE NORTHWARD EXTENT OF THIS STRATUS DECK. THERE
IS A LOW END POTENTIAL FOR THIS DECK TO EXTEND NORTHWARD CLOSE
TO BOS AFTER 09Z. LOW CEILINGS APPEAR IN TAFS WITH HIGHER
CONFIDENCE FOR THE STRATUS (CAPE/ISLANDS) WHILE THE OTHER
TERMINALS HAVE EITHER FEW/SCT DECKS HINTING AT THE LOWER CIGS
FOR NOW. WILL HAVE TO RE-ASSESS FOR THE 00Z TAF.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.
SEA BREEZE THIS AFTERNOON AROUND 10 KTS. KICKS OUT 23-00Z TO SSW
FLOW LESS THAN 10 KTS FOR REMAINDER OF NIGHT. SCT 4000-5000FT
DECKS THIS AFTERNOON WITH AN ISOLATED SHOWER POSSIBLE. IF A
SHOWER WERE TO DEVELOP IT WOULD MORE LIKELY BE WEST OF THE
TERMINAL.
THERE IS LOW PROBABILITY FOR A STRATUS DECK TO EXTEND NORTH
ENOUGH TO BRING LOWER MVFR/IFR CEILINGS TO OR NEAR BOS 09-13Z.
CONFIDENCE TOO LOW TO INCLUDE IN TAF. MESSAGED AS A FEW DECK
AT THIS TIME. WILL NEED TO MONITOR FOR A STRONGER SIGNAL FOR 00Z
TAF.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.
POTENTIAL FOR MVFR/IFR CEILINGS AFTER 06Z THROUGH AROUND 12Z
WITH BR. CONFIDENCE LOWER IN THE EXTENT/COVERAGE OF A LOW
STRATUS DECK.
OUTLOOK /SUNDAY THROUGH THURSDAY/...
SUNDAY: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. BREEZY.
SUNDAY NIGHT: MVFR/IFR CONDITIONS POSSIBLE. BREEZY. SHRA
LIKELY, SLIGHT CHANCE TSRA, PATCHY BR.
MONDAY: MVFR/IFR CONDITIONS POSSIBLE. WINDY WITH LOCAL GUSTS UP
TO 30 KT. SHRA, CHANCE TSRA.
MONDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. BREEZY.
CHANCE SHRA, CHANCE TSRA.
TUESDAY: VFR. CHANCE SHRA, CHANCE TSRA.
TUESDAY NIGHT: VFR. SLIGHT CHANCE SHRA.
WEDNESDAY: VFR. CHANCE SHRA, CHANCE TSRA.
WEDNESDAY NIGHT: MAINLY VFR, WITH LOCAL MVFR POSSIBLE. SLIGHT
CHANCE SHRA, SLIGHT CHANCE TSRA.
THURSDAY: 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.
WINDS AND SEAS BELOW SMALL CRAFT ADVISORY LEVELS THROUGH
SUNDAY. LIGHT SW TONIGHT THEN PICK UP TO AROUND 10-15 KT THIS
AFTERNOON AND TO 15-20 KT TONIGHT. SEAS 3 FT OR LESS THROUGH
TONIGHT, THEN INCREASE TO 3-4 FT.
OUTLOOK /SUNDAY THROUGH THURSDAY/...
SUNDAY: WINDS LESS THAN 25 KT.
SUNDAY NIGHT: LOW RISK FOR SMALL CRAFT ADVISORY WINDS WITH
GUSTS UP TO 25 KT. CHANCE OF RAIN SHOWERS, SLIGHT CHANCE OF
THUNDERSTORMS, PATCHY FOG.
MONDAY: MODERATE RISK FOR SMALL CRAFT ADVISORY WINDS WITH GUSTS
UP TO 30 KT. LOCAL ROUGH SEAS. RAIN SHOWERS LIKELY, SLIGHT
CHANCE OF THUNDERSTORMS.
MONDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF ROUGH SEAS. RAIN
SHOWERS LIKELY, CHANCE OF THUNDERSTORMS.
TUESDAY: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT. SLIGHT CHANCE
OF RAIN SHOWERS.
TUESDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT. SLIGHT CHANCE OF RAIN SHOWERS.
WEDNESDAY: WINDS LESS THAN 25 KT. SLIGHT CHANCE OF RAIN
SHOWERS.
WEDNESDAY NIGHT: WINDS LESS THAN 25 KT.
THURSDAY: WINDS LESS THAN 25 KT. SLIGHT CHANCE OF RAIN SHOWERS.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
DISCUSSION...BW
AVIATION...MENSCH
MARINE...BW
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