755
FXUS61 KBOX 021811
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOSTON/NORTON MA
211 PM EDT SUN AUG 2 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES.
KEY MESSAGES
- A COLD FRONT BRINGS THE RETURN OF HEAVY RAIN AND GUSTY WINDS
SUNDAY NIGHT AND MONDAY.
- STILL UNSETTLED LATE IN THE WEEK WITH PERIODS OF SHOWERS AND
STORMS.
DISCUSSION
KEY MESSAGE 1...A COLD FRONT BRINGS THE RETURN OF HEAVY RAIN AND
GUSTY WINDS SUNDAY NIGHT AND MONDAY.
THE MID-LEVEL RIDGE SLOWLY BREAKS DOWN OVER THE NEXT 24 TO 48 HOURS
AS AN ANOMALOUS LOW DIGS INTO THE OHIO VALLEY AND BECOMES CUTOFF.
THIS WILL MEAN SLOW MOVEMENT EAST PLACING SNE AND THE WHOLE EASTERN
SEABOARD BENEATH DEEP, MOIST SW FLOW. AS A 30-45KT LLJ DEVELOPS IT
ADVECTS 2+INCH PWATS OVERHEAD (2 SD ABOVE NORMAL). THIS COMBINED
WITH IMPRESSIVE DYNAMICS FROM THE COLD FRONT, PLACEMENT BENEATH THE
RRQ OF A 120KT UPPER JET, AND SOME ELEVATED INSTABILITY WILL LEAD TO
A WASHOUT FOR MONDAY FEATURING WIDESPREAD RAIN, HEAVY AT TIMES,
ALONG WITH GUSTY WINDS AS THAT LLJ GETS MIXED DOWN. SPECIFIC
LOCATIONS OF HEAVIEST RAINFALL TOTALS ARE DIFFICULT TO PLACE AT THIS
JUNCTION, BUT A WIDESPREAD HALF INCH TO INCH OF RAIN IS LIKELY, WITH
ENSEMBLES SHOWING CHANCES OF 2+ INCHES ESSENTIALLY NIL. THAT BEING
SAID, IN THIS SUPER MOIST AIRMASS ANY GIVEN LOCATION COULD PICK UP A
QUICK HITTING 1"+ THAT MAY LEAD TO STREET FLOODING.
KEY MESSAGE 2...STILL UNSETTLED LATE IN THE WEEK WITH PERIODS OF
SHOWERS AND STORMS.
BY TUESDAY THE TROUGH AXIS MOVES INTO THE MARITIMES AND MID LEVEL
RIDGING/BUILDING SURFACE HIGH PRESSURE SHOULD KEEP RAIN AT BAY FOR
THE MOST PART. UNCERTAIN AS TO EXACTLY WHEN OUR NEXT BOUT OF
UNSETTLED WEATHER ARRIVES BUT THE SYNOPTIC PATTERN LOOKS TO BE
ACTIVE, SO PERIODIC SHORTWAVES (RAIN/T-STORM CHANCES) ARE EXPECTED
TO MOVE THROUGH MID TO LATE WEEK, AND EVEN CONTINUING INTO THE
WEEKEND FOR DAILY AFTERNOON/EVENING RAIN CHANCES.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
FORECASTER CONFIDENCE LEVELS...
LOW - LESS THAN 30 PERCENT.
MODERATE - 30 TO 60 PERCENT.
HIGH - GREATER THAN 60 PERCENT.
18Z TAF UPDATE:
TODAY: HIGH CONFIDENCE.
VFR CONDITIONS WITH SCT TO BKN CLOUD DECKS THIS AFTERNOON. SSW
WINDS AROUND 8-12 KTS WITH OCCASIONAL GUSTS TO 20 KT.
SUNDAY NIGHT: MODERATE CONFIDENCE.
CEILINGS FALL TO IFR FROM SOUTH TO NORTH AFTER 00Z WITH LIFR
POSSIBLE IN AREAS AFTER 03Z. SCATTERED -SHRA DEVELOP 00-02Z
WITH POTENTIAL FOR A BAND OF MORE MODERATE SHOWERS TO PUSH FROM
SOUTH TO NORTH BETWEEN 06-10Z. EMBEDDED THUNDER IS POSSIBLE, BUT
TOO LOW CONFIDENCE TO INCLUDE IN TAF AT THIS TIME. LLJ PUSHES
IN FROM THE SOUTH AFTER 06Z, SO ADDED WIND SHEAR TO CAPE
TERMINALS, BOS, AND PVD.
MONDAY: MODERATE CONFIDENCE.
IFR/LIFR IN RA/+RA THROUGH THE DAY. EMBEDDED STORMS POSSIBLE
WITHIN THE FIRST FEW ROUNDS OF RAIN 12-21Z. INCLUDED IN TAFS AS
PROB30S UNTIL WE HAVE HIGHER CONFIDENCE IN THE
TIMING/PROBABILITY OF STORMS. ANOTHER ROUND OF SCATTERED
THUNDERSTORMS LIKELY PUSHES THROUGH FROM WEST TO EAST 19Z-02Z
AHEAD OF THE APPROACHING COLD FRONT. WIND SHEAR LIKELY CONTINUES
IN THE EAST/SOUTHEAST TERMINALS DURING THE DAY. SW WINDS 10-20
KTS WITH GUSTS 20-30 KTS. COULD SEE PERIOD IN THE AFTERNOON
THAT WINDS GUST 25-35 KTS FOR THE EAST AND ESPECIALLY SE
TERMINALS IF WE CLEAR OUT BEFORE THE EARLY EVENING ROUND OF
STORMS.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.
OUTLOOK /MONDAY NIGHT THROUGH FRIDAY/...
TUESDAY THROUGH TUESDAY NIGHT: VFR.
WEDNESDAY THROUGH WEDNESDAY NIGHT: VFR. SLIGHT CHANCE SHRA.
THURSDAY: VFR. BREEZY. CHANCE SHRA, SLIGHT CHANCE TSRA.
THURSDAY NIGHT: VFR. BREEZY. SLIGHT CHANCE SHRA, SLIGHT CHANCE
TSRA.
FRIDAY: VFR. BREEZY. CHANCE SHRA, 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. WINDS AND SEAS INCREASE LATE SUNDAY NIGHT INTO EARLY
MONDAY MORNING ACROSS THE SOUTHERN AND EASTERN WATERS. SEAS
5-8 FT FOR THE OUTER COASTAL WATERS, ESPECIALLY SOUTH. 5-7 FT
SEAS STRETCH INTO PORTIONS OF THE INNER SOUTHER WATERS. SW WINDS
15-20 KTS WITH GUSTS AROUND 30 KTS. SCAS ARE IN EFFECT FOR THE
SOUTHERN AND EASTERN WATERS INCLUDED THE BUZZARDS BAY, VINEYARD
SOUND, AND NANTUCKET SOUND STARTING EARLY MONDAY MORNING.
ELEVATED SEAS WILL KEEP SCAS AROUND THROUGH TUESDAY FOR THE
SOUTHERN WATERS.
OUTLOOK /MONDAY NIGHT THROUGH FRIDAY/...
TUESDAY: WINDS LESS THAN 25 KT. SEAS UP TO 5 FT.
TUESDAY NIGHT: WINDS LESS THAN 25 KT. AREAS OF SEAS APPROACHING
5 FT.
WEDNESDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING
5 FT.
WEDNESDAY NIGHT: WINDS LESS THAN 25 KT.
THURSDAY: WINDS LESS THAN 25 KT. SEAS LOCALLY APPROACHING 5 FT.
THURSDAY NIGHT THROUGH FRIDAY: WINDS LESS THAN 25 KT. AREAS OF
SEAS APPROACHING 5 FT.
BOX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT MONDAY FOR ANZ230-
236.
SMALL CRAFT ADVISORY FROM 8 AM TO 5 PM EDT MONDAY FOR ANZ231-
251.
SMALL CRAFT ADVISORY FROM 8 AM MONDAY TO 2 AM EDT TUESDAY FOR
ANZ232>234.
SMALL CRAFT ADVISORY FROM 5 AM MONDAY TO 2 PM EDT TUESDAY FOR
ANZ235-237.
SMALL CRAFT ADVISORY FROM 8 AM MONDAY TO 2 PM EDT TUESDAY FOR
ANZ250-254.
SMALL CRAFT ADVISORY FROM 5 AM MONDAY TO 8 PM EDT TUESDAY FOR
ANZ255-256.
DISCUSSION...BW
AVIATION...MENSCH
MARINE...BW
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