Marine Weather Net

Coastal Waters out 25 NM South of Marthas Vineyard and Nantucket Marine Forecast


REST OF TONIGHT

SW
WINDS
10 - 15
KNOTS

FRI

SW
WINDS
10 - 15
KNOTS

FRI NIGHT

S
WINDS
10 - 15
KNOTS

SAT

S
WINDS
20 - 25
KNOTS

The Marine Weather Forecast In Detail:
ANZ255 Forecast Issued: 104 AM EDT Fri Apr 25 2025

Rest Of Tonight...Sw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft. Wave Detail: Sw 3 Ft At 4 Seconds And Se 2 Ft At 10 Seconds.
Fri...Sw Winds 10 To 15 Kt With Gusts Up To 25 Kt. Seas 2 To 3 Ft. Wave Detail: Sw 3 Ft At 4 Seconds And Se 2 Ft At 10 Seconds.
Fri Night...S Winds 10 To 15 Kt. Gusts Up To 20 Kt After Midnight. Seas 2 To 3 Ft. Wave Detail: Sw 3 Ft At 4 Seconds And Se 2 Ft At 9 Seconds.
Sat...S Winds 20 To 25 Kt With Gusts Up To 30 Kt. Seas 3 To 5 Ft, Building To 5 To 7 Ft In The Afternoon. Wave Detail: S 5 Ft At 5 Seconds And Se 2 Ft At 9 Seconds, Becoming S 7 Ft At 7 Seconds And Se 2 Ft At 9 Seconds. A Chance Of Rain In The Morning, Then Showers In The Afternoon With Vsby 1 To 3 Nm.
Sat Night...Sw Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 5 To 7 Ft. Wave Detail: S 7 Ft At 7 Seconds And S 5 Ft At 8 Seconds. Showers. Vsby 1 To 3 Nm In The Evening.
Sun And Sun Night...Nw Winds 15 To 20 Kt With Gusts Up To 25 Kt. Seas 4 To 6 Ft. Wave Detail: Sw 6 Ft At 7 Seconds And N 1 Foot At 4 Seconds.
Mon...Nw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 3 To 5 Ft.
Mon Night And Tue...Sw Winds 10 To 15 Kt. Gusts Up To 20 Kt. Seas 2 To 4 Ft.
Tue Night...Sw Winds 15 To 20 Kt With Gusts Up To 25 Kt. Seas 4 To 6 Ft. Seas Are Reported As Significant Wave Height, Which Is The Average Of The Highest Third Of The Waves. Individual Wave Heights May Be More Than Twice The Significant Wave Height.
SHARE THIS PAGE:           
Area Forecast Discussion
National Weather Service Boston/Norton MA
121am EDT Fri April 25 2025

Synopsis
Other than a hit or miss shower in northern Massachusetts early tonight, mild and dry weather continues into tonight. Unseasonably warm temperatures are expected away from the coast Friday, with a few areas reaching to around 80 degrees. Cloud cover increases Friday night. Cooler with widespread rain showers Saturday ahead of our next system, drying out for Sunday. Cooler and breezy on Sunday, followed by continued dry weather through Wednesday and mild temperatures. A front arrives Wednesday with next chance of showers.

Near Term - Until 6am This Morning
415pm Update:

Key Messages:

* Passing, hit-or-miss showers northern MA early tonight, but many will remain dry tonight.

* Mild with lows in the 40s to near 50.

Details:

Sunny and rather mild day for many away from the coasts cooler by seabreezes, with current temps inland reaching into the lower to mid 70s. To our north and west in northern NY is a surface warm front and a weak 500 mb impulse in WNW flow aloft associated with it located back in the northern Gt Lakes region. Current radar shows a cluster of showers in regime of weak elevated instability associated with this warm front, trailing from near Watertown NY on ESE towards the northwest suburbs of Albany NY
. Recent radar trends as well as trends in GOES-16 Day Cloud Phase RGB imagery indicate this activity is not generating lightning. With similar lapse rates but drier conditions east of the ongoing activity, not expecting lightning to pop in any of these, with this shower activity expected to progress towards the east or east-southeast through 10 PM. Best chance for rain showers in northern MA given W to WNWly 850-500 mb winds but we don't expect any downpours or washouts to result from these passing showers, with dry weather in all areas by midnight.

Most of the evening should feature mostly clear to partly cloudy skies, higher cloud cover to the north, but will be of the mid to high level type of clouds. Although we should have some radiational cooling, warm/moist advection and continued southerly winds are expected to keep temperatures from falling too far. Tonight's lows should be rather mild in the mid 40s to lower 50s.

One other aspect that I'll make mention is the potential for a smoky/hazy look to skies overnight from the sizable wildfire burning in SE NJ. It's been difficult to track the smoke plume given canopy of high clouds on satellite images nearby the site, although today's HRRR-Smoke model offers the potential for some of the smoke from it to move into southern and central portions of Southern New England overnight tonight, although its surface visibility output suggests no restrictions to visbys are forecast. The warm temps aloft coming in should allow for a pretty good temperature inversion to develop. Confidence is low but given the thermal profile/inversion, it wouldn't entirely be surprising if people may at least smell some smoke as we move into the overnight to early morning hours.

Short Term - 6am This Morning Through 6pm Saturday
415pm Update:

Key Messages:

* Very warm and still rather dry Friday, with cooler seabreezes near the coasts. Highs inland well into the 70s/around 80!

* Increasing clouds early Friday night, with rains developing overnight. Mild with lows in the 50s, maybe a few areas staying above 60 degrees.

Friday:

Partly to mostly sunny conditions for Friday - a little more than expected today but with still quite a bit of sun. Coastal areas will again see seabreezes develop and likely to be pretty early in the day, with temperatures along the immediate coast reaching into the 60s. Have to watch for additional spotty rain showers over northern MA into the North Shore during the afternoon associated with a warm front, but many areas will be dry. However the main story for Friday is the very warm temperatures expected inland, with enough sunshine and 925 mb temps around +18. Highs should soar to well into the 70s to a few low-80s in western portions of Southern New England. Note again carrying over from the overnight that there may be some wafts of smoke around from the wildfire in southern NJ, but we don't expect visbys to be restricted or rise to the level of causing health problems.

Friday Night:

Cloud cover then increases significantly towards full overcast early Friday evening, ahead of a frontal system that moves into the Northeast into Saturday. Most areas however should be dry for the first part of the evening. Probability of Precipitation then increase into the Likely to Categorical range as we move into the overnight to early Saturday morning timeframe, but the bulk of the rains arrive on Saturday. Total rain amts thru 12z Saturday should be less than a quarter- inch, even as PW values (Precipitable Water values) start to rise to around 1.2". Stands to be even milder Friday evening, and while I showed lows dropping into the 50s, some areas in western MA and CT could stay just above 60 degrees, making it one of the mildest nigheights yet seen so far in 2025.

Long Term - Saturday Night Through Thursday
Key Messages:

* Widespread rainfall expected Saturday.

* Drier and cooler Sunday with breezy NW winds. Isolated showers possible in the afternoon.

* First half of next week trends dry with above normal temperatures

Saturday - Sunday:

A northern stream trough moves across the region this weekend with an associated upper level low tracking across the Great Lakes and New England. Synoptic ascent increases ahead of the trough with a plume of amomalous moisture (200-240% of normal) advecting into southern New England. This will support widespread rainfall Saturday. It will also be breezy with with the presence of a southern LLJ shifting across the region. Can't rule some rumbles of thunder in the afternoon/early evening with marginal instability in the mid-levels. A cold front pushes through in the afternoon bringing a switch from southerly winds to windy NW winds. Front could bring a quick onset of gusts with it as well. Can't rule out a few strong gusts with the onset of the front with gusts up to 30-40 mph. The bulk of the rain exits to the east late Saturday night into early Sunday morning. In terms of totals, ensemble means for Quantitative Precipitation Forecast sit in the 0.50-0.75" range with a lower probability (30-50%) of > 1" being highlighted for parts of of western MA.

Sunday trends overall drier and cooler (seasonable). As the upper low tracks east, the backside of the system swings across the region in the afternoon with some marginal wrap around moisture. This may be enough to support some isolated showers, mainly in northern MA. A NW-SE oriented LLJ positions across the region Sunday which will support another windy day with NW winds with gusts 25-35 mph, perhaps a few isolated gusts to 40 mph.

Monday - Wednesday:

Early next week trends dry with ensembles showing high temperatures leaning above normal as mid-level ridging builds in. Next chance for precipitation arrives mid-week.

Marine
Forecaster Confidence Levels:

Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent.

Tranquil boating conditions for mariners through Friday, with southerly winds around 10-15 kt and seas 2-3 ft. Dry weather prevails.

SW winds then increase Friday evening to around 20 kt, with seas rising to around 4 ft. Conditions are borderline for SCA (Small Craft Advisory) but will be increasing further into Saturday. Rain develops Friday night, with visbys reduced to around 4 miles.

Outlook /Saturday Night through Tuesday/... Saturday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of rough seas. Rain showers, isolated thunderstorms.

Saturday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Rain showers.

Sunday: Winds less than 25 kt. Seas up to 5 ft. Slight chance of rain showers.
Sunday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain showers.
Monday: Winds less than 25 kt. Seas locally approaching 5 ft.
Monday Night: Winds less than 25 kt.

Tuesday: Winds less than 25 kt. Areas of seas approaching 5 ft.

NOAA Boston MA Office: Watches - Warnings - Advisories
CT...None. MA...None. RI...None.

Marine
None.