Marine Weather and Tide Forecast for Onset, MA
April 30, 2025 10:08 AM EDT (14:08 UTC)
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![]() | Sunrise 5:39 AM Sunset 7:42 PM Moonrise 7:21 AM Moonset 11:51 PM |
ANZ234 Buzzards Bay- 705 Am Edt Wed Apr 30 2025
.small craft advisory in effect until noon edt today - .
Today - W winds 10 to 15 kt, becoming nw 5 to 10 kt this afternoon. Gusts up to 25 kt. Seas 2 to 4 ft. Wave detail: sw 4 ft at 7 seconds and W 2 ft at 4 seconds.
Tonight - W winds around 5 kt, becoming N after midnight. Seas around 2 ft. Wave detail: sw 2 ft at 7 seconds and N 1 foot at 3 seconds.
Thu - NE winds around 5 kt, becoming S in the afternoon. Seas around 2 ft. Wave detail: sw 2 ft at 7 seconds and N 1 foot at 4 seconds.
Thu night - S winds 10 to 15 kt. Seas around 2 ft in the evening, then 1 foot or less. Wave detail: ne 1 foot at 4 seconds and S 1 foot at 4 seconds, becoming S 1 foot at 3 seconds and ne 1 foot at 4 seconds.
Fri - S winds 10 to 15 kt, increasing to 15 to 20 kt in the afternoon. Gusts up to 25 kt. Seas 2 to 4 ft. Wave detail: sw 3 ft at 4 seconds and se 1 foot at 9 seconds.
Fri night - SW winds 15 to 20 kt, diminishing to 10 to 15 kt after midnight. Gusts up to 25 kt. Seas 2 to 4 ft. Wave detail: sw 3 ft at 4 seconds and se 1 foot at 9 seconds. A chance of showers after midnight.
Sat - SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 4 ft. A chance of showers.
Sat night - SW winds 10 to 15 kt. Seas 2 to 4 ft. Showers likely.
Sun - W winds around 10 kt. Seas 2 to 3 ft. Showers likely.
Sun night - NW winds around 10 kt. Seas around 2 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.
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.
ANZ200 705 Am Edt Wed Apr 30 2025
Synopsis for massachusetts and rhode island coastal waters - A cold front crosses the region through daybreak followed by high pres building in from the west tonight into Thu. This high shifts east of the waters Fri into the weekend as a wave or two of low pres and an associated cold front approach from the west.
7 Day Forecast for Marine Location Near Onset, MA

NEW! Add second zone forecast
Cape Cod Canal Click for Map Wed -- 05:39 AM EDT Sunrise Wed -- 06:55 AM EDT -0.80 feet Low Tide Wed -- 07:21 AM EDT Moonrise Wed -- 11:45 AM EDT 3.78 feet High Tide Wed -- 07:05 PM EDT 0.23 feet Low Tide Wed -- 07:40 PM EDT Sunset Wed -- 11:50 PM EDT Moonset Tide / Current data from XTide NOT FOR NAVIGATION |   |
Cape Cod Canal, Buzzards Bay Entrance, Massachusetts, Tide feet
12 am |
4.9 |
1 am |
4 |
2 am |
2.7 |
3 am |
1.4 |
4 am |
0.5 |
5 am |
-0.1 |
6 am |
-0.6 |
7 am |
-0.8 |
8 am |
-0.3 |
9 am |
1 |
10 am |
2.5 |
11 am |
3.5 |
12 pm |
3.8 |
1 pm |
3.2 |
2 pm |
2.2 |
3 pm |
1.2 |
4 pm |
0.6 |
5 pm |
0.5 |
6 pm |
0.4 |
7 pm |
0.2 |
8 pm |
0.5 |
9 pm |
1.4 |
10 pm |
2.9 |
11 pm |
4.2 |
Cape Cod Canal Click for Map Wed -- 02:41 AM EDT -5.05 knots Max Ebb Wed -- 05:39 AM EDT Sunrise Wed -- 05:48 AM EDT 0.10 knots Slack Wed -- 07:21 AM EDT Moonrise Wed -- 08:55 AM EDT 4.86 knots Max Flood Wed -- 12:22 PM EDT -0.01 knots Slack Wed -- 03:12 PM EDT -4.72 knots Max Ebb Wed -- 06:15 PM EDT 0.21 knots Slack Wed -- 07:40 PM EDT Sunset Wed -- 09:12 PM EDT 4.46 knots Max Flood Wed -- 11:50 PM EDT Moonset Tide / Current data from XTide NOT FOR NAVIGATION |   |
Cape Cod Canal, Massachusetts Current, knots
12 am |
-2.1 |
1 am |
-4 |
2 am |
-4.9 |
3 am |
-5 |
4 am |
-4.4 |
5 am |
-3.1 |
6 am |
1.5 |
7 am |
3.7 |
8 am |
4.6 |
9 am |
4.9 |
10 am |
4.6 |
11 am |
3.7 |
12 pm |
2 |
1 pm |
-2.7 |
2 pm |
-4.2 |
3 pm |
-4.7 |
4 pm |
-4.5 |
5 pm |
-3.6 |
6 pm |
-1.6 |
7 pm |
2.8 |
8 pm |
4 |
9 pm |
4.4 |
10 pm |
4.3 |
11 pm |
3.6 |
FXUS61 KBOX 301020 AFDBOX
Area Forecast Discussion National Weather Service Boston/Norton MA 620 AM EDT Wed Apr 30 2025
SYNOPSIS
Plenty of sunshine with very pleasant temperatures on tap for today and Thursday. Warmer air returns Friday and Saturday but there will be the risk for scattered showers and a few thunderstorms at times.
Depending on the timing of a cold front the risk for a few showers may linger into Sunday...but cooler air should return for early next week.
NEAR TERM /UNTIL 6 PM THIS EVENING/
Key Messages...
* Plenty of sunshine today with highs in the upper 60s to the lower 70s...but a tad cooler across parts of the Cape and Nantucket
Details...
A dry cold front will cross the region through daybreak ushering in a beautiful post-frontal airmass. While temps will be cooling aloft...plenty of sunshine along with a mild start should result in high temps in the upper 60s to the lower 70s in most locations. It will be a tad cooler across the high terrain and parts of the Cape/Nantucket...but still a very nice day. Northwest winds will gust to between 20 and 25 mph with a few gusts up to 30 mph through about lunchtime...but gradually diminish during the second part of the day.
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/
Key Messages...
* Dry & cool tonight with lows in the 30s & 40s with some frost possible in the normally cooler outlying locations
* Plenty of sun Thu with highs mainly between 65 and 70 but upper 50s/near 60 on the immediate coast with sea breezes
Details...
Tonight...
High pressure builds in from the west tonight and will result in winds becoming light/calm. This coupled with a relatively dry airmass in place will result in good radiational cooling conditions tonight and cool temperatures. Overnight low temps should bottom out in the lower to middle 30s in the normally coolest outlying locations...where some frost will be possible. Later shifts may need to consider some frost advisories where the season is now open.
Meanwhile...expect overnight lows in the lower to middle 40s for the urban centers of Boston and Providence.
Thursday...
High pressure will remain in control of our weather Thu gradually sliding further east. Plenty of sunshine with just a bit of mid/high clouds working into the region. This will allow highs to reach between 65 and 70 in most locations
However
a weak pressure gradient will allow for sea breeze development holding highs in the upper 50s to near 60 on the very immediate coast.
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/
Key Messages:
* Possible showers/thundershowers Thurs night/Fri, with perhaps another round of showers and embedded thunderstorms (a couple strong?) Fri aftn.
* Another round of rainy conditions Sat.
* Large uncertainty in pattern for early next week...including either dry weather and mild temps under high pressure, or cloudy/cooler and unsettled with periods of rain as low pressure lingers offshore.
Details:
Thursday Night and Friday:
A surface low moves across southern Ontario Thursday night into Friday morning, bringing a warm front and the first round of showers to southern New England. Guidance continues to indicate modest amounts of instability across the western portion of the CWA, allowing for the chance of thunder into early Friday morning.
Expecting at least a few hours of dry weather through the early afternoon, but it's becoming increasingly likely that skies will remain overcast. If we can get some breaks in the clouds to allow for surface heating, and combined with MUCAPE near 1500 J/kg, it's possible some storms could be on the stronger side.
Cloudiness will likely be one of the largest limiting factors on Friday, not only with the strength of storms, but also with general temperatures. Deterministic guidance is suggesting widespread high 70s, even into the low 80s in some areas; however, similar set ups this week have seen the CWA fall short of 80.
We may briefly dry out early Fri night, but the system's frontal boundary stays nearby or washes out, setting the stage for the next round of showers/t-storms for Sat.
Weekend:
A secondary low looks to form Friday night across the Midwest/Mid- Atlantic and push into the vicinity later Saturday morning, bringing yet another round of showers to southern New England. Rain chances really start to increase for the afternoon/evening hours and taper off by early Sunday morning. Sunday's temps drop dramatically as we get some northern air funneled in from Canada... highs likely only in the low to mid 60s.
Early Next Week:
The start to next week becomes tricky... GFS continues to indicate dry and mild under a broad high, but ECMWF and Canadian show widespread showers with more marine influence via an upper level low and onshore flow. Very messy, changeable pattern and stuck with NBM until there's better agreement.
AVIATION /10Z WEDNESDAY THROUGH SUNDAY/
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
12z TAF update...
Today...High Confidence.
VFR. NW wind gusts of 20 to 25 knots with a few gusts up to 30 knots through lunchtime.
Tonight...High Confidence.
VFR. Winds becoming light/calm.
Thursday...High Confidence.
VFR. Winds becoming S at 5-10 knots except for localized sea breezes developing along portions of the immediate coast by late morning.
KBOS TAF...High Confidence in TAF.
KBDL TAF...High Confidence in TAF.
Outlook /Thursday Night through Sunday/...
Thursday Night: Mainly VFR, with local IFR possible. Slight chance SHRA.
Friday: Mainly VFR, with local IFR possible. Breezy. Slight chance SHRA, isolated TSRA.
Friday Night: VFR. Breezy. Chance SHRA, isolated TSRA.
Saturday: MVFR/IFR conditions possible. Breezy. SHRA likely, isolated TSRA.
Saturday Night: MVFR/IFR conditions possible. SHRA likely, isolated TSRA.
Sunday: VFR. Chance SHRA.
MARINE
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Today...High Confidence.
A cold front crosses the region through daybreak. Behind this front...winds shift to the NW with gusts between 20 and 25 knots through lunchtime with the strongest of those winds nearshore.
Will continue to small craft headlines through lunchtime...but gradient weakens this afternoon so will let most of the headlines expire except for our southern waters with lingering swell.
Tonight and Thursday...High Confidence.
High pressure builds over the waters which will keep winds/seas below small craft advisory thresholds tonight and Thu.
Outlook /Thursday Night through Sunday/...
Thursday Night: Winds less than 25 kt. Slight chance of rain showers.
Friday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Slight chance of rain showers.
Friday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Chance of rain showers, isolated thunderstorms.
Saturday: Winds less than 25 kt. Local rough seas. Chance of rain showers.
Saturday Night: Winds less than 25 kt. Local rough seas. Rain showers likely, isolated thunderstorms.
Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Chance of rain showers.
FIRE WEATHER
After collaboration with our surrouding WFO/s and Fire Weather partners...a special weather statement remains in effect today for the elevated risk of fire spread. NW wind gusts of 20-25 mph through lunchtime with a few brief gusts near 30 mph will combine with minimum afternoon RH values dropping to between 15 and 30 percent.
BOX WATCHES/WARNINGS/ADVISORIES
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until noon EDT today for ANZ230>237-250- 251.
Small Craft Advisory until 10 PM EDT this evening for ANZ254>256.
Area Forecast Discussion National Weather Service Boston/Norton MA 620 AM EDT Wed Apr 30 2025
SYNOPSIS
Plenty of sunshine with very pleasant temperatures on tap for today and Thursday. Warmer air returns Friday and Saturday but there will be the risk for scattered showers and a few thunderstorms at times.
Depending on the timing of a cold front the risk for a few showers may linger into Sunday...but cooler air should return for early next week.
NEAR TERM /UNTIL 6 PM THIS EVENING/
Key Messages...
* Plenty of sunshine today with highs in the upper 60s to the lower 70s...but a tad cooler across parts of the Cape and Nantucket
Details...
A dry cold front will cross the region through daybreak ushering in a beautiful post-frontal airmass. While temps will be cooling aloft...plenty of sunshine along with a mild start should result in high temps in the upper 60s to the lower 70s in most locations. It will be a tad cooler across the high terrain and parts of the Cape/Nantucket...but still a very nice day. Northwest winds will gust to between 20 and 25 mph with a few gusts up to 30 mph through about lunchtime...but gradually diminish during the second part of the day.
SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/
Key Messages...
* Dry & cool tonight with lows in the 30s & 40s with some frost possible in the normally cooler outlying locations
* Plenty of sun Thu with highs mainly between 65 and 70 but upper 50s/near 60 on the immediate coast with sea breezes
Details...
Tonight...
High pressure builds in from the west tonight and will result in winds becoming light/calm. This coupled with a relatively dry airmass in place will result in good radiational cooling conditions tonight and cool temperatures. Overnight low temps should bottom out in the lower to middle 30s in the normally coolest outlying locations...where some frost will be possible. Later shifts may need to consider some frost advisories where the season is now open.
Meanwhile...expect overnight lows in the lower to middle 40s for the urban centers of Boston and Providence.
Thursday...
High pressure will remain in control of our weather Thu gradually sliding further east. Plenty of sunshine with just a bit of mid/high clouds working into the region. This will allow highs to reach between 65 and 70 in most locations
However
a weak pressure gradient will allow for sea breeze development holding highs in the upper 50s to near 60 on the very immediate coast.
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/
Key Messages:
* Possible showers/thundershowers Thurs night/Fri, with perhaps another round of showers and embedded thunderstorms (a couple strong?) Fri aftn.
* Another round of rainy conditions Sat.
* Large uncertainty in pattern for early next week...including either dry weather and mild temps under high pressure, or cloudy/cooler and unsettled with periods of rain as low pressure lingers offshore.
Details:
Thursday Night and Friday:
A surface low moves across southern Ontario Thursday night into Friday morning, bringing a warm front and the first round of showers to southern New England. Guidance continues to indicate modest amounts of instability across the western portion of the CWA, allowing for the chance of thunder into early Friday morning.
Expecting at least a few hours of dry weather through the early afternoon, but it's becoming increasingly likely that skies will remain overcast. If we can get some breaks in the clouds to allow for surface heating, and combined with MUCAPE near 1500 J/kg, it's possible some storms could be on the stronger side.
Cloudiness will likely be one of the largest limiting factors on Friday, not only with the strength of storms, but also with general temperatures. Deterministic guidance is suggesting widespread high 70s, even into the low 80s in some areas; however, similar set ups this week have seen the CWA fall short of 80.
We may briefly dry out early Fri night, but the system's frontal boundary stays nearby or washes out, setting the stage for the next round of showers/t-storms for Sat.
Weekend:
A secondary low looks to form Friday night across the Midwest/Mid- Atlantic and push into the vicinity later Saturday morning, bringing yet another round of showers to southern New England. Rain chances really start to increase for the afternoon/evening hours and taper off by early Sunday morning. Sunday's temps drop dramatically as we get some northern air funneled in from Canada... highs likely only in the low to mid 60s.
Early Next Week:
The start to next week becomes tricky... GFS continues to indicate dry and mild under a broad high, but ECMWF and Canadian show widespread showers with more marine influence via an upper level low and onshore flow. Very messy, changeable pattern and stuck with NBM until there's better agreement.
AVIATION /10Z WEDNESDAY THROUGH SUNDAY/
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
12z TAF update...
Today...High Confidence.
VFR. NW wind gusts of 20 to 25 knots with a few gusts up to 30 knots through lunchtime.
Tonight...High Confidence.
VFR. Winds becoming light/calm.
Thursday...High Confidence.
VFR. Winds becoming S at 5-10 knots except for localized sea breezes developing along portions of the immediate coast by late morning.
KBOS TAF...High Confidence in TAF.
KBDL TAF...High Confidence in TAF.
Outlook /Thursday Night through Sunday/...
Thursday Night: Mainly VFR, with local IFR possible. Slight chance SHRA.
Friday: Mainly VFR, with local IFR possible. Breezy. Slight chance SHRA, isolated TSRA.
Friday Night: VFR. Breezy. Chance SHRA, isolated TSRA.
Saturday: MVFR/IFR conditions possible. Breezy. SHRA likely, isolated TSRA.
Saturday Night: MVFR/IFR conditions possible. SHRA likely, isolated TSRA.
Sunday: VFR. Chance SHRA.
MARINE
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Today...High Confidence.
A cold front crosses the region through daybreak. Behind this front...winds shift to the NW with gusts between 20 and 25 knots through lunchtime with the strongest of those winds nearshore.
Will continue to small craft headlines through lunchtime...but gradient weakens this afternoon so will let most of the headlines expire except for our southern waters with lingering swell.
Tonight and Thursday...High Confidence.
High pressure builds over the waters which will keep winds/seas below small craft advisory thresholds tonight and Thu.
Outlook /Thursday Night through Sunday/...
Thursday Night: Winds less than 25 kt. Slight chance of rain showers.
Friday: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Slight chance of rain showers.
Friday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Local rough seas. Chance of rain showers, isolated thunderstorms.
Saturday: Winds less than 25 kt. Local rough seas. Chance of rain showers.
Saturday Night: Winds less than 25 kt. Local rough seas. Rain showers likely, isolated thunderstorms.
Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Chance of rain showers.
FIRE WEATHER
After collaboration with our surrouding WFO/s and Fire Weather partners...a special weather statement remains in effect today for the elevated risk of fire spread. NW wind gusts of 20-25 mph through lunchtime with a few brief gusts near 30 mph will combine with minimum afternoon RH values dropping to between 15 and 30 percent.
BOX WATCHES/WARNINGS/ADVISORIES
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until noon EDT today for ANZ230>237-250- 251.
Small Craft Advisory until 10 PM EDT this evening for ANZ254>256.
Wind History for Borden Flats Light at Fall River, MA
toggle option: (graph/table)
Airport Reports
Airport | Dist | Age | Wind kt | Vis | Sky | Weather | Air | DewPt | RH | inHg |
KFMH CAPE COD COAST GUARD AIR STATION,MA | 9 sm | 12 min | W 11 | 10 sm | A Few Clouds | 63°F | 54°F | 72% | 29.86 | |
KEWB NEW BEDFORD RGNL,MA | 16 sm | 15 min | W 11G17 | 10 sm | Clear | 66°F | 43°F | 43% | 29.85 | |
KHYA BARNSTABLE MUNIBOARDMAN/POLANDO FIELD,MA | 21 sm | 12 min | W 06 | 10 sm | A Few Clouds | 63°F | 52°F | 68% | 29.83 | |
KMVY MARTHA'S VINEYARD,MA | 24 sm | 15 min | W 09 | 10 sm | Mostly Cloudy | 61°F | 52°F | 72% | 29.86 |
Link to 1 hour of 5 minute data for KFMH
Terminal Aerodrome Forecast (TAF) for KFMH
Wind History Graph: FMH
(wind in knots)GEOS Local Image of north east
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