Montauk NY to Marthas Vineyard out 20 NM South of Block Island Marine Forecast
| Tonight...E Winds 15 To 20 Kt. Gusts Up To 30 Kt This Evening. Seas 3 To 4 Ft. Wave Detail: E 4 Ft At 6 Seconds And S 3 Ft At 7 Seconds. Patchy Drizzle. |
| Sun...Sw Winds 20 To 25 Kt With Gusts Up To 30 Kt. Seas 5 To 8 Ft, Building To 8 To 11 Ft In The Afternoon. Wave Detail: Se 5 Ft At 7 Seconds, Becoming Se 8 Ft At 8 Seconds And Sw 7 Ft At 7 Seconds. Patchy Drizzle In The Morning, Then Showers In The Afternoon. |
| Sun Night...Sw Winds 15 To 20 Kt, Becoming Nw After Midnight. Gusts Up To 30 Kt. Seas 7 To 10 Ft, Subsiding To 5 To 8 Ft After Midnight. Wave Detail: S 8 Ft At 8 Seconds And Sw 2 Ft At 5 Seconds, Becoming S 6 Ft At 8 Seconds And W 1 Foot At 3 Seconds. Showers In The Evening. |
| Mon...W Winds 15 To 20 Kt With Gusts Up To 25 Kt. Seas 5 To 6 Ft. Wave Detail: S 6 Ft At 8 Seconds And Nw 2 Ft At 4 Seconds. |
| Mon Night And Tue...W Winds 15 To 20 Kt. Seas 3 To 5 Ft. Wave Detail: Sw 5 Ft At 8 Seconds. |
| Tue Night...Nw Winds 15 To 20 Kt With Gusts Up To 25 Kt. Seas 3 To 4 Ft. Wave Detail: Nw 4 Ft At 5 Seconds And Se 1 Foot At 8 Seconds. |
| Wed And Wed Night...Ne Winds 15 To 20 Kt, Becoming S 5 To 10 Kt. Seas 2 To 4 Ft. |
| Thu And Thu Night...S Winds 10 To 15 Kt. Gusts Up To 20 Kt. Seas 3 To 5 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. |
| Area Forecast Discussion National Weather Service Boston/Norton MA 242pm EDT Sat April 4 2026 .WHAT HAS CHANGED... Small craft advisories now in effect for all waters through Sunday. Best chance for widespread rains is during Sunday afternoon, then a cooldown to temperatures into early next week. .KEY MESSAGES... - Turning overcast with cool onshore breezes and perhaps some drizzle thru midnight, then another round of scattered showers overnight into the pre-dawn hours. - Still overcast most of Sunday but with modest warming; while generally dry during the morning, widespread rains develop during the afternoon with a cold front, clearing into the waters by evening. - Rain/snow showers possible Monday night into Tuesday morning, but otherwise dry and cool. - Temperatures increase through the second half of next week and conditions remain dry. KEY MESSAGE 1...Turning overcast with cool onshore breezes and perhaps some drizzle thru midnight, then another round of scattered showers overnight into the pre-dawn hours. A backdoor cold front was working its way through central MA and eastern CT, bringing increasing marine cloudiness, much cooler air (40s to low 50s common) and a gusty ENE wind in the 25-35 mph range across eastern MA and RI. This backdoor front will continue to surge westward toward the spine of the Berkshires thru late afternoon. As the PBL continues to cool, expect cloudiness to continue to fill in and lower/thicken as we move into the mid evening hours. There could be some patchy drizzle around as the overcast stratus layer takes hold, but much of the time is dry. Will be rather cool and moist with temps in the mid 30s to low 40s by midnight, with E/ESE winds around 5-10 mph this evening (gusts to 20 mph near the coast). The lingering frontal boundary then begins to return northward as a warm front overnight, in response to strengthening 925-850 mb warm/moist advection on SWly 40-45 kt LLJ. Rising PWATs (Precipitable Waters) and lowering Showalter indices to around 0 units then should allow for a round of scattered showers to develop and move northward sometime thru the 11 pm to 5 am timeframe. Wouldn't rule out a rumble of thunder given falling Showalter indices but this seems like the exception vs the rule. That will also bring with it slowly rising temperatures and dewpoints into the pre-dawn hours, although overcast conditions to continue. KEY MESSAGE 2...Still overcast most of Sunday but with modest warming; while generally dry during the morning, widespread rains develop during the afternoon with a cold front, clearing into the waters by evening. We then get into a cloudy warm sector with SW winds around 10 mph (a bit stronger over the Cape and Islands). This cloud cover will be tough to shake free of as shallow moisture remains trapped underneath very mild 925-850 mb temps around +10C. Thus warming would be driven more through advective processes with very little to nil insolational heating. NBM high temps in the upper 50s to mid 60s seem optimistic and brought these down about 5 degrees into the 50s in most areas. Wouldn't rule out a hit or miss shower during the morning in the cloudy warm sector, but it looks as though the best chance for widespread showers is during Sunday afternoon as a cold front moves in from the west. A round of steady light to at times moderate showers, perhaps with a rumble or two of thunder as Showalter indices dip to -1, as the front gradually trudges east toward the eastern coastal waters by early evening. Additional/lingering rains should persist toward southeast MA, southern RI and the Cape and Islands thru midnight; but the majority of Southern New England to see decreasing cloudiness and falling dewpoints with westerly winds post-frontal. Rain amounts range from about a quarter to third of a inch, perhaps as much as a half-inch in steadier showers. Lows Sunday night in the 30s, with values in the 30-32F range in interior higher terrain as WNW winds pick up. KEY MESSAGE 3...Rain/snow showers possible Monday night into Tuesday morning, but otherwise dry and cool. Following Sunday's cold front, colder and drier conditions take hold as surface high pressure starts to take hold and an upper level trough settles overhead. A shortwave may move through the region Monday night into Tuesday morning, which would interrupt this brief dry period with a mix of rain and snow showers. These are not expected to be very impactful to travel or roads as temperatures remain mostly in the 40s and upper 30s. Higher elevations may dip below freezing, but temperatures there will also improve quickly heading into Tuesday morning. Outside of the risk for showers that could linger through the day as the shortwave passes through, drier conditions can be expected as dewpoints fall into the 20s across the region (30s over the Cape and Islands). Tuesday night will be noticeably cooler as the trough sits overhead and 925 mb temperatures fall to -8C to -5C after being just at or below 0C Monday/Monday night. Winds remain mostly W and NW for the start of the week in the post-frontal airmass. KEY MESSAGE 4...Temperatures increase through the second half of next week and conditions remain dry. High pressure moves into the Mid-Atlantic region during the second half of the week then shifts more offshore, which will aid in bringing back SW flow over southern New England and keep the region dry. Temperatures will improve as the week goes on and the upper level trough moves off to the east. Highs will likely end up back in the 50s and 60s. Some uncertainty remains, though, towards the end of the week as the GEFS hints at another backdoor front that could lead to cooler temperatures, particularly across eastern MA and RI. If that plays out, highs could struggle to hit 60F Friday afternoon. By comparison, the other ensembles do not have this feature and have highs in the mid to upper 60s. We should get more clarity as we get closer in time. Marine Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. High confidence. Given NE/E gusts are currently in very solid SCA (Small Craft Advisory) to near-gale- force range with the immediate passage of the backdoor front, and that SWly gusts for Sunday look to be more in the SCA (Small Craft Advisory) range with strongly- inverted profiles, have hoisted SCAs (Small Craft Advisories) for all waters starting now through 00z Monday (thus, gale watches on southern waters converted to SCAs). Expect gusts to be strongest thru Saturday afternoon at around 25-30 kt (occasional gusts to 35 kt possible), then settle in around 25-30 kt range. Seas remain in the 3-5 ft range thru tonight, then increase more markedly as southerly winds increase the fetch, building offshore to nearly 10 ft on southern waters. Winds Sunday night to shift to NW at sub-SCA (Small Craft Advisory) levels briefly, but could gust to around SCA (Small Craft Advisory) ranges late overnight Monday. Low chance at mist/fog overnight, but better chance for rain showers late Sunday afternoon to early Sunday evening. Outlook /Sunday Night through Thursday/... Monday: Winds less than 25 kt. Local rough seas. Monday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Tuesday: Winds less than 25 kt. Chance of rain showers. Tuesday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Wednesday: Winds less than 25 kt. Areas of seas approaching 5 ft. Wednesday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Thursday: Winds less than 25 kt. Seas up to 5 ft. NOAA Boston MA Office: Watches - Warnings - Advisories CT...None. MA...None. RI...None. Marine Small Craft Advisory until 8pm EDT Sunday for ANZ230>237-250- 251-254>256. |
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