Marine Weather Net

Block Island Sound Marine Forecast


TONIGHT

NW
WINDS
10 - 15
KNOTS

WED

SW
WINDS
5 - 10
KNOTS

WED NIGHT

SW
WINDS
15
KNOTS

THU

SW
WINDS
10 - 15
KNOTS

The Marine Weather Forecast In Detail:
ANZ237 Forecast Issued: 313 PM EDT Tue Oct 06 2026

Tonight...Nw Winds 10 To 15 Kt With Gusts Up To 20 Kt, Diminishing To 5 To 10 Kt After Midnight. Seas 2 To 3 Ft. Wave Detail: W 2 Ft At 4 Seconds And N 1 Foot At 4 Seconds.
Wed...Sw Winds 5 To 10 Kt, Increasing To 10 To 15 Kt With Gusts Up To 25 Kt In The Afternoon. Seas 1 Foot Or Less, Then 2 To 3 Ft In The Afternoon. Wave Detail: W 1 Foot At 2 Seconds And N 1 Foot At 2 Seconds, Becoming Sw 2 Ft At 3 Seconds And Ne 1 Foot At 3 Seconds.
Wed Night...Sw Winds Around 15 Kt With Gusts Up To 25 Kt. Seas 2 To 4 Ft. Wave Detail: S 3 Ft At 5 Seconds And E 1 Foot At 8 Seconds.
Thu...Sw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft. Wave Detail: S 3 Ft At 7 Seconds And W 1 Foot At 4 Seconds.
Thu Night Through Fri Night...Nw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft. Wave Detail: S 3 Ft At 7 Seconds And W 1 Foot At 3 Seconds.
Sat Through Sun...Sw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft. Wave Detail: S 2 Ft At 3 Seconds And Nw 2 Ft At 3 Seconds.
Sun Night...Sw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft. A Chance Of Showers. 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
Issued by National Weather Service New York NY
407pm EDT Tuesday Oct 6 2026

.WHAT HAS CHANGED... No significant changes to the forecast.

.KEY MESSAGES... - Dry & chilly tonight with widespread frost outside the urban centers. Sunny & becoming breezy Wednesday with milder high temps reaching well into the 60s. Much milder Wednesday night with S-SW winds holding low temps mainly in the upper 40s-lower 50s.

- Very low chance of a spot shower Thursday, otherwise a mild day. An early look at the holiday weekend favors dry weather, though late Sunday into Monday bears watching for rain.

KEY MESSAGE 1...Dry & chilly tonight with widespread frost outside the urban centers. Sunny & becoming breezy Wednesday with milder high temps reaching well into the 60s. Much milder Wednesday night with S-SW winds holding low temps mainly in the upper 40s-lower 50s.

Large high pressure builds overhead tonight. This coupled with the dry/cool airmass and mainly clear skies will result in good radiational cooling and unseasonably chilly temps tonight. Low temperatures should bottom out well down into the 30s in many locations with even some upper 20s in the normally coolest low-lying areas of western MA. Frost and even freeze headlines are in effect for much of the region outside the urban heat islands. The mild spot will be downtown Boston...where low temps will only drop into the middle 40s.

This high pressure system moves east of the region on Wed. This results in a return southwest flow of milder air to work back into the region. Sunny skies and 925T warming to around +10C by afternoon will allow for a very nice recovery in temps. Highs should reach the lower 60s in the high terrain with middle to upper 60s in most other locations. It will become a bit breezy Wednesday afternoon with Bufkit soundings supporting SW wind gusts of 20-25 mph...but still a very nice day.

A modest southwest LLJ of 30-40 knots ahead of an approaching cold front Wednesday night will prevent surface winds from decoupling. This will result in a much milder low temperatures that what is on tap for tonight. Low temps will only drop into the upper 40s and lower 50s in most locations.

KEY MESSAGE 2...Very low chance of a spot shower Thursday, otherwise a mild day. An early look at the holiday weekend favors dry weather, though late Sunday into Monday bears watching for rain.

There aren't many changes to the extended forecast. As previously mentioned, a vertically stacked low near Hudson Bay will send a few subtle shortwaves through New England Thursday. Limited moisture should preclude significant rainfall, though a spot shower cannot be ruled out. The NBM doesn't show this particularly well, but CAMs do indicate low-end Probability of Precipitation during the day Thursday associated with a surface cold front. Southwest flow aloft also brings somewhat elevated PWATs (Precipitable Waters) into the region. Thus, felt it best to introduce Slight Chance (15-20%) PoPs. This is far from a washout, with much of the region and day remaining dry, though the setup does favor a few spot showers. Otherwise, dry weather prevails Friday through the start of the holiday weekend.

Forecast uncertainty increases late Sunday into Columbus Day and will depend largely on potential tropical development over the Bay of Campeche. Development of AL92 is expected, and if named would become Isaias. Some guidance brings remnant tropical moisture north into southern New England sometime late Sunday night or Monday, while other solutions keep it suppressed to our south as a strong 1030 mb high extends across much of southern Canada. Plenty of time to watch trends, with no reason to alter outdoor plans at this point.

Temperatures remain fall-like with highs mainly in the middle to upper 60s, except upper 60s to mid 70s Thursday. Overnight lows are mostly in the upper 40s and 50s, though cooler upper 30s to middle 40s are possible Friday night into Saturday morning. Even cooler conditions are possible where effective radiational cooling develops beneath the surface high.

Marine
Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent.

Tonight through Thursday night...High confidence.

Winds will continue to diminish through early evening as high pressure builds in from the west. Winds then shift to the SW Wed into Wednesday night. Some SW wind gusts of 20-25 knots expected Wednesday afternoon and night. Later shifts may need to consider some small craft advisory headlines Wednesday PM...but felt it was too marginal for a late 2nd/3rd period event.

Outlook /Wednesday Night through Sunday/... Thursday through Thursday Night: Winds less than 25 kt. Areas of seas approaching 5 ft.
Friday: Winds less than 25 kt. Seas locally approaching 5 ft.

Friday Night through Saturday Night: Winds less than 25 kt.

Sunday: Low risk for Small Craft Advisory winds with gusts up to 25 kt.

NOAA Boston MA Office: Watches - Warnings - Advisories
CT...Frost Advisory from 11pm this evening to 9am EDT Wednesday for CTZ002>004. MA...Frost Advisory from 11pm this evening to 9am EDT Wednesday for MAZ004>006-009-011>013-017-018-020-021-026. Freeze Warning from 11pm this evening to 9am EDT Wednesday for MAZ002-003-008-010. RI...Frost Advisory from 11pm this evening to 9am EDT Wednesday for RIZ001-003-006.

Marine
None.