Montauk NY to Marthas Vineyard out 20 NM South of Block Island Marine Forecast
| Rest Of Tonight...S Winds Around 5 Kt. Seas Around 2 Ft. Wave Detail: N 1 Foot At 3 Seconds And Se 1 Foot At 6 Seconds. |
| Wed...Sw Winds Around 5 Kt, Increasing To 5 To 10 Kt In The Afternoon. Seas Around 2 Ft. Wave Detail: Sw 2 Ft At 9 Seconds And E 1 Foot At 5 Seconds. |
| Wed Night...Sw Winds 5 To 10 Kt. Seas Around 2 Ft. Wave Detail: Sw 2 Ft At 3 Seconds And E 2 Ft At 7 Seconds. |
| Thu...Sw Winds 5 To 10 Kt. Seas Around 2 Ft. Wave Detail: Sw 2 Ft At 3 Seconds And W 2 Ft At 4 Seconds. |
| Thu Night...Sw Winds 10 To 15 Kt, Increasing To 15 To 20 Kt After Midnight. Seas 2 To 4 Ft. Wave Detail: Sw 3 Ft At 4 Seconds And E 2 Ft At 7 Seconds. |
| Fri And Fri Night...Ne Winds 15 To 20 Kt. Seas 2 To 4 Ft. Wave Detail: Ne 3 Ft At 4 Seconds And W 3 Ft At 5 Seconds. |
| Sat And Sat Night...E Winds 15 To 20 Kt, Becoming Se Around 10 Kt. Seas 2 To 4 Ft. |
| Sun And Sun Night...Se Winds 10 To 15 Kt, Becoming Ne 15 To 20 Kt. Seas 3 To 5 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. |
| Area Forecast Discussion National Weather Service Boston/Norton MA 241am EDT Wednesday September 16 2026 .WHAT HAS CHANGED... No significant changes to the forecast. .KEY MESSAGES... - Warmer temperatures expected today with increased humidity levels. - Scattered showers possible Thursday evening into Friday morning, followed by dry conditions Friday. - Rain chances return for the second half of the weekend. There remains uncertainty in the details such as coverage, timing, amounts. KEY MESSAGE 1... Warmer temperatures expected today with increased humidity levels. Patchy fog possible early this morning, but should burn off with sunrise. High pressure in place will keep things mainly dry today. The exception is a line of light showers moving through upstate NY early this AM. At most this line may bring a sprinkle and period of clouds as it moves through this morning. Expect a warmer day with a touch more humidity. A strong upper level ridge/high remains positioned across the southeast CONUS, subtly building into the northeast. Warmer mid-level temperatures advect in within the SW flow with 925mb temperatures 16-18C. This should yield highs in the mid and upper 70s with low 80s in the valleys (seasonably warm for mid-Sept). There will also be some moisture advection as well within the SW flow which will bring dewpoints back up into the low 60s. This will make it feel more humid than the previous day or two. KEY MESSAGE 2...Scattered showers possible Thursday evening into Friday morning, followed by dry conditions Friday. The first part of Thursday should remain dry with shower chances increasing later in the day as a weak shortwave trough approaches. Ahead of this shortwave, a plume of anomalous moisture advects in from the west. PWATs (Precipitable Waters) run around 180-200 percent of normal or more directly put, PWAT (Precipitable Water) values 1.7-1.9". This has also been signaled as anomalous across the NAEFS guidance. Despite the anomalous moisture, the lift/forcing with this wave is weaker. Most guidance tracks the better forcing further north (New England). Being further from the stronger forcing will likely limit the potential for widespread heavy rain across the region. For timing, showers become more likely late afternoon into early evening, continuing through early Friday morning. For rain totals, ensembles show low probabilities (< 15%) for rain totals greater than 0.50". Amounts generally range from a trace to a few tenths across the GFS/ECMWF/Canadian are their ensembles. If this wave tracks further south as a small portion of guidance has been indicating, amounts will likely trend higher so this will continue to be monitored. There is potential for some elevated instability Thursday night which could result in an isolated heavier downpour, but otherwise the model consensus leans toward a period of showers with overall lighter amounts. A drier airmass pushes in behind the exiting shortwave Friday which will gradually clear clouds through the day. Temperatures are likely to be in seasonable ranges in the 70s. A cooler airmass sinks across the region by Saturday bringing the return of Fall-like temperatures. Surface high pressure dominates bringing dry conditions. KEY MESSAGE 3... Rain chances return for the second half of the weekend. There remains uncertainty in the details such as coverage, timing, amounts. Confidence in the pattern decreases for the second half of the weekend into early next week. Ensembles continue to indicate potential for a shortwave trough to drop southward across the northeast Sunday into Monday. The strength/track of the trough and how it interacts with a surface high over the Great Lakes has varied across guidance leading to uncertainly in rain chances, timing, and amounts. If the shortwave tracks closer to southern New England the lift associated with the wave combined with a plume of anomalous moisture will better support rain across the region Sunday. However, there are also solutions that favor a stronger high pressure that would suppress the system further south/west resulting in more limited shower chances. Still plenty of details to iron out, but should become more clear as we get closer. Surface high pressure shifts across eastern Canada into early next week. There are indications across ensemble guidance for another disturbance to push through potentially bringing a period of showers in the Tue-Wednesday timeframe. Confidence remains on the lower end with question on how the high pressure suppresses the incoming system and moisture advection. Marine Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Surface high pressure continues with SW winds 10-15 kts today and Thursday. Occasional gusts 18-22 kts are possible both days in the afternoon/evenings. Outlook /Thursday through Sunday/... Thursday: Winds less than 25 kt. Thursday Night: Winds less than 25 kt. Chance of rain showers. Friday: Winds less than 25 kt. Seas locally approaching 5 ft. Slight chance of rain showers. Friday Night: Low risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of seas approaching 5 ft. Saturday: Winds less than 25 kt. Areas of seas approaching 5 ft. Saturday Night: Winds less than 25 kt. Slight chance of rain showers. Sunday: Winds less than 25 kt. Seas locally approaching 5 ft. Chance of rain showers. NOAA Boston MA Office: Watches - Warnings - Advisories CT...None. MA...None. RI...None. Marine None. |
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