Narragansett Bay Marine Forecast
| Tonight...E Winds 10 To 15 Kt With Gusts Up To 20 Kt, Diminishing To 5 To 10 Kt After Midnight. Waves 2 To 3 Ft. Patchy Fog. A Chance Of Showers. A Slight Chance Of Tstms This Evening. Vsby 1 To 3 Nm. |
| Thu...N Winds 5 To 10 Kt. Waves 2 To 3 Ft. Patchy Fog. Showers Likely. Vsby 1 To 3 Nm In The Morning. |
| Thu Night...N Winds 5 To 10 Kt. Waves 2 To 3 Ft. Patchy Fog In The Evening. |
| Fri...Nw Winds 5 To 10 Kt. Waves 2 To 3 Ft. A Chance Of Sprinkles In The Afternoon. |
| Fri Night...Sw Winds 5 To 10 Kt. Waves Around 2 Ft. A Chance Of Sprinkles In The Evening. |
| Sat And Sat Night...Sw Winds 5 To 10 Kt. Waves Around 2 Ft. |
| Sun...S Winds 5 To 10 Kt. Waves Around 2 Ft. |
| Sun Night...S Winds 5 To 10 Kt. Waves Around 2 Ft. A Chance Of Showers. |
| Mon And Mon Night...Sw Winds 5 To 10 Kt, Becoming W. Waves 2 To 3 Ft. A Chance Of Showers. Winds And Waves Higher In And Near Tstms. 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 252pm EDT Wednesday July 29 2026 .WHAT HAS CHANGED... No significant changes. .KEY MESSAGES... - Heavy rain at times continues into this evening, leading to the potential street and flash flooding, especially across western New England. * Light showers linger into Friday, with improving conditions for the upcoming weekend. * Unsettled weather returns late Sunday night into Monday, followed by drier conditions Tuesday. KEY MESSAGE 1...Periods of heavy rainfall continue into Wednesday evening, leading to potential street and flash flooding, especially across western portions of MA. High amplitude vertically stacked low over southeast NYS this afternoon, with a deep Atlantic moisture plume pivoting cyclonically across New England. A very atypical system for late July, with cool season jet dynamics (negative tilt mid/upper trough) via strong cyclonically curved flow aloft, combined with 35-45kt of moist low level SE jet providing upslope enhancement, acting on a warm season moisture plume up to 150% of normal. This will continue to support the ongoing forecast of potential flash flooding, with the greatest threat across the eastern slopes of the Berkshires. As the low level jet pivots and lifts north into NH/VT, the heaviest rainfall shifts north into NH/ME tonight. This will result in lower rainfall rates and more of a stratiform rain across MA/RI/CT tonight. Thursday the vertically stacked low aloft drifts over SNE, with surface low over the Gulf of Maine. Moist cyclonic flow aloft continues, yielding overcast conditions along with scattered showers. -10C to -12C at 500 mb will provide some elevated instability and some of the CAMS indicate isolated to scattered heavy showers with embedded thunder across CT/RI and southeast MA. Moisture plume also across this area with PWATs (Precipitable Waters) up to 1.5 inches. Thus, a low risk for isolated flash flooding across this region Thu PM. As for temperatures, persistent easterly flow and thick cloudcover/rainfall will depress high temperatures into the low to mid 70s Thursday. Drying trend Thu night as vertically stacked low lifts northeast into Maine and the Maritimes. However, low clouds, drizzle and fog may linger. KEY MESSAGE 2...Light showers linger into Friday, with improving conditions for the upcoming weekend. The aforementioned vertically stacked low pressure system begins to lift northeast away from southern New England Friday morning. Friday serves as a transition day as the departing low gives way to subtle mid-level ridging and weak surface high pressure heading into the weekend. While periods of light rain and drizzle remain possible Friday, the overall trend is toward improving conditions. Even as the primary low departs, its trailing mid-level trough will linger over the region, allowing weak shortwave energy to rotate through southern New England. With PWATs (Precipitable Waters) remaining around 1.3 inches and the lowest several thousand feet of the atmosphere remaining saturated, scattered light showers or areas of drizzle remain possible. Winds gradually shift from onshore to northerly and eventually north-northwesterly by late Friday. Combined with abundant cloud cover, highs will remain below normal, generally in the middle 70s to around 80. The weekend will not be as sunny as last weekend, but it should be considerably drier. A mix of clouds and sunshine is expected both Saturday and Sunday. PWATs (Precipitable Waters) remain near climatological normals Saturday before increasing to around 1.2 to 1.5 standard deviations above normal by Sunday afternoon ahead of the next system. While most locations should remain dry, a passing shortwave could produce an isolated afternoon shower or even a rumble of thunder. Overall, subtle mid-level ridging and developing south to southwest return flow will support a warming trend, with highs returning to seasonable levels in the lower to middle 80s both Saturday and Sunday. KEY MESSAGE 3...Unsettled weather returns late Sunday night into Monday, followed by drier conditions Tuesday. Attention then turns to the next system, as a mid-level trough and associated cold front approach late Sunday night into Monday. While uncertainty remains regarding the exact timing and evolution of the system, this currently appears to be the next opportunity for widespread rainfall. Ensemble guidance indicates PWATs (Precipitable Waters) will be slightly above normal, with most solutions favoring a progressive system that should limit the flash flood threat. Current ensemble probabilities for 24-hour rainfall amounts exceeding one-half inch range from 20 to 40 percent. High pressure is then expected to build into the region Tuesday, bringing a return to drier conditions, although confidence in the timing of the frontal passage remains lower given the 5 to 6 day forecast horizon. Marine Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Surface low over western Long Island Wednesday afternoon, will continue to yield ESE winds 20 to 30 kt. As this low slowly moves east, the strongest winds will lift north into NH/ME tonight. However, seas will remain rough. Heavy showers at times will limit vsby at times. During Thu and Thu night, the low over the Gulf of ME will slowly continue to move NE. Light N-NE winds with seas slowly subsiding. Vsby 1-3NM at times in areas of fog and showers. Outlook /Thursday Night through Monday/... Friday through Friday Night: Winds less than 25 kt. Seas up to 5 ft. Saturday: Winds less than 25 kt. Seas locally approaching 5 ft. Saturday Night through Sunday: Winds less than 25 kt. Sunday Night: Winds less than 25 kt. Chance of rain showers. Monday: Winds less than 25 kt. Areas of rough seas. Chance of rain showers. NOAA Boston MA Office: Watches - Warnings - Advisories CT...Flood Watch until 8pm EDT this evening for CTZ002>004. MA...Flood Watch until 8pm EDT this evening for MAZ002>004-008>012. RI...Flood Watch until 8pm EDT this evening for RIZ001-002. Marine Small Craft Advisory until 8pm EDT this evening for ANZ230>237-251. Small Craft Advisory until 8pm EDT Thursday for ANZ250. Small Craft Advisory until 2pm EDT Thursday for ANZ254>256. |
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