Marine Weather Net

Rhode Island Sound Marine Forecast


TODAY

SW
WINDS
10 - 15
KNOTS

TONIGHT

SW
WINDS
10 - 15
KNOTS

FRI

SW
WINDS
5 - 10
KNOTS

FRI NIGHT

SW
WINDS
10
KNOTS

The Marine Weather Forecast In Detail:
ANZ235 Forecast Issued: 403 AM EDT Thu May 23 2024

Today...Sw Winds 10 To 15 Kt. Gusts Up To 20 Kt This Afternoon. Seas 2 To 3 Ft. Wave Detail: Sw 2 Ft At 5 Seconds And Se 1 Foot At 8 Seconds. Patchy Fog. A Chance Of Showers. Vsby 1 Nm Or Less, Increasing To 1 To 3 Nm This Afternoon.
Tonight...Sw Winds 10 To 15 Kt, Diminishing To 5 To 10 Kt After Midnight. Seas Around 2 Ft. Wave Detail: Sw 2 Ft At 5 Seconds And Se 1 Foot At 8 Seconds. Patchy Fog. A Chance Of Showers. Vsby 1 To 3 Nm, Decreasing To 1 Nm Or Less After Midnight.
Fri...Sw Winds 5 To 10 Kt. Seas Around 2 Ft. Wave Detail: Sw 2 Ft At 5 Seconds And Se 1 Foot At 8 Seconds.
Fri Night...Sw Winds Around 10 Kt, Becoming Nw After Midnight. Seas Around 2 Ft. Wave Detail: Sw 2 Ft At 5 Seconds And Se 1 Foot At 8 Seconds.
Sat...E Winds Around 5 Kt, Becoming S In The Afternoon. Seas Around 2 Ft In The Morning, Then 1 Foot Or Less. Wave Detail: S 2 Ft At 6 Seconds And Se 1 Foot At 9 Seconds, Becoming S 1 Foot At 5 Seconds And Se 1 Foot At 9 Seconds.
Sat Night...S Winds 5 To 10 Kt. Seas Around 2 Ft. Wave Detail: S 2 Ft At 5 Seconds And Se 1 Foot At 9 Seconds. A Chance Of Showers.
Sun And Sun Night...S Winds 5 To 10 Kt. Seas 1 Foot Or Less, Then Around 2 Ft.
Mon...Se Winds 10 To 15 Kt. Seas Around 2 Ft. A Chance Of Rain.
Mon Night...Se Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 4 Ft. Rain Likely. 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.
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Area Forecast Discussion
National Weather Service Boston/Norton MA
345am EDT Thu May 23 2024

Synopsis
A high pressure remains just southeast of New England, setting the stage for summerlike warmth through today away from the immediate south coast. An approaching cold front will bring a round of showers and thunderstorms this afternoon through at least the evening. A few strong to severe storms are possible. Mainly dry on Friday with it remaining mild. Dry for much of Saturday and mild. Could see a few spot showers/storms across the interior late. Essentially rinse and repeat on Sunday, but will be a bit warmer. Turning more seasonable early to mid next week, but a better shot for widespread rains.

Near Term - Until 6pm This Evening
Relatively quiet weather early this morning, with only a band of stratus across the coastal waters southeast of New England. This was mainly impacting Nantucket, but also barely clipping Chatham as well. Elsewhere, mid level cloud debris from convection well to our west was overspreading

Expecting a different story to unfold as this day progresses. A cold front will approach from the west, and provide a risk for showers and thunderstorms into this afternoon and evening. Modest buoyancy of 1,000-1,500 J/kg is possible with enough sunshine. However, the shear profiles are not all that ideal for widespread severe weather. That said, isolated strong to severe thunderstorms are possible, with the main threats being from straight-line winds and hail. The window of greatest concern remains from noon until 8 PM. Have the greatest confidence in stronger thunderstorms south of the Mass Pike, but that does not mean it is impossible elsewhere in southern New England.

Thinking there will be less insolation today, so high temperatures should be a few degrees lower than yesterday. Still quite humid for late May as well.

Short Term - 6pm This Evening Through 6pm Friday
This cold front should stall somewhere near the south coast of New England tonight into early Friday. Expecting convection to weaken after sunset. However, mid level lapse rates look to be steep enough to support at least a few thunderstorms overnight. Becoming drier Friday as this front slowly moves offshore.

Well above normal temperatures continue.

Long Term - Friday Night Through Wednesday
Highlights

* Dry and quiet weather for much of Sat and mild. Could see a spot shower/storm late in the afternoon or evening.

* Should be dry for most on Sun, but spotty showers/storms possible especially during the second half of the day. Still mild.

* Unsettled early to mid next week with a better shot for widespread rain late Monday into Tue. Temps trending more seasonable.

Friday Night through Saturday... A ridge axis extends from the Mid Atlantic to Ontario late Fri, with a shortwave over the OH Valley. The ridge axis builds into New England by early Sat, while the shortwave lifts into the Mid Atlantic. The ridge builds into northern New England by late Sat, while the shortwave lift toward southern New England. High pressure overhead Fri Night before it builds offshore on Sat. A frontal system lifts toward southern New England late Sat.

Dry and quiet weather anticipated for much of Sat with high pressure in control. Could see some spot showers/storms late in the day across the interior as a frontal system approaches. For most looks like a pleasant, but mild Sat. Should see W to SW flow bring in 15- 19 degree Celsius 925 hPa temps. The result will be highs in the 70s to mid 80s for much of the region. The only exception is across the south coast where readings range from the mid 60s to the low 70s.

Sunday... A ridge axis builds over the eastern Great Lakes early on Sun, while another shortwave is located over the Mid Mississippi River Valley. The ridge builds into New England, while the shortwave lifts into the eastern Great Lakes/Mid Atlantic by late in the day. High pressure nudges into our region during this timeframe, but we may still have a frontal boundary associated with the system on Sat that has stalled out over our region.

Generally am anticipating dry and quiet weather through much of this timeframe as high pressure nudges in. There really isn't a whole lot of forcing available given the synoptic setup and actually will see rising 500 hPa heigheights through the timeframe. Despite this we may still have a stalled out front overhead and PWATs (Precipitable Waters) around 1 inch. This in combination with diurnal heating may be enough to trigger some hit/miss showers and thunderstorms, especially during the afternoon. Given the weaker forcing confidence not the highest, so think the NBM slight chances of precipitation suffice for now.

As mentioned in the highligheights will have another day of above normal temps. Should see the 925 hPa temps range from 15-20 degrees. The result will be highs in the 80s for most. Though the south coast still will see temps range from the mid 60s to the mid 70s.

Memorial Day through Wednesday... Turning more unsettled during this period. A shortwave lifts into New England on Mon, while a more substantial trough/cutoff lifts into the Great Lakes Region. The cutoff/trough over the Great Lakes moves into the eastern Great Lakes/Mid Atlantic on Tuesday before another trough digs around the cutoff into the Great Lakes region/OH Valley on Wed. A frontal system lifts toward southern New England on Monday and Tue. The system may still be nearby as we head into the middle of the week.

Will be our next opportunity for widespread rain and there could be some embedded thunder as well. Not exactly sure how things specifically will evolve timing wise as guidance is all over the place, especially in the Mon/Tuesday timeframe. Does appear that a dry slot could punch in, which could erode steadier precipitation a bit quicker on Tue. For now have stuck with the NBM given the uncertainty. Will need to keep an eye on how things evolve in the coming days as there are signals for heavier downpours. The NAEFS/EPS guidance show PWATs (Precipitable Waters) ranging from 1-2 STD above model climo and PWATs (Precipitable Waters) roughly between 1-2 inches. There are also signals for strong winds with the EPS indicating wind of 1-1.5 STD above model climo, but the V component is 2-3 STD above model climo late Monday through Tue. The NAEFS is not as gung ho with winds around 1 STD above model climo and the V component of 1-2 STD above model climo. Something to stay tuned on at this point, but a stronger north/south component of the wind can aid in pumping in more moisture. Warm cloud layer depths range from 3-4 km per deterministic guidance, so rainfall processes may be efficient. The GEFS/GEPS at this point not as amped up on the heavier rain with nil probs of 24 hr Quantitative Precipitation Forecast at or above 1 inch into early Tue. The EPS still indicating low to mod probs (10-40 percent) of 24 hr Quantitative Precipitation Forecast at or above 1 inch.

Marine
Forecaster Confidence Levels:

Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent.

Through Friday...High Confidence.

High pressure south of the waters maintains relatively light winds and seas through Friday. The main concern will be poor visibility in areas of fog reducing visibility to less than 1 mile at times this morning around Nantucket and just east of Cape Cod.

Outlook /Friday Night through Monday/... Friday Night through Saturday: Winds less than 25 kt.

Saturday Night: Winds less than 25 kt. Slight chance of rain showers.
Sunday: Winds less than 25 kt. Slight chance of rain showers, isolated thunderstorms.

Sunday Night: Winds less than 25 kt. Slight chance of rain showers.
Memorial Day: Winds less than 25 kt. Chance of rain, isolated thunderstorms.

NOAA Boston MA Office: Watches - Warnings - Advisories
CT...None. MA...None. RI...None.

Marine
None.