Marine Weather Net

Montauk NY to Marthas Vineyard out 20 NM South of Block Island Marine Forecast


TODAY

NW
WINDS
15 - 20
KNOTS

TONIGHT

NW
WINDS
15 - 20
KNOTS

SAT

W
WINDS
20 - 25
KNOTS

SAT NIGHT

W
WINDS
15 - 20
KNOTS

The Marine Weather Forecast In Detail:
ANZ256 Forecast Issued: 402 AM EDT Fri Mar 29 2024

GALE WARNING IN EFFECT THROUGH SATURDAY MORNING
Today...Nw Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 4 To 6 Ft. Rain, Mainly This Morning. Patchy Fog This Morning. Vsby 1 To 3 Nm.
Tonight...Nw Winds 15 To 20 Kt, Becoming W 20 To 25 Kt After Midnight. Gusts Up To 30 Kt. Seas 5 To 7 Ft.
Sat...W Winds 20 To 25 Kt With Gusts Up To 30 Kt. Seas 5 To 7 Ft.
Sat Night...W Winds 15 To 20 Kt, Diminishing To 10 To 15 Kt After Midnight. Gusts Up To 25 Kt. Seas 3 To 5 Ft.
Sun...W Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft.
Sun Night...Nw Winds Around 10 Kt, Becoming N After Midnight. Seas 2 To 3 Ft.
Mon...E Winds 5 To 10 Kt. Seas 2 To 3 Ft.
Mon Night...Se Winds Around 10 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft. A Chance Of Rain.
Tue...E Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 3 To 5 Ft. Rain Likely.
Tue Night...E Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 5 To 6 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
323am EDT Fri Mar 29 2024

Synopsis
Dry but windy and cooler weather overspreads southern New England Friday. However, rain will linger across RI and eastern MA in the morning, possibly into early afternoon for Cape Cod and Nantucket. Partial sunshine develops Friday afternoon, but clouds will be slower to exit Cape and Islands. Sunny Saturday with winds diminishing late in the day. Then a chance for a few showers Saturday night into Sunday morning. Dry weather follows Sunday afternoon along with a mix of sun and clouds and continuing into Monday, with near to above normal temperatures. Very unsettled mid next week perhaps a few chances for some accumulating snow!

Near Term - Until 6pm This Evening
2 AM

Key Points Friday... * Rain may briefly mix with snow before ending...but no impacts * Rain ends this morning, except early afternoon Cape Cod/Nantucket * Partial clearing this afternoon away from the Cape/Islands * Windy with highs in the upper 40s to the middle 50s

Details... Mid level trough taking on a negative tilt early this morning, enhancing forcing for ascent over RI and eastern MA, resulting in widespread rain for this region and moderate at times. Hourly rainfall rates only on the order of 0.10 to 0.20 inches. Fairly modest stratiform rainfall event, thus not expecting too much impact for the morning commute across RI and eastern MA. The Flood Watch continues early this morning for northeast CT, RI and eastern- central MA, but this is mainly for river and Small Stream flooding given all the rain we have had this month, resulting in very little river/stream capacity.

Farther to the west across CT into western MA, NW flow on the backside of the developing offshore cyclone, is advecting drier low level air and resulting in much lighter rains across this area. As for ptype, the NAM remains the most amplified of the models with sufficient column cooling for rain to mix with snow later this morning across eastern MA, before the qpf shield moves offshore by midday or so. However, with surface temps remaining above freezing, any wet snow mixing in at times will have no impact on road conditions.

By midday, rain shield will be exiting offshore with the exception of Cape Cod and Nantucket, where it may wait until 21z as model trends have been more amplified and slower with evolving closed mid level low just east of Cape Cod. Developing comma-head will delay sunshine this afternoon. Partial sunshine should develop midday across western CT/MA then slowly progressing eastward but may wait until then just before sunset across eastern MA.

Given Cold Air Advection and good boundary layer mixing along with downsloping NW winds from strengthening offshore storm, temps will overachieve with highs in the low to mid 50s, a few degs above normal for late March. Although, it will feel much cooler given blustery NW winds 20-30 mph, gusting up to 40 mph at times.

Short Term - 6pm This Evening Through 6pm Saturday
2 AM

Key Messages... * Still quite blustery & cold Fri night with lows in the 30s * Lots of sunshine Sat (inc clouds late) & diminishing winds

Details... Friday night... Sub 980 mb low lifts north through the Canadian Maritimes. This will continue to result in quite blustery conditions to persist with gusts in the 20 to 30 mph range and up to 35 mph or so in spots during the evening. Lows will be seasonable for late March, in the 30s but gusty NW winds will combine to yield wind chills in the 20s.

Saturday... Deep, cold mid level trough moves farther away from SNE, resulting in rising heigheights and warming temps aloft across the region. This will result in abundant sunshine and diminishing winds in the afternoon. After a chilly start to the day, temps will respond to the late March sun along with downsloping NW winds, will push highs into the mid 50s. It will be pleasant in the afternoon given ample sunshine and diminishing winds later in the day. Mid/high clouds arrive late in the day across the western horizon, as next short wave trough approaches.

Long Term - Saturday Night Through Thursday
Long Term

Highlights

* Dry and pleasant weather Sunday and Monday with a mix of sun and clouds and seasonable temperatures

* Unsettled Tuesday through Thursday next week with the potential for a long duration precipitation event and perhaps some elevation snow

Sunday and Monday

A mid-level ridge builds over The Northeast during the second half of the weekend. This will bring the period of gusty northwest winds to an end. Surface high pressure should support generally light winds and a good amount of sunshine on Sunday afternoon. 925 hPa temps are forecast to be slightly above the 0 Celsius mark. Cold air aloft will support steep lapse rates all the way through the mid- levels. The surface pressure gradient looks tight enough to support at least some shallow mixing. Therefore with the 925 hPa temps just above 0 Celsius, we can expect diurnal mixing to support surface temps in the low to mid 50s on Sunday afternoon. This is pretty close to the climatological normal in SNE for late March/early April.

Monday will feature similar conditions, but with some increasing cloudiness across the western areas thanks to a plume of mid-level moisture streaming into the Northeast. Areas that observe more sunshine, mainly across eastern MA and RI may experience slightly warmer temps than on Sunday with highs in the mid to upper 50s as some modest warm advection will result in a marginally warmer air mass. Winds continue to remain on the lighter side. Low temps Saturday and Sunday night close to normal as well ranging from the low to upper 30s across the region.

Tuesday through Thursday

The forecast becomes more unsettled Tuesday through Thursday as a deep upper level trough digs into the east CONUS. This is expected to support the development of another robust low pressure system that will likely result in another multi-day precipitation event Tuesday through Thursday. Details are vague as the development of the surface low-pressure system will be the product of northern and southern stream PV anomalies merging over The Midwest. Thus, confidence in storm track and potential impacts are low at this time. Regardless of storm track, confidence is moderate to high that this system will track somewhere over The Northeast and support higher rain chances from mid to late week. NBM probs of 72 hour precipitation exceeding 2 inches between Tuesday and Thursday morning are 20 to 30 percent across southern New England, with a higher bull eye over Rhode Island and southeastern MA in the 30 to 40 percent range. Furthermore, ensemble guidance reveals several solutions that resolve a storm track that could support some measurable snowfall across the higher elevations of The Worcester Hills and The Berkshires. Probs of 24 hour snowfall exceeding 3 inches of snow over the higher elevations currently range from 20 to 30 percent with the higher probs focused closer to the MA/NH border. We'll have more details and higher confidence with respect to impacts for our region by early next week.

Marine
Forecaster Confidence Levels:

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

2 AM

* NW Gales Friday/Fri night

Friday and Saturday...High Confidence.

Low pressure just SE of the 40N/70W benchmark intensifies into a gale center today as it becomes a 980 mb low approaching Nova Scotia late Fri. This will yield NW gales across the MA/RI waters Friday and Friday night. As the low exits thru the maritimes and into eastern Quebec Sat, winds slowly slacken later Sat across MA/RI waters.

Outlook /Saturday Night through Tuesday/... Saturday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain.

Sunday through Sunday Night: Winds less than 25 kt.

Monday: Winds less than 25 kt. Slight chance of rain.

Monday Night: Winds less than 25 kt. Chance of rain.

Tuesday: Low risk for Small Craft Advisory winds with gusts up to 30 kt. Areas of seas approaching 5 ft. Rain likely.

NOAA Boston MA Office: Watches - Warnings - Advisories
CT...Flood Watch until 6am EDT early this morning for CTZ004. MA...Flood Watch until 6am EDT early this morning for MAZ004>007- 012>024-026. RI...Flood Watch until 6am EDT early this morning for RIZ001>007.

Marine
Small Craft Advisory until 8am EDT Saturday for ANZ230-236. Gale Warning until 11am EDT Saturday for ANZ231-250-251- 254>256. Gale Warning from 8am this morning to 11am EDT Saturday for ANZ232>235-237.