Marine Weather Net

Long Island Sound East of New Haven CT/Port Jefferson NY Marine Forecast


TODAY

NW
WINDS
20 - 25
KNOTS

TONIGHT

NW
WINDS
10 - 15
KNOTS

FRI

S
WINDS
5 - 10
KNOTS

FRI NIGHT

SW
WINDS
10 - 15
KNOTS

The Marine Weather Forecast In Detail:
ANZ331 Forecast Issued: 627 AM EDT Thu Mar 30 2023

SMALL CRAFT ADVISORY IN EFFECT UNTIL 11 AM EDT THIS MORNING
Today...Nw Winds 20 To 25 Kt, Diminishing To 10 To 15 Kt. Seas 2 To 4 Ft.
Tonight...Nw Winds 10 To 15 Kt, Diminishing To Around 5 Kt After Midnight. Seas Around 2 Ft In The Evening, Then 1 Ft Or Less.
Fri...S Winds 5 To 10 Kt, Increasing To 10 To 15 Kt With Gusts Up To 20 Kt In The Afternoon. Seas 1 Ft Or Less. Chance Of Showers In The Afternoon.
Fri Night...Sw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas Around 2 Ft. Chance Of Showers In The Evening, Then Showers After Midnight.
Sat...Sw Winds 20 To 25 Kt With Gusts Up To 30 Kt. Seas 2 To 4 Ft. Showers. Slight Chance Of Tstms In The Afternoon.
Sat Night...W Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 2 To 4 Ft.
Sun...Nw Winds 15 To 20 Kt With Gusts Up To 30 Kt. Seas 2 To 4 Ft.
Sun Night...N Winds 5 To 10 Kt. Seas Around 2 Ft.
Mon...S Winds 10 To 15 Kt With Gusts Up To 25 Kt. Seas Around 2 Ft.
Mon Night...Sw Winds 15 To 20 Kt With Gusts Up To 25 Kt. Seas 1 To 2 Ft. Winds And Seas May Be Higher In And Near Tstms.
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Area Forecast Discussion
National Weather Service New York NY
720am EDT Thu Mar 30 2023

Synopsis
High pressure builds in today, remaining in control through tonight. Deepening low pressure over the Central Plains on Friday will track across the Great Lakes, sending a strong frontal system through the area into Saturday. High pressure will build in on Sunday and then move offshore to start the week.

Near Term - Through Tonight
Received a few reports of slick conditions in parts of southern Connecticut early this morning from lingering ground moisture as temperatures have fallen below freezing in the wake of a cold frontal passage overnight. Conditions should begin to improve later this morning as surface heating gets going and temperatures rise into the mid 30s. Only minor adjustments made with this update to account for current observations, but otherwise, forecast remains on track and previous discussion follows.

Skies have cleared out and a cooler air mass briefly settles in today. Blustery NW winds persist early this morning as a 1030 mb high over the Midwest builds in, adding to the chill. BUFKIT soundings indicate a well-mixed BL this afternoon as broad upper troughing shifts east of the region. With 850 mb temps falling to around -10C to -12C, it will make for a chilly late March day. Highs will be about 10 degrees cooler than Wednesday, generally in the low-to-mid 40s, or as much as 10 degrees below climatology. The NW flow advects in drier air, and dew points mix down into the single digits and teens much of the day.

The flow lightens late as the high builds overhead, allowing abundant sunshine to prevail during the day. With clear skies and light winds, tonight looks ideal for efficient radiative cooling. Much of the interior, as well as the LI Pine Barrens, fall into the 20s, with even a few isolated teens possible. High clouds begin to approach however in the early morning hours as the high slips offshore and the light flow goes southerly. The timing of the wind shift and clouds could mitigate the cooling a bit. Blended in MAV/MET data for lows tonight, otherwise generally stayed close to national blended guidance.

Short Term - Friday Through Saturday Night
Guidance remains in general agreement with the upper air pattern and surface features into the first half of the weekend. A closed upper low over the Central Plains on Friday sends a deepening surface low across the Great Lakes Friday night, and then into eastern Canada on Saturday.

The associated frontal system impacts the area during this time, with overrunning rain developing late Friday through Friday night ahead of the warm front and then occasional showers with a chance of thunderstorms in the warm sector Saturday. The best chance for thunderstorms will be north and west of the NYC/NJ metro in the afternoon/early evening hours along and ahead of the cold front where there will be marginal instability and strong deep- layer shear. The question is whether the instability will be sufficient to overcome the shear and work in tandem.

The warm sector Saturday will also feature gusty SW winds with the potential for gusts in excess of 30 mph. It's always tricky at this time of year as to how much of the LLJ mixes down at the coast with a strong onshore flow and marine layer in place. 925 mb winds currently forecast at 55-70 kt over eastern LI and SE CT at times late Friday night and Saturday. Rainfall amounts look to average between half and three quarters of an inch.

Cold front passes through early Saturday evening with cold air advection and gusty W-NW winds continuing. Any shower activity comes to an end in the evening, with conditions drying out Saturday night.

Long Term - Sunday Through Wednesday
High pressure builds in on Sunday with diminishing winds and highs a few degrees below normal. The ridge of this high pressure system reaches us late at night, so with light to calm winds and a clear sky, blended in the colder MEX MOS with the typically too warm NBM for lows where radiational cooling is typically the strongest. A return flow from the high then helps boost temperatures on Monday into the 60s away from the influence of the nearby waters.

A cold front drops down from the north on Tuesday with a chance of showers. Some disagreement among the global models regarding how far south the front progresses before stalling, then moving back north as a warm front on Wednesday. Went with NBM for highs on Tuesday, but wouldn't be surprised if these need to be lowered eventually. The front shifts north on Wednesday as the associated low heads toward the western Great Lakes region. Just like on Tuesday, NBM is possibly too warm regarding high temperatures on Wednesday, especially if the front sags to our south before lifting. Climatologically, the front would otherwise be more likely to remain to our south this time of the year until either the low center reaches the eastern Great Lakes and/or a strong enough low level jet develops and helps push the front northward. Showers will be possible Tuesday through Wednesday, but overall chances look to be higher on Wednesday.

Marine
In the wake of a cold frontal passage, gusty NW flow continues into the morning hours with gusts 25 to 30 kt on all waters. A Small Craft Advisory remains in effect through 10 AM. Building high pressure diminishes the winds and seas this afternoon, with sub- SCA (Small Craft Advisory) conditions everywhere into the first half of Friday.

A tightening pressure gradient from an approaching storm system leads to a strengthening southerly flow Friday, with SCA (Small Craft Advisory) conditions developing on the ocean waters Friday afternoon, spreading to remaining waters Friday night. SCA (Small Craft Advisory) winds continue on all waters through Saturday night, with gales also possible Saturday, especially on the ocean waters. Ocean seas build to 10 to 15 ft during this time.

SCA (Small Craft Advisory) conds will continue on all waters into Sunday, and by evening, only the eastern ocean waters probably remains within advisory criteria as seas still remain elevated. Seas here likely subside below 5 ft during the overnight hours, and as a high pressure ridge reaches the eastern seaboard, all waters remain below advisory criteria through most of Monday before winds and seas increase on the return flow of high pressure moving farther out to sea.

Hydrology
No hydrologic concerns are expected through the forecast period.

NOAA New York NY Office: Watches - Warnings - Advisories
CT...None. NY...None. NJ...None.

Marine
Small Craft Advisory until 11am EDT this morning for ANZ331- 332-335-338-340-345-350-353-355.