Marine Weather and Tide Forecast for Sag Harbor, NY

KEY MESSAGES
1) Tranquil weather with dry conditions, slightly below normal temperatures and comfortable humidity through the weekend.

2) A slow moving frontal system may bring an extended period of unsettled weather late Monday into Thursday.

DISCUSSION

KEY MESSAGE 1
Mean troughing expected over the NE US this weekend, amplifying over the East coast east next week. At the surface, Canadian Maritime high pressure remains in control through the weekend.

This will keep conditions dry, with slightly below normal temperatures (as much as 5 degrees below normal) and comfortable humidity levels. High temperatures will remain in the upper 70s to mid 80s, and low temperatures in the upper 50s across the interior and the Long Island pine barrens, and 60s for city/coast on Saturday, with lows 3 to 5 degrees warmer Sunday night into Monday morning.

With the weak pressure gradient, E-NE winds will remain fairly light giving way to afternoon coastal sea breezes.

KEY MESSAGE 2
Models in general agreement with an Eastern US trough amplifying down the US East Coast through the early to mid week time frame as a series of weak shortwaves rotate through the western side of Western US ridging, with potential closed upper low developing over the NE US midweek.

At the surface, a slow moving cold front approaches late Monday into Tuesday, gradually crossing Wednesday. Scattered late day shower/thunderstorm potential west of the Hudson River Monday.
Greatest potential for shower and embedded thunderstorms activity for the entire area appears to be during Tuesday- Wednesday time frame with potential low pressure development along the front. Model spread exists on exact timing of closed low and surface low withing the Tue-Thu timeframe. Even if surface low pressure clears on Tuesday, could have lingering aft/eve instability shra/tsra on Wed and Thu.

Inherently low predictability on details this far out, but the slow movement of this system, shortwave forcing, and moistening environment poses a low flash flood threat at this time. The Weather Prediction Center has place the entire area in a marginal threat for excessive rainfall for Tuesday into Wednesday. Astronomical tides will be rising thru this period as well. The anomalous upper low/cold pool does bring potential for diurnally enhanced convection, but severe thunderstorm potential would be predicated on development/track of surface low pressure and extent of diurnal heating and instability development. More details as the weekend progresses.

Gradually improving conditions likely for late week, but mean troughing likely remains.

Near seasonable temps likely during this time period.

AVIATION /09Z SATURDAY THROUGH WEDNESDAY/
High pressure remains nearby.

VFR.

The winds become NE and E this morning at around 5 kt, then becoming ESE to SE around 10 kt in the afternoon. Speeds could be just over 10 kt at KJFK/KLGA/KISP/KBDR and possibly KGON in the afternoon.

...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Winds may become more southerly than what is reflected in TAFs this afternoon, otherwise unscheduled AMD are not expected.

OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY

Late Saturday night and Sunday: VFR.

Monday: MVFR possible in the afternoon and evening. Chance of showers and possibly a tstm from the NYC metros north/west.

Tuesday: MVFR or lower conditions possible. Showers likely and chance of tstms especially in the afternoon and evening. S winds G15-20kt.

Wednesday: Chance of MVFR with showers and possibly a tstm.

Detailed information, including hourly TAF wind component forecasts, can be found at: https:/ www.weather.gov/zny/n90

MARINE
With high pressure over the waters and remaining nearby into the weekend, a prolonged stretch of sub advisory conditions expected through the weekend and to begin next week. That said, persistent E flow 15 kt with gusts up to 20 kt this weekend will likely have seas building to around 4ft, occasionally touching 5 ft.

Thereafter, SCA conditions may return to the ocean waters and possibly to all waters Tue-Wed, but will be dependent on timing of a frontal system and possible low development.

Rip Currents: A moderate risk within an E to W longshore current regime is expected through the weekend, with a 1-2 ft SE wind wave/swell, and gradually building 3-4 E wind wave/swell.

OKX WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...None.
NJ...None.
MARINE...None.