Marine Weather and Tide Forecast for Groton Long Point, CT

KEY MESSAGES
1) A frontal system brings light rain late tonight into Wednesday, with milder weather returning mid to late week.

2) Conditions look potentially unsettled over the weekend, but there is still a fair amount of uncertainty.

DISCUSSION

KEY MESSAGE 1
A weak frontal system tracking east of the Great Lakes today, and then across the region tonight into Wednesday will bring a warm front through the region late tonight into Wednesday, and be accompanied with showers. The system is a little slower and today will be dry. With weak forcing along the warm front showers will become late tonight into Wednesday morning, and CAM's and NAM are showing widespread precipitation, so increased probabilities to likely. Warm advection and the frontal passage ill bring milder air into the area with temperatures nearing normal levels tonight into Wednesday.
Thursday is likely the mildest day of the week with highs in the upper 60s/lower 70s from NYC north/west, and lower/mid 60s east as weak upper ridging builds behind the low.


KEY MESSAGE 2
Not much change for the weekend from the earlier forecast.
Upper air pattern heading into the weekend will a feature a weakening upper ridge just west of the area, sandwiched between an upper low over the Northern Plains and another east of New England and the Canadian Maritimes. At the same time, a surface high builds over the area on Friday, following what appears to be a back door cold front. A warm front associated with the western system then moves nearby on Saturday. This results in a strengthening boundary in close proximity to the area. This will be a key player in determining the coverage and extent of rain this weekend.

The 00Z operational global models still indicate that the surface ridge could be strong enough to keep eastern areas, in particular eastern Long Island and southeast CT on the drier side, with higher probabilities of rain back toward NYC and northern NJ. The latest ECMWF has trended just a bit drier for the area, but still one of the wetter solutions. Either way, it looks like there will be a tight gradient somewhere close to the area, going from rain to no rain. Also, there is decent agreement in a persistent easterly flow which will keep high temperatures in the 50s both days, especially for eastern and coastal areas. Using the NBM, this results in cloudy conditions with a chance of rain everywhere Saturday and likely Pops for NYC north and west, but decreasing on Sunday as a frontal wave and boundary get suppressed to the south by strengthening high pressure.

AVIATION /15Z TUESDAY THROUGH SATURDAY/
High pressure along the Mid Atlantic coast will shift offshore today, with a frontal system approaching the area late tonight.

VFR through this evening. MVFR vsby possible with showers as early as 06Z tonight. Cigs drop to MVFR after 12Z Wed for most, with chances for showers continuing into the morning.

Winds are starting to become SE 5-10 kt closer to the coast, and are still light/vrb inland. A more southerly wind direction should develop by afternoon, with wind speeds increasing to near 10 kt, then diminishing slightly tonight. There could be a brief period of 20-25 kt gusts for some coastal terminals late tonight into early Wed morning.

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

Some uncertainty in wind direction before about 17Z, also with duration of light ENE flow at KLGA into early this afternoon.

OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY

Wednesday afternoon and evening: MVFR or lower cond with chance of showers, improving later in the day and at night with VFR returning. S winds G15-20kt possible early.

Late Wednesday night through Friday evening: VFR.

Late Friday night into Saturday: MVFR or lower cond possible with chance of showers.

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

MARINE
With the approach of a frontal system late tonight into Wednesday southerly gusts will be marginally at SCA levels across the western ocean waters, west of Moriches Inlet, and Long Island south shore bays by late tonight through Wednesday and a Small Craft Advisory has been issued. East of Moriches Inlet and the Long Island eastern bays and eastern Long Island Sound may see gusts approaching 25 kt by mid to late Wednesday afternoon, and a SCA may be needed there. Mixing may be be limited tonight into Wednesday with warmer air moving into the region along with showers. After the passage of the frontal system winds and seas will be below SCA levels on the waters Wednesday night through Saturday night.

OKX WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 6 AM to 6 PM EDT Wednesday for ANZ345-353.
Small Craft Advisory from 2 AM to 6 PM EDT Wednesday for ANZ355.