Marine Weather and Tide Forecast for Shelter Island, NY

KEY MESSAGES
1) Mainly dry conditions through Wednesday with cooler temperatures Monday before gradually warming Tuesday into Wednesday.

2) Heat and humidity may build late week, with potential of unsettled weather.

DISCUSSION

KEY MESSAGE 1
Mid level shortwave trough will swing across New England through this evening. The passage of the upper trough may also be enough to develop isolated showers this evening, mainly across portions of SE CT and potentially the forks of Long Island this evening. Most places should remain dry this evening.

High pressure builds down from the north tonight into Monday and will then remain overhead on Tuesday. Dry and cooler conditions are expected on Monday. Highs will largely be in the mid to upper 70s although a few spots in NE NJ, NYC metro and Lower Hudson valley could reach the low 80s. Some slight moderation is likely on Tuesday with temperatures above normal in the lower to middle 80s. Developing sea breezes will keep the immediate coast a bit cooler.

High pressure shifts to the western Atlantic on Wednesday. The ridge aloft looks to weaken slightly with a shortwave passing across the northeast late in the day. Temperatures should be warmer compared to the start of the week with highs in the mid to upper 80s, warmest across NE NJ and the interior. Sea breezes will continue to keep the immediate coast a bit cooler. A few showers, possibly a thunderstorm, cannot be ruled out late in the day and evening with the passing shortwave.


KEY MESSAGE 2
Heat and increasing humidity are possible Thursday and Friday as an upper level ridge will slide across the eastern seaboard.
Guidance is hinting at a shortwave passing across the northeast on Friday/Friday night. The timing of this system is still in question given it is still several days out. The approach of the shortwave may help advect some higher humidities into the area, especially to end the week. Temperatures on Thursday should rise well into the 80s with the usual warmer spots rising into the lower 90s. There is a chance for some mid 90s in the warmest spots of urban NE NJ. Similar conditions are possible on Friday. Closer to the coast and across SE CT, temperatures will likely only be in the mid to potentially upper 80s before sea breezes level temps off or lower them in the latter part of the day.

The increase in humidity could allow apparent temperatures to approach heat advisory criteria in parts of NE NJ, NYC metro, and Lower Hudson Valley Thursday and Friday, with heat indices near 95- 100F away from the coast both Thursday and Friday.

Convective chances exist Thursday and Friday afternoon and evening, but hinge on the timing shortwaves, which are difficult to resolve this far out. It is also too early for any confidence in severe thunderstorm potential.

Temperatures will likely remain hot for the upcoming weekend, but a decrease in humidity is possible behind the passing shortwave.

AVIATION /21Z SUNDAY THROUGH FRIDAY/
A cold front will move through this afternoon. High pressure will then build to the north through Mon morning, then over the area Mon afternoon.

Sct tstms around the NYC metros with the cold front should be through all except KJFK, which may still have impact before 19Z.
After that, NW flow 15G20-25kt should veer more to the NNW and diminish slightly this evening to 10-15G20kt, then become NNE 10 kt or less overnight. As the high builds over the area or just S Mon afternoon, winds will shift SE-S around or just over 10 kt.

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

No unscheduled AMD expected.

OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY

Monday through Tuesday night: VFR.

Wednesday: Chance of a late day tstm from the NYC metros north/west, then throughout at night. SW winds G20kt in the afternoon.

Thursday: Chance of showers early in the morning, then chance of afternoon/evening showers/tstms.

Friday: Chance of afternoon/evening showers/tstms from the NYC metros north/west.

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

MARINE
NW flow behind a cold front late this afternoon and evening could bring gusts around 20 kt. There is also a chance for a gust close to 25 kt away from the shore on the ocean east of Moriches Inlet tonight. Otherwise, high pressure building in will lead to conditions below SCA levels through Tuesday. The next chance for SCA conditions will be Wednesday on the ocean as S-SW flow increases ahead of a weak frontal system. Conditions should then remain below SCA levels for the end of the week.

Rip Currents...

There's a moderate rip current risk at all local ocean beaches today with a 10 to 15 kt flow parallel to the shoreline and a 4-ft 7-sec S swell.

By Monday, the rip current risk is low with the lingering S swell falling to 2 ft at 6s and lightening winds.

A S/SW flow picks up Tuesday which may lead to a moderate risk during the afternoon. For now, stuck with a low risk, but there is potential for this to be upgraded to a moderate. Otherwise, there is just a lingering 2 ft swell at 7-8s out of the SE.

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