Marine Weather and Tide Forecast for Larchmont, NY

KEY MESSAGES
1) Areas of of fog tonight into early Sunday morning.

2) Chance of showers Sunday afternoon and then rain Sunday night into Monday.

3) Unsettled weather expected toward mid to late next week.

DISCUSSION
KEY MESSAGE 1...
Confidence is higher for fog development tonight into early tomorrow morning after the rain ends, especially for Long Island and southern CT, where the fog could become locally dense late tonight. Should dense fog become widespread, a dense fog advisory may need to be issued.

KEY MESSAGE 2...
Sunday morning and early afternoon looks to be mostly dry between systems as a cold front approaches from the west. Scattered showers are possible from mid to late afternoon from NYC north/west. A more organized rainfall event is then expected Sunday night into Monday as an amplifying upper trough sends the cold front across, with one or more weak frontal waves passing well to the south and east.
Another 1/4 to 1/2 inch of beneficial rainfall is expected, with lesser amounts of 1/10 to 1/4 inch NW of NYC.

Highs on Sunday have the potential to near 80 degrees in portions of NE NJ and NYC metro. Otherwise, highs will be in the 70s across the area. The chance for thunder appears low in the afternoon/evening, but a few thunderstorms are possible given strong warming at the surface if timed well with lift from the frontal boundary.

KEY MESSAGE 3...
Low pressure over the Northern Plains Tuesday is expected to dive southeast over the southern to central Great Lakes region Tuesday night, then eject off the Mid-Atlantic Coast late in the day Thursday into Thursday night. This coastal low then slowly heads northeast through the rest of the forecast period, with some slow strengthening.

An inverted trough extending northward from the low as it passes south of the area will likely be the primary focus for showers for late Wednesday into Wednesday night. Of course, this far out, there are timing differences with the track and strength of the low, which would lead to differences in timing of any precipitation and amounts. This also leads to high uncertainty with the track of the eventual coastal low that passes south and east of the area at the end of the week, and whether we see any rainfall as it heads out to sea.

AVIATION /00Z SUNDAY THROUGH THURSDAY/
Terminals will be between systems as one exits to the east tonight and a cold front approaches from the west. The latter is expected to pass through the area Sunday evening.

The combination of light winds, clearing skies, and residual low-level moisture is likely to produce widespread IFR/LIFR conditions overnight. The highest chance for LIFR appears to be from JFK/LGA/HPN on east across Long Island and Southern Connecticut. Conditions then improve to VFR after 12Z Sunday with a chance of sub-VFR conditions in showers during the afternoon and evening hours. There is some uncertainty with the timing of development and then dissipation of the lower conditions.

Winds will weaken this evening, becoming light and variable overnight. A light W-SW flow develops Sunday morning, increasing to around 10 kt in the afternoon. There is the potential for gusts up to 20 kt in the afternoon, but confidence in not high due to uncertainty in the depth of the mixed layer. Winds will then veer to the NW-N in the evening behind the cold front.

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

Amendments are likely overnight into Sunday morning due to some uncertainty with the timing of lowering categories tonight, and then the improvement on Sunday.

Chance of gusts up to 20 kt Sunday afternoon.

OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY

Sunday Night: Chance of showers and MVFR in the evening. Showers likely, especially closer to the coast at night along with MVFR, potentially IFR at times.

Monday: Chance of showers and MVFR early, especially near the coast, then VFR.

Tuesday: Mainly VFR. NW winds G15-20 kt possible in the afternoon.

Wednesday: Showers developing through the day. MVFR or lower conditions. S winds G15-25 kt in the afternoon and evening.

Thursday: Showers possible with MVFR or lower conditions.

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

MARINE
5-ft seas are expected to linger into this evening on the ocean waters east of Fire Island Inlet, but dropping below by midnight. Sunday afternoon into Sunday night, another period of 5 ft seas is possible on eastern ocean waters with a cold frontal passage. Below SCA- criteria is then expected to remain through Tue Night.

Waves build late in the day Wednesday as a southerly flow increases due to an approaching low pressure system to the west. SCA conditions are possible for the ocean waters for a brief period from Wednesday afternoon into the first half of Wednesday night.
Thereafter, winds and waves are expected to remain below SCA criteria.

OKX WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ345- 355.
Small Craft Advisory until 11 PM EDT this evening for ANZ350- 353.