Marine Weather and Tide Forecast for Head of the Harbor, NY

NEAR TERM /UNTIL 6 PM THIS EVENING/
A warm front approaches today. Isentropic lift will lead to an overspreading stratiform rain moving in late this morning through the afternoon. Rain will be light to moderate intensity.

Forecast highs will be limited from SE winds at the surface along with increasing clouds and the rain. The highs were a blend of MAV guidance and consensus of model raw temperatures, lower 40s to lower 50s.

SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/
For the upper levels, after initial ridging in the area tonight into Tuesday, a strong upper level low moves from South Central Canada into the Great Lakes Tuesday night through Wednesday night. This is part of a deep upper level trough that will be developing with phasing and tapping into the Gulf of Mexico as it digs southward Tuesday night and then as it moves east it will access the Western Atlantic waters for Wednesday. The associated strong vort max moves across the local region Wednesday night.

For tonight, warm front moves into the area. Rain will still be ongoing but will be mostly across Southern CT and Long Island for the evening hours. Rainfall eventually tapers off for the entire local region overnight. With moisture laden boundary layer and decreasing winds, low levels will be favorable for fog development.
Kept coverage patchy and over the land with this fog. Lows forecast a blend of NBM and consensus of raw model temperatures, upper 30s to mid 40s.

For Tuesday, the warm front does not make much progress, remaining within the region. Exact position of this front is uncertain.
However, so more northward progress is expected by the afternoon and more so for Tuesday night. Boundary layer remains moist with fog expected to become greater in coverage. Chances for rain will be forecast as well as with some increase in low level convergence.
Forecast highs actually will likely be set late in the evening as southerly flow increases, bringing increasing low level warm air advection and temperatures getting into upper 40s to lower 50s.

For late Tuesday night, temperature further rise with low level warm air advection increasing. Vertical forcing will be increasing as well with rain developing and moving into the region. Region gets more into warm sector.

For Wednesday, a strong cold front approaches and rain will be heavy at times. Elevated instability forecast as well for much of the coastal areas, so have a slight chance of thunderstorms.
The strong cold front moves across Wednesday night. The rain continues into Wednesday evening especially across Southern CT and Long Island. Precipitation becomes more showers late Wednesday night and with strong cold air advection, rain expected to mix and eventually change over to snow showers.

Low pressure develops and approaches for Wednesday along the cold front moving into the coastal sections of the area. This low more rapidly intensifies for Wednesday night into early Thursday morning, with models indicating around a 15 to 20 mb drop in 12 hours, traveling from near the region to New England vicinity to Quebec.

Pressure gradient becomes very tight Wednesday into Wednesday night in advance of deepening low pressure. Low level jet intensifies Wednesday into Wednesday evening. Gusty winds expected with some strong wind gusts possible up to near 45 to 55 mph Wednesday into Wednesday night.

LONG TERM /THURSDAY THROUGH SUNDAY/
Cold front will be exiting the forecast area first thing Thursday morning. The only chances of any showers appear to be associated with the potential of ocean and sound effect rainfall as cold air filters in on a strong westerly flow with water surface temperatures still near 50. It'll probably be gusty much of the day, but sustained winds and gusts should lower during the afternoon hours.
Gusts in the morning still potentially 35-40 mph. High temperatures on Thursday could very well occur during the pre-dawn hours for most spots. Strong downsloping/compressional heating will offset the strong cold air advection to some extent, but afternoon temps probably only reach 35-40.

High pressure will be building into the region through at least Friday night with the high moving offshore most likely during Saturday. Global models agree that low pressure of some sort potentially impacts the forecast area Saturday night into Sunday, but differ on the details. Will go with slight chance to chance PoPs for the time being. Kept precip types simplified due to the low confidence on the evolution and track of this potential system 7 days out. Some moderation through the weekend after below normal high temperatures on Friday.

AVIATION /09Z MONDAY THROUGH FRIDAY/
A weak low pressure center along with a warm front approach today, passing through some of the terminals this afternoon into evening.
The warm front remains in the vicinity through Tuesday.

VFR this morning. Rain with lowering flight categories start early this afternoon. IFR likely by around 21z. The rain ends by 00z for most terminals, but IFR remains likely with some terminals lowering to LIFR overnight.

Light and variable winds, possibly favoring NE through most of the morning push, then easterly winds increasing later this morning to around 10kt. A relatively quick veering to the SW occurs for the city terminals at approx 21-00z with the weak low center passing nearby. Winds bcmg light and variable overnight.

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

Amendments possible for timing of lowering flight categories this afternoon. Still a chance of improvement to MVFR for a few hours late this afternoon into early evening, but confidence in this is low. Chance of fog reducing vsbys below 3/4SM overnight.

OUTLOOK FOR 06Z TUESDAY THROUGH FRIDAY...

Late tonight: IFR with a chance of drizzle.

Tuesday: IFR with potential improvement to MVFR at times. Light rain or drizzle possible.

Tuesday night: IFR and rain. SE-S gusts around 20kt with LLWS late.

Wednesday: IFR and rain, possibly heavy at times. Chance of thunder.
S-SW gusts increase through the day, potentially up to 40-45 kt afternoon and evening. VFR returns late Wednesday night with west winds gusting 30-35kt.

Thursday: VFR with W winds G30-35kt in the morning, then 25-30kt in the afternoon.

Friday: VFR.

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

MARINE
After SCA expires 6am this morning on eastern ocean waters, sub-SCA conditions expected on forecast waters for today through Tuesday evening. SCA conditions then expected to develop on the ocean late Tuesday night. The seas and winds further trend higher on Wednesday and Wednesday night. SCA conditions likely for all waters Wednesday and Wednesday night with potential for gales on most if not all of the forecast waters as well.

Gales will be possible, especially on the ocean waters, for a part of the day Thursday with cold air advection behind a cold front moving through the waters during the morning. Advisory conditions otherwise would prevail through the day and last in to Thursday night. Winds probably below thresholds by Friday morning everywhere, but seas remain elevated on Friday on the ocean - perhaps falling below 5 ft by the afternoon.

HYDROLOGY
No hydrologic issues expected through Tuesday. Heavy rain is possible at times late Tuesday night through Wednesday with the potential for flooding in at least low lying and poor drainage areas. Steady rain, heavy at times, persists Wednesday night across Southern CT and Long Island. Flash flooding cannot be ruled out, and WPC has a slight risk of excessive rainfall across the eastern half of the area on Wednesday, with the rest in a marginal risk. Model potential for PWATs of near 1.3 to 1.5 inches Wednesday, which would be above the 90th percentile and around to above the max for OKX sounding climatology for December 11th.

Total rainfall Tuesday night through Wednesday night ranges from about 2 to 3 inches, lowest across NYC, interior NE NJ and the Lower Hudson Valley and highest across parts of Southern CT and Long Island.
There could be locally higher amounts, dependent on the heavy rain axis setup. There remains some uncertainty and these rainfall amounts could shift some in subsequent forecasts.

OKX WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 AM EST early this morning for ANZ350.