Marine Weather and Tide Forecast for Northwest Harbor, NY

NEAR TERM /THROUGH SUNDAY/
For this evening update, hourly temperatures and dewpoints were adjusted slightly on the CT coast and in the LI Pine Barrens.
They were likely off due to differences in observed winds and forecasted winds, but as winds pick up more across the area into tonight, the temperature and dewpoint forecast will likely fall back in line.

Low pressure will scoot north of the area fairly quickly tonight.
The main mid and upper level support with the system will be north of the area bringing some light accumulating snows to the mountains of New England and Upstate NY tonight and early Sunday morning. For our area we get mainly clouds with some light precip in the form of very light snow or flurries across northern most sections towards this late this evening, mainly towards and after 02z. This activity is expected to remain light and move essentially from west to east towards and after midnight. The higher res guidance differs as to how far south precip or measurable precip can ultimately get. Went with a consensus with regard to PoPs and sensible wx. Therefore have chance to slight chance of light snow from north to south, with essentially nothing across southern most portions of the area. Even places further north may see nothing, but thought consensus approach was best. Any precip should be quite light and should not see what we saw earlier in the week across northern areas. The system will be a quick mover and will race by as it is rather progressive. Towards daybreak any light precip should get north and northeast of the region. Winds out of the SW will keep temperatures up a bit compared to the last few night along with cloud cover in place. Temperatures should range from the upper half of the 20s up north to mainly lower and some middle 30s across the NYC metro and southern most sections.

As the system exits northeast the winds will switch around to the west ushering in drier air, but not necessarily cooler air. In fact it will be milder as Pacific air has gotten into the pattern and there will be a lack of colder Canadian air in the wake of the system passing by to the north. Temperatures under breezy, but partly sunny conditions should get to normal, or perhaps even a few degrees above normal for the afternoon. Although, the breeze may make it feel a touch cooler. Most locations should get into the upper 40s, with some lower 50s towards the NYC metro and out on LI and southern portions of NE NJ.

SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/
Partly cloudy skies are expected Sunday night as the winds lighten out of the west. Some clouds will be around, with more in the way of higher and mid level clouds arriving towards daybreak in advance of the next rapidly approaching system. Temperatures will be fairly close to normal with upper 20s to middle 30s in most locations.

For Monday expect clouds to increase and thicken up quickly for the mid to late morning. At this point the morning looks to be primarily dry, with only a chance to slight chance that some precip could break out across western portions of the area before midday. This system will move well northwest of the area and bring a warm front through. It will be another quick mover and there will be a lack of cold air in front of the system. Therefore this next system should be all plain rain. Temperatures on a E to SE flow should stay in the upper 30s to around 40 well inland, to the upper 40s and right around 50 further south and east at the coast and into the city. The rainfall deficit will continue to get knocked down some, with rainfall totals expected to range from a quarter to a half inch across the area. Because it will move quickly expect the rain to taper quickly from SW to NE late Monday evening and into the early portions of the overnight. In fact, the entire region could be dry towards midnight. Somewhat drier air then starts to work in briefly behind it late Monday night into early Tuesday morning. Temperatures overall will average a few degrees above normal Monday and Monday night.

LONG TERM /TUESDAY THROUGH SATURDAY/
Amplified pattern shaping up for Tuesday through Wednesday.
Deepening upper level trough with strong SW to NE jet will strengthen a frontal system approaching the area. The associated warm front moves across Tuesday with an associated cold front moving across Wednesday night.

The timeframe of Tuesday through Wednesday expected to have rain across the region much of the time period. Wednesday night, the precipitation becomes more intermittent, more in the way of showers.
With a strong cold air advection behind the front, potential for mixing with snow and for some pure snow showers across the region before all precipitation comes to a close.

Dynamic forcing appears with enhanced lift Wednesday will have some potential for heavy rain. With how dynamic the flow is, model trends will have to be analyzed for any changes in trough positioning and low pressure. Also, if the low pressure deepens more than forecast, resulting in further tightening of the pressure gradient, this would make for higher winds than forecast. Current model consensus shows the low just starting its deepening process as it traverses over the local region Wednesday afternoon with more rapid deepening occurring once the low is north and east of the region Wednesday night into early Thursday.

Dry conditions expected thereafter through Friday as high pressure builds in from the west. Temperatures above normal Tuesday through Wednesday and then below normal Wednesday night through Friday night.

AVIATION /00Z SUNDAY THROUGH THURSDAY/
A low passes to the north tonight into tomorrow, west to east.

Mainly VFR for the TAF period. A few light snow showers are possible tonight for KSWF/KBDR. Mixed light rain-snow possible tonight for KGON. Sleet is now being ruled out as ground temperatures will be warming to above freezing as the low passes, so only a transition from snow to rain is expected. MVFR is possible in showers, but low confidence in occurrence of MVFR. Its very possible it will remain VFR in showers, given their light nature.

W-WSW winds have weakened to at or below 10 kts at the time of the 00Z TAF issuance. However, winds are expected to pick up again later tonight as showers pass to our north to above 10 kts, becoming SW direction. WInd gusts between 18-25 kt expected to begin late tonight and remain gusty through tomorrow from a SW direction, while winds tomorrow may be sustained 10-15 kts.
Winds quickly ramp down below 10 kts and lose their gusts tomorrow evening.

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

Timing for the return of gusts late tonight may be off by a few hours.

Showers currently in NE PA are expected to remain well north of NYC terminals. However, should showers develop in a way inconsistent with the latest guidance, an amendment may be required.

OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY...

Sunday Night: VFR.

Monday: MVFR to IFR, at times, in rain, particularly in the afternoon and evening.

Tuesday: MVFR or lower during the day. Increasing chance of rain late Tue into Tue night. IFR or lower possible at night.

Wednesday: MVFR to IFR. Possible sub-IFR at times. Rain day into early evening with rain and snow showers for the rest of the night. SW gusts 15-20 kt during day. W-NW gusts 15-20 kt at night. Some NW gusts up to 25-30 kt possible at night.

Thursday: Mainly VFR with gusty W to NW winds 20-25kt.

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

MARINE
Winds do pick up tonight into Sunday as an area of low pressure passing to the north tightens the pressure gradient. SCAs therefore go into effect this evening through Sunday afternoon for all waters, with the nearshore / non-ocean waters having small craft conditions just before midnight. Occasional gusts may approach gale force late tonight into Sunday morning on the central and eastern ocean, but not enough occurrence, coverage, or length of time for gale warning consideration at this time. SCA conds then continue on the ocean through a portion of Sunday night. Seas subside below 5 ft by early Monday morning and likely remain below 5 ft through Monday night.
Gusts may however briefly approach 25 kt as relatively weak area of low pressure passing through attempts to strengthen.

Some lingering eastern ocean SCA conditions are anticipated Tuesday into Tuesday night, followed by small craft conditions likely returning for Wednesday on all ocean waters, with small crafts becoming possible for the non-ocean waters late Wednesday and Wednesday night. Small craft conditions will persist on the ocean for Thursday with elevated seas, and may linger on the non-ocean waters with marginal small craft gusts.

HYDROLOGY
No hydrologic issues expected through Tuesday. Heavy rain possible at times on Wednesday with the potential for minor flooding in low lying and poor drainage areas. Model potential for PWATs of near 1.3 to 1.4 inches Wednesday, which would be above the 90th percentile and around the max for OKX sounding climatology for December 11th.
Integrated Water Vapor Transport (IVT) values from the ECMWF and the GFS are projected to run high for eastern section for this time of year with the mid week storm system.

OKX WATCHES/WARNINGS/ADVISORIES
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EST Sunday for ANZ331-332-335- 338-340-345.
Small Craft Advisory until 6 PM EST Sunday for ANZ350-353-355.