Long Island Sound West of New Haven CT / Port Jefferson NY Marine Forecast
|Today...W Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft.|
|Tonight...Nw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 2 To 3 Ft.|
|Thu...N Winds 5 To 10 Kt, Becoming E In The Afternoon. Seas 1 Ft Or Less.|
|Thu Night...Se Winds Around 5 Kt. Seas 1 Ft Or Less. Chance Of Snow In The Evening, Then Snow After Midnight. Vsby 1 To 3 Nm.|
|Fri...Ne Winds Around 5 Kt, Becoming W In The Afternoon. Seas 1 Ft Or Less. Rain And Snow In The Morning With Vsby 1 To 3 Nm.|
|Fri Night...Nw Winds 5 To 10 Kt. Seas 1 Ft Or Less.|
|Sat...N Winds 5 To 10 Kt, Becoming Ne In The Afternoon. Seas 1 Ft Or Less. Chance Of Snow In The Afternoon With Vsby 1 To 3 Nm.|
|Sat Night...E Winds 10 To 15 Kt. Seas 1 Ft Or Less, Then Around 2 Ft After Midnight. Rain And Snow Showers. Vsby Less Than 1 Nm.|
|Sun...Se Winds 10 To 15 Kt, Becoming W 15 To 20 Kt In The Afternoon. Seas 1 Ft Or Less, Then Around 2 Ft In The Afternoon. Rain.|
|Sun Night...Nw Winds 15 To 20 Kt. Seas Around 2 Ft. Snow Likely In The Evening With Vsby 1 To 3 Nm.|
|Area Forecast Discussion|
National Weather Service New York NY
423am EST Wednesday Jan 16 2019
Synopsis: High pressure is shunted southward ahead of an approaching cold front that will cross the region tonight. Arctic high pressure then quickly moves north of the area then offshore for Thursday. Low pressure and a weakening warm front then pass through Thursday night into Friday. High pressure briefly builds in late Friday and Friday night. A strong frontal system with developing low pressure will impact the region Saturday into Sunday night. Arctic high pressure builds in Monday and Tuesday.
Near Term - Until 6pm This Evening
Winds will quickly strengthen through the day ahead of an approaching frontal system. Although there is some uncertainty with regards to the depth of the mixed layer, with 20-25 kt low level winds, gusts of around 25-30 mph will be possible. Overnight trends have shown a stratus deck gradually developing eastward, so initially mostly sunny skies will see increasing cloudiness by afternoon, especially across the lower Hudson Valley and portions of northeastern NJ. Regardless, temperatures will be close to climatological normals in subtle warm advection
Short Term - 6pm This Evening Through 6pm Thursday
A cold front will move through the area by evening, though given the dry antecedent air mass, no precipitation is expected with its passage. Although winds may initially gust in its wake, with arctic high pressure building in behind, winds will quickly diminish overnight. Cold/dry advection will then prevail, with temperatures overnight close to climatological normals.
Continued cold advection into Thursday as high pressure passes to the north will lead to below normal high temperatures, generally in the upper 20s to lower 30s. Cloud cover will steadily increase through the day ahead of an approaching frontal system
Long Term - Thursday Night Through Tuesday
Fast moving system via the southern branch of the jet stream will provide a taste of winter to begin the period. In general good model agreement with precipitation timing, with the NAM still dragging its heels a bit with precipitation onset. Ptype looks to be mainly snow through Thursday night with a change over for to plain rain for far eastern sections perhaps just before 12z Fri. The timing works out that the Friday morning commute will be impacted to some degree with cold ground temperatures to start so snow should stick on most surfaces. For now thinking a general 1 to 2 inch snowfall, with less than an inch far east, and perhaps in the 2 to 3 inch range in far northwestern sections. The lift is not impressive with this system as the southern branch energy is not consolidated well as there is little backing in the mid levels to support liquid precipitation amounts over a quarter inch. Therefore it makes sense that the modeling by and large has lowered its Quantitative Precipitation Forecast output over the past couple of runs. The precipitation will change to plain rain as warmer air noses in from the southeast in the lower levels during Friday morning before it moves out shortly thereafter. Most places should completely dry out by the late morning and towards lunch time on Friday, with high pressure to follow briefly for Friday night into early Saturday.
A more significant precipitation event is taking shape for the weekend as elongated low pressure moves into the lower Tennessee Valley by Saturday afternoon. Due to the strung out nature of the upper level energy in the southern branch and its positive tilt, low pressure will not consolidate initially. The models agree that an inverted trough is forecast to run SSW to NNE. Along and to the east of this boundary is where most of the liquid precipitation will set up for late Saturday through early Sunday. Northwest of this is where a heavy stripe of frozen precipitation will fall. We will have to keep an eye out for far NW part of the CWA at least for this potential. Precip types will be tricky with the front almost taking on a anafront type nature with the nose of warm air from the initial warm surge during Saturday night getting into the mid levels just above the boundary layer. As the colder air rushes in as the surface reflection begins to get better organized over the region look for a period of freezing rain in a stripe across inland zones to the northwest. During Sunday into Sunday evening as the wave amplifies and gets further northeast the leading edge of arctic air dives in and any precipitation should transition quickly to all snow. Difficult at this time to tell if there will still be any precipitation along the coast by the time the colder air moves in. Regardless if there is a period of wintry precipitation at coast into Sunday evening, there will likely be a hard freeze of any standing water that is left from the rain that fell earlier. Places that are mainly all rain will get about 2 inches of rain, before the colder air plows in. Therefore a quick freeze of all surfaces could make for hazardous travel during Sunday night.
An airmass of Siberian origin is crossing the pole right now and will deliver the region the coldest air of the season thus far. With wind chills likely to be below zero, at least for inland and northern zones into Monday morning. Temperatures will be hard pressed to reach the lower 20s at the coast during the day on Monday with the new ECMWF run forecasting below 500 dm thickness to the coast by 18z Monday. Therefore windchills would be hovering in the near zero to the single digits for most places during the day on Monday. As the winds diminish Monday night should be the coldest night of the season with respect to the actual air temperatures even though the wind chills should abate into Tuesday morning. As the high slips offshore Tuesday night into Wednesday temperatures will begin to recover quickly. The next system is forecast by the global models to be an inside runner or even track well to our west by late Wednesday of next week. At this time any precipitation looks to be primarily in the form of rain as temperatures recover quickly.
Winds will quickly strengthen today ahead of an approaching frontal system, with Small Craft Advisory level gusts developing on the ocean, eastern Long Island Sound, and southern and eastern bays. Ocean seas will briefly build to Small Craft Advisory levels in response, before gradually subsiding overnight in concert with decreasing winds in the wake of the frontal passage.
Winds and seas are expected to remain below Small Craft Advisory levels across all the forecast waters Thursday through Saturday as a weak frontal system moves through the waters Thursday night and Friday.
As another frontal system approaching and the pressure gradient increases Saturday night into Sunday, Small Craft Advisory level wind gusts will be possible. Then as the frontal system passes to the east and deepens late Sunday into Sunday night, gale conditions will be possible on the ocean waters, with Small Craft Advisory level winds and gusts on the remainder of the forecast waters
No hydrologic issues anticipated through Thursday.
For Thursday night into Friday morning light precipitation is expected with liquid amounts generally under a quarter inch. Confidence continues to increase for a significant precipitation event over the weekend for late Saturday into Sunday. Up to 2 inches of precipitation is expected to fall, with some of the precipitation in frozen form for parts of the event, especially for northwestern inland zones. No significant hydrological impacts are expected at this time
NYC Central Park winds are out of service until further notice. Loss of data is due to a severed cable. Parts are on order.
NYC NOAA Weather Radio Station KWO35 (162.55 MHz) will remain off the air for an extended period of time
NOAA New York NY Office: Watches - Warnings - Advisories
CT...None. NY...None. NJ...None.
Small Craft Advisory from 6am this morning to 1am EST Thursday for ANZ330-340-345.
Small Craft Advisory from 6am this morning to 6am EST Thursday for ANZ350-353-355.