New York Harbor Marine Forecast
|Tonight...Nw Winds 10 To 15 Kt. Waves 1 To 2 Ft This Evening, Then 1 Ft Or Less. Chance Of Showers Early This Evening.|
|Sun...W Winds 5 To 10 Kt, Becoming Sw In The Afternoon. Waves 1 To 2 Ft. Chance Of Rain In The Afternoon.|
|Sun Night...Se Winds 5 To 10 Kt. Waves 1 To 2 Ft. Rain Likely.|
|Mon...Nw Winds 5 To 10 Kt. Waves 1 Ft Or Less. Chance Of Rain In The Morning.|
|Mon Night...Nw Winds 5 To 10 Kt. Waves 1 Ft Or Less.|
|Tue...Nw Winds 10 To 15 Kt. Waves 1 Ft Or Less, Then Around 2 Ft In The Afternoon.|
|Tue Night...Nw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Waves 1 Ft Or Less.|
|Wed...Nw Winds 10 To 15 Kt With Gusts Up To 20 Kt. Waves 1 To 2 Ft.|
|Wed Night...Nw Winds 5 To 10 Kt. Waves 1 Ft Or Less.|
|Thu...W Winds 5 To 10 Kt. Waves 1 Ft Or Less.|
|Thu Night...Sw Winds 5 To 10 Kt. Waves 1 Ft Or Less.|
| 320 PM EDT Sat May 8 2021 |
Synopsis for the Long Island Waters and New York Harbor - ANZ300
A surface trough passes across the waters this evening. Weak high pressure briefly builds to the south tonight into Sunday morning before a warm front approaches Sunday afternoon into Sunday night. Low pressure develops along the front, moving across early Monday. High pressure then returns through the middle of the week. Another storm system approaches for late in the week.
| Area Forecast Discussion|
National Weather Service New York NY
325pm EDT Sat May 8 2021
A surface trough passes across the region this evening. Weak high pressure briefly builds to the south tonight into Sunday morning before a warm front approaches Sunday afternoon into Sunday night. Low pressure develops along the front, moving across early Monday. High pressure then returns through the middle of the week. Another storm system approaches for late in the week.
Near Term - Until 6am Sunday Morning
A convergence zone along a weak low pressure/surface trough will slowly shift southeast and offshore by early this evening. The northeast also lies under a large upper level trough, with one closed upper low moving towards the Canadian Maritimes and a broader shortwave lying across the Middle Atlantic. Strong energy within the trough is pivoting to our south this afternoon and evening. The energy is providing PVA aloft and combining with the convergence zone to bring mainly scattered showers across NE NJ and portions of the NYC metro. Instability remains weak, but it is not out of the question for a lightning strike in any stronger showers. Pea-sized hail also is possible in stronger showers due to a low freezing level (around 5 kft) and relatively steep lapse rates. The HRRR (High-Resolution Rapid Refresh) has been handling the convection well today, and based on its recent runs, most of the convection should be south of the area or offshore around or just after 6 pm.
The models also continue to indicate a spoke of energy over southern New England, which could develop a few showers across interior CT late this afternoon or early evening. Weak sea breeze convergence may also play a roll in the development of these showers. However, lingering subsidence and dry low level dew points may prevent much in the way of measurable rain here.
Otherwise, the overall trend heading into the overnight is for the return of dry conditions and clearing skies. Clouds will linger longest out east. Light NW flow, mostly clear skies, and dry conditions will lead to a cool night with lows generally in
Short Term - 6am Sunday Morning Through Monday
The break in unsettled weather is temporary as another frontal system impacts the area late Sunday into Sunday night. Mostly clear skies to start Sunday along with weak ridging aloft will lead to dry conditions. A surface high will push off the southern Middle Atlantic, leading to a return S-SE flow developing across the area in the afternoon. A progressive middle level shortwave under a closed 500 mb low over southern Ontario approaches late in the day. A wave of low pressure ahead of the shortwave develops moves out of the midwest towards the Ohio Valley by evening. The associated warm front is expected to lie well south of the area in the evening. Clouds will increase in the afternoon. There may also be a band of rain well ahead of the system as region is forecast to lie within the right entrance of a 100-120 kt departing upper jet. The location of this potential band of rain continues to fluctuate in the models, but recent trends give enough confidence in increasing PoPs with the likelihood of rain by evening across the western half of the area.
Rain will continue to overspread the region Sunday night as the warm front approaches. The warm front should end up getting close to the area, but not fully lift north as the low pressure rides along it late Sunday night. A consensus of the latest model runs takes the low just south of Long Island after midnight. The rain should be most widespread the first half of the night before a middle level dry slot brings tapers the rain off from west to east.
Rainfall amounts are expected to range from about three tenths to six tenths, highest north of the NYC metro and Long Island.
Highs on Sunday should be in the lower 60s for most. Lows Sunday night range from around 45 to 50 degrees.
Long Term - Monday Night Through Saturday
Nearby low pressure exits east on Monday with lingering showers possible in the morning. Surface ridging will occur during the rest of the day through Tuesday morning with dry weather. A longwave trough with embedded shortwaves then approach from the Great Lakes. A cold pool(a region of relatively cold air) aloft will destabilize the mid levels somewhat Tuesday afternoon, but overall moisture appears to be lacking for any mention of showers at this time. The upper trough axis should be to our east by Wednesday morning with high pressure building back in at the surface and keeping us dry through Thursday.
Global models disagree on the surface features here Friday and Saturday, but show some longwave troughing. Any low pressure system would be relatively weak given the forecast amplitude of the longwave trough. Will go with lower-end Probability of Precipitation for this time period for the potential of a surface trough or weak low impacting the weather.
High temperatures through the long term generally around or a few degrees below normal.
Conditions remain well below SCA (Small Craft Advisory) criteria on the waters through tonight. Winds on the waters will increase Sunday ahead of an approaching frontal system. Most wind gusts will peak around 20 kt, but a gust up to 25 kt cannot be ruled out east of Moriches Inlet late Sunday afternoon into early Sunday evening. Winds should stay around 20 kt or less for much of Sunday night as well. Ocean seas gradually build late Sunday and especially Sunday night. 5 ft seas become likely by early Monday morning. Since winds on the waters look marginally small craft at worst late Sunday/Sunday night and seas do not build to criteria till late Sunday night, have elected to hold off on issuing an SCA (Small Craft Advisory) at this time.
Winds should remain below 25kt on Monday, however a lingering swell on the ocean will maintain advisory conditions through the day and into the evening hours. An offshore flow of 10-15 kt expected thereafter through Tuesday afternoon with sub-advisory conditions. The pressure gradient then tightens over the waters and SCA (Small Craft Advisory) conds will therefore be possible over the ocean Tuesday night into Wednesday morning. An approaching high pressure ridge otherwise results in sub-advisory conds Wednesday afternoon through Thursday night.
No hydrologic impacts are expected through next week.
NOAA New York NY Office: Watches - Warnings - Advisories
CT...None. NY...None. NJ...None. MARINE...None.