Long Island Sound West of New Haven CT / Port Jefferson NY Marine Forecast
|Tonight...Sw Winds 10 To 15 Kt, Becoming E Around 5 Kt Late. Seas 1 Ft Or Less.|
|Thu...E Winds 5 To 10 Kt. Seas 1 Ft Or Less.|
|Thu Night...E Winds 5 To 10 Kt. Seas 1 Ft Or Less. Chance Of Showers After Midnight.|
|Fri...E Winds 5 To 10 Kt, Becoming Se In The Afternoon. Seas 1 Ft Or Less. Chance Of Showers In The Morning.|
|Fri Night...S Winds 5 To 10 Kt. Seas 1 Ft Or Less.|
|Sat...S Winds 5 To 10 Kt, Increasing To 10 To 15 Kt With Gusts Up To 20 Kt In The Afternoon. Seas 1 Ft Or Less.|
|Sat Night...S Winds 10 To 15 Kt. Seas 1 Ft Or Less.|
|Sun...S Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 1 Ft Or Less.|
|Sun Night...S Winds 10 To 15 Kt With Gusts Up To 20 Kt. Seas 1 Ft Or Less.|
|Mon...S Winds 10 To 15 Kt. Seas 1 Ft Or Less.|
|Mon Night...S Winds 10 To 15 Kt. Seas 1 Ft Or Less.|
| 1056 PM EDT Wed Jun 23 2021 |
Synopsis for the Long Island Waters and New York Harbor - ANZ300
High pressure gradually retreats offshore through Thursday. Weak low pressure lifts north through the region Thursday night into early Friday. High pressure over the western Atlantic will then remain the dominant weather feature through the first half of next week, allowing a warm, humid airmass to build into the region.
| Area Forecast Discussion|
National Weather Service New York NY
127am EDT Thu Jun 24 2021
High pressure gradually retreats offshore through Thursday. Weak low pressure will lift north through the region Thursday night into early Friday. High pressure over the western Atlantic will then remain the dominant weather feature through the first half of next week, allowing a warm, humid airmass to build into the region.
Near Term - Until 6am This Morning
Just some cosmetic adjustments to the hourly forecast database, with the forecast remaining on track. Southerly winds have held on a bit longer than anticipated at some coastal locations, but winds will lighten everywhere overnight.
High pressure remains in place over the northeast with generally clear skies and dry conditions as dew points remain in the 40s and low 50s region-wide. With relatively weak winds overnight, some radiational cooling will be possible allowing temperatures to drop into the low 50s and upper 40s for the interior locations (as well as FOK on LI) with coastal areas dropping into the middle to upper 50s.
Short Term - 6am This Morning Through 6pm Friday
Quiet conditions continue into Thursday as high pressure shifts offshore. Mostly sunny skies will control much of the day with high temperatures rising into the middle to upper 70s and possible low 80s in some spots. With high pressure to the northeast, winds will become more easterly toward the end of the day as the high pressure pushes an inverted trough/weak surface low into the area toward evening. Models are still having difficulties in terms of the structure of this disturbance and its timing but either way skies should become cloudy into the evening and overnight hours.
Some light rain showers will be possible with this weak disturbance but with preceding dry conditions, high pressure to the northeast, and our positioning under and upper-level ridge, widespread showers do not appear likely. Have capped Probability of Precipitation at 30 percent for now. Lows will be in the 50s for the Interior and low 60s along the coast.
Long Term - Friday Night Through Wednesday
Global models area all in good agreement with an anomalously strong upper level ridge expanding westward across the Atlantic and into the eastern U.S. There is some uncertainty with how quickly the western periphery of the ridge breaks down Tuesday into Wednesday of next week, as there are varying solutions with the interaction of energy within the upper trough over the mid section of the country. The 12Z ECMWF (European Centre for Medium-Range Weather Forecasts) is slowest with this weakening and differs from the GFS and GDPS, which bring an amplifying norther branch trough into the picture for the second half of next week.
What is clear and with high confidence is an increasingly warmer, humid airmass building in through the weekend into early next week. Highs will get up into the upper 80s/lower 90s by Sunday from NYC and points north and west, with the lower to mid 80s closer to the coast. The immediate coastline with a persistent southerly flow (15 to 20 mph each afternoon Sat-Tue) will be even cooler (likely in the 70s). Temperatures will be similar through next Wednesday
Due to the warming aloft, most if not all isolated to scattered convection will be diurnally driven, and mainly north and west of NYC.
Below SCA (Small Craft Advisory) conditions expected across all the waters through at least Friday. A prolonged period of southerly flow will produce near SCA (Small Craft Advisory) conditions for the ocean waters Sat through Mon. Elsewhere, non-SCA (Small Craft Advisory) conditions can be expected.
No hydrologic impacts are expected through the period.
Tides / Coastal Flooding
There is a moderate rip current risk on Thursday and Friday with 3-4 ft @6-7 sec SE swell.
Increasing astronomical tides and long period swells will have vulnerable spots in southern Nassau approaching and possibly touching minor flood thresholds the next two nights. The best chance looks to be Thursday night, due to a E/NE flow ahead of a weak wave and astronomical tides peaking. No special products are planned at this time.
NOAA New York NY Office: Watches - Warnings - Advisories
CT...None. NY...None. NJ...None. MARINE...None.